Hole’s Essentials of
Human Anatomy
and Physiology
High School Second Edition
Teacher Manual
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CONTENTS
Using Your Teacher Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI
PC
Preview Chapter: Foundations for Success . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P1
P.1 Introduction . . . . . . . . . . . . . . . . P2
P.3 Strategies for Your Success . . . . . . . P3
P.2 Science Literacy Skills . . . . . . . . . . P2
Chapter Assessment Answers . . . . . . P4
1
Levels of Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1
Introduction to Human Anatomy and Physiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
1.1 Introduction . . . . . . . . . . . . . . . . . . 4
1.5 Maintenance of Life . . . . . . . . . . . . 10
1.2 Anatomy and Physiology . . . . . . . . . 5
1.6 Organization of the Human Body . . . . 12
1.3 Levels of Organization . . . . . . . . . . . 6
1.7 Anatomical Terminology . . . . . . . . . . 14
1.4 Characteristics of Life . . . . . . . . . . . 8
Chapter Assessment Answers . . . . . . . 17
2
Chemical Basis of Life . . . . . . . . . .
2.1 Introduction . . . . . . . . . . . . . . . . 2.2 Fundamentals of Chemistry . . . . . . 2.3 Bonding of Atoms . . . . . . . . . . . . . 2.4 Molecules, Compounds,
and Chemical Reactions . . . . . . . . . . . .
UNIT
UNIT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5 Acids and Bases . . . . . . . . . . . . . . 29
2.6 Chemical Constituents of Cells . . . . 30
Chapter Assessment Answers . . . . . . 34
22
23
25
27
3
Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.1 Introduction . . . . . . . . . . . . . . . . . 39
3.4 The Cell Cycle . . . . . . . . . . . . . . . 46
3.2 Composite Cell . . . . . . . . . . . . . . 40
Chapter Assessment Answers . . . . . . 50
3.3 Movement Into and Out of the Cell . 44
4
Cellular Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.1 Introduction . . . . . . . . . . . . . . . . . 55
4.5 DNA (Deoxyribonucleic Acid) . . . . . . 61
4.2 Metabolic Reactions . . . . . . . . . . . 56
4.6 Protein Synthesis . . . . . . . . . . . . . 63
4.3 Control of Metabolic Reactions . . . . 57
Chapter Assessment Answers . . . . . . 67
4.4 Energy for Metabolic Reactions . . . . 59
5
Tissues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.1 Introduction . . . . . . . . . . . . . . . . . 71
5.5 Muscle Tissues . . . . . . . . . . . . . . . 78
5.2 Epithelial Tissues . . . . . . . . . . . . . . 72
5.6 Nervous Tissues . . . . . . . . . . . . . . 79
5.3 Connective Tissues . . . . . . . . . . . . 74
Chapter Assessment Answers . . . . . . 82
5.4 Types of Membranes . . . . . . . . . . . 77
2
Support and Movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6
Integumentary System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.1 Introduction . . . . . . . . . . . . . . . . . 88
6.4 Skin Functions . . . . . . . . . . . . . . . 94
6.2 Skin and its Tissues . . . . . . . . . . . . 89
Chapter Assessment Answers . . . . . . 98
6.3 Accessory Structures of the Skin:
Epidermal Derivatives . . . . . . . . . . . . . 92
7
Skeletal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
7.1 Introduction . . . . . . . . . . . . . . . . 103
7.8 Thoracic Cage . . . . . . . . . . . . . . . 114
7.2 Bone Structure . . . . . . . . . . . . . . . 104
7.9 Pectoral Girdle . . . . . . . . . . . . . . . 115
7.3 Bone Function . . . . . . . . . . . . . . . 106
7.10 Upper Limb . . . . . . . . . . . . . . . . . 116
7.4 Bone Development, Growth,
7.11 Pelvic Girdle . . . . . . . . . . . . . . . . 117
and Repair . . . . . . . . . . . . . . . . . . . . 107
7.12 Lower Limb . . . . . . . . . . . . . . . . . 118
7.5 Skeletal Organization . . . . . . . . . . 109
7.13 Joints . . . . . . . . . . . . . . . . . . . . . 119
7.6 Skull . . . . . . . . . . . . . . . . . . . . . . .111
Chapter Assessment Answers . . . . . . 123
7.7 Vertebral Column . . . . . . . . . . . . . 112
8
Muscular System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
8.1 Introduction . . . . . . . . . . . . . . . . 128
8.3 Skeletal Muscle Contraction . . . . . . 131
8.2 Structure of Skeletal Muscle . . . . . . 129
8.4 Muscular Responses . . . . . . . . . . . 133
III
8.5
8.6
8.7
Smooth Muscle . . . . . . . . . . . . . . 135
Cardiac Muscle . . . . . . . . . . . . . . 136
Skeletal Muscle Actions . . . . . . . . . 138
Major Skeletal Muscles . . . . . . . . . 139
Chapter Assessment Answers . . . . . . 142
8.8
3
Integration and Coordination .
9
Nervous System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
9.1 Introduction . . . . . . . . . . . . . . . . 149
9.9 Impulse Processing . . . . . . . . . . . 160
9.2 General Functions of the
9.10 Types of Nerves . . . . . . . . . . . . . . 161
Nervous System . . . . . . . . . . . . . . . . 150
9.11 Neural Pathways . . . . . . . . . . . . . 162
9.3 Neurons . . . . . . . . . . . . . . . . . . . 151
9.12 Meninges . . . . . . . . . . . . . . . . . . 163
9.4 Neuroglia . . . . . . . . . . . . . . . . . . 152
9.13 Spinal Cord . . . . . . . . . . . . . . . . 165
9.5 Charges Inside a Cell . . . . . . . . . . 154
9.14 Brain . . . . . . . . . . . . . . . . . . . . . 166
9.6 Impulse Conduction . . . . . . . . . . . 156
9.15 Peripheral Nervous System . . . . . . 170
9.7 The Synapse . . . . . . . . . . . . . . . . 157
9.16 Autonomic Nervous System . . . . . 172
9.8 Synaptic Transmission . . . . . . . . . . 158
Chapter Assessment Answers . . . . . . 176
10
The Senses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
10.1 Introduction . . . . . . . . . . . . . . . . 182
10.6 Sense of Taste . . . . . . . . . . . . . . 189
10.2 Receptors, Sensations,
10.7 Sense of Hearing . . . . . . . . . . . . . 191
and Perception . . . . . . . . . . . . . . . . . 183
10.8 Sense of Equilibrium . . . . . . . . . . 193
10.3 General Senses . . . . . . . . . . . . . . 185
10.9 Sense of Sight . . . . . . . . . . . . . . 194
10.4 Special Senses . . . . . . . . . . . . . . 187
Chapter Assessment Answers . . . . . . 199
10.5 Sense of Smell . . . . . . . . . . . . . . 188
11
Endocrine System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
11.1 Introduction . . . . . . . . . . . . . . . 204
11.7 Adrenal Glands . . . . . . . . . . . . . . 213
11.2 Hormone Action . . . . . . . . . . . . . 206
11.8 Pancreas . . . . . . . . . . . . . . . . . . 215
11.3 Control of Hormone Secretions . . 207
11.9 Pineal, Thymus, and Other Glands . 216
11.4 Pituitary Gland . . . . . . . . . . . . . . 209
11.10 Stress and Health . . . . . . . . . . . . 218
11.5 Thyroid Gland . . . . . . . . . . . . . . . 211
Chapter Assessment Answers . . . . . . 221
11.6 Parathyroid Gland . . . . . . . . . . . . 212
UNIT
UNIT
4
12
13
Transport .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
145
224
Blood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
12.1 Introduction . . . . . . . . . . . . . . . . 227
12.4 Hemostasis . . . . . . . . . . . . . . . . 234
12.2 Blood Cells . . . . . . . . . . . . . . . .228
12.5 Blood Groups and Transfusions . . .236
12.3 Blood Plasma . . . . . . . . . . . . . . . 232
Chapter Assessment Answers . . . . . 239
Cardiovascular System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Introduction . . . . . . . . . . . . . . . 244
13.5 Blood Pressure . . . . . . . . . . . . . . 252
Structure of the Heart . . . . . . . . . 245
13.6 Arterial System . . . . . . . . . . . . . .254
Heart Actions . . . . . . . . . . . . . . 248
13.7 Venous System . . . . . . . . . . . . . . 256
Blood Vessels . . . . . . . . . . . . . . 250
Chapter Assessment Answers . . . . . 259
13.1
13.2
13.3
13.4
14
Lymphatic System and Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Introduction . . . . . . . . . . . . . . . .264
14.6 Innate (Nonspecific) Defenses . . . 270
Lymphatic Pathways . . . . . . . . . . .265
14.7 Immunity: Adaptive (Specific)
Tissue Fluid and Lymph . . . . . . . . 266
Defenses . . . . . . . . . . . . . . . . . . . . . 271
Lymphatic Tissue and Organs . . . . 267
Chapter Assessment Answers . . . . . . 277
Body Defenses Against Infection . .269
14.1
14.2
14.3
14.4
14.5
UNIT
5
15
IV
Absorption and Excretion .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
279
Digestive System and Nutrition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
15.1 Introduction . . . . . . . . . . . . . . . .283
15.5 Pharynx and Esophagus . . . . . . . 289
15.2 General Characteristics of the
15.6 Stomach . . . . . . . . . . . . . . . . . . 290
Alimentary Canal . . . . . . . . . . . . . . . 284
15.7 Pancreas . . . . . . . . . . . . . . . . . . 292
15.3 Mouth . . . . . . . . . . . . . . . . . . . 286
15.8 Liver and Gallbladder . . . . . . . . . 293
15.4 Salivary Glands . . . . . . . . . . . . . 288
15.9 Small Intestine . . . . . . . . . . . . . . 295
15.10
15.11
Large Intestine . . . . . . . . . . . . . 296
Nutrition and Nutrients . . . . . . . 298
Chapter Assessment Answers . . . . . 304
16
Respiratory System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
16.1 Introduction . . . . . . . . . . . . . . . 309
16.5 Alveolar Gas Exchanges . . . . . . . . 317
16.2 Organs of the Respiratory System . . 310
16.6 Gas Transport . . . . . . . . . . . . . . . 318
16.3 Breathing Mechanism . . . . . . . . . 312
Chapter Assessment Answers . . . . . . 321
16.4 Control of Breathing . . . . . . . . . . 314
17
Urinary System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
17.1 Introduction . . . . . . . . . . . . . . . .326
17.4 Urine Elimination . . . . . . . . . . . . .333
17.2 Kidneys . . . . . . . . . . . . . . . . . . . 327
Chapter Assessment Answers . . . . . 337
17.3 Urine Formation . . . . . . . . . . . . . 329
18
Water, Electrolyte, and Acid-Base Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
18.1 Introduction . . . . . . . . . . . . . . . . 341
18.5 Acid-Base Balance . . . . . . . . . . . 348
18.2 Distribution of Body Fluids . . . . . 342
18.6 Acid-Base Imbalances . . . . . . . . . 350
18.3 Water Balance . . . . . . . . . . . . . . 345
Chapter Assessment Answers . . . . . 353
18.4 Electrolyte Balance . . . . . . . . . . 346
UNIT
6
The Human Life Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .355
19
Reproductive Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
19.1 Introduction . . . . . . . . . . . . . . . 358
19.6 Hormonal Control of Female
19.2 Organs of the Male
Reproductive Functions . . . . . . . . . . . 367
Reproductive System . . . . . . . . . . . . . 358
19.7 Mammary Glands . . . . . . . . . . . . 370
19.3 Spermatogenesis . . . . . . . . . . . . 361
19.8 Birth Control . . . . . . . . . . . . . . . 371
19.4 Electrolyte Balance . . . . . . . . . . .363
19.9 Sexually Transmitted Infections . . . 373
19.5 Organs of the Female
Chapter Assessment Answers . . . . . .376
Reproductive System . . . . . . . . . . . . . 365
20
Pregnancy, Growth, Development, and Genetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
20.1 Introduction . . . . . . . . . . . . . . . 380
20.5 Genetics . . . . . . . . . . . . . . . . . 388
20.2 Fertilization . . . . . . . . . . . . . . . . 381
Chapter Assessment Answers . . . . . 392
20.3 Pregnancy and the
Prenatal Period . . . . . . . . . . . . . . . . .382
20.4 Aging: The Human Life Span . . . . 386
V
USING YOUR TEACHER MANUAL
This teacher manual is intended to guide anatomy and physiology teachers
through how to use the tools provided by the Hole’s Essentials of Human
Anatomy and Physiology program.
Unit Opener
Each Unit Opener of the teacher manual provides pacing for the chapters
within the unit and an introduction to the Unit Project for teachers.
This Pacing Guide provides suggestions as to how many days should be
devoted to each chapter in the unit.
UNIT
Support and
Movement
Chapter
2
Pacing (class periods)
6 Integumentary System
8
7 Skeletal System
12
8 Muscular System
10
Unit 2 Resources
Unit Project Engineer a Healthier World—Engineering in Anatomy and Physiology
Unit Project: Engineer a Healthier World—
Engineering in Anatomy and Physiology
Project 2: Mending a Broken Heart
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Stem Cells to Treat Diseases” (p. 191), and use this
to start their investigation into regenerative medicine.
A teacher guide for this project can be found online.
UNIT 2
VI
|
Support and Movement
85
Chapter Opener
Each chapter opens with a pacing chart. This chart indicates the
recommended number of class periods that should be devoted to each
section of the chapter. The chart also includes the chapter Learning
Objectives and a list of the resources teachers can use as part of their
instruction including Focus Activities, Test Banks, Vocabulary Flashcards,
Laboratory Exercises, and APR Modules.
A Suggested Approach
Following the pacing chart, the suggested approach provides helpful hints
and guidance for teachers on how to teach the chapter.
CHAPTER
6
Integumentary System
Section
Pacing
(class periods)
Learning Objectives
6.1 Introduction
—
1. Describe what constitutes an organ, and
name the large organ of the integumentary
system.
6.2 Layers of the Skin
2
1. Describe the structure of the layers of the
skin.
2. Summarize the factors that determine skin
color.
6.3 Accessory Structures
of the Skin: Epidermal
Derivatives
2
1. Describe the accessory structures
associated with the skin.
6.4 Skin Function
1
1. List various skin functions and explain how
the skin helps regulate body temperature.
2. Describe wound healing.
Focus Activities Workbook
Focus Activities: Labeling (6)
Focus Activities: Vocabulary (4)
Chapter Resources
Extended Summary Review
Chapter 6 Test Bank
Chapter 6 Interactive Question Bank
Vocabulary Flashcards
APR Module 4: Integumentary System
Laboratory Exercise 7: Integumentary System
A Suggested Approach
This chapter familiarizes students with the functions, anatomical features, and
accessory organs of the skin.
Emphasize the importance of both skin color and Vitamin D production for our
health with the following videos: TEDEd: Breaking the Illusion of Skin Color and
HHMI BioInteractive: The Biology of Skin Color.
Students can examine how the skin is responsible for maintaining the internal
temperature of the body regardless of the external temperature by observing
thermoregulation. Students can soak their hand and forearm in a bucket of ice water
for approximately 10 minutes and record changes in internal and external
temperatures. Students could also map their sweat glands on their palms using
cornstarch and iodine. These activities with the addition of reviewing the self—
care products and their effectiveness, will assist the students’ understanding of the
importance and functions of the accessory organs.
86
UNIT 2
|
Support and Movement
Lastly, students can investigate the variety of skin diseases and disorders by
researching a disorder that interest them, and writing a short magazine article about
the disease or disorder. Begin by asking students what skin diseases and disorders
they have heard about, and how they learned about them. Encourage students to
review magazine articles as a reference point for their own research and writing.
Have students share their written articles by reading them outloud or publishing
them on an online source such as Issuu or Flipboard.
This lesson is expected to take five class periods including Lab 7.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
VII
USING YOUR TEACHER MANUAL
(CONTINUED)
Case Study
Guidance and additional resources for the student Case Study are provided
at the beginning of each chapter of the teacher manual. The Case Study is
essential to enhancing student understanding of clinical situations and
develops students' abilities to make and defend claims, essential skills for any
anatomy and physiology course.
Theme Activities
Each chapter in the student edition begins with a theme. This theme aligns
the chapter to one of seven crosscutting concepts. This activity is designed
to provide teachers with an opportunity to see how the theme relates to the
chapter content. Teachers can choose to use this activity at any time during
the study of the chapter.
A Suggested Approach
This chapter familiarizes students with the functions, anatomical features, and
accessory organs of the skin.
Introduction
the Theme
Emphasize the importance of both skin
color and Vitamin D to
production
for our
health with the following videos: TEDEd:
Breaking
theProportion,
Illusion of Skin
Color and
Theme:
Scale,
Quantity
The level at which the integumentary
HHMI BioInteractive: The Biology of system
Skin Color.
protects the body from the environment is in proportion and quantity of
and bacteria
which occupy
the surface. This system is truly the largest
Students can examine how the skin isglands
responsible
for maintaining
the internal
system
in the body.
temperature of the body regardless of
the external
temperature by observing
thermoregulation. Students can soakTheme
their hand
and forearm
in a bucket
ice water
Activity:
The Role
of theofIntegumentary
System
for approximately 10 minutes and record changes in internal and external
The integumentary system is a large and complex system that affects all other
temperatures. Students could also map their sweat glands on their palms using
systems of the body. For this activity, students will play a matching game describing
cornstarch and iodine. These activities with the addition of reviewing the self—
how the integumentary system interacts with these other systems.
care products and their effectiveness, will assist the students’ understanding of the
Print and
cut out the following cards. One set provides the system that the
importance and functions of the accessory
organs.
integumentary system affects and one set is how it interacts.
Lastly, students can investigate the variety of skin diseases and disorders by
Shuffle
thewriting
cards aand
have
studentsarticle
play the
matching game with one another.
researching a disorder that interest them,
and
short
magazine
about
When
they have
go through
the correct answers.
the disease or disorder. Begin by asking
students
whatfinished,
skin diseases
and disorders
they have heard about, and how they learned about them. Encourage students to
review magazine articles as a reference point for their own research and writing.
regulate body
produces
Have students share their written articles
by reading them outloud
or publishing Cardiovascular
Skeletal System
temperature
System
Vitamin D
them on an online source such as Issuu or Flipboard.
(blood vessels)
This lesson is expected to take five class periods including Lab 7.
Case Study
Muscular
System
controls body
temperature (shivering)
Lymphatic
System
first line of defense for
the immune system
Nervous System
provides information
about the outside world
Digestive System
stores excess
calories as fat
Endocrine
System
increase skin blood flow
during exercise
After reading the case study, students should access their online Claim,
water
and
Evidence, Reasoning (CER) chart and make their claim.
CER
is electrolyte
a strategy
Urinary
System
loss
compensated
used to teach students how to construct
explanations
andare
craft
scientific
kidneys to a
arguments. A scientific claim answers a question or offers by
a solution
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
Section 6.1: Introduction
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
Learn
from a variety of sources, such as research,
experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
Classroom
a claim. Encourage students to return
to their claimsActivities
and add evidence at
multiple points in the chapter. Section 6.1 sets the groundwork for activities in sections 6.2 and beyond.
For more information on Ozti, show students the following video:
Additional Discussion Questions
https://www.smithsonianchannel.com/videos/
this-5300-year-old-corpse-was-found-by-accident/36308
Ask students to develop a chart that illustrates the levels of structural organization
in the
body.
This is a wonderful topic to explore
the human
anatomy
and physiology of tissues
(which can be preserved, which are
more
disintegrate)
as well as
The
chartlikely
shouldtoinclude
atoms, molecules,
organelles, cells, tissues, organs, organ systems,
explore various pathologies.
and organisms.
Ask students to discuss why the skin is vitally important to the functioning of all
other organs.
Responses will vary.
CHAPTER 6
VIII
88
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Integumentary System
Support and Movement
87
Learn, Practice, Assess
The teacher manual uses the same pedagogy as the student edition and is
divided into a three-part structure (learn, practice, and assess). Let’s take a
closer look at what support is provided to teachers in each of these sections.
Learn
A variety of classroom activities are provided throughout the teacher manual.
These include EL Strategies, Writing Connection, Visual Literacy, Group
Activities, and others. Many of these activities also provide differentiated
instruction to address the needs of varying learning styles.
In addition to activities, Additional Discussion Questions provide starting
Practice Questions points for individual writing assignments or class discussions.
Practice
1. What constitutes an organ?
Two or more types of tissues structurally connected and performing shared, specialized
functions constitute an organ.
Use the Practices 6.1
Using Mathematics The skin is the largest organ in the body by weight,
making up approximately 16%. Calculate how much the skin of a 150-pound
person contributes to that person’s body weight .
150(0.16) = 24 pounds
Section 6.2: Skin and its Tissues
Learn
Classroom Activities
EL Strategy: Vocabulary Preteaching
Beginning Look at the Aid to Understanding Words at the beginning of the
chapter. Define the vocabulary in English and provide examples. Say the terms
out loud and have students repeat the words. The students should then go on
a “word scavenger hunt”, finding examples of words that use the roots in Aid
to Understanding Words. Students then write the word in their interactive
notebooks and the section where they found the word.
Writing Connection: Skin Cancer Research
Open the activity with a class discussion about skin cancer, and if students have
ever had it or know someone who is affected from skin cancer. Highlight for
students that ultraviolet radiation causes mutations that could cause skin cancer.
Put students into small groups and have them come up with five research questions
about skin cancer they are going to research based on information revealed in the
a take-home
project
or going
simplyto
create
discussion. Students should write out theireither
questions
and where
they’re
go the recipe. Students must label their
ingredients to correspond to the different layers and components of the skin. Refer
to look for answers.
students to Figures 6.1 and 6.2.
Differentiated Instruction
Instead of discussing skin cancers asAdditional
a class, the teacher
could focus the Questions
Discussion
discussion on careers and different occupations related to studying skin. See
Askdisorders.
students This
to bring
in lead
several
the appendix for a list of common skin
could
intophotographs
different or pictures depicting a baby, a child,
an adolescent,
a person
middle
age, and an elder. Discuss these samples based on
repairs and types of skin disorders that
affect different
layersinof
skin. Students
comparisons
of skin, nails, and hair.
could work on this research individually
or in groups.
Responses will vary.
Demonstration Activity: Skin Deep
Dessert
causes
freckles?
For this activity, students will try to designWhat
a layered
dessert
that best represents
the different layers of the skin. You may either
bring
ingredients
to high concentrations of melanin. Exposure to
Freckles
are actually
areasinoffor
thestudents
skin containing
use, create the layered dessert as you lecture,
ormay
haveincrease
students
this activity
sunlight
thedo
numbers
of theseaslocations.
Ask students to discuss the irony of the statement—Beauty is only skin deep in light
of the information learned by studying this chapter objective.
The statement is ironic in that, technically speaking, the stratum corneum, or outermost layer of
CHAPTERalready
6 | Integumentary
skin, is actually
dead andSystem
is waiting to89
be sloughed off and replaced by other skin cells
approximately once a month.
Explain the difference between a mole and a melanoma.
The common mole is a benign tumor called a nevus. It is sometimes referred to as a melanoma.
The nevus is congenital, but may change shape, size, or color later in life. This benign tumor
can convert into a malignant melanoma, the cancerous form of a mole.
Practice
Practice Questions
1. List the layers of the skin.
IX
USING YOUR TEACHER MANUAL
(CONTINUED)
Practice
The Practice section of the teacher manual provides teachers the answers to
all the Practice questions in the student edition. This section also provides
answers to the Use the Practice activities and Figure Questions.
Practice
Practice Questions
1. Describe the structure of the nail bed.
Specialized epithelial cells continuous with the epithelium of the skin produce the nail
bed. The whitish, thickened, half-moon-shaped region at the base of a nail plate is the
most actively growing region. The epithelial cells here divide and become keratinized,
giving rise to tiny, keratinized, scales that become part of the nail plate, pushing it
forward over the nail bed. The nail plate extends beyond the end of the nail bed and
with normal use gradually wears away.
2. Explain how a hair forms.
Each hair develops from a group of stem cells at the base of a tubelike depression called
a hair follicle. These stem cells originate from a region near the bottom of the hair follicle
known as the hair bulge, and migrate downward. The follicle contains the hair root, which
can extend from the surface through the dermis into the subcutaneous layer. The
deepest portion of the hair root is the hair bulb, composed of epithelial cells that are
nourished from dermal blood vessels in a projection of connective tissue called the hair
papilla. As these epithelial cells divide and grow, they push older cells toward the
surface. The cells that move upward and away from their nutrient supply become
keratinized and die. Their remains constitute the structure of a developing hair shaft that
extends outward, away from the skin surface.
3. What is the function of the sebaceous gland?
Sebaceous glands produce globules of oily, fatty material called sebum. Sebum moves
through small ducts into the hair follicles and helps keep the hair and skin soft, pliable,
and waterproof.
4. Distinguish between merocrine sweat glands and apocrine sweat glands.
Merocrine glands are the most numerous and widespread sweat glands. They respond
throughout life to body temperature elevated by environmental heat or exercise. They
also release moisture on the palms and soles during stressful times. Merocrine glands are
found on the forehead, neck, and back as well. Apocrine glands are sweat glands that
become active at puberty and are found in the axilla and groin.
Use the Practice 6.3
Asking Questions Accessory structures of the skin (nails, hair, and glands) are
in the skin of all mammals. Develop a question to investigate the relationship
between the anatomy and physiology of a specific mammalian skin accessory.
Answers will vary. What would be a possible function of a cat’s longer claws? Why do we
refer to a cat’s nails as claws and a dog’s as toe nails?
Figure Questions
Figure 6.4, page 171: What is the most actively growing region of the nail?
The lunula, the whitish half-moon region at the base of the nail.
CHAPTER 6
X
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Integumentary System
93
more rapidly than usual, and the newly formed cells fill the gap. If the injury extends into
the dermis or subcutaneous layer, blood vessels break, and the released blood forms a
clot in the wound. The blood clot and dried tissue fluids form a scab that covers and
protects the underlying tissues. Fibroblasts migrate into the injured region and begin
secreting collagen fibers that bind the edges of the wound.
6. Explain the role of phagocytic cells in wound healing.
As healing continues, blood vessels extend into the area beneath the scab. Phagocytic
cells remove dead cells and other debris. Eventually the damaged cells are replaced,
and the scab sloughs off.
Assess
7. Define granulation.
In large, open wounds, healing may be accompanied by formation of small, rounded
masses called granulations that develop in the exposed tissues. A granulation consists of
The Assess section
provides
to the questions
that accompany the
a new branch
of a blood vesselanswers
and a cluster of collagen-secreting
fibroblasts that the
vessel nourishes.
Career Corner feature, Case Study Connection, and special features found
the Practice 6.4
throughoutUse
the
student edition.
Arguing from Evidence If the skin around a cut is red and slightly swollen, is it
infected? Why or why not?
Part of wound healing is vasodilation, and increase in blood flow. This vasodilation
can lead to both redness in the area as well as slight swelling.
Assess
Career Corner: Massage Therapist
Consider This: Imagine you are a massage therapist talking with a new client.
The client mentions pain and tenderness in his shoulder. What kinds of
questions would you ask to assess whether or not massaging the injury is a
good idea?
Answers will vary, but students should indicate that they would ask questions to indicate
the type of injury and the tissues involved.
Diseases, Diagnosis, & Treatment:
Skin Cancer
1. Describe the role of melanin in the skin.
Melanin absorbs ultraviolet light and protects the skin from damage from UV rays.
2. Explain the characteristics looked for in trying to determine if a mole is a
melanoma.
The “ABCDE” rule provides a checklist for melanoma: A for asymmetry; B for border
(irregular); C for color (more than one); D for diameter (more than 6 millimeters); and E for
evolution or change.
Diseases, Diagnosis, and Treatment:
Burns
1. Describe the differences in wound healing between shallow and full-thickness
burns.
Third-degree burns are very serious because the skin provides a crucial barrier against
microorganisms (bacteria, fungi, etc.) that are present everywhere. Patients with thirddegree burns are very likely to develop sepsis, which can be deadly, as a result of
bacteria gaining entry to the bloodstream. To prevent this from occurring, patients with
third-degree burns are kept on special burn units with extremely strict sterilization
procedures.
2. Explain the “rule of nines.”
96
UNIT 2
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Support and Movement
The rule of nines is used by physicians to subdivide the skin into regions, each accounting
for 9% (or multiples thereof) of the total surface area. This estimation of skin area is used
to plan for skin replacements or substitutes, and for replacing body fluids and
electrolytes to support repairing tissues.
Case Study Connection
page 164: Where are the tattoo pigments located, can you find the location
on this skin diagram? Think about the pathway of the tattooist’s needle as it
comes into the skin to deposit the pigment.
The pigment is located in the upper layer of the dermis. Students may recall from
the opening vignette that initially, the ink is injected between the dermis and the
epidermis.
page 165: Would you expect to find any of the tattoo pigment in the
subcutaneous layer?
No, the subcutaneous layer lies below the thick dermis and is unlikely to be pierced by
the needle.
page 166: As the tattooist’s needle is inserted, is it likely to cause much
bleeding? Why or why not? Will a tattooist require a different length of
needle when tattooing the bottom of a customer’s foot than they would
require when tattooing the skin of the forearm?
Some but not too much bleeding. Most of the blood vessels lie deeper in the dermis.
The skin of the foot is thicker than that of the forearm so it might require a longer
needle.
page 168: Eumelanin and phenomelanin are naturally occurring skin pigments.
Are they found in the same or different locations than the tattoo pigments?
No these pigments are produced by melanocytes in the epidermis.
page 170: The beau’s lines observed on Ozti are due to a temporary halt in
nail formation when he was seriously ill. Which part of the nail had stopped
functioning during the illness?
The lunula, or base of the nail plate where growth occurs.
CHAPTER 6
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Integumentary System
97
XI
USING YOUR TEACHER MANUAL
(CONTINUED)
The Chapter Assessment section provides the questions and answers to the
student edition Chapter Review.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. The largest organ in the body by weight is the
a. liver.
b. skin.
c. large intestine.
d. brain.
2. Which of the following is considered a true layer of skin?
a. epidermis (outer layer)
b. dermis (inner layer)
c. hypodermis (subcutaneous layer)
d. both a and b
3. Which of the following correctly matches skin tones to their
cause?
a. Bluish skin tone can be caused by a liver malfunction.
b. Orange-yellow skin tone can be caused by a diet high in
carrots and sweet potatoes.
c. Pinkish skin tone can be caused by oxygen-rich jaundice in
blood vessels.
d. Yellowish skin tone can be caused by cyanosis.
4. Which of the following statements is false regarding the
pigment melanin?
a. All people have the same number of melanocytes in their
skin.
b. Cytocrine secretion transfers melanin granules into cells
neighboring melanocytes.
c. Melanin protects nuclei from the sun’s UV radiation.
d. Melanocytes lie in the deepest portion of the dermis.
5. What causes some hair to appear gray in color?
a. mixture of pigmented and unpigmented hairs
b. a lack of melanin
c. an abundance of eumelanin
d. an abundance of pheomelanin
6. All of the following are components of sweat except —.
a. water
b. uric acid
c. kerotin
d. urea
7. All of the following describe functions of the integumentary
system except
a. Skin helps to increase water loss from deeper tissues.
b. Skin cells produce a vitamin D precursor.
c. Skin helps to regulate body temperature.
d. Skin prevents harmful substances from entering the body.
8. What is the term used for the tissue’s response to stress that
includes pain, warmth, redness, and swelling?
a. Healing
b. Inflammation
c. Homeostasis
d. None of these
98
UNIT 2
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Support and Movement
9. Which of the following most closely lists the steps to healing
a skin wound in the correct chronological order?
a. fibroblasts produce collagen fibers; scar tissue develops; a
blood clot forms; a scab forms and protects
b. fibroblasts produce collagen fibers; a scab forms and
protects; a blood clot forms; scar tissue develops
c. a blood clot forms; fibroblasts produce collagen fibers; a
scab forms and protects; scar tissue develops
d. a blood clot forms; scar tissue develops; a scab forms and
protects; fibroblasts produce collagen fibers
10. Suturing (stitching) or otherwise closing a large break in the
skin speeds the process of
a. the provision of nutrients and oxygen to the wound
b. the extension of blood vessels into the area beneath the scab
c. the formation of scar tissue
d. collagen fibers binding the edges of the wound.
Short Answer
1. Explain why the skin is considered an organ system.
The skin is also known as the integumentary system because it
is comprised of several types of organs. First, the epidermis
and dermis together are an organ. Other organs include hair,
glands, muscles, and nails.
2. List and describe the functions of the skin.
The skin functions in protection, thermoregulation, the sense of
touch, excretion, and the production of vitamin D.
3. Describe the structure of the epidermis.
The epidermis is a stratified squamous epithelium. The
outermost layers are filled with the hard protective protein
keratin and are no longer alive. They are always shed. They
are replaced by the mitotically active stratum basal layer that
is next to the basement membrane.
4. Describe the structure of the dermis.
The dermis is a sea of loose connective tissue which houses
the blood vessels, hairs, glands, muscles and nerves.
5. Explain the role of melanocytes in the integumentary system.
Melanocytes are the cells in the epidermis that produce the
pigment melanin that is responsible for skin color.
6. What effects do sunlight and carotene have on skin color?
Sunlight activates melanocytes, resulting in the production of
more melanin, which makes skin darker. Carotene is yellow/
pigment found in certain foods. It will cause skin to have an
Laborange
Data tint.
Analysis: Wound Healing Rates
7. Describe the subcutaneous layer. Is it part of the skin?
Think
Critically
The
subcutaneous layer lies beneath the dermis and is
comprised of collagen fibers, blood vessels, and adipose.
1. Which HbA1c category of patients has the fastest wound
healing? The slowest?
The first group along the x-axis (HbA1c <7.0%) has the highest
‘mean change in wound area per day’, or in other words, their
wounds are shrinking the quickest. The third group (HbA1c ≥
8.0%) clearly demonstrates the slowest wound healing rates
among the three groups, with a considerable drop from the
middle range group (HbA1c 7.0-8.0%).
2. Which HbA1c category likely includes patients with severe
diabetes?
The third group along the x-axis (HbA1c ≥ 8.0%) includes the
patients with severe diabetes because they demonstrate the
XII
slowest wound healing among the three groups. We know that
diabetes slows wound healing, so it follows that the mean
change in wound area per day on the y-axis (aka, how much
the wound is shrinking per day) would be smallest in this
group.
3. Which group of patients would you most want to counsel on
the risks of eventually developing severe diabetes?
The first group along the x-axis is presumably in the normal
range, and the third group already has severe diabetes. So, it
would be most prudent to counsel the patients in the middle
group (HbA1c 7.0-8.0%) on the dangers of not controlling their
blood sugar and the effects that it could eventually have on
their wound healing capabilities if their HbA1c continues to
increase.
PREVIEW
CHAPTER
Foundations for Success
Section
Pacing
(class period)
P.1 Introduction
Review only
P.2 Science Literacy
Skills
P.3 Strategies for Your
Success
Review only
Review only
P
Learning Objectives
1. Explain the importance of an individualized
approach to learning.
1. Explain the importance of science literacy.
1. Summarize what you should do before
attending class.
2. Identify student activities that enhance the
classroom experience.
3. List and describe several study techniques
that can facilitate learning new material.
PREVIEW CHAPTER
P1
A Suggested Approach
The preview chapter contains little to no anatomy and physiology content, but is a
good reading exercise for students at the start of the course. It encourages students
to take an active role in their learning, and to identify their learning styles.
Section P.1: Introduction
Practice
Practice Questions
1.List some difficulties a student may experience when studying the human body.
Answers will vary. Difficulties studying the human body can include trouble memorizing
long and complex names of different anatomical structures, understanding how organ
systems work individually and together, and comprehending the complexity of body
systems. From memorization to critical thinking and application, there is a lot of work
that goes into forming a deep understanding of the human body.
2.Describe the ways people learn.
Most students use several modes of learning, which can include read-write, visual, auditory,
and/or kinesthetic. Read-write learning uses lists, glossaries, and tables. Visual learners
take advantage of diagrams, flow charts, and figures. Auditory learners benefit from
pronunciations for new scientific terms, and kinesthetic learners gain a better understanding
of the material through real-life examples and applications to their own activities. See the
answer in P.1 for more details on these learning modes, and answers will vary.
Use the Practice P.1
Using Models Create a graphic organizer to describe and explain the
different modes of learning used by students. Identify the modes of learning
that are most effective for you.
Answers will vary. The graphic organizer will include the different modes of learning, possibly
with the following examples: visual (looking at photographs, drawings, diagrams, and flow
charts), auditory (hearing the information or explaining it to someone else), kinesthetic
(using multiple senses to put the material in a memorable context, like in a lab setting), and
read-write (reading and digesting the material; writing the material down). The modes of
learning most effective to me are auditory (explaining it to someone else) and read-write.
Section P.2: Science Literacy Skills
Practice
Practice Questions
1.Summarize how scientific literacy can help you in this course and in everyday
life.
Answers will vary. Scientific literacy will help you not just understand scientific issues in this
course and beyond, such as climate change and the importance of vaccination, but helps
develop your critical thinking skills to analyze, evaluate, and critique myriad topics you come
across in your everyday life. It encourages you to ask questions, carry out investigations,
interpret data, construct explanations, use evidence, and communicate information.
P2
PREVIEW CHAPTER
Use the Practice P.2
Arguing from Evidence Defend the importance of being scientifically literate
to your classmates.
Answers will vary. Some reasons include: a better understanding of our everyday world:
from health and disease, to drug use, pollution, and ethical issues. Scientific literacy also
helps people outside of scientific issues. It helps you become a high-valued employee
and an educated consumer due to your critical thinking skills.
Section P.3: Strategies for
Your Success
Practice
Practice Questions
1. Why is it important to prepare before attending class?
Answers will vary. It is important to prepare before class so you are aware of the material
that will be presented, as well as new terms. If you create an outline, you will be better
equipped to multitask while in class – listening and taking notes at the same time.
Preparing before class will make it easier to follow along with the lecture and be a more
active student. This is turn will help you understand the material better and faster.
2. Name two ways to participate in class discussions.
Answers will vary but two ways to participate are by asking questions of the instructor
and answering questions he or she poses.
3. List several aids for remembering information.
Answers will vary but some aids include making lists, using mnemonic devices, forming
study groups, and making flash cards.
Use the Practice P.3
Communicating Information Create a poster highlighting the strategies for
academic success you find most helpful.
Posters and answers will vary. A poster could contain information on the benefits of
preparing for class by reading the assigned text and taking notes to get acquainted with
the upcoming topics. It could also contain recommendations to attend class regularly, be
on time, pay attention, take notes, and participate in class discussions. It helps to ask
questions about topics you don’t understand. After class, students can organize, edit, and
review the notes to reinforce the material learned that day. There are many ways to
review the notes, including making lists, using mnemonic devices, forming study groups,
and creating flash cards.
PREVIEW CHAPTER
P3
Chapter Assessment
Chapter Review Questions
Short Answer
1. Explain why the study of the human body can be
overwhelming.
Answers will vary. Answers may include: new terminology, a
large number of systems, critical thinking skills.
2. Define science literacy.
Science literacy is the combined knowledge and
understanding of scientific concepts, mechanisms, and
techniques that helps you apply critical thinking and other
science-based skills to real world situations.
3. List three science and engineering practices and give
examples of situations in which they might help you.
Answers include: asking questions, developing and using
models, planning and carrying out investigations, analyzing
and interpreting data, using mathematics, constructing
explanations, engaging in argument from evidence, and
obtaining, evaluating, and communicating information.
Examples will vary.
4. Explain the methods to help you prepare for class.
Reading the chapter, outlining the chapter, and making a
vocabulary list.
5. Describe how you can participate in class discussions.
Answers will vary. You can participate in class discussions by
asking questions of the teacher and answering questions he or
she poses, being sure to respect class policy.
6. Forming the phrase “I passed my anatomy test” to remember
the cell cycle (interphase, prophase, metaphase, anaphase,
telophase) is a
device.
mnemonic
7. Name a benefit and a drawback of small study groups.
Benefits include hearing the material to help auditory learners,
comparing notes, verbalizing the material to help the speaker
commit it to memory, and using anatomical and physiological
terms more regularly. One drawback could be that the groups
can become vehicles for social interaction if you don’t stay on
topic.
8. Give an example of effective time management used in
preparation for success in the classroom.
Examples of effective time management include multitasking
(e.g. review notes when waiting for a ride) and having several
short study periods instead of one cram session.
Critical Thinking and Clinical Applications
1. Which study methods are most successful to you?
Answers will vary.
2. WRITING Connection Design a personalized study
schedule.
Answers will vary but should include time blocked for
preparing for class, attending class, and reviewing the material
after class. Ideally, there would be at least some review every
day to not overwhelm the student right before the test.
3. CLINICAL Connection Review an example of promotional
material for a product or service that includes a health claim.
P4
PREVIEW CHAPTER
Note what you would infer from this material. Then, outline
steps to evaluate and verify the scientific information related
to the product or service. Did your analysis change your
inferences? How?
Answers will vary. Students could review an advertisement for
vitamins, detox tea, even crystals, juice cleanses, or medical
marijuana. They should rely on some of the science and
engineering practices listed in section P.2 to evaluate and
verify the scientific information. Answers will vary on whether
their analysis changed their inferences based on the example
they chose and their initial inferences.
UNIT
Levels of
Organization
Chapter
1
Pacing (class periods)
1 Introduction to Human Anatomy and Physiology
4
2 Chemical Basis of Life
4
3 Cells
4
4 Cellular Metabolism
4
5 Tissues
5
Unit 1 Resources
Unit Project Engineer a Healthier World—Engineering in Anatomy and Physiology
nit Project: Engineer a Healthier World—
U
Engineering in Anatomy and Physiology
Project 1: Necessity Breeds Invention
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Radioactive Isotopes: Helpful and Harmful” (p. 51),
and use this to start their investigation into the use of radioisotopes.
A teacher guide for this project can be found online.
UNIT 1
|
Levels of Organization
1
CHAPTER
1
Introduction to Human
Anatomy and Physiology
Section
Pacing
(class periods)
Learning Objectives
1.1 Introduction
Review only
1. Identify some of the early discoveries that led to
our understanding of the body.
1.2 Anatomy and
Physiology
Review only
1. Explain how anatomy and physiology are related.
1.3 Levels of
Organization
Review only
1. List the levels of organization in the human body
and the characteristics of each.
1.4 Characteristics
of Life
Review only
1. List and describe the major characteristics of life.
1.5 Maintenance
of Life
Review only
2. Give examples of metabolism.
1. List and describe the major requirements of
organisms.
2. Explain the importance of homeostasis to survival.
3. Describe the parts of a homeostatic mechanism
and explain how they function together.
1.6 Organization of 2
the Human Body
1. Identify the locations of the major body cavities.
2. List the organs located in each major body cavity.
3. Name and identify the locations of the
membranes associated with the thoracic and
abdominopelvic cavities.
4. Name the major organ systems, and list the
organs associated with each.
5. Describe the general functions of each organ
system.
1.7 Anatomical
Terminology
2
1. Properly use the terms that describe relative
positions, body sections, and body regions.
Focus Activity Workbook
Focus Activities: Labeling (10)
Focus Activities: Vocabulary
Extended Summary Review
Chapter Resources
Chapter 1 Test Bank
Chapter 1 Interactive Question Bank
Vocabulary Flashcards
APR Module 1: Body Orientation
Laboratory Exercise 1: Scientific Method and Measurements
Laboratory Exercise 2: Body Organization, Membranes, and Terminology
2
UNIT 1
|
Levels of Organization
A Suggested Approach
Chapter 1 introduces students to the sciences of anatomy and physiology along with
the organization of the human body and the terms we use to describe it.
In addition to becoming familiar the hierarchy of organization within an organ
system, students become familiar with the 12 body systems. Since students most
likely already have a basic knowledge of many of the body systems, as well as a few
misconceptions, you might have students brainstorm a few curiosity questions about
each body system. Use The Human Organism Reference Plates (pp. 33–40), as a
reference while you identify and offer basic information about each body system.
Briefly discuss one or two questions for each system.
Students also acquire an understanding of homeostasis and feedback cycles, key
concepts that will be revisited often in the course. To assist students understanding
of the feedback mechanisms, students can make flowcharts similar to the one of the
heating system in a house, but their flowcharts will represent daily processes that
happen in their bodies. Develop at least four scenarios depicting homeostasis in the
body. Ask students to count off by four and assign each student one of the four
scenarios. Then students will share flowcharts with other students in their group.
Lastly, the anatomical terminology discussed in section 1.7 (p. 22) is the language
used when they need to give descriptions to someone else. Providing accurate,
concise descriptions is a key skill for communicating in anatomy and physiology—and
in all health science professional roles. Students can demonstrate their knowledge
of these key terms by labeling a favorite stuff bear or other animal. Use a teddy bear
or other stuffed animal to demonstrate the key anatomical terminology terms.
This lesson is expected to take 4 class periods including Lab 1 and Lab 2.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
Additional case study resources include:
This video, from Bloomberg, could be a fun introduction to prosthetics
technology: https://www.youtube.com/watch?v=sk1NkWl_W2Y
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Introduction to the Theme
Theme: Structure and Function The human body has natural built systems that
depend on the structure and function of key parts as well as the substances of
which they are composed.
Theme Activity: How Doctors use the Scientific Method
How do doctors and medical researchers determine the structure and function of
systems in the human body? They use the scientific method. The scientific method
allows us to understand how and why our bodies work the ways in which they do.
For this activity, break students into five groups.
Present each group with one of the following medical cases – or make up your own:
Case 1: Patient has sinus pain
Case 2: Patient complains of loud, barking cough
Case 3: Patient has stiffness in knee
Case 4: Patient is admitted with high body temperature
Case 5: Patient has laceration that will not stop bleeding
Tell students to use Chapter 1 and the Human Organisms Reference Plates to come
up with a hypothesis of what might be wrong with the patient and how they would
test this hypothesis. When the students have come up with a hypothesis and test,
have the students share this information with the class. Start a discussion about
whether the tests are valid and what they would do if their test came back with
either negative or positive results.
Section 1.1: Introduction
Learn
Classroom Activities
EL Strategy: Word Origins
Beginning or Intermediate Look at the root words at the beginning of the
chapter. Students should pick two roots and list other words that use the root.
For example: meta- metamorphosis, metabolism; -logy- biology, geology.
Students can then share their words with the class.
Discuss how the root words apply specifically to this chapter by reviewing the
words at the beginning of the chapter. Have students find the Aid to Understanding
Words table to find the cognates, or words that have come from a common
ancestor, which can help them understand new vocabulary.
Additional Discussion Questions
Ask students to develop a chart of basic terms found in the language of anatomy
and physiology.
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Responses should include a minimum of 50 modern terms accompanied by their Greek/Latin
derivatives.
Compare and contrast several ancient uses of herbs and potions.
Students may be required to research this topic via the library, used-book stores, or Internet.
Practice
Practice Questions
1. What factors probably stimulated an early interest in the human body?
The study of the human body likely began when our early ancestors became curious
about how their bodies worked, as we are today.
2.What kinds of activities helped promote the development of modern medical
science?
Over time, people began to believe that humans could understand forces that caused
natural events. They began observing the world around them more closely, asking
questions and seeking answers. This curiosity set the stage for the development of
modern medical science.
Use the Practice 1.1/1.2
Arguing from Evidence Use what you know about the scientific method to
indicate if there is enough evidence to support the following claim: Taste is not
just a physiological function of the tongue. Protein receptors for molecules of
sugar exist both on tongue cells and cells lining the small intestine.
Disagree (not enough evidence) Taste is more than sugar receptors; it also involves brain
function.
Agree (enough evidence) Since the chemical receptors are the same, taste could occur in
our intestines.
Section 1.2: Anatomy and Physiology
Learn
Classroom Activities
Visual Literacy: Anatomy vs. Physiology
In small groups, students will work as a team to analyze several pictures or
descriptions of structures of the body as well as pictures or descriptions of the body
completing a function. Each small group should receive five sets of pictures that
pair a body structure with a body function. The pairs should not be attached and be
10 separate pictures mixed together. An example is below. Students in each small
group must work together to identify if the picture is a body structure (anatomy) or
a representation of a body function occurring (physiology). After categorizing each
picture, the second step is to pair the correct body structure with the correct
function. Encourage group discussion about why or why not a certain structure
might be the cause to the function and what evidence supports the group’s final
decision.
Example of a pair of pictures or descriptions (Note: the teacher would develop
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five pairs or however many they need depending on how they choose to execute
the activity). Provide an x-ray image of a hand displaying the long-jointed bones in
the fingers (anatomy). This would pair with a picture of a hand grasping a pencil or
other object (physiology).
Differentiated Instruction
Before the activity above, have students discuss in their small groups ways
certain designs of structures determine a more efficient function and why that
is important. After the discussion, assign each group one pair of pictures or
descriptions instead of all five. Each group can present to the whole class
which picture represent the structure (anatomy) and function (physiology) and
then why. This will allow for more whole class collaboration and promote
real-life examples to be discussed during class.
Additional Discussion Questions
Ask students to choose a body part and explain how its unique structure is related
to its function.
Some examples would include the hand, (adapted for grasping), the heart, (adapted for
receiving and pumping blood), and the mouth, (adapted for speaking and receiving food).
Ask students to consider the implications of changes in function of a body part that
has been altered in structure.
Examples may include loss of pumping ability of the heart due to scar tissue formation, loss of
the ability to grasp when the thumb, (opposable digit), is injured, or inability to plantar flex or
evert the foot due to injury to the peroneus muscles.
Practice
Practice Questions
1. Why is it difficult to separate the topics of anatomy and physiology?
The topics of anatomy and physiology are difficult to separate because the structures of
body parts are so closely associated with their functions.
2.List examples that illustrate how the structure of a body part makes possible
its function.
The human hand with its jointed fingers makes it easy to grasp objects; the shape of the
mouth enables it to receive food; and teeth are shaped to break foods into small pieces.
Section 1.3: Levels of Organization
Learn
Classroom Activities
Visual Literacy: Ice Breaker Organization
Students will need to work together in this activity to complete this task. This
activity is best for the beginning of the course and focuses on understanding the
levels of organization, targeting social interactions, and working effectively in small
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groups. The teacher will use Figure 1.3 from the book to create poster-sized cards
that represent each individual level of organization. Each student in the group will
hold one of the cards in front of them, without viewing their own card. Groups must
work together to organize themselves in the order of increasing levels of
organization. Once groups think they are in the correct order, everyone is given
permission to view their own card and evaluate if they were correct.
Differentiated Instruction
The activity is designed for each member to be holding a card and to work as a
group to order themselves. Another way to complete this activity would be to
allow each group member to view their cards, but then assign mock
communication barriers to different group members based on the reality that
many students do have these communication barriers. Barriers assigned could
be verbal (not allowing a member to talk), visual (not allowing a member to
see), language barrier (one member is only allowed to speak in foreign
language), mobility (one member is not allowed to move from their location).
This could raise awareness for social barriers that students can have as well as
support teamwork throughout the activity.
Group Activity: Can you design it better?
For this activity, begin by reminding students of what an organelle is and have
students come up with a list of organelles in the human body.
From here, divide students into small groups. Assign an organelle from the list to
each group. One organelle may be assigned to more than one group.
To first have the students understand how the shape of the organelle dictates its
function, provide students with the following to help aid in the design of a concept
map for each organelle the students:
Organelle:
Structure
Function
Once students determine why the shape of organelles inside a cell determines
function, challenge them by having them come up with a better shape that achieves
the same function.
Additional Discussion Questions
Ask students to apply their knowledge of levels of organization to an example
outside the human body.
For example, begin with a single book. Combining several books together will form a
bookshelf. Several bookshelves combine to form a bookcase. Many bookcases are joined
together to form a section of a library. Many sections of the library can combine to form one
whole library. Many libraries are linked together to form a library system, etc.
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Ask students to describe a system from the simplest to most complex level.
The skeletal system serves as an excellent example. Discussion should begin with a brief
overview of atoms, molecules, macromolecules, and organelles, followed by a description of bone
cells (osteocytes), which combine to form osseous tissue, which form more complex structures
called bones (organs). The 206 bones of the human body, when taken together, form the skeletal
system (organ system). This system combines with other organ systems to become an organism.
Practice
Practice Questions
1. How does the human body illustrate levels of organization?
Cells may be organized into layers or other structures that have common functions. Such
a group of cells forms a tissue. Groups of different tissues that interact form organs:
complex structures with specialized functions, Groups of organs that function closely
together compose organ systems.
2. What is an organism?
Organ systems make up an organism, which is a living thing.
3. How do body parts at different levels of organization vary in complexity?
Body parts can be described in terms of different levels of organization, such as the atomic
level, the molecular level, or the cellular level. Furthermore, body parts differ in complexity
from one level to the next. That is, atoms are less complex than molecules, molecules are
less complex than organelles, tissues are less complex than organs, and so forth.
Use the Practices 1.3
Using Models The human body is composed of many levels of organization.
Similar to a school each level is dependent on the other. Use a school as your
example to develop a model for each level of organization.
Level
Human
School
Molecular
Molecule
Molecules
Cellular
Cardiac muscle cell
Brick
Tissue
Muscular, epithelia
Wood, steel, plastic
Organ
Heart
Desk, computer, book
Organ System
Cardiovascular
Classroom
Organism
Human
School
Section 1.4: Characteristics of Life
Learn
Classroom Activities
Group Activity: Teach the Class
There are five common qualities all living organisms share: growth, reproduction,
responsiveness, movement, and metabolism. Split the class into five groups and
secretly assign each group one of the five qualities. Each group will be responsible
for finding an image that represents their characteristic of life. Each group member
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should create a question to ask the class about the image they found that will guide
the class to reveal which characteristic of life the group was assigned. Once each
group member has asked the class their question, the class will guess which
characteristic of life the group was assigned.
Example: Group 1 found a picture of a cheetah running:
Member 1 developed the following question for the class: How does a
cheetah run?
Member 2 developed the following question for the class: Why is it important
for a cheetah’s body to be very flexible?
Member 3 developed the following question for the class: Does a cheetah
always stay in one location?
The class will discuss answers to the above questions and decide which
characteristic of life the group was focusing on. In the example above, Group 1
focused on Movement.
Differentiated Instruction
This activity could be completed within a small group instead of with the
whole class. Within a small group, assign each member a characteristic of
life. Each group member would then find an image representing their
characteristic of life and take turns presenting to their small groups about
why their picture aligns with that characteristic of life. This could save on
time and also give students options of presenting to a smaller group instead
of the large group.
Additional Discussion Questions
Ask students to list the major characteristics of life and briefly describe why each
characteristic is important in maintaining human life. Relate each characteristic to a
specific body system.
Responses should include a discussion of movement (muscular and skeletal systems),
responsiveness (nervous and integumentary systems), growth (all systems), reproduction
(reproductive system), respiration (respiratory system), digestion (digestive system), absorption
(all systems), circulation (cardiovascular and lymphatic systems), assimilation (digestive system),
and excretion (digestive and urinary systems).
Ask students to compare human metabolic processes with processes of other
animals.
Comparisons may include mammals, fish, invertebrates, insects, etc.
Ask students to describe the importance of monitoring vital signs and their
relationships to the major characteristics of life.
Vital signs include the measurement of various organ system functions that are necessary to
maintain life. They include measurements of breathing, pulse, responsiveness, blood pressure,
temperature, movement, reflexes, and brain activity.
Ask students to predict the dire effects on the human body when one of the major
metabolic processes malfunctions.
Responses should include a discussion of the effects on homeostasis.
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Practice
Practice Questions
1. What are the characteristics of life?
Living things gain energy by ingesting (taking in), digesting (breaking down), absorbing,
and assimilating the nutrients in food. The absorbed substances circulate throughout the
internal environment of bodies. Through respiration, living things use the energy in these
nutrients for such vital functions as movement, growth, and repair of tissues. Finally, living
things excrete wastes.
2. How are the characteristics of life dependent on metabolism?
Taken together, these physical and chemical events that obtain, release, and use energy
are a major part of metabolism, which refers to all of the chemical reactions in cells.
Use the Practices 1.4/1.5
Conducting Investigations A patient’s vital signs are an observable indication
of the essential metabolic activities necessary for life. Select one of the
requirements of organisms and plan an investigation that would demonstrate
how the requirement is related to a function of life.
Answers will vary. Examples:
Oxygen is a requirement of organisms and is measured by breathing rate. Vary the
amount of oxygen a person is receiving, and measure the breathing rate.
Heat is a measurement of the metabolic reactions, often controlled by enzymes. Measure
the effect of an enzyme, in varying temperatures.
Section 1.5: Maintenance of Life
Learn
Classroom Activities
Writing Connection: Homeostatic Mechanisms
Pair students with a partner to work with for collaboration and discussion. Each pair
of students should choose a type of homeostatic mechanism they are interested in
learning more about. The pair of students will research their mechanism and identify
what it is, why it is important to survival, and how often it occurs in the human body.
Finally, the pair of students will create a flow chart showing the steps that occur to
trigger and resolve the mechanism (example: the thermostat in a house ). Students
should be provided with research resources to complete this activity.
Differentiated Instruction
Instead of students completing research on one type of mechanism of their
choosing, the teacher could provide students with a handout for an assigned
homeostatic mechanism. The research would already be complete, and
students would then just have to complete the questions and flow chart. This
would allow time for students to complete a rotation with their partner and
observe all the different types of homeostatic mechanisms most commonly
occurring in the human body and discuss their flow chart compared to other
charts students made in the class.
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Additional Discussion Questions
Apply the requirements of organisms to the structure and function of body parts.
Ask students to explain how each requirement helps to maintain life.
Responses should include a discussion of water, food, oxygen, heat, and pressure.
Ask students to apply their knowledge of a homeostatic mechanism to a situation
outside of the human body.
Responses may include the analogy of a homeostatic mechanism used by a furnace or air
conditioning system. In any case, the discussion should include a self-regulating mechanism
that receives signals about changes within the system that have deviated from the norm. The
self-regulating mechanism provides feedback to the system to allow it to initiate the changes
necessary to return to normal conditions.
Ask students to apply the concept of homeostasis to the maintenance of blood
pressure.
The maintenance of blood pressure is based upon sensors in the walls of the blood vessels that
send feedback to a control center in the brain. This initiates messages from the brain to the
heart, telling it to contract more slowly or more rapidly depending upon the situation.
Ask students to describe an example of the effects upon a body system when it is
subjected to a less than optimal quantity and quality of its basic environmental
requirements.
Examples may include a dysfunctional cardiovascular system when blood pressure falls
above or below normal limits, dehydration of tissues when water levels are too low, or
edema when fluids accumulate in the tissues, or malnutrition when food does not supply the
body with the correct nutrients in optimal amounts. It should be noted that malnutrition
might result from overeating the wrong things as well as not eating enough of the right
things.
Ask students to trace the steps of a homeostatic mechanism within the human body.
One example is the maintenance of optimal body temperature. When body temperature rises,
the brain detects the change and causes increased sweating and the dilation of skin blood
vessels. These reactions initiate the loss of heat, thus stimulating the body temperature to
return to normal.
Ask students to describe the effects of environmental pollution, i.e., water, air, or
soil upon maintaining homeostasis in the human body.
The possible responses are limitless, but should include a discussion of the body’s attempts to
maintain a stable internal environment.
Practice
Practice Questions
1. Which requirements of organisms does the external environment provide?
water, food, oxygen, heat, and pressure
2. Why is homeostasis important to survival?
If an organism is to survive conditions within the fluid surrounding its body cells, which
compose its internal environment, must remain relatively stable. In other words, body
parts function only when the concentrations of water, nutrients, and oxygen and the
conditions of heat and pressure remain within certain narrow limits.
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3. Describe two homeostatic mechanisms
Examples include temperature receptors and pressure receptors. If a person's body
temperature begins to drop, the temperature receptors sense this change and
temperature control center triggers heat-generating and heat-conserving activities, such
as shivering. Pressure-sensitive receptors in the walls of blood vessels sense changes in
blood pressure and signal a pressure control center in the brain. If blood pressure is
above the set point, the brain signals the heart chambers to contract more slowly and
with less force. This lowers blood pressure.
Figure Questions
Figure 1.6, p. 13: What would happen to room temperature if the set point were
turned up?
The set point tells the furnace or air conditioner what the temperature should be. If, as in the
example, the set point was changed from 20°C to 25°C, this would instruct the furnace to kick
on and the room temperature to become warmer.
Section 1.6: Organization of the
Human Body
Learn
Classroom Activities
Writing Connection: Visual Word Associations Activity
It is important for students to be able to identify the structure and function of the
membranes and cavities of the human body. Students will move in small groups
completing each station. The teacher will prepare station materials ahead of time
using the figures from section 1.6. Each station will contain an image of one of the
following figures: 1.8a, 1.8b., 1.9, 1.10, and 1.11. The teacher will remove the words from
the image in the figure and create movablemovable drag-and-drops for each figure
using a poster board and printed out word choices. Students will rotate through the
stations and work as a team to identify the correct term with the correct location on
the figure. One a blank sheet of paper at each station, groups will write down hints,
tips, and word associations to help them remember difficult areas to identify in each
figure. At the end of the rotation activity, the teacher can compile all the tips and
tricks the different groups wrote down and share with the class.
Differentiated Instruction
This activity could easily be turned into a team or individual game through the
use of a free virtual resource such as quizlet or kahoot. This would eliminate
the use of posters, paper, and printing and allow students to have options of
learning kinesthetically or interacting via the web. The same type of game
could also be created for the organ systems.
Demonstration Activity: The Wheels on the Bicycle
There are several ways to examine a bicycle. A bicycle can be looked as a whole, a
machine that allows you to travel from point A to point B. However, that bicycle
would not be a whole machine without its part. Therefore, when we look at a bicycle,
we must also consider its parts. How do these parts make the whole machine work?
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For this activity, bring in a bicycle or provide students with a picture of one. Begin a
discussion with students. How do the shapes of each part dictates its specific function?
To help facilitate discussion, provide students with the following table:
Bicycle Part
Wheels
Shape
Round
Function
Propels bicycle forward
Brakes
Handle bars
Small gear
Additional Discussion Questions
Ask students to apply their knowledge of the major body cavities by drawing and
identifying, on an illustration of the human body, the nine abdominal regions.
Responses should include drawings and identification of the right hypochondriac region,
epigastric region, left hypochondriac region, right lumbar region, umbilical region, left lumbar
region, right iliac region, hypogastric region, and left iliac region.
Provide the students with an illustration of the human body. Ask them to label each
organ system and to identify as many organs as possible within each of those systems.
Illustrations should include identification of the organs in the integumentary system, skeletal
system, muscular system, nervous system, endocrine system, cardiovascular system, lymphatic
system, respiratory system, digestive system, urinary system, and reproductive system.
By utilizing the directional terms learned in this chapter, ask students to choose a
body part and to describe its relative position.
Students may use relative directional terms, body planes, abdominal regions, and terms used
to describe body regions. Remind them of the importance of maintaining the correct
anatomical position before they begin to use directional terms.
Which major body functions are served by more than one organ system? Name the
functions that they serve.
Support and movement - skeletal and muscular systems; integration and coordination - nervous
and endocrine systems; transport - cardiovascular and lymphatic systems; absorption and
excretion - digestive, respiratory, and urinary systems.
Practice
Practice Questions
1. Which organ occupies the cranial cavity? The vertebral canal?
The brain occupies the cranial cavity, and the spinal cord occupies the vertebral canal.
2. What does viscera mean?
Viscera are the organs within the thoracic and abdominopelvic cavities.
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3. Name the cavities of the head
The cavities of the head are: the cranial cavity, the oral cavity, the nasal cavity, the
orbital cavities, and the middle ear cavities.
4.Describe the membranes associated with the thoracic and abdominopelvic
cavities.
Within the thoracic cavity, the compartments that contain the lungs are lined with a
membrane called the parietal pleura. The visceral pleura covers each lung. The heart
is surrounded by pericardial membranes, parietal and visceral. In the abdominopelvic
cavity, the membranes are called peritoneal membranes. A parietal peritoneum lines
the wall, and a visceral peritoneum covers each organ in the abdominal cavity.
5. Name and list the organs of the major organ systems.
The integumentary system: skin, hair, nails, sweat/sebaceous glands; skeletal system:
bones, ligaments, cartilage; muscular system: muscles; nervous system: brain, spinal cord,
nerves, sensory organs; endocrine system: pituitary glands, adrenal glands, pancreas;
cardiovascular system: heart, blood vessels, blood; lymphatic system: lymph nodes,
thymus, spleen; digestive system: mouth, stomach, intestines; respiratory system: lungs,
trachea; urinary system: bladder, kidneys; reproductive systems: testes, ovaries.
6. Describe the general functions of each organ system.
The integumentary system protects underlying tissues, helps regulate body
temperature, houses sensory receptors and synthesizes certain products. The skeletal
and muscular systems support and move body parts. Tissues within bones also produce
blood cells and store inorganic salts. The nervous and endocrine systems control and
adjust organ functions to maintain homeostasis. The cardiovascular system transports
substances throughout the internal environment. The lymphatic system transports
tissue fluid back to the bloodstream and carries fatty substances away from the
digestive organs. Cells of the lymphatic system also defend against infection. The
digestive system receives and breaks down food. The respiratory system removes
oxygen from the air and carbon dioxide from the blood. The urinary system maintains
the body’s water balance and remove wastes from the blood. The reproductive
systems work to produce new organisms.
Section 1.7: Anatomical Terminology
Learn
Classroom Activities
Study Strategy: Using Visual and Contextual Support
Intermediate Before reading, have students take a close look at the visual
support. Have the students grouped in small groups use the image as they
work to create a chart or mnemonic device (see example) to teach their peers
the assigned section (relative position, body sections, or body regions).
Example of a mnemonic device for relative position: Midline, Medial, Lateral,
Distal, Proximal (MMLDP).
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M – Many
M – Monkeys
L – Love
D – Dill
P – Pickles
Group Activity: Simon-Says Terminology
This is a class game where each student participates as an individual. The teacher
can demonstrate being the leader first and then students can take turns being
“Simon”. The leader will ask students to identify a region on their body or a printout
of the human body that matches the term given.
For example: Simon says identify the right hypochondriac region. Then, students
must all point to that area of their body, which in this example is the upper right
abdominal area under the lungs.
The teacher can prepare choices for the leader to state to ensure appropriateness
of the game. Interaction with identifying anatomical terminology will increase
retention and build better associations of the term to its location.
Differentiated Instruction
Instead of completing this activity as a game, students could pair with each
other and quiz each other over the different areas of the human body with the
same leader commands and a printout of the human body. This would provide
an option for students who may not want to be front of the whole group and
reduce the competitive atmosphere of the game. This could also be an
advantage for ESL students to work together and help each other understand
the science vocabulary words and associations in their own language.
Additional Discussion Questions
Apply the student’s knowledge of directional terms learned in this chapter to
situations outside the human body.
Responses will vary, but may attempt to describe relative positions of items in a cupboard,
relative positions of student seating in the classroom, etc.
If a patient enters the emergency room with a gunshot wound to the epigastric
region, which visceral organs may have been traumatized?
Damage to the liver, stomach, transverse colon, gall bladder, pancreas, kidneys, and
associated blood vessels would be of major concern.
Practice
Practice Questions
1. Describe the anatomical position.
Standing up, face forward, with the arms at the sides and the palms facing forward.
2.Using the appropriate terms, describe the relative positions of several
body parts.
The thoracic cavity is superior to the abdominopelvic cavity. The neck is inferior to the
head. The eyes are anterior to the brain. The pharynx is posterior to the oral cavity. The
nose is medial to the eyes.
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3. Describe the three types of body sections.
The body can be sectioned into sagittal (lengthwise, right/left) transverse (horizontal,
superior/inferior) and frontal (coronal, anterior/posterior) planes.
4. Name the nine regions of the abdomen.
The nine regions of the abdomen are: The right and left hypochondriac regions, the
epigastric region, the right and left lateral regions, the umbilical region, the right and left
inguinal regions, and the pubic region.
Use the Practices 1.7
Communicating Information Anatomical terms help us accurately describe
our observations. Rewrite the sentences below using the correct anatomical
terms:
The esophagus is in front of the spinal cord, toward the chest.
The knee is below the hip on the leg, but above the foot.
The esophagus is posterior to the spinal cord.
The knee is distal to the hip, but proximal to the foot.
Figure Questions
Which is more lateral, the hand or the hip?
the hand
Assess
Career Corner: EMT
Consider This: In this scenario, the woman involved in the car accident was
conscious when the EMTs arrived. If you were an EMT, how would you
approach the same situation if the woman was unconscious?
Answers will vary. Students might note that they would first determine whether or not the
patient has a pulse. If there is no pulse, students might initiate CPR.
iseases, Diagnosis, and Treatments:
D
Computerized Tomography
1.What parts of the body would be particularly hard to view without CT
technology? Use the correct anatomical vocabulary.
Answers will vary, but students should indicate that soft tissues, especially in the
abdominal region, would be difficult to visualize without CT technology.
2.Why might a clinician order a CT scan for a patient?
Answers will vary but students should show understanding that CTs are used to look for
internal injuries that would not appear on x-rays.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which of the following statements about the trajectory of
the study of the human body is true?
a. Anatomy is the study of the functions of body parts while
physiology deals with the structures of body parts and
how they are organized.
b. Our knowledge of the human body reflects centuries of
developing more sophisticated technologies and methods
for testing hypotheses.
c. Ancient science gave wrong explanations while modern
science gives us all the answers.
d. Modern science relies on superstitions and magic to cure
illnesses and heal injuries.
2. Which of the following models best reflects the levels of
organization within the human body, from most inclusive/
most complex to least inclusive/least complex?
a. tissue, molecule, organ, cell, atom
b. atom, macromolecule, cell, organ
c. organ, macromolecule, atom, cell
d. tissue, cell, molecule, atom
3. The use or release of energy by combined chemical reactions of
synthesizing larger molecules from smaller ones and breaking
down larger molecules into smaller ones is known as
.
a. anabolism
b. catabolism
c. metabolism
d. physiology
4. Antidiuretic hormone is released in the body to promote the
reabsorption of water and prevent water loss when body
fluid volume is low. Antidiuretic hormones are examples
of
.
a. effectors
b. receptors
c. set points
d. homeostasis
5. Which of the following is the key difference between
negative feedback mechanisms and positive feedback
mechanisms in the way they respond to homeostasis
becoming unbalanced?
a. Negative feedback mechanisms work to bring conditions
back to the set point, while positive feedback mechanisms
progress further from the set point for a relatively short
time period.
b. Negative feedback mechanisms progress further from the
set point for a relatively short time period, while positive
feedback mechanisms work to bring conditions back to
the set point as soon as possible.
c. Negative feedback mechanisms have lower set points than
positive feedback mechanisms, requiring the body’s
effectors to spend more energy responding to stimulus
than in the case of positive feedback mechanisms.
d. Positive feedback mechanisms have lower set points than
negative feedback mechanisms, requiring the body’s
effectors to spend more energy responding to stimulus
than in the case of negative feedback mechanisms.
6. The abdominopelvic cavity contains of all of the following
components except
.
a. stomach
b. spleen
c. mediastinum
d. urinary bladder
7. The urinary system works to maintain osmotic balance and
excrete wastes out of the body. It consists of all of the
following components except
.
a. kidneys
b. urethra
c. ovaries
d. urinary bladder
8. The body system that transports fatty substances away from
the digestive organs and into the bloodstream as well as
plays a role in the body’s defense systems is called the
.
a. cardiovascular system
b. digestive system
c. integumentary system
d. lymphatic system
9. Which of the following terms is used to describe the distance
of one reference point being far from another, such as the
head from the feet?
a. anterior
b. distal
c. ipsilateral
d. proximal
10. Which adjective best describes where the lobe of the brain
that functions in vision processing is located, if it is found in
the lower backside of the brain, above the cerebellum and
brain stem?
a. mental
b. occipital
c. orbital
d. sacral
CHAPTER 1
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Introduction to Human Anatomy and Physiology
17
Short Answer
1. Define anatomy, physiology, and surface anatomy.
Anatomy is the study of the structure of the body parts.
Physiology is the study of the function of the body’s organs.
Surface anatomy is the study of landmarks on the outside of
the body.
2. List the levels of organization in the human body.
Levels are: atoms, molecules, cells, tissues, organs, organ
systems, and the whole organism.
3. Define organ.
An organ is two or more tissues types that together perform a
specific function. For example, the heart.
4. Define organ system.
An organ system is composed of two or more organs and
usually performs multiple functions. For example, the digestive
system.
5. Define homeostasis. How is homeostasis maintained?
Homeostasis is the maintenance of a constant internal
environment. It is mostly maintained through negative
feedback systems.
6. How does a negative feedback system function? Give an
example.
A negative feedback system ensures that physiology remains
usually within a narrow range, such as body temperature.
When a deviation occurs in either direction there are
mechanisms to put it back in normal range: shivering when you
get too cold, sweating when you get too hot.
7. What is the anatomical position?
You are in anatomical when you are standing upright, with
your arms at your side and palms facing forward.
8. What are the four quadrants system and the nine regions
systems?
They are both ways to dived abdominal region. The quadrant
system divides into four regions: left and right upper quadrants
and left and right lower quadrants. The none region system
divides into a “tic-tac-toe” board. The regions are: Right and
left hypochondriac, epigastric, right and left lateral, umbilical,
right and left inguinal, and pubic.
9. How are the terms transverse, sagittal, and frontal used?
These are terms used to describe how a specimen can be
dissected. A transverse (horizontal)plane will divide the body
into superior (top) and inferior (bottom) halves. A sagittal plane
will divide the body into left and right halves. A frontal
(coronal) plane will divide the body into anterior (front) and
posterior (back) halves.
18
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Levels of Organization
10. How are the terms superior, inferior, anterior, and posterior
used. Give examples.
Superior refers to a structure that is above another structure or
is toward the head. Inferior is the opposite. Anterior refers to a
structure that is front of another structure. Posterior is the
opposite. Examples: the heart is superior to the stomach. The
sternum lies anterior to the heat.
11. What are the common characteristics of living systems?
Living systems grow, reproduce, engage in metabolism (nutrient
cycling and energy production), and exhibit movement.
12. What are the major organ systems and their functions?
Integument: protection, temperature regulation, and sense
of touch
Skeletal: Protection, support, movement, and mineral storage
Muscular: Movement and temperature regulation
Nervous: Coordination of all body functions and senses
Endocrine: Produce chemical messengers called hormones
Cardiovascular: Transport of oxygen, carbon dioxide, nutrients,
and hormones
Lymphatic: Fluid regulation and immune responses
Digestive: Transform food into usable nutrients
Respiratory: Transports air into and out of lungs to capture
oxygen and get rid of carbon dioxide
Urinary: Water and electrolyte balance and waste removal
Reproductive: Produce offspring
13. Describe the major trunk cavities and their divisions.
The cranial cavity is in the head and houses the brain. Other
cavities in the head: oral, nasal, orbital, and middle ear.
Thoracic cavity house the ribs, heart, and lungs. It contains the
pleural cavities. The abdominal cavity houses the many of the
internal organs. The pelvic cavity contains the bladder and
reproductive organs.
14. In which quadrant would you experience pain if you had a
stomach problem?
Stomach pain would most likely present in the left upper
quadrant.
15. Describe the position of the head relative to the liver.
The head is superior to the liver.
Critical Thinking and Clinical Applications
1. Which characteristics of life does a computer have? Why is a
computer not alive?
unconscious patient? Describe the body parts involved in the
treatment, using correct directional and regional terms.
Movement, responsiveness to stimuli, respiration, circulation of
energy substrates, and excretion of waste products are all
characteristics of life seen in a computer. A computer is not
alive because it does not experience growth, reproduction,
digestion, absorption, or assimilation.
An unconscious person would need: oral tracheal suctioning
(to keep the airway open and administer oxygen); nasogastric,
gastric, or intravenous feedings; urinary catheter (for urine
collection); turning in bed (to prevent decubitus ulcers, or
bedsores); elastic stockings (to prevent blood clots and
thrombophlebitis); stool softeners or suppositories; range-ofmotion exercises to the extremities; and possibly a
hypothermia or hyperthermia blanket to maintain body
temperature.
2. What environmental characteristics would be necessary for a
human to survive on another planet?
Human needs include water, food, oxygen, and heat. In order
to survive on another planet, a human would have to fill these
needs from the new environment.
3. In health, body parts interact to maintain homeostasis. Illness
can threaten the maintenance of homeostasis, requiring
treatment. What treatments might be used to help control a
patient’s (a) body temperature, (b) blood oxygen
concentration, and (c) water content?
Treatment of :
(a) Body temperature-increased fluid intake, hypothermia
blanket, antipyretic medications, antibiotics if fever is due
to an infection, rest, and maintaining nutritional intake.
(b) Blood oxygen-oral tracheal suction to keep airway open,
administering oxygen.
(c) Water content-increased fluid intake, administering
intravenous fluid, controlling room temperature and
humidity.
4. WRITING Connection How might health-care
professionals provide the basic requirements of life to an
5. CLINICAL Connection Suppose two individuals develop
benign (noncancerous) tumors that produce symptoms
because they occupy space and crowd adjacent organs. If
one of these persons has the tumor in the thoracic cavity and
the other has the tumor in the abdominopelvic cavity, which
person would be likely to develop symptoms first? Why?
Which might be more immediately serious? Why?
The individual with the tumor in the thoracic cavity would
probably develop symptoms first. Since the thoracic cavity is
smaller and the tumor would exert pressure against the lungs
and/or heart which would cause great distress to the
individual.
6. If a patient complained of a “stomach ache” and pointed to
the umbilical region as the site of discomfort, which organs
located in this region might be the source of the pain?
The organs in the umbilical region that could be the source of
pain include the small intestine (obstruction), pancreas
(pancreatitis), abdominal aorta (aneurysm), transverse colon
(diverticulitis), or a distended urinary bladder.
Lab Data Analysis: Human Temperature Regulation
Think Critically
1. How do the points labeled “Lower critical temperature” and
“Upper critical temperature” relate to shivering and sweating?
When the body’s temperature reaches the lowest end of
the Thermoneutral zone (represented graphically to the
left), it hits the Lower critical temperature which induces
the body to shiver in order to increase metabolic rate.
Conversely, at the high end of the Thermoneutral zone
(to the right), Upper critical temperature is reached
which induces sweating in an attempt to lower the
metabolic rate.
are sweating to allow them to lower their operative
temperature back to the Thermoneutral zone, thus moving
left on the graph.
3. If a person has a disease such as hypothyroidism, which
lowered their baseline metabolic rate, would they be more
prone to shivering or sweating?
Shivering. If metabolic rate is low, the individual will have more
difficulty producing enough heat to reach the Thermoneutral
zone. Thus, they would be more intolerant of the cold and
more prone to shivering.
2. If a person is actively sweating, identify in which direction
they would be moving along the curve in the graph above.
Left. If they are sweating, then they must be at a
temperature to the right of the Thermoneutral zone. They
CHAPTER 1
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Introduction to Human Anatomy and Physiology
19
CHAPTER
2
Chemical Basis of Life
Section
Pacing
(class periods)
2.1 Introduction
2.2 Fundamentals of
Chemistry
—
Review only
Learning Objectives
1. Give examples of how the study of living
materials requires an understanding of
chemistry.
1. Describe the relationships among matter,
atoms, and molecules.
2. Describe the general structure of an
atom.
2.3 Bonding of Atoms
Review only
1. Define the three types of bonding.
2. Describe the difference between ionic
and covalent bonding.
3. Describe how atomic structure
determines how atoms interact.
2.4 Molecules, Compounds, Review only
and Chemical Reactions
1. Explain how molecular and structural
formulas symbolize the composition of
compounds.
2. Describe three types of chemical
reactions.
2.5 Acids and Bases
Review only
1. Define acids, bases, and buffers.
2. Define pH and be able to use the pH
scale.
2.6 Chemical Constituents
of Cells
2
1. List the major inorganic chemicals in cells
and identify the functions of each.
2. Describe the general functions of the four
main groups of organic chemicals in cells.
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (5)
Chapter Resources
Extended Summary Review
Chapter 2 Test Bank
Chapter 2 Interactive Question Bank
Vocabulary Flashcards
APR Module 2: Cells & Chemistry
Laboratory Exercise 3: Chemistry of Life
20
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Levels of Organization
A Suggested Approach
Since the majority of high school students enrolled in Anatomy and Physiology have
already been exposed to introductory chemistry in their biology course and
chemistry courses, this chapter should serve as a review. But as biochemistry offers
insight into the continuous changes within body system, it is imperative to review
this material.
Our food directly affects our bodies. This chapter provides an opportunity for
students to think critically about what happens to the food they eat. A variety of
lessons can be found which detail how macronutrients and micronutrients are
ingested, digested, and assimilated by the human body and the consequences of
nutritional deficiencies. These activities make an excellent introduction to
biochemistry.
This lesson is expected to take two class periods including Lab 3.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
The internet is bursting with info about gluten. Here is a science paper that is
particularly interesting: https://www.sciencemag.org/news/2018/05/what-sreallybehind-gluten-sensitivity.
A neat way to draw connections between this chapter, Chapter 3 and
Chapter 15 would be to talk about how gluten allergies and insensitivities lead
to their most common symptom: diarrhea. Absorption of water from the gut
lumen back into the blood (Chapter 15) occurs by establishing an osmotic
gradient (Chapter 3). When gluten is incompletely broken down,
oligosaccharides (groups of several monosaccharides) are left in the gut
lumen, unable to be absorbed. This changes the osmotic gradient, pulling
water into the gut lumen as well. Water left in the gut lumen, instead of being
reabsorbed, leads to watery feces, otherwise known as diarrhea.
CHAPTER 2
|
Chemical Basis of Life
21
Introduction to the Theme
Theme: Energy and Matter Energy drives the cycling of matter within and
between human body systems. The transfer of this energy is between the bonds of
all the body’s macromolecules.
Theme Activity:What’s in your breakfast cereal?
For this activity, bring in a few different types of breakfast cereals. Try to bring in a
variety of kinds. If this isn’t possible, look for cereal labels on the internet to print
out and distribute. Pass the boxes or labels out to your students.
Ask the students to examine the labels. Ask the students the following questions:
1.
What macronutrients are in your cereal?
2. What micronutrients are in your cereal?
3. Which ones are missing?
Go around the room and have the students discuss which cereal they think is the
healthiest or how their cereal would affect their body.
Pose the question: Could you eat this cereal every day for every meal? Why or why not?
Section 2.1: Introduction
Learn
Classroom Activities
Section 2.1 sets the groundwork for activities in sections 2.2 and beyond.
Additional Discussion Questions
Provide students with a copy of the periodic table of elements. Choose 50 of the
most common element symbols and ask students to make a set of flash cards that
indicate the element name on one side and the element symbol on the other.
Repetition is the key word. Students should become very familiar with elements and their
symbols. Quiz the students often.
Ask students to examine a copy of the periodic table of elements. Choose a particular
column or row, and ask students to comment on any relationships among the
elements you have chosen.
For example, all of the elements in column 1 (Group IA) have one electron in their outer orbit.
These elements tend to donate this outer electron to form an ionic bond with other elements
seeking to receive an electron. Also, since the number of protons increases as we proceed
down the column, the atomic mass will also increase.
Practice
Practice Questions
1. Define chemistry.
Chemistry is the branch of science that considers the composition of matter and how this
composition changes.
22
UNIT 1
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Levels of Organization
Use the Practice 2.1
Communicating Information All the food that we eat, liquid that we drink,
and medications that we take are composed of chemicals. List a few of the
foods, liquids, or medicines that you have taken today. As you read through
the chapter, identify the types of chemicals that are found in each.
Answers will vary. Accept all reasonable responses.
Section 2.2: Fundamentals
of Chemistry
Learn
Classroom Activities
Group Activity: Build an Atom Activity
Organize students into pairs. This activity can be completed through hands-on
interaction with materials prepared by the teacher or the use of a free web resource,
Phet simulation. Use the list of major elements in the body to create a station for
each element. At each station, the teacher should create a blank atom template with
moveable protons, neutrons, and electrons and then also provide the periodic table
block for each element. By providing the periodic table block, students will be able to
use the atomic number and mass number to determine the subatomic particles in a
neutral atom. Students will work in pairs to build a neutral atom of the element at
that station correctly representing the number of protons, neutrons, and electrons.
They can check their answer with a provided answer sheet. Students should also
explore creating ions and isotopes of the element at each station. This can also be
completed virtually using a free Phet simulation called “Build and Atom”.
Differentiated Instruction
If students are struggling to create elements, the teacher could create a
pre-made atom of each element such as in Figure 2.1. Students would then
work in pairs to identify which atom is which type of element based on
evidence they find in the pre-made atom such as the number of protons,
electron, and neutrons. For students who are beyond creating elements, they
should dive deeper into ions and isotopes. The teacher could provide students
with practice math questions to determine protons, electron, and neutrons of
different ions and isotopes and compare them to the neutral atom. For
example, the teacher could provide students with O-2 or Mg+2. Students could
explain how these atoms are different than the neutral O and Mg atom in
terms of charge and number of subatomic particles and then calculate
subatomic particles based on the charge.
Demonstration Activity: Modeling Energy Transfer
For this activity, you will show students how energy is transferred between atoms.
This activity can be found at the SEP’s Daly Ralston Resource Center website:
Exploring chemical bonding: http://www.seplessons.org/node/2241 and comes
with paper templates for the atoms, if molecule kits are not readily assessable in
your school.
Discuss with your students: what molecules are made up. Can you design it better?
CHAPTER 2
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Chemical Basis of Life
23
Additional Discussion Questions
Provide students with a list of the major and trace elements identified in the chapter.
Then, ask them to indicate the number of protons, electrons, and neutrons in each
element.
The list should include oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium,
sulfur, chlorine, sodium, magnesium, chromium, cobalt, copper, fluorine, iodine, iron, manganese,
and zinc.
Prepare ball-and-stick models of several simple molecules and compounds. Ask
students to identify them based on the combination of elements the models
contain.
Some examples include water, carbon dioxide, glucose, and methane.
Practice
Practice Questions
1. What are elements?
The simplest examples of matter with specific chemical properties are called
elements.
2. Which elements are most common in the human body?
Oxygen, carbon, hydrogen, and nitrogen make up more than 95% (by weight) of the
human body.
3. Where are electrons, protons, and neutrons located in an atom?
The nucleus of an atom contains protons and neutrons. Electrons move around outside
the nucleus of an atom.
4. What is the difference between atomic number and atomic weight?
The number of protons in the atoms of a particular element is called the element’s
atomic number. The atomic weight of an atom of an element approximately equals the
number of protons and neutrons within its nucleus.
Use the Practices 2.2
Using Mathematics Molecular formulas give us information about the number
and types of atoms in a molecule. For the following molecules, identify the
type and number of each atom:
Glucose: C6H12O6
Caffeine: C8H10N4O2
Glucose (sugar): C6H12O6 6 carbons,12 hydrogen, 6 oxygen
Caffeine: C8H10N4O2 8 carbons, 10 hydrogen, 4 nitrogen, 2 oxygen
24
UNIT 1
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Levels of Organization
Section 2.3: Bonding of Atoms
Learn
Classroom Activities
EL Strategy: Activate Prior Knowledge
Advanced Students should complete the chart. The K section can be
completed individually, then the W section with a partner. After students
complete the L section of the chart, have them work in small groups to
compare answers and add each other’s information to their own charts.
Subject: Atomic Bonding
K- What I Already Know
From experience
From previewing
There are 3 different types of atomic
bonds.
Ionic bonds
There are different types of atomic
structures.
Hydrogen bonds
Covalent bonds
W – What I Want to Learn
How does an atom become an ion?
When does an atom make an ionic bond? A covalent bond? A hydrogen bond?
L-What I Learned
Atoms become ions when they gain or lose an electron and become electrically charged.
An ionic bond is formed when atoms with opposite electrical charges attract.
The covalent bond occurs when atoms bond by sharing electrons rather than exchanging
them.
A hydrogen bond is the attraction of the positive hydrogen end of a polar molecule to the
negative nitrogen or oxygen end of another polar molecule.
What I Want to Know More About
How the bonds affect the chemistry of the
body.
How Will I Learn More
Review chemistry
Read articles
Ask an expert
Group Activity: Bonding Scramble Activity
Assign each student an element that is involved in many common bonds. Note: The
teacher may want to make duplicates of common atoms (e.g. assign four students
hydrogen since it is used readily in common bonds). Each student should draw a
diagram of their atom including the shells and information on the number of
subatomic particles in the atom just like in Figure 2.3. Once each student has created
their atom diagram and familiar with how their atom will bonds, students will begin a
scramble activity to create bonds with other atoms. Provide students a table where
they can note which other atoms they bond with (can be more than one, for example
water is H2O) and also which type of bond they created (ionic, covalent). They could
also identify if their bond involved any polar characteristics or any hydrogen bonding.
CHAPTER 2
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Chemical Basis of Life
25
Differentiated Instruction
This activity requires mobility and students interacting with each other. This
could also be changed to an individual or small group activity that doesn’t
require any moving by creating mini element cards with the same information
such as the shell diagram and subatomic particles. Each group could work
together to create as many combinations of bonds and identify them on their
table. Working in small groups would scaffold individuals who needed extra
support creating and identifying bonds while also encouraging group
brainstorming and collaboration.
Demonstration Activity: Almond Burning Joy
Students have been exposed to the idea that chemical energy comes from the food
we eat in Chemistry. However, preforming this experiment is a great visual
reminder.
In this experiment, you will burn an almond (or other nut) using a calorimeter. The
data collected from the calorimeter will be used by the students to measure the
amount of energy in the nut.
The outline for this lab can be found at the National Science Teacher’s Association
website: https://www.nsta.org/publications/press/extras/files/adi-lifescience/
Lab6Handout-EnergyInFood.pdf
Remind students that:
Calories = Q = mCpΔT
where m = the mass of the water
(g), Cp=1 cal/g °C
ΔT=change in temperature
Practice
Practice Questions
1. What is an ion?
Atoms that gain or lose electrons become electrically charged and are
called ions.
2. Describe two ways that atoms bond with other atoms.
Atoms can bond with other atoms through either ionic (electrovalent) or covalent
bonding. An ionic (electrovalent) bond occurs when oppositely charged atoms attract to
form crystals or arrays. Covalent bonding occurs when two atoms share electrons to form
discrete molecules.
3. Distinguish between an ion and a polar molecule.
An ion is an atom that gains or loses electrons to become electrically charged. Unlike an
ion, a polar molecule has an equal number of protons and electrons, but more of the
electrons are at one end of the molecule, making that end slightly negative, while the
other end of the molecule is slightly positive.
26
UNIT 1
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Levels of Organization
Use the Practice 2.3
Conducting Investigations Biomarkers are chemicals in the body that
clinicians can measure, which might indicate a disease or exposure to a toxin.
Propose a biomarker that could be used to test for a specific disease or
condition such as diabetes or renal failure.
Answers will vary, but might include C-reactive protein for inflammation, LDL for
cholesterol levels, or carbon monoxide for smoking.
Section 2.4: Molecules, Compounds,
and Chemical Reactions
Learn
Classroom Activities
Writing Connection: Chemical Research Activity
Ask each student to bring in an ingredient label off of a favorite product or food or
the teacher can bring in a few. Put students into small groups and allow them to
discuss some of the ingredients on the back of their labels. Ask students to think
about which elements do they think make up some of the common ingredients. Next
provide students access to research what the molecular formula is for one or two of
their ingredients. Example: sugar glucose is C6H12O6. Once they find the formula,
they should identify which elements are in the formula and how many atoms there
are based on the subscripts. Finally, ask students to pair up and create mock
chemical reactions with their molecular formulas representing the following
reactions; synthesis, decomposition, exchange, and reversible.
Differentiated Instruction
This would be a great opportunity to allow students to discuss what type of
food or product label they brought in and how it relates to their culture and
likes/dislikes. Instead of the teacher allowing students to research their own
food label ingredients, the teacher could assign each group a type of cultured
food such as Italian, Mexican, American, Chinese. Each group could then
research common ingredients in that culture of food and the different
molecular formulas in many of the ingredients for that culture. Students should
still create and review the mock chemical reactions with their molecular
formulas representing the following reactions; synthesis, decomposition,
exchange, and reversible.
Additional Discussion Questions
Provide students with a number of examples of chemical reactions and ask them to
determine whether the reaction would be considered synthesis, decomposition, or
exchange.
An example of a synthesis reaction would include iron + oxygen gas yields iron (III) oxide, or
rust. Another example of a synthesis reaction is sodium oxide + water yields sodium hydroxide.
An example of a decomposition reaction would be potassium chlorate decomposing to yield
CHAPTER 2
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Chemical Basis of Life
27
potassium chloride and oxygen. Another example is calcium hydroxide decomposing to form
calcium oxide and water. An example of a simple exchange reaction would be zinc + copper (II)
sulfate reacts to yield copper + zinc sulfate.
Ask students to complete a chart that illustrates the reaction of table salt dissolved
in water.
The chart should contain information demonstrating the release of sodium ions and chloride
ions in water.
Provide students with a number of common compounds. Based on the
information learned in this chapter, ask them to identify which elements are
present in each.
Examples may include sucrose, baking soda, ethyl alcohol, natural gas, aspirin, human blood,
table salt, etc.
Glucose is converted to carbon dioxide and water within body cells. Ask students to
describe which type of chemical reaction this is. Then, briefly describe to students
the intermediate steps involved in this reaction.
Glucose is first converted into glucose-6-phosphate, which is broken down by catalysts into
pyruvate. Pyruvate is decomposed to carbon dioxide and water by a sequence of reactions
requiring oxygen.
Practice
Practice Questions
1. Distinguish between a molecule and a compound.
When two or more atoms bond, they form a new kind of particle called a molecule. If
atoms of the same element bond, they produce molecules of that element. When atoms
of different elements bond, they form molecules called compounds.
2. What is a molecular formula?A structural formula?
A molecular formula represents the numbers and types of atoms in a molecule. Such a
formula displays the symbols for the elements in the molecules and the number of atoms
of each element. Symbols and lines depict the bonds (single lines represent single bonds,
and double lines represent double bonds) present in molecules. These illustrations are
called structural formulas.
3. Describe three kinds of chemical reactions.
The three kinds of chemical reactions are synthesis, decomposition, and exchange
reactions. Synthesis reactions combine to or more atoms (reactants) to form a more
complex structure. Decomposition reactions break up complex molecules into simpler
molecules or their component atoms. Exchange reactions take parts of two different
types of molecules and rearrange their combinations to form new molecules.
Use the Practice 2.4
Communicating Information Create a graphic organizer to delineate
between the three kinds of chemical reactions.
Answers will vary, accept all reasonable graphic organizers.
28
UNIT 1
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Levels of Organization
Section 2.5: Acids and Bases
Learn
Classroom Activities
Group Activity: Species Relationship
Certain physiological functions in the body are affected by the concentrations of
ions in different body fluids. Students should be paired in small groups and each
group will complete the same activity. Provide students a list of different body fluids
anywhere from cellular cytoplasm to saliva. Students should research what levels of
ions, H+ or OH- each fluid has in them and identify whether the body fluid would be
more acidic or more basic. As an extension, the teacher could assign each group
one of the body fluids to research deeper and determine what negative adverse
effects would occur if the pH level changed from what it normally is.
Differentiated Instruction
Students could be provided with the research about each body fluid and
the type of majority of ions. Their job would be to identify about what pH
level the body fluid is and then to research deeper how the level of pH
supports the function of the body fluid and what negative adverse effects
would occur if the pH level changed from what it normally is. This shortened
and more supported activity would allow time for each group to share with
the class what they learned.
Additional Discussion Questions
Ask students to draw a pH scale and label it with 10 examples of common
substances based on their pH.
The scale should be labeled from 0 to 14, with 7 being neutral. All substances that fall below 7
are considered to be acidic; all substances with a pH of greater than 7 are considered to be
basic, or alkaline. It should be noted that there is a tenfold increase in hydrogen ion
concentration when the pH decreases by one whole number, and a tenfold increase in the
hydroxyl ion concentration when the pH increases by one whole number.
Ask students to discuss the effects of electrolyte imbalance on homeostasis.
Responses will vary, but should include, at a minimum, a discussion of sodium, chloride,
potassium, and bicarbonate.
Ask students to describe the implications when the pH of human blood falls below
or rises above normal ranges. What is the normal range for blood pH? Is this range
considered to be acidic or alkaline? Why?
The normal pH range of human blood is approximately 7.35 to 7.45. When the blood’s pH falls
below this level, a patient is in acidosis. When the pH rises above this range, the patient is
experiencing alkalosis. Either abnormality may be clinically significant. Human blood is slightly
alkaline in nature, since its pH is above 7.0, or neutral.
CHAPTER 2
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Chemical Basis of Life
29
Practice
Practice Questions
1. Compare the characteristics of an acid with those of a base.
Acids are electrolytes that release hydrogen ions in water. Electrolytes that release ions
that bond with hydrogen ions are called bases. Both acids and bases can be considered
electrolytes.
2. What does pH measure?
The measurement of hydrogen ion concentration in a solution is the pH.
3. What is a buffer?
Buffers are chemicals that resist pH change. They combine with hydrogen ions when
these ions are in excess, or they donate hydrogen ions when these ions are depleted.
Section 2.6: Chemical
Constituents of Cells
Learn
Classroom Activities
EL Strategy: Comprehension Skills
Intermediate Ask questions about the lesson content to elicit one or twoword answers: What are molecules called that have hydrogen and carbon
atoms? Organic molecules. Are organic molecules usually nonelectrolytes or
electrolytes? Nonelectrolytes. What is the most abundant compound in the
body? Water. In organic substances, what provides much of the required
energy for cells? Carbohydrates.
Writing Connection: Class Study Guide
In this activity, students will work in small groups to create a chapter of a study
guide about the chemical constituents of cells. Each group will write one chapter,
and at the end the chapters can be combined to create a full guide. Assign groups
one of the following topics: organic substances, inorganic substances, enzymes,
DNA vs. RNA, steroids, and a phospholipid. More can be added by the teacher are
replaced based on students’ needs. Once assigned a topic, each small group should
create an outline about their topic and then create multiple choice questions that
cover important concepts about their topic. Other types of questions can be added
depending on time and learning styles such as key vocabulary or short answer.
Differentiated Instruction
Instead of students working in small groups, pair students together and have
them work through each topic taking turns asking each other review questions.
They could also use a scratch pad and play a Pictionary-type game drawing out
the different types of molecules and structures of the macromolecules. This
would support visual and kinesthetic learners to physically draw out the
different shapes of molecules and labelling them.
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Additional Discussion Questions
Ask students to complete a chart that lists the major inorganic molecules and ions
common in cells. The chart should include the molecule or ion name, symbol or
formula, and function.
The chart should contain information regarding water, oxygen, carbon dioxide, bicarbonate
ions, calcium ions, carbonate ions, chloride ions, magnesium ions, phosphate ions, potassium
ions, sodium ions, and sulfate ions.
Ask students to develop a chart describing the major organic compounds in cells.
Quiz them on the information that they provide in their charts.
The chart should include information on carbohydrates, lipids, proteins, and nucleic acids. For
each of the four organic compounds, include elements present, building blocks, and functions.
Students should provide specific examples.
Using the chart developed in the above application question and the information
learned in the previous chapter, ask students to comment on the imbalances to
homeostasis that would occur should the levels of any of the inorganic molecules or
ions become compromised.
Responses will vary but should emphasize the importance of maintaining a stable internal
environment.
Using ball-and-stick models and illustrations, ask students to identify and compare
the chemical composition of carbohydrates, lipids, proteins, and nucleic acids.
Comparisons may include the ring structure of a glucose molecule, a triglyceride molecule
consisting of a glycerol portion and three fatty acid portions, an amino acid chain of protein
twisted to form a coil, and a nucleic acid molecule consisting of nucleotides joined in a chain.
Practice
Practice Questions
1. How do inorganic and organic molecules differ?
Compounds that include carbon and hydrogen atoms are called organic. The rest are
inorganic.
2. How do electrolytes and nonelectrolytes differ?
Substances that release ions when dissolved in water are called electrolytes. Substances
that do not release ions when dissolved in water are called nonelectrolytes. Most organic
substances are nonelectrolytes, while most inorganic substances are electrolytes.
3. Name the inorganic substances common in body fluids.
The inorganic substances common in body fluids are water, oxygen, carbon dioxide,
bicarbonate, calcium, carbonate, chloride, hydrogen, magnesium, phosphate, potassium,
sodium, and sulfate.
4.Compare the chemical composition of carbohydrates, lipids, proteins, and
nucleic acids.
Carbohydrates are made of carbon, hydrogen and oxygen. These usually have twice as
many hydrogen atoms as oxygen atoms. The number of carbon atoms in a carbohydrate
molecule varies with the type of carbohydrate (pentoses, hexoses, etc.). Lipids are
organic and generally insoluble in water. They include triglycerides, phospholipids, and
CHAPTER 2
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Chemical Basis of Life
31
steroids. Triglycerides are built from three fatty acid chains and glycerol. Phospholipids
are similar to triglycerides, but have two fatty acid chains and a phosphate group.
Steroids are complex molecules that have four connected carbon rings and are the base
of several hormones. Proteins are structural materials, energy sources, or hormones. They
are made of carbon, hydrogen, oxygen, and nitrogen or sulfur atoms. Proteins are formed
from combining amino acids. Nucleic acids form genes and take part in the synthesis of
proteins. They are large molecules composed of carbon, hydrogen, nitrogen, oxygen, and
phosphorus. Nucleic acids are built from nucleotides, which have three components: a
phosphate group, a sugar, and a nitrogenous base.
5. How does an enzyme affect a chemical reaction?
Enzymes catalyze specific chemical reactions, allowing them to occur faster than if the
enzymes were not present.
6. What is the chemical basis of the great diversity of proteins?
Amino acids also have an “R” group which is highly variable. Proteins also have four
levels of structure: primary, secondary, tertiary, and quaternary structure. Each level
adds complexity and diversity.
7. What are the functions of nucleic acids?
Nucleic acids make up DNA and RNA, which compose genes and take part in protein
synthesis. RNA molecules carry out protein synthesis and are synthesized from DNA in a
process called transcription. DNA molecules store information in a type of molecular
code created by the sequences of the four types of nitrogenous bases.
Use the Practice 2.6
Asking Questions You are examining an unknown molecule, but you know
that it is one of the four types of organic compounds found in cells. Come up
with a list of questions you could investigate about the molecule’s structure,
form, and composition to determine what type of molecule it is.
Answers will vary, accept all reasonable responses.
Figure Questions
Figure 2.14, p. 60: Why is it incorrect to say that "fat" is another word for lipid?
Fat is a synonym for triglyceride, which is a subset of lipid.
Figure 2.11, p. 56: How does the hydrogen ion concentration compare between a
solution at pH 6.4 and a solution at pH 8.4?
A higher concentration of H+ ions makes for a more acidic solution, so the concentration of H+
ions would be less in a solution of 8.4 than in 6.4.
Assess
Career Corner: Pharmacy Technician
Consider This: While you are working as a pharmacy technician, your friend
comes in complaining about having the flu. “Why can’t they just give me some
antibiotics?” your friend exclaims. Research and explain why antibiotics are not
a standard treatment for the flu.
Students should explain in their answer that the flu is not caused by bacteria, but rather
a virus. Antibiotics are ineffective against viruses, which is why they are not prescribed
for the flu..
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Healthy Lifestyle Choices:
Biomarkers
1. Define the term “biomarker.”
A biomarker is a chemical in the body that indicates a disease process or exposure to a
toxin.
2.To diagnose HIV, physicians use two different tests. Physicians use an enzymelinked immunosorbent assay (ELISA) when they suspect a patient might have HIV.
They use a Western blot test to confirm a case of HIV after a positive ELISA result.
Which test do you think is more specific? Which test do you think is more sensitive?
In general, a sensitive test is used for screening; thus, the ELISA is the more sensitive of
the tests. Physicians use specific tests when they want to confirm a diagnosis; thus, the
Western blot is the more specific test.
Case Study Connection
. 52: What type of bonds are in gluten? What might be required to break
p
those bonds during gluten digestion?
Hydrogen bonds are common within proteins. Energy may be required to break bonds.
p. 53: Is gluten a molecule? An ion? An atom?
Gluten is a molecule
p. 54: In gluten intolerance, gluten molecules cannot be broken-down
What type of reaction is not occurring?
Decomposition
p. 58: In individuals without gluten intolerance, gluten in broken down
into what kind of monomer?
Amino acids
p. 64: The pH of the human stomach is between a pH of 1.0 and 2.0. What
might happen to gluten in this low pH environment? Is this helpful or unhelpful
in digestion?
The bonds between the atoms may begin to degrade. This would be helpful in digestion.
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Chemical Basis of Life
33
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. One of the ways carbon is essential for life is by storing
energy in the bonds it forms within macromolecules such as
carbohydrates and lipids. What are these bonds, where
carbon shares electrons with another atom, called?
a. Covalent bonds
b. Disulfide linkages
c. Hydrogen bonds
d. Ionic bonds
2. The elemental composition of plants and humans is notably
similar, particularly in that the same four elements make up
the majority of their mass. Which of the following lists these
major elements in order of abundance within humans?
a. Nitrogen, carbon, oxygen, hydrogen
b. Hydrogen, oxygen, carbon, nitrogen
c. Oxygen, nitrogen, carbon, hydrogen
d. Oxygen, carbon, hydrogen, nitrogen
3. Which of the following is true?
a. An ion of hydrogen cannot exist, since it only has one
electron in its outer shell.
b. Fluorine readily accepts an electron from lithium, forming
an ionic bond due to the attraction of their resulting
opposing charges.
c. The isotope Lithium-7 has greater natural abundance on
Earth than Lithium-6 because Li-7 has an equal number of
protons, neutrons, and electrons.
d. Helium and neon are quick to form ionic bonds in nature
to avoid being inert.
4. In your hand you have a list of the following monosaccharides,
listed only by molecular formula: C6H12O6, C5H10O4, and
C5H10O5. Which of the following options pairs the
monosaccharide label with its correct chemical formula?
a. galactose - C6H12O6, ribose - C5H10O4, deoxyribose - C5H10O5
b. glucose - C6H12O6, ribose - C5H10O4, deoxyribose - C5H10O5
c. fructose - C6H12O6, deoxyribose - C5H10O4, ribose - C5H10O5
d. sucrose - C6H12O6, deoxyribose - C5H10O4, ribose - C5H10O5
5. Lipase, a naturally-occurring enzyme, helps the body to break
down fat into fatty acids and monoglycerides after a meal.
Which of the following types of reactions most closely
resembles this type of process?
a. Synthesis reaction
b. Decomposition reaction
c. Exchange reaction
d. Ionic reaction
6. Which of the following lists substances from the lowest
hydrogen ion concentration to the highest on the pH scale?
a. Ammonia, blood, distilled water, gastric juice
b. Gastric juice, blood, distilled water, ammonia
c. Gastric juice, distilled water, ammonia, blood
d. Ammonia, gastric juice, blood, distilled water
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7. Cell membranes are made up of molecules consisting of two
fatty acid molecules and a phosphate group bound to a
glycerol molecule known as
a. steroids.
b. phospholipids.
c. cholesterol.
d. glycogen.
8. The structure and shape of proteins determine their
functions. Which of the following can denature proteins by
changing the shape?
a. Pleating or coiling of polypeptide chains
b. The presence of amino groups or carboxyl groups
c. Breaking of hydrogen bonds with a change in pH
d. Folding of polypeptides into protein molecules
9. Nucleotides are to nucleic acids as amino acids are to _____.
a. carbohydrates
b. proteins
c. triglycerides
d. DNA
10. While many compounds in the human body serve a storage
function, these compounds store information for protein
synthesis that results in the functioning of cellular activities.
a. carbohydrates
b. lipids
c. proteins
d. nucleic acids
Short Answer
1. Define chemistry. What does studying chemistry have to do
with the human body?
Chemistry is the science that studies the composition and
properties of all chemical substances.
2. What is matter?
Matter is everything in the universe (living and nonliving) that
occupies space.
3. Distinguish between mass and weight.
Mass refers to the amount of matter present. Weight refers to
the gravitational pull on mass.
4. Distinguish between atom and element.
An atom is the smallest complete unit of an element. An
element is a unique type of atom with specific chemical
properties. All elements differ is size and weight.
5. Describe the structure of an atom.
An atom has a central nucleus with protons and neutrons. The
nucleus is surrounded by electrons. Protons have a positive
electrical charge, electrons are negatively charged, and
neutrons are “neutral” with no charge.
6. What is an ion?
An ion is an atom that has a different number of electrons and
therefore has a negative or positive charge.
7. Distinguish between ionic, covalent, and hydrogen bonds.
An ionic bond occurs when two atoms with opposite charges
come together and one of the atoms “transfers” an electron to
the other. A covalent bond occurs when two atoms “share” an
electron. Hydrogen bonds occurs when polar covalently
bonded atoms come together and the slightly positive
hydrogen atoms of one molecule is attracted to the slightly
negative charged nitrogen or oxygen atoms of the other
molecule.
8. What is the difference between a compound and a
molecule?
When atoms of the same element bond, they form a molecule
of that element. When atoms of two different elements bond,
they form a compound.
9. What is a chemical reaction?
A chemical reaction occurs when bonds are formed or broken
between atoms.
10. Distinguish between synthesis, decomposition, and exchange
reactions.
When two or more atoms (reactants) bond to form a more
complex structure (product), the reaction is called synthesis. If
bonds between within a molecule break down to form simpler
molecules or atoms the reaction is called decomposition. In an
exchange reaction, atoms of two different molecules exchange
positions.
11. What is the difference between anabolic and catabolic
reactions? Give examples of each.
Catabolic reactions break larger molecules into smaller
ones, anabolic reactions combine smaller molecules into
larger ones.
12. What does “pH” mean? How is it measured?
pH means “potential hydrogenation.” It refers to the potential
of a system to accept hydrogen ions. pH is a measure of
hydrogen ion concentration.
13. What are buffers? Why are they important in living
systems?
Buffers help maintain pH by accepting or donating hydrogen
ions. Living systems need to maintain a constant pH.
14. What is the difference between inorganic and organic
chemistry?
Organic substances contain chains of carbon atoms such as
carbohydrates, lipids, proteins, and nucleic acids. Inorganic
substances include water, oxygen, and carbon dioxide
molecules.
15. Distinguish between carbohydrates, lipids, proteins, and
nucleic acids.
Carbohydrates are built from carbon, hydrogen, and oxygen
atoms usually in the ratio of 1:2:1. For example, glucose
(C6H12O6). Lipids are also built from carbon, hydrogen, and
oxygen. But, there are far more hydrogen atoms than oxygen
atoms. Proteins are built from carbon, hydrogen, oxygen, and
nitrogen atoms. Nucleic acids are built from carbon, hydrogen,
oxygen, nitrogen in the form of a base.
Critical Thinking and Clinical Applications
1. WRITING Connection Water is the main component in
the juices in the digestive tract. Describe how this relates to
the differences in the ways carbohydrates and lipids are
digested?
Carbohydrates are water soluble. Lipids are not. Therefore,
the digestive juices will not be enough to digest lipids into
smaller pieces.
2. CLINICAL Connection Cellulose is a polysaccharide that
humans cannot digest because we lack the enzyme cellulase.
If a dietary supplement contained cellulase, could it cause
weight loss?
No. Cellulose is a carbohydrate. So, if you could digest it into
smaller pieces, that would increase your carbohydrate intake
and therefore the result would be a gain in weight.
components of tissues such as collagen, muscle fibers, cell
membranes, elastin, and keratin, and also have functional roles
as antibodies, enzymes, and certain hormones. Amino acids are
the substances which form proteins.
4. Many scientists agree that gluten insensitivity stems from an
inability to break bonds. Some scientists blame gluten
insensitivity specifically on a lack of human-made enzymes.
Other scientists blame it on an imbalance in the microbiome
(the bacteria that live in our intestines). How could they both
be correct?
Answers will vary, accept all reasonable responses. Example: a
microbiome that is out of balance may interfere with the
enzyme required to break down gluten.
3. What is the relationship between cellular respiration and
building proteins from amino acids?
The body utilizes carbohydrates to provide energy for metabolic
reactions. Proteins are important in that they comprise structural
CHAPTER 2
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Chemical Basis of Life
35
Lab Data Analysis: ATP and Cancer Research
Think Critically
1. Summarize how the ATP concentrations in the graph change
over time.
ATP concentration (shown on the y-axis and measured in
micrograms/milliliter) starts at 0.6 at time=0 minutes.
Measurements are taken every 15 minutes, eventually
decreasing to 0.1 at time=60 minutes. The ATP concentrations
inside the cancer cells clearly decrease over time in a linear
fashion, representative of the cells dying after treatment with
chemotherapy.
2. Is this particular chemotherapy drug effective against the
cancer cells in this experiment? How can you tell?
Yes. Because the ATP concentrations within the cells decrease
over time after being treated with the chemotherapy agent,
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we can conclude that this particular chemotherapy drug is
contributing to the decrease in ATP production within the cell
and ultimately leading to its demise.
3. If this chemotherapy drug were not effective against these
cancer cells, how would you expect the graph to look?
There would not be a decrease in measured ATP
concentrations over the course of 60 minutes, as the drug
would be ineffective at preventing ATP production within the
cancer cells. The measured ATP concentrations, therefore,
would be relatively constant at each measured interval.
CHAPTER
3
Cells
Section
Pacing
(class periods)
Learning Objectives
3.1 Introduction
—
1. Explain how cells differ from one another.
3.2 Composite Cell
1
1. Explain how the structure of a cell membrane
makes possible its functions.
2. Describe each type of organelle, and explain its
function.
3. Describe the cell nucleus and its parts.
3.3 Movements Into
and Out of the
Cell
1
1. Explain how substances move into and out of
cells.
3.4 The Cell Cycle
2
1. Explain why regulation of the cell cycle is
important to health.
2. Describe the cell cycle.
3. Explain how stem cells and progenitor cells
make possible the growth and repair of tissues.
4. Explain how two differentiated cell types can
have the same genetic information, but different
appearances and functions
Focus Activity Workbook
Focus Activities: Labeling (7)
Focus Activities: Vocabulary (3)
Chapter Resources
Extended Summary Review
Chapter 3 Test Bank
Chapter 3 Interactive Question Bank
Vocabulary Flashcards
APR Module 2: Cells & Chemistry
Laboratory Exercise 4: Cell Structure and Function
Laboratory Exercise 5: Movements Through Membranes
CHAPTER 3
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Cells
37
A Suggested Approach
Chapter 3, like Chapter 2, is primarily review since the majority of students have
already learned about cells in their biology courses.
Display a composite cell illustration (figure 3.2). Ask students to discuss the
following prompts with each other, and then with the whole class: “What do you
recognize in the diagram of the cell? When did you learn about it before?” Listen
to suggestions from students to get a sense of the level of their prior knowledge.
Build upon this prior knowledge to cover the necessary components of cells, as
well as Lab 4.
As our cell membranes serve as a major contributor to homeostasis within a number
of body systems, understanding the movement through the cell membrane is
imperative. In addition to Lab 5, students can investigate a variety of case studies to
determine the effects of hypertonic and hypertonic environments on cells.
Cancer is a topic which is probably familiar to many students, and a concrete
application of knowledge around the chemical constituents of cells and the cell
cycle. Cancer develops when mutations occur in genes that normally operate to
control cell division. Being able to compare and discern normal and abnormal cell
division is a necessity for the diagnosis of cancer.
This chapter is expected to take three class periods including Lab 4 and Lab 5.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
Extension activity: hold a class discussion around why reprogrammed cells
(called induced pluripotent stem cells or iPSCs) are preferable to using
human embryonic stem cells (hESCs). Differences include that the starting
material (adult cells) is abundant or ethical reasons.
iPSC technology has been used in the laboratory for the last 13 years.
However, scientists have been reluctant to implant cells derived from iPSCs
until recently due to the concern that implanted stem cells may cause cancer.
The article by Zimmer (2018) in The Scientist (https://www.the-scientist.com/
news-opinion/increasing-number-of-ips-cell-therapies-in-clinical-trials–65150)
discusses some clinical trials that are underway to implant iPSCs. You could
use the concern over cancer to discuss the cell cycle phases and controls.
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Introduction to the Theme
Theme: Structure and Function Cells are the basic unit of life. Each cell has
many compartmentalized organelles that work together to perform a common
function.
Theme Activity: Cell Theory Timeline
The knowledge that cells make up the human body was not always a well-known
fact. To elucidate how science arrived at this knowledge, students will prepare a
timeline of Cell Theory. To create a timeline, have students use resources such as
Biology textbooks or academically approved websites. Students may work alone or
in pairs on this project.
Before your students being this project, review simple questions; such as “What
defines life?” and “What is a cell?”
After students have completed their timelines, go around the room and highlight
key events.
Extension: Have students compare prokaryotic cells, eukaryotic cells, and
viruses.
Extension: Have students detail the discovery and roles of the different organelles
in eukaryotic cells.
Section 3.1: Introduction
Learn
Classroom Activities
Section 3.1 sets the groundwork for activities in sections 3.2 and beyond.
Additional Discussion Questions
Provide students with microscope slides of various types of tissue. Ask them to
draw what they see and provide an explanation of the interrelationships between
structure and function.
The samples should include an array of different muscle tissue types, nerve cells, organ tissues,
epithelial cells, etc
Practice
Practice Questions
1. What is a cell?
A cell is the unit of life and contains several types of structures that house chemical
reactions that make life possible.
2. Give three examples of how a cell’s shape makes possible the cell’s function.
Nerve cells have long, threadlike extensions that conduct electrical impulses from one
part of the body to another. Epithelial cells that line the inside of the mouth are thin,
CHAPTER 3
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Cells
39
flattened, and tightly packed into a tile-like layer that protects cells beneath them.
Muscle cells are slender and rodlike. The precise alignment of the protein fibers in
muscle cells provides the strength to withstand the contractions that pull closer
together the structures to which they attach.
Use the Practice 3.1
Constructing Explanations Describe how the structure of a cell informs its
function.
Cells are small in size with a relatively large surface area, which allows them to easily
exchange nutrients and waste products across their membranes. Cells with specific
purposes have additional features, for example, nerve cells have long extensions for
conducting electrical impulses.
Section 3.2: Composite Cell
Learn
Classroom Activities
Writing Connection: Cell Structure and Function Metaphor
A city as a metaphor for celluar components is very popular and common. Put
students in small groups and ask them to review Table 3.1. Students must then
come up with a new up-to date model metaphor to teach their classmates about
the many different organelles and parts in a cell and what their purpose is.
Encourage students to think creatively about their own real-life experiences to be
able to help their peers understand a cell better. Students should present their
metaphor model they created to the class.
Differentiated Instruction
Learning the parts of the cell may be easier for visual learner students to pair
the name of the cell part with the picture. The teacher should prepare ahead
of time images from the text as individual handouts. Students in pair can
practice identifying the cell organelle or part the picture is depicting. They
should also describe how the cell part is designed that supports the function
or job of the identified cell part.
Group Activity: Cell Building 101
For this activity, students will build models organelles out of edible parts. Have
students brainstorm what types of edible materials they think would work well for
each part. For instance, if ribosomes are small, round looking objects that are easy
to move, they might want to use a small round rolling object, such as a pea or a
sprinkle. You may either provide materials in class or assign this as a homework
assignment. Stress the importance of both structure and function – and why the two
are related.
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To jump start students thinking about what they would use and why as they build
their models, provide them with the following chart:
Organelle
Shape
Function
Material used
In model
Additional Discussion Questions
Provide students with a diagram of a typical cell membrane. Ask them to label it as
completely as possible.
The diagram should include information regarding the bilayer nature of the cell membrane.
The extracellular side of the membrane includes carbohydrates and fibrous proteins.
Intracellular (cytoplasmic side) structures include globular proteins and cholesterol.
Ask students to develop a set of flash cards that identify the major organelles in a
composite cell. Quiz them regularly with the flash cards regarding the names and
functions of each.
The cards should include information for the endoplasmic reticulum, ribosomes, Golgi
apparatus, mitochondria, lysosomes, centrosomes, cilia, flagella, vesicles, microfilaments, and
microtubules.
Ask students to develop a chart that describes the major structures of the nucleus.
The chart will contain information regarding the structure’s name, a description of its physical
structure, and major functions. The nuclear envelope, nucleolus, and chromatin should be
included on the chart.
Proteins found within the phospholipid bilayer of the cell membrane serve a variety
of functions. Which functions are these?
These proteins serve as receptor sites, enzymes, binding sites, and transporters. Some proteins
can also combine with sugar complexes to determine blood type.
Why would the mitochondria be described as the powerhouse of the cell?
Mitochondria are the major sites of chemical reactions that transform energy from glucose and
other nutrient molecules into a chemical form the cell can use. This energy-releasing process
provides the energy necessary, (in the form of ATP), for the cell to conduct its activities.
Ask students to prepare a short report on the functions of DNA and RNA.
Responses will vary.
Practice
Practice Questions
1. Name the three major parts of a cell and their functions.
The three major parts of a cell are the cell membrane, the nucleus, and the cytoplasm.
The cell membrane encloses the cell, the nucleus houses the genetic material (DNA) and
controls cellular activities, and the cytoplasm fills out the cell.
CHAPTER 3
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Cells
41
2. Define organelles and explain their general functions in a cell.
Organelles are specialized structures within the cytoplasm of a cell. Organelles perform
specific functions such as partitioning off biochemical that might harm other cell parts,
dismantling debris, processing secretions, and extracting energy from nutrients.
3. What is a selectively permeable membrane?
The cell membrane is selectively permeable, meaning that only certain substances can
enter or leave the cell.
4. Describe the chemical structure of a cell membrane.
The cell membrane is mainly lipids and proteins arranged into double layer (bilayer) of
phospholipid molecules. Each phospholipid molecule includes a phosphate group and
two fatty acids bound to a glycerol molecule. The water-soluble phosphate heads form
the intracellular and extracellular surfaces of the membrane, and the water-insoluble
fatty acid “tails” make up the interior of the membrane. The two membrane layers form a
flexible but stable fluid film. Cholesterol molecules embedded in the cell membrane’s
interior help make the membrane less permeable to water-soluble substances and
provide structural support. Integral proteins (transmembrane proteins) extend through
the bilayer and through both sides of the membrane. Peripheral membrane proteins
associate outside only one side of the membrane. Another protein on a cell’s surface is a
cellular adhesion molecule (CAM), which guides the cell’s interactions with other cells.
5.What are the functions of ribosomes, the endoplasmic reticulum, vesicles, and
the Golgi apparatus?
Ribosomes provide structural support and synthesize proteins. The ER also participates
in the synthesis of proteins and lipids and acts as a “quality-control” center for the cell,
identifying and dismantling misfolded proteins. Vesicles are membranous sacs that store
or transport substances within a cell and between cells. The Golgi refines, packages, and
transports proteins synthesized by the rough ER.
6.Explain how organelles and other structures interact to secrete substances
from the cell.
Organelles interact with each other to secrete substances from the cell. Ribosomes of
the rough ER synthesize proteins and export those proteins in vesicles to the Golgi
apparatus where they undergo further modification and are re-packaged into vesicles for
export outside of the cell via fusion with the cell membrane or passage through
specialized membrane channels.
7. What is the function of mitochondria?
Mitochondria house most of the biochemical reactions that extract energy from the
nutrients in digested food and store that energy in the chemical bonds of ATP.
8. What are the functions of lysosomes and peroxisomes?
Lysosomes bud off sections of the Golgi and house enzymes that dismantle debris as
well as maintain the acidic pH that allows those enzymes to function, while shielding the
cell from those acidic conditions that would otherwise be harmful. Peroxisomes also
house enzymes (different from those found in lysosomes) that catalyze a variety of
biochemical reactions and break down hydrogen peroxide, fatty acids, and alcohol.
9. How do microfilaments and microtubules differ?
Microfilaments are tiny rods of actin that form meshworks or bundles and provide for
movement of the cell. Microtubules are long, slender (though wider than microfiliments)
tubes made of tubulin. Microtubules are important for cell division.
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10. What is a centrosome and what does it do?
Centrosomes are located near the Golgi and the nucleus. They are non-membranous and
consist of two hollow cylinders called centrioles that lie at right angles to each other.
During mitosis, the centrioles distribute chromosomes to newly forming cells.
11.Locate cilia and flagella and explain what they are composed of and what they do.
Cilia and flagella are motile structures composed of microtubules that extend from the
surfaces of certain cells. Cilia fringe the free surfaces of some cells and move in
coordinated “to-and-fro” manner, so that rows of them beat in succession, producing a
wave of motion that moves fluids, such as mucus, over the surface of certain tissues.
Flagella are much longer than cilia and usually a cell only has one. Flagella move in
undulating waves, enabling the cell to “swim.” In humans, the only cells that have flagella
are sperm cells.
12. Identify the structure that separates the nuclear contents from the cytoplasm.
The contents of the nucleus are separated from the cytoplasm by a double-layered
nuclear envelope. The nuclear envelope has protein-lined channels called nuclear pores
that allow certain molecules, such as RNA, to exit the nucleus.
13. What is produced in the nucleolus?
Ribosomes form in the nucleolus and then migrate into the cytoplasm.
14. Describe chromatin and how it changes.
Chromatin consists of loosely coiled fibers of DNA and protein. During cell division,
chromatin fibers coil tightly to form the individual chromosomes. At times when the cell is
not dividing, chromatin unwinds to permit access of its information by other genes.
Use the Practices 3.2
Using Models Imagine a cell as a miniature city. Each organelle might
represent a company, place, or part of the city by performing a specific task.
Using a city as your example, create a model that explains the role of each
organelle.
City Part
Function
Cell Part
City limits
Controls what goes in and
out of the city
cell membrane
Road system
Allows for movement
throughout the city
endoplasmic reticulum
City Hall
Controls all the activities in
of the city
nucleus
City Auditor
Stores all the records of the
city and passes them on as
the city grows
chromosomes
City Planning Office
A place in the city hall where
plans are made for the
construction of the city
nucleus
Construction company
Builds structures for the city
ribosomes
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Delivery van
Delivers products made at
the construction company to
other locations in the city
vesicle
Food processing plant
Processes large quantities of lysosomes
food entering the city into
smaller packages that can be
used more easily
Warehouse
Stores materials needed by
the city
vacuole
Power company
Produces energy for the city
mitochondria
Solar power plant
Uses the sun’s energy to
produce power for the city
chloroplast
Figure Questions
Figure 3.10, p. 85: What structures are inside the nucleus of a cell?
The nucleus contains a nucleolus (composed of RNA and protein) and chromatin (loosely
coiled DNA) floating in nucleoplasm.
Section 3.3: Movement Into
and Out of the Cell
Learn
Classroom Activities
EL Strategy: Making Connections
Beginning Help students access text by using a diagram or an illustration to
demonstrate key points. For example, label the parts of a diagram. Before
reading, explain the diagram and labels to students using gestures and short
phrases. An example for Figure 3.12: Look at container 1, why are the two
solutions separate? How is this different in container 2? Or 3? What is
happening to make the solutions combine? Can you give an example from
previous classes or personal experience to explain diffusion? As you read, point
out each labeled item on the diagram to show students how the information in
the diagram connects to information in the text.
Writing Connection: Flow Charts of the Cell Membrane
Students should work in small groups. Assign each group one of the ways items
move through the cell membrane such as: diffusion, active transport, passive
transport, osmosis, endocytosis, and exocytosis. Students should create a flow chart
or diagram showing the movement of particles throughout the cell. Encourage
students to label molecules, the cell membrane including phospholipids, and high or
low amounts of energy required at different points for the process to occur.
Students can share their work or post in the classroom.
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Differentiated Instruction
The above activity is very open ended and there are multiple ways students
could represent any of the identified movement of particles above. In order to
give the activity more guidance and support to students, the teacher should
provide each group with a pre-made guided flowchart of their specific
movement. Students can fill in the flow chart and then should also create a
visual drawing of the process they represented.
Demonstration Activity: Osmosis and Diffusion
For this activity, students will demonstrate how osmosis and diffusion occur across a
selectively permeable membrane. They will measure the change in mass of two or
more potato slices in various sucrose solutions after 24 hours. Students should then
plot the change in mass for each sucrose concentration on a line graph. This simple
but effective experiment shows how permeable potato cells are to sucrose.
For further instructions see: http://www.bbc.co.uk/education/guides/zc9tyrd/
revision/7 A great resource on how to link this experiment back to body function in
A&P can be found at the Yale National Initiative website: http://teachers.yale.edu/
curriculum/viewer/initiative_11.07.07_u
Practice
Practice Questions
1. What types of substances diffuse most readily through a cell membrane?
Substances that are soluble in the lipids that compose the cell membrane diffuse most
readily. Examples of these substances include oxygen and carbon dioxide.
2. Explain the differences among diffusion, facilitated diffusion, and osmosis.
Diffusion is the tendency of molecules a solution or air to move freely from areas of
higher concentration to regions of lower concentration. Facilitated diffusion is the
process by which substances are moved from areas of higher concentration to areas of
lower concentration with the assistance of carrier molecules, usually proteins. Osmosis
refers specifically to the movement of water across a selectively permeable membrane.
3. Distinguish among hypertonic, hypotonic, and isotonic solutions.
Hypertonic solutions are solutions with higher osmotic pressure than body fluids. Hypotonic
solutions are solutions with lower osmotic pressure than body fluids. Isotonic solutions are
solutions that have equal osmotic pressure to the osmotic pressure of body fluids.
4. How does filtration happen in the body?
Filtration is the process by which molecules are forced through membranes by exerting
pressure on those molecules. The force for this movement in the body is the blood
pressure generated by the heart. Blood pressure is greater inside a blood vessel than
outside a blood vessel, forcing molecules out of the vessel.
5.Explain the mechanism that maintains unequal concentrations of ions on
opposite sides of a cell membrane.
Active transport is a process that moves particles through membranes from a region of
lower concentration to a region of higher concentration. In the case of the sodiumpotassium pump, active transport continually moves sodium ions through cell membranes
from regions of lower concentration (inside the cell) to regions of higher concentration
(outside the cell). Active transport moves potassium ions in the opposite direction, such
that potassium ions are at a higher concentration inside the cell.
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6. How are facilitated diffusion and active transport similar and different?
Active transport is similar to facilitated diffusion in that it uses specific carrier molecules
in cell membranes. It differs from facilitated diffusion in that particles are moved from
regions of low concentration to regions of high concentration, and energy from ATP is
required.
7. How do endocytosis and exocytosis differ?
Two processes use cellular energy to move substances into or out of a cell without
actually crossing the cell membrane. In endocytosis, molecules are conveyed in a vesicle
that forms from a portion of the cell membrane itself. In exocytosis, the reverse process
occurs; the contents of a vesicle are secreted from the cell.
8.Explain how receptor-mediated endocytosis is more specific than pinocytosis
or phagocytosis.
Pinocytosis and phagocytosis engulf any molecules in the vicinity of the cell membrane.
In contrast, receptor-mediated endocytosis moves very specific kinds of particles into the
cell. In this process, protein molecules extend through the cell membrane to the outer
surface and function as receptors for specific molecules, called ligands.
Use the Practice 3.3
Constructing Explanations Some recipes call for you to salt watery
vegetables, such as tomatoes, before adding them to salads. Describe why
adding salt to the tomatoes would draw the water out.
Osmosis. By adding salt to the outside of the tomatoes, you are increasing the solute
concentration outside of the tomato cells. This will cause the water to move from the
area of lower concentration (inside) to the area of higher concentration (outside).
Figure Questions
Figure 3.19, p. 92: What are two requirements for active transport to occur? Why
would the Na+ –K+ pump, but not osmosis, cease to function after a cell dies?
Active transport requires a concentration differential and energy. Osmosis could continue after
cell death because ions could still move from high to low concentration, but without the energy
from ATP, the Na+/K+ pump would cease to function.
Section 3.4: The Cell Cycle
Learn
Classroom Activities
EL Strategy: Sequencing: The Cell Cycle
Beginning To enhance and confirm students’ understanding, provide images
that represent each step in the sequence. After reviewing for the whole class,
student should work in pairs using figure 3. 22 to describe and illustrate one
step in the cell cycle. They will post it to a word wall. Then students copy the
word into their interactive notebook and draw their own image to represent
the step.
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Visual Literacy: Mitosis Three Ways
This activity is an individual activity, but it can be completed in small groups. Each
student will represent mitosis in three different ways: written description, drawing
or organizing an image of each step, and finally giving an oral presentation using
any props or support materials including the written description or drawings.
Students may use Figure 3.22 to guide them in their drawings and description.
Differentiated Instruction
Students will all be presenting on the same topic. Encourage students to be
creative and incorporate their own twist on presenting. Students who speak a
different language are encouraged to present in their native language.
Students listening should identify cognates and science words throughout the
presentation.
Additional Discussion Questions
Ask students to give examples of the effects of an abnormal cell cycle upon
homeostasis.
Responses will vary. Cancer will be a typical topic of discussion. Ask students to develop a set
of flash cards that identify the major organelles in a composite cell. Quiz them regularly with
the flash cards regarding the names and functions of each.
Ask students to prepare a poster that illustrates the major events in each phase of
cell division.
The posters should include information about prophase, metaphase, anaphase, telophase, and
interphase. Also, the student should mention the starting and ending points of cytokinesis.
Where might you see a large number of nuclei in the process of mitosis?
In the growing embryo, sites of wound repair, excised liver tissue, and tumor sites.
Discuss why stress may be harmful to health.
Severe stress may affect normal cell division, by interfering with an —internal clock which
regulates this cycle.
Discuss the common characteristics of cancers as it pertains to this chapter
objective.
Answers should include a discussion of hyperplasia, dedifferentiation, metastasis, and mutation.
Ask students to discuss various causes of cell death.
Responses may include a discussion of radiation, bacteria, sites where blood clotting has
occurred, chemical poisons, decreased oxygen supply to tissue, etc.
Practice
Practice Questions
1. Outline the cell cycle.
The major phases of the cell cycle are interphase, mitosis, and cytoplasmic division
resulting in “daughter” cells that may or may not undergo further changes. During
interphase, which is separated into the G1, S, and G2 phases, the cell grows and
prepares for division. Mitosis, which is division of the nucleus, is separated into
prophase, metaphase, anaphase, and telophase. Cytoplasmic division completes the
cell cycle.
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2. Explain regulation of the cell cycle.
The cell cycle is very precisely regulated. Groups of special proteins interact at certain
times in the cell cycle (checkpoints) in ways that control whether the cell cycle
progresses and if any mistakes have been made. A specific checkpoint, the “restriction
checkpoint,” determines the cell’s fate: the cell can continue along the cycle, become a
non-dividing cell, or die.
3. Describe the events that occur during mitosis.
Mitosis is separated into prophase, metaphase, anaphase, and telophase. During
prophase, chromosomes condense and centrioles, which have previously replicated,
move to opposite ends of the cell. The nuclear envelope and nucleolus disappear and
spindle fibers associate with the centrioles and chromosomes. During metaphase, the
chromosomes line up midway between the centrioles. During anaphase, the centromeres
are pulled apart by the spindle fibers, and the chromatids, now individual chromosomes
move in opposite directions. Cytokinesis begins. In telophase, chromosomes complete
their migration and unwind to become chromatin fibers, the nuclear envelope reforms,
and microtubules disassemble. Cytokinesis continues.
4. Why must cells divide and specialize?
The ability to generate new cells is essential to the growth and repair of tissues.
5. Distinguish between a stem cell and a progenitor cell.
Cells that retain the ability to divide repeatedly without specializing are called stem
cells. A stem cell divides to yield either two daughter cells like itself (stem cells), or one
daughter cell (stem cell) and one cell that will become partially specialized; the cell that
becomes partially specialized is called a progenitor cell.
6. How are new cells generated and how do they specialize?
Stem cells can divide and give rise to at least one other stem cell, a process called
self-renewal. Stem cells can give rise to progenitor cells. Progenitor cells can then
differentiate and specialize. Cells progressively specialize by “turning on” or “turning off”
parts of the complete genetic instructions, or genome, present in every cell’s nucleus.
7. How is cell death a normal part of development?
Apoptosis is a form of cell death that occurs in normal cells and is a normal process.
During apoptosis, cells of a particular region or body part that are in excess can be
removed. For example, the webbing between fingers and toes present in the developing
fetus are carved away before birth.
Use the Practice 3.4
Analyzing Data A student observes dividing cells under the microscope and
notes that 58% are in interphase, 28% in prophase, 8% in metaphase, 4% in
anaphase, and 2% in telophase. Based on these data, what can you conclude
about the time a cell spends in each phase of the cell cycle?
Since the majority of cells can be seen in interphase, this must be the longest phase of
the cell cycle. Additionally, since few cells are seen in metaphase, anaphase and
telophase, these must be less time of the cell cycle.
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Assess
Career Corner: Cytotechnologist
Consider This: As a cytotechnologist, you are examining a blood smear under
a microscope from a patient who has been feeling rundown and tired for
several weeks. You note numerous neutrophils in the sample. Using your book
(Chapters 12 and 14) and Internet resources, determine what neutrophils are
and what their presence in the sample might mean.
Neutrophils are a type of immune cell involved in fighting bacterial infections. During
inflammation, neutrophils are the first cells to arrive on the scene. Under a microscope,
neutrophils are identified by their characteristic multi-lobed nuclei. The presence of neutrophils,
combined with the feelings of fatigue, might indicate that the patient has an infection.
Genetic Engineering: Cancer
1. Describe the characteristics shared by the different types of cancer.
Cancers share hyperplasia (accelerated cell division), dedifferentiation (loss of specialized
structures), invasiveness (breaking through basement membranes), angiogenesis
(extending into nearby blood vessels), and metastasis (spreading to other tissues).
2. Describe how the cell cycle is abnormal in cancer.
In most cancers, the cell cycle has been disrupted such that it does not stop, and cells
replicate too frequently.
Case Study Connection
p. 74: Stem cells are cells that have not yet specialized. Do you think stem cells
will have any of the shapes illustrated in figure 3.1? Why or why not? What
evidence can you use to answer this question?
Students should understand that the structure of a cell is connected to its function. If
stem cells do not have a specialized function they will not obtain a specialized shape.
p. 81: Do you think that different types of specialized cells have different
proportions of organelles? For example, do muscle cells and skin cells have
different concentrations of mitochondria?
Students will likely say yes – a cell in a muscle which must regularly contract would be
likely to have more mitochondria to produce more energy.
p. 84: Motor neurons, like the ones affected in ALS, do not divide. Do you expect
that you would be able to find centrioles in motor neurons? Would you expect to
find DNA unwound in motor neurons, or wound into the chromosome form?
No – centrioles are used to separate chromosomes during cell division. Similarly,
chromosomes condense from chromatin prior to cell division. If motor neurons do not
divide, then they are unlikely to have either centrioles or condensed DNA.
p. 99: In cell reprogramming a differentiated skin cell is de-differentiated back to a
cell that can become either a skin cell or a nervous system cell. Which cell in figure
3.23 would represent the ideal place to de-differentiate the skin cell towards?
The progenitor cell directly to the right of the stem cell is the base of the branches that
end in skin cells and neurons.
CHAPTER 3
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which of the following components of the cell membrane aid
in the selective permeability of the membrane while adding
rigidity to its structure?
a. peripheral proteins
b. glycolipids
c. cholesterol molecules
d. phospholipids
2. The mis-folding of proteins is thought to lead to a number
of neurological conditions, such as Alzheimer’s. Which
organelle is likely the structure where protein mis-folding
takes place?
a. endoplasmic reticulum
b. Golgi apparatus
c. cytoplasm
d. lysosomes
3. Loosely coiled fibers of DNA and protein are known as
a. centrosomes.
b. chromatin.
c. microfilaments.
d. microtubules.
4. Which of the following factors would contribute to an
increase in the rate of collisions of particles, and thereby the
rate of diffusion, in a cell?
a. decreasing the temperature
b. decreasing the number of particles
c. increasing phagocytes in the cell
d. increasing the density of particles
5. Patients in the hospital are often kept hydrated using
intravenous saline fluids. Which of the following statements
is true about IV fluids used in this capacity?
a. IV fluids are isotonic so that the osmotic pressure is similar
inside and outside the body’s cells.
b. IV fluids are hypotonic to the cells and cause the body’s
cells to swell due to their higher osmotic pressure.
c. IV fluids are hypertonic to the cells and cause the
body’s cells to shrink due to their lower osmotic
pressure.
d. IV fluids are isotonic to the cells and cause the body’s
cells to swell with hydration as they accept the new
solution.
6. ATP (adenosine triphosphate) is required to transport
molecules from areas of lower concentration to areas of
higher concentration during which transport process?
a. facilitated diffusion
b. filtration
c. active transport
d. receptor-mediated endocytosis
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7. Which types of enzymes are associated with phagocytosis?
a. lipid synthesis enzymes of the smooth ER
b. enzymes related to cellular respiration in the cristae of
mitochondria
c. peroxisomal enzymes in liver and kidney cells
d. lysosomal digestive enzymes
8. Mature nerve cells normally do not divide. Which phase of
the cell cycle are mature nerve cells most likely restricted to?
a. M phase
b. G1 phase
c. S phase
d. G2 phase
9. During which phase does DNA replication occur?
a. interphase
b. prophase
c. metaphase
d. anaphase
10. A daughter cell of a stem cell whose own daughter cells are
restricted to follow specific lineages is called a ___.
a. apoptotic cell
b. cancer cell
c. progenitor cell
d. stem cell
Short Answer
1. What is the cytoplasm?
A gel-like material inside the cell that supports organelles.
2. What is an organelle?
Structures with specific jobs inside of cells.
3. Describe the structure and function of the cell membrane.
The cell membrane is a selectively permeable barrier around a
cell. It is a phospholipid bilayer with embedded proteins.
4. Describe the structure of the mitochondria.
The inner layer contains folded cristae that increases the
surface area for the reactions that produce ATP. Mitochondria
have their own DNA.
5. What is a centriole?
Centrioles are composed of microtubules that have contractile
proteins. They move chromosomes during mitosis.
6. Describe the structure and function of cilia and flagella.
Cilia and flagella are cellular extensions that are composed
of microtubules in a “9 + 2” arrangement. Cilia help move
substances past cells. Flagella enable some cells to “swim.”
7. What happens to a cell put into hypotonic and hypertonic
solutions?
A cell put into a hypertonic solution will lose water and shrink.
A cell put into a hypotonic solution will gain water, swell up
and possibly burst.
8. What are diffusion and facilitated diffusion? Give examples
of what passes into and out of cells in these ways.
Diffusion is the movement of particles from high
concentration to low concentration. Example: how oxygen
moves across cell membranes. Facilitated diffusion employs
protein channels to move ions and larger molecules across
a cell membrane. Na+/K+ and glucose move across cell
membranes in this way. Neither require energy.
9. What is active transport? How does it differ from diffusion?
Active transport moves particles against the gradient, from low
to high concentration. It requires energy.
10. What are the stages of mitosis, and what occurs during them?
Prophase: chromosomes become visible and centrioles move
to opposite sides of the cell; metaphase: chromosomes line up
in the middle of the cell; anaphase: centrioles begin to pull
apart chromatids into individual chromosomes; telophase:
individual chromosomes start to “disappear” as the DNA
becomes housed into the new nuclei.
11. What is the function of the Golgi apparatus?
The Golgi apparatus functions to refine and package proteins
that are synthesized on ribosomes.
12. What is cell differentiation?
Cell differentiation is the process by which cells from a
fertilized egg become unique and specialized. For example,
some become muscle cells whereas others become bone cells.
13. What is apoptosis?
Apoptosis is programmed cell death. This is a part of normal
development to give the proper shape and function to organs.
14. Describe pinocytosis and phagocytosis.
Pinocytosis and phagocytosis are versions endocytosis, a process
that enables a cell to engulf large quantities of substances.
Pinocytosis brings in liquids. Phagocytosis brings in solids.
15. Describe the structure and function of the nucleus.
The nucleus is membrane bound organelle that houses the
DNA that ultimately directs all of a cell metabolic processes.
Critical Thinking and Clinical Applications
1. If a cell had many mitochondria with very well developed ER
and Golgi, what can you infer about its major function?
expectorated. If cilia are immobile, secretions may remain in
the lower respiratory tract where they may cause infections.
The cell makes a great deal of energy and synthesizes
protiens. The Golgi will package and process these proteins.
4. CLINICAL Connection Which process—diffusion, osmosis,
or filtration—is utilized in the following situations?
2. During an autopsy a coroner can tell if a person drowned in
freshwater or salt water. Explain this.
Saltwater is hypertonic compared to body cells, so cells would
shrivel. Freshwater is hypotonic compared to body cells, so
they would swell.
3. WRITING Connection Exposure to tobacco smoke
immobilizes cilia, and they eventually disappear. How might
this effect explain why smokers have an increased incidence
of coughing and respiratory infections?
The rhythmic beating of cilia aids in moving respiratory
secretions into the pharynx where they are swallowed or
(a) Injection of a drug that is hypertonic to the tissues
stimulates pain.
Osmosis: the hypertonic drug solution would cause water
to leave the cells, causing swelling of the tissues, exerting
pressure on nerves, and causing pain.
(b) The urea concentration in the dialyzing fluid of an
artificial kidney is decreased.
Diffusion: urea would need to diffuse from a higher
concentration in the patient’s blood to a lower
concentration in the dialyzing fluid if it is to be removed.
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Lab Data Analysis: Blood Cells and Dehydration
Think Critically
1. Does dehydration cause blood to become hypotonic (lower
osmolarity) or hypertonic (higher osmolarity)?
Hypertonic. Isotonic blood is 290 mOsmol/L (shown before
dehydration), and after dehydration the blood is ~295
mOsmol/L.
2. When an individual is dehydrated, would their red blood cells
shrink or swell?
In dehydration, the surrounding blood plasma is hypertonic.
Water would leave the cells via osmosis causing them to shrink.
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3. Why might a person who is dehydrated from heat have blood
that is hypertonic compared to a normally hydrated
individual?
Heat causes sweating, which leads to loss of body water, and
dehydration. If an individual does not replenish water, the
amount of water in their blood plasma decreases relative to
the solutes. Their blood changes from isotonic to hypertonic.
CHAPTER
4
Cellular Metabolism
Pacing
(class periods)
Learning Objectives
4.1 Introduction
—
1.Explain the overall function of metabolism.
4.2 Metabolic Reactions
1/2
1.Compare and contrast anabolism and
catabolism.
4.3 Control of Metabolic
Reactions
1
Section
1.Describe how enzymes control metabolic
reactions.
2.Describe a metabolic pathway.
4.4 Energy for Metabolic
Reactions
1
1. Identify the source of biological energy.
2.Describe how energy in the form of ATP
becomes available for cellular activities.
3.Explain how cellular respiration releases
chemical energy.
4.5 DNA (Deoxyribonucleic
Acid)
1/2
1.Describe how DNA molecules store
genetic information.
2.Describe how DNA molecules are
replicated.
3.Explain how stem cells and progenitor
cells make possible the growth and repair
of tissues.
4.Explain how two differentiated cell types
can have the same genetic information,
but different appearances and functions
4.6 Protein Synthesis
1
1. Describe the steps of protein synthesis.
Focus Activity Workbook
Focus Activities: Labeling (6)
Focus Activities: Vocabulary (5)
Chapter Resources
Extended Summary Review
Chapter 4 Test Bank
Chapter 4 Interactive Question Bank
Vocabulary Flashcards
APR Module 2: Cells & Chemistry
CHAPTER 4
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Cellular Metabolism
53
A Suggested Approach
Chapter 4 should serve as a review for most students, who have likely studied
cellular metabolism in a prerequisite biology class.
Trillions of chemical reactions happen simultaneously in the body. These chemical
reactions, known as metabolism, drive the processes that keep us alive. These
chemical processes are key to understanding how different organ systems function
at the cellular level.
Enzymes are critical in understanding how many of the biological processes occur in a
timely fashion. Without these biological catalysts, reactions may not occur quickly
enough in our bodies. Since specific enzymes will be covered in subsequent chapters, it is
important to remind students of enzyme’s action and their control of metabolic pathways.
Although the process of cellular respiration can’t be observed, the effects of
aerobic and anaerobic respiration in the human body can be observed. By relating
an increase in pulse rate, body temperature, or respiratory rate during exercise to
the increased need for energy and the cycling of oxygen and carbon dioxide
through the body, students can observe our need for energy and the process of
cellular respiration. Further, students can relate muscle fatigue to lactic acid
produced through anaerobic respiration.
Protein synthesis provides an opportunity for students to review their knowledge of
DNA and RNA structure and function while also applying their knowledge of cellular
processes. Students can model the process from DNA to functional protein by using
normal and mutated DNA sequences. Students transcribed a specific DNA
sequence, then match tRNA templates to codons and determine the amino acid
sequence represented by different colored beads. The beads are threaded onto
pipe cleaners in a specific order, and then folded into a functional protein.
This lesson is expected to take four class periods.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
Extension activity: discuss how different cells use energy/cellular respiration
differently. Compare a bacterium from the gut to a fast-glycolytic muscle
fiber and each of these to a slow-oxidative muscle fiber (Chapter 8).
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Introduction to the Theme
Theme: Energy and Matter Cellular metabolism is composed of the many
reactions that are constantly occurring within a cell. These reactions store and
release energy that cells then use to carry out a variety of functions.
Theme Activity: The Cell Dance
Many processes occur in the cell. This chapter highlights many of the metabolic
processes: anabolism, catabolism, dehydration, hydrolysis, protein synthesis, etc. For
this activity, have students break into group. Assign each group a particular process.
Have the students study the steps in the chapter for their assigned process. Ask the
students the following questions:
What is the outcome of this process?
What are the steps of this process?
Where does the energy come from/go?
Then, encourage the students to be creative and come up with a dance they think
best represents this process. Encourage them to pick a classroom appropriate song
to set to their dance. After their dance, have each student explain their roles. Were
they Enzymes? Cofactors? ATP? How did their movements represent the process
they were trying to illustrate?
Section 4.1: Introduction
Learn
Classroom Activities
Section 4.1 sets the groundwork for activities in sections 4.2 and beyond.
Practice
Practice Questions
1. What is cellular metabolism?
Cellular metabolism is the set of chemical reactions that acquire, store, and release
energy in cells.
2. What are enzymes?
Enzymes are special proteins that allow chemical reactions in the body to proceed fast
enough to sustain life.
Use the Practice 4.1
Asking Questions Using your understanding from biochemical molecules
(Chapter 2), develop a question about the sources of this cellular energy.
Answers will vary. Example: Our DNA must be copied to produce a new cell. Where does
the fuel for this reaction come from?
CHAPTER 4
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Cellular Metabolism
55
Section 4.2: Metabolic Reactions
Learn
Classroom Activities
Group Activity: Marshmallow Metabolism
For this activity, students will show the process of catabolism and anabolism by
creating moving dioramas using marshmallows and toothpicks.
Each student needs 22 toothpicks and eight marshmallows. The marshmallows will
represent hydroxyl groups and the toothpicks will represent carbon bonds.
Use the figure (Figure 4.2 from page 109) as the model of catabolism and anabolism.
As the students create their dioramas ask them which process is catabolism and
which is anabolism and why.
Visual Literacy: T-Chart Activity
Students can complete this as a whole group or in small groups. Provide each group
with a T-chart to compare Anabolism and Catabolism. Encourage students to
brainstorm multiple ways to compare these two processes and ensure they include the
products of each process. If the activity is done in small groups, save time at the end of
the session to bring the whole group together and share findings between groups.
Differentiated Instruction
Instead of allowing students to brainstorm ways to compare Anabolism and
Catabolism, the teacher could make pre-defined rows on the T-chart. This
would support the learner on what information they need to research and
discuss. The teacher could also add in a third column where students could
create visual images to help remember the differences between the two.
Practice
Practice Questions
1. What are the general functions of anabolism and catabolism?
Anabolism provides the biochemicals required for cell growth and repair by joining
individual molecules together to form more complex molecules. Catabolism reactions, on
the other hand, break down larger molecules into smaller ones.
2.What are the products of the anabolism of monosaccharides, glycerol and fatty
acids, and amino acids?
The anabolism of monosaccharides produces glycogen and water. The anabolism of
glycerol and fatty acid molecules forms a triglyceride (fat) and three molecules of water.
The anabolism of amino acids forms proteins and water.
3. Distinguish between dehydration synthesis and hydrolysis.
Dehydration synthesis joins simple sugars to form larger glycogen molecules and
produces water as a by-product. Hydrolysis reactions break down complex molecules
into their simpler components, as well as split water molecules. Dehydration synthesis
and hydrolysis are opposite processes.
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Use the Practice 4.2
Analyzing Data Determine if the processes listed below involve dehydration
synthesis or hydrolysis:
• Breaking down complex carbohydrates with salivary amylase.
Hydrolysis
• Building up muscle proteins by linking specific amino acids.
Dehydration synthesis
Section 4.3: Control of Metabolic
Reactions
Learn
Classroom Activities
Demonstration Activity: Enzyme Scramble
This activity that demonstrates how enzymes work and affect the rate of reactions.
Prepare by making 8-10 enzyme-substrate complexes (making half have a different
shape than the other half) as well as the product molecules. Use Figure 4.5 as a
guide. The result should be 8-10 individual orange colored substrate molecules, blue
colored substrate molecules, purple enzyme molecules, and green product
molecules. Pass out the correct number of cut-outs to students in the class based on
the goal of the activity. Below are two versions of the activity.
Option 1: Normal concentration levels of each enzyme-substrate complex
Pass out the cut-outs so that students represent the following: 1/3 purple, 1/3 blue,
1/3 orange. The green product molecule is always carried by the student with the
enzyme molecule. The goal is for the student who is carrying the enzyme molecule
to find the two matching substrates and create the product molecule. Mix students
up around the room. Students should hold their particle out in front so all can see
the shape. Just as in a cell, each enzyme must recognize its specific substrate based
on their shapes. Everyone starts moving around slowly. The purple enzymemolecules must look for and attach to their matching substrate molecules (blue and
orange). Once the student with the enzyme molecule finds the two matching
substrates, they will raise their hand and hold of the product molecule.
Discuss with the class how easy or difficult it was for the enzyme molecules to find
their matching substrates. How long did it take to make a product molecule?
Option 2: Concentration levels and how they affect reaction rate
Pass out the cut-outs so that one set of matching enzyme-substrate complex
represents 2/3 of the class while the other shape of matching enzyme-substrate
complex represents 1/3 of the class. Repeat the procedure in A where the goal is for
the student who is carrying the enzyme molecule to find the two matching
substrates and create the product molecule.
Discuss with the class how easy or difficult it was for the enzyme molecules that
made up 2/3 of the class to find their matching substrates compared to the
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enzyme-substrate complex that represented 1/3 of the class. How long did it take to
make a product molecule? Students should recognize that the increased
concentrations of the one matching enzyme-substrate complex made the reactions
go much quicker than the less concentrated enzyme-substrate complex.
Differentiated Instruction:
This activity requires students to physical move around the room. Depending
on the space and mobility of students, this activity could also be completed at
a table within a small group. The teacher would prepare smaller puzzle like
pieces of each particle in the enzyme-substrate complex. Each group member
would take turns timing and creating the different enzyme-substrate complex
out of the middle pile. Discussions could still occur in the smaller group setting.
Practice
Practice Questions
1. What is an enzyme?
Enzymes are specialized proteins that lower the amount of energy necessary for a
chemical reaction to begin (the activation energy). Enzymes speed chemical reactions
and are themselves not expended in the process, allowing for multiple and continued use.
2. How does an enzyme recognize its substrate?
Each enzyme is specific, acting only a particular type of molecule, called its substrate.
The ability of an enzyme to recognize its substrate arises from the three-dimensional
shape, or conformation, of the enzyme molecule. Each enzyme’s polypeptide chain twists
and coils into a unique conformation that fits the particular shape of its substrate
molecule.
3. List factors that affect the rate of an enzyme-controlled reaction.
The rate of an enzyme-controlled reaction depends on the number of enzyme and
substrate molecules in the cell. A reaction is faster if the concentrations of the enzyme or
the substrate increase.
4. What is a metabolic pathway?
Sequences of enzyme-controlled reactions that lead to synthesis or breakdown of
particular biochemicals are called metabolic pathways.
5. What is a rate-limiting enzyme?
The rate of a metabolic pathway is often determined by a regulatory enzyme that
catalyzes one of its steps. A regulatory enzyme that controls an entire pathway is called
a rate-limiting enzyme.
6. What does a cofactor do?
Some enzymes become active only when they combine with a nonprotein component
called a cofactor. Cofactors may be elements or small organic molecules, called
coenzymes. Several vitamins are coenzymes.
7. List factors that can denature enzymes.
Like other proteins, exposure to heat, radiation, electricity, certain chemicals, or fluids
with extreme pH values can denature enzymes.
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Use the Practice 4.3
Conducting Investigations Design an experiment to test how changing
conditions in the mouth (such as temperature or pH) affect the enzyme salivary
amylase, which breaks down complex carbohydrates into simple sugars.
Measure the amount of simple sugars produce by altering the pH in the mouth (water,
baking soda, orange juice)
Measure the amount of simple sugars produced by altering the temperature (hot water,
warm water, cold water)
Section 4.4: Energy for Metabolic
Reactions
Learn
Classroom Activities
EL Strategy: Sequencing
Advanced In groups or individually, students should complete a graphic
representation of the steps of the catabolic process. Use figure 4.11 can be
used as a model. The figure is divided in three sections. The students could be
divided into three collaborative groups to create one whole class model of
catabolism, or students can individually complete a step and three students
can combine to create a larger model. Students should present their part of
the process.
Writing Connection: Energy into ATP
Pair students together and give them the following challenge to complete. Ask each
pair of students to brainstorm their favorite foods and decide on one type of food
to use in the challenge. Each group will write a short story or poem describing how
the food they eat is eventually turned into energy to power bodily functions.
Provide students with a rubric highlighting what to include such as which type of
macromolecule their food is, the location and process of cell respiration, and any
other important cellular processes such as cell membrane passage that may be
involved with their specific food.
Differentiated Instruction
In the above activity, students are asked to brainstorm a food, research the
process, and then create a story representing the steps. Teachers could
support struggling learners by providing students with 3 different examples
of a food turning into ATP. Students would analyze the process and then
create their own story representing the example. This would promote
students to have to understand the material and reteach it through
storytelling to their partner.
Group Activity: Cellular Respiration Lab
Before you begin this activity, be sure to go over the process of cellular respiration with
your students. Where does it occur? What does it require? And what are its byproducts?
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Be sure to put the equation of cellular respiration up for students to look at before
this experiment:
C6H12O6 + O2 → 6CO2 + 6H2O + energy
Next, talk about yeast. What is yeast? Students may need to be reminded that yeast
is a cellular organism, and, therefore, undergoes cellular respiration.
Provide students with a test tube, balloon, yeast, warm water, sugar, and a
measuring tape. Students will then mix the yeast, water, and sugar in the test tube,
and empty the contents into the balloon. Have students measure their balloon’s
circumference before placing the balloons in a warm place. Throughout the class
period, have your students periodically check and measure their balloons.
Discuss what they are observing.
More detailed instructions for this activity can be found through the Science
Outreach program of the University of Florida: http://saacs.chem.ufl.edu/outreach/
Blow%20Up%20a%20Balloon%20with%20Cellular%20Respiration.pdf
Additional Discussion Questions
Ask students to develop a diagram that illustrates a comparison of the cellular sites
for the processes of anaerobic and aerobic respiration.
The diagram should illustrate that anaerobic respiration occurs in the cytosol, whereas aerobic
respiration occurs in the mitochondria. During anaerobic respiration, glucose molecules are
broken down into pyruvic acid molecules. Aerobic respiration, the second phase, transfers
energy to more ATP molecules in the presence of oxygen. The final products of glucose
oxidation are carbon dioxide, water, and energy.
Ask students to create a poster for the class that illustrates the actions of
mitochondria in utilizing ATP and recycling ADP.
Demonstrations will vary, but should include a discussion of how ATP and its 3 phosphate
groups release energy during cellular respiration. The terminal phosphate group detaches,
releasing energy stored in its bonds. By losing the terminal phosphate group, ATP now
becomes ADP. ADP can reconvert into ATP by capturing another phosphate group and
some energy.
Practice
Practice Questions
1. Define energy.
Energy is the capacity to change something; the ability to do work.
2.Explain how oxidation inside cells differs from burning in the outside
environment.
Burning is an example of an intervention that can break the bonds of chemicals in the
external environment (outside the body) by applying heat. Cells “burn” glucose
molecules, breaking their chemical bonds to supply the energy necessary for metabolism
to occur in a process called oxidation. Oxidation produces heat.
3. What is the general function of ATP in metabolism?
The cell uses ATP for many functions, including active transport and synthesis of various
compounds (anabolism).
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4. Describe what happens during glycolysis.
Glycolysis is the first series of reactions that take place during the process of cellular
respiration. The reactions take a molecule of glucose (6 carbons) and break it into 2
molecules of pyruvic acid (3 carbons each). This happens in the cytosol and does not
require oxygen; an anaerobic process.
5. What is the function of oxygen in cellular respiration?
When oxygen is present, the chemical reactions that started with glycolysis in the cytosol
can progress into the mitochondria. In the mitochondria, a region known as the electron
transport chain exists and oxygen acts as the final acceptor of electrons at the end of
the electron transport chain.
6. What are the final products of cellular respiration?
The complete oxidation of a single glucose molecule yields a maximum of 32 ATP
molecules. Glycolysis generates 2 ATP, the citric acid cycle generates 2 ATP, and the
electron transport chain generates 28 ATP molecules.
Use the Practice 4.4
Using Mathematics Calculate how many molecules of ATP a cell can yield in
five minutes. Assume that the cell is capable of aerobic respiration, is
operating at maximum efficiency, that each cycle of aerobic respiration takes
one second, that a cell has 200 mitochondria, and that each mitochondrion can
do 30 cycles simultaneously.
5 minutes = 300 seconds
38 ATP per cycle x 30 cycles per second x 300 seconds x 200 mitochondria =
68,400,000 molecules of ATP
Figure Questions
Figure 4.10, p. 116: Where in a cell does glycolysis occur?
In the cytosol
Section 4.5: DNA
(Deoxyribonucleic Acid)
Learn
Classroom Activities
EL Strategy: Listening and Speaking
Intermediate Working in partner groups, assign students two paragraphs.
The students will slowly read aloud each paragraph. The students will write the
important idea in the left column of their Table Notes and write a phrase or
short sentence restating what they heard about the ideas in the right column.
They will then switch roles for the second paragraph. The students can then
switch partners and explain their paragraphs to the next person until all
students have a complete understanding of the section.
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Writing Connection: DNA Replication Gone Wrong
Pair students into small groups. Each group should explain the process of DNA
replication using bulleted steps. Once each group has their steps written down, ask
each group to now go in and make a purposeful error in one of the steps. The
purpose of the activity will be for each group to explore the other group’s DNA
replication explanation and identify and correct the hidden error. Rotate the groups
through each station so they can identify the error hidden in the steps. Once the
error is identified, the group should write the correction on their own record
keeping sheet to turn into the teacher.
Differentiated Instruction
Students may still complete this activity but as individuals. Instead of having
groups rotate through together to identify the hidden error to correct, the
teacher can create a worksheet of the different DNA Replication explanations
for each individual to complete. Students may then complete it outside of class
and using external resources. Allow ESL students to provide the correction of
the hidden error in their own language and underline science cognate words.
Other students may choose to draw or insert an image to use in their
explanation to better help them understand the correct explanation.
Additional Discussion Questions
How can the sequence of DNA be used to identify a particular person?
It is a well-known fact that each individual has a unique set of fingerprints that distinguishes
him from anyone else. Similarly, the sequencing of cellular DNA is unique in each individual
and can be used as a means of identification. Thus, DNA fingerprinting, as well as traditional
fingerprinting, is very useful in the field of forensic medicine.
Ask students to prepare a chart that compares DNA and RNA molecules in a variety
of criteria.
Charts may contain comparisons of these two molecules based on main location, the fivecarbon sugar present, basic molecular structure, the included organic bases, and each
molecule’s major functions.
Ask students to develop a poster that illustrates the human genome project. Discuss
their findings in the classroom.
The human genome project is a survey of the sites of action of known genes. Gene
identification continues to provide information about a plethora of pathological conditions,
and is an excellent topic to initiate classroom discussion.
Students may tend to confuse the processes of transcription and translation. Ask them
to develop a chart for the class that compares these two facets of protein synthesis.
A comparison is summarized in Table 4.1 of the textbook.
Practice
Practice Questions
1. Distinguish between gene and genome.
A complete set of genetic instructions for an individual constitutes the genome, while
segments of the genome that encode proteins are called genes.
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2. Why must DNA molecules replicate?
When a cell divides, each newly formed cell must have a copy of the original cell’s
genetic information (DNA) so it will be able to synthesize the proteins to build cellular
parts and metabolize.
3. List the steps of DNA replication.
As replication begins, hydrogen bonds between complementary base pairs in each DNA
molecule break. The double helix unwinds and the two strands pull apart, exposing the
nitrogenous bases. DNA polymerase then brings in new DNA nucleotides, which form
complementary pairs with the exposed bases on the separated strand. Enzymes then knit
together the sugar-phosphate backbone, creating a new strand of complementary
nucleotides along each of the old strands. The end product is two complete DNA
molecules, each with one old strand and one new strand.
Use the Practices 4.5
Arguing from Evidence Explain why the idea of “the” human genome or “the”
exome is not realistic.
Answers will vary but students might describe that while only 1.5% of the genome
encodes proteins, much of the rest of the genome is involved in controlling and activating
protein-coding genes.
Section 4.6: Protein Synthesis
Learn
Classroom Activities
Group Activity: Protein Synthesis Around the World
This is a whole group activity. Ask each student in the class to write down two
questions on an index card to test their classmates over the process of translation,
RNA vs DNA, or complimentary base pairing. The two questions must be from
different topics to get a wide variety of questions. Once students have each wrote
down the two questions on individual note cards, the teacher collects the notecards
and shuffles them up. Start in the first row. The first student stands up next to the
next student sitting in the row. The teacher pulls the top index card and reads the
question. The first student between the two that answers correctly will get to move
to the next student. The goal is for a student to make it all around the classroom and
back to their original seat. If the standing student misses the question, meaning the
sitting student got it correct first, the siting student will now stand and move on
while the student who was incorrect replaces the sitting student and waits for the
round to come back again. Continue the game until a student as traveled all around
the classroom and back to their original seat.
Differentiated Instruction
This activity could also be played through a free virtual website where
students could collaborate and play with less confrontation and every student
would get to participate on each question. The game would keep a running
score of all participants correct and incorrect responses. One such resource
would be Kahoot.
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Additional Discussion Questions
Ask students to create a chart that illustrates the steps of protein synthesis.
The chart should include the processes of transcription and translation.
Ask students to lead a discussion regarding mutations.
Responses may include a discussion of inherited illnesses, mutagens, cancers, genetic
testing, etc.
Practice
Practice Questions
1. Define genetic code.
Cells can synthesize specific proteins because of the sequence of nucleotide bases in the
DNA of genes specifies a particular sequence of amino acid building blocks. The
correspondence of gene and protein building block sequence is called the genetic code.
2. What is the function of DNA?
The function of DNA is to provide the instructions for the synthesis of proteins, which in
turn help make life possible.
3. How is genetic information carried from the nucleus to the cytoplasm?
DNA molecules stay in the nucleus of a cell. The genetic information reaches the
cytoplasm by being copied into molecules of ribonucleic acid (RNA) in a process called
transcription. RNA can exit the nucleus because it is much shorter than DNA and is
single-stranded. A specific type of RNA, messenger RNA (mRNA) is responsible for
carrying the genetic code out of the nucleus to the ribosomes in the cytoplasm.
4. List the steps of protein synthesis.
A molecule of mRNA leaves the nucleus with the genetic code instructions for protein
synthesis and associates with the ribosomes in the cytoplasm. The mRNA is then
“translated” from the language of nucleic acids to the language of amino acids,
determined by the codon sequences found on the mRNA. Translation begins with the
mRNA binding the ribosome in a specific location, the start point. A molecule called
transfer RNA (tRNA) brings the first amino acid, which is complementary (called the
anticodon), to the first codon of the mRNA chain and forms hydrogen bonds with the
first mRNA codon. A second tRNA then binds to the next codon, bringing its amino acid
to an adjacent site on the ribosome. Then a peptide bond forms between the two amino
acids, beginning a chain. The first tRNA molecule is released from its amino acid and
recycled. The steps repeat to elongate the peptide chain until a specific region, the stop
point, is reached.
Use the Practices 4.6
Using Models What is the sequence of the peptide that the following DNA
sequence encodes:
TAC TGA TCG ACC CCC
MET THR SER TRY GLY
Figure Questions
Figure 4.14, p. 124: What is the name of the molecule that carries DNA information so
that it can be translated into protein?
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Assess
Career Corner: Personal Trainer
Consider This: If you have an interest in helping people become and remain
physically fit, you might consider a career in either personal training or physical
therapy. Research the differences and similarities between these careers.
Answers will vary. Students should address differences in certification and education, as
well as the different goals of most personal training vs. physical therapy patients.
Genetic Engineering: Exome Sequencing
1. Compare and contrast a person’s genome and exome.
A person’s genome is all of their DNA. A person’s exome is the part of their genome that
codes for proteins.
2.What are “unsolicited” findings? What sort of ethical concerns exist around
unsolicited findings?
Unsolicited findings are secondary or incidental discoveries found during exome
sequencing which are unrelated to the patient’s symptoms. Ethical considerations exist
around unsolicited findings as these findings may have health implications.
Genetic Engineering: Mutations
1. What are recessive mutations? What are dominant mutations?
Recessive mutations must be present in both copies of an affected gene to cause symptoms.
A dominant mutation only needs to occur in one copy of a gene to have an impact.
2.Describe how a mutation in a cell’s DNA would lead to that cell producing an
incorrect protein.
If the mutation occurred in a particular codon, it could signal for a different mRNA
sequence, which in turn could lead to a different amino acid being placed in sequence.
This could result in a different protein being produced than the one intended.
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Case Study Connection
p. 111: Is arsenic an inhibitor of anabolism or catabolism?
Catabolism
p. 113: Arsenic prevents an enzyme from working in a reaction that transforms
pyruvic acid into acetyl coenzyme A. If the second victim died of arsenic
poisoning, would you expect to find more pyruvic acid or more acetyl
coenzyme A in the second victim’s cells compared to a healthy human cell?
If arsenic prevents the formation of acetyl coenzyme A, someone who died from
arsenic poisoning should have more pyruvic acid.
p. 114: Recall the two cases facing the coroner in the Chapter Opener. Will there
be any substantial difference in the amount of ATP in the cells of the two victims?
Students may use several reasons to explain the differences between victims, accept
all reasonable response. Example: if a drowning victim was deprived of oxygen, they
would be unable to complete aerobic respiration and thus produce less ATP.
p. 117: If arsenic prevents acetyl coenzyme A formation, what happens to the
rate of cellular respiration in the cells? What would happen to the amount of
lactic acid? Where will cellular respiration be arrested in victim one (oxygen
deprivation due to drowning) and victim two (arsenic poisoning)?
Decreases; increases. Cellular respiration in victim one will stop at the beginning
of aerobic respiration because of lack of oxygen and in victim two will stop in the
citric acid cycle because production of Acetyl CoA will be inhibited.
p. 120: In the same town there have been many still living patients of arsenic
poisoning showing up at the local hospital. Upon arrival they describe being
incredibly thirsty. As we have been learning, arsenic poisoning arrests
metabolism early, what effect will it have on hydration?
Arsenic poisoning arrests metabolism meaning less water is produced as a
byproduct. This increases the need for the body to obtain water from drinking.
p. 123: Protein synthesis requires energy. What affect would arsenic
poisoning have on protein synthesis, if any?
If arsenic poisoning reduces metabolic production, meaning lessening ATP
availability, it will also reduce the ability for cells to synthesize proteins.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which of the following words would best complete the
following statement? Metabolism is the combined chemical
reactions of anabolism and catabolism that use or release
a. water.
b. energy.
c. carbohydrates.
d. enzymes.
2. Which of the following statements is not an example of
dehydration synthesis?
a. One molecule of glucose and one molecule of fructose are
joined to form a sucrose, a disaccharide, and water.
b. Two molecules of glucose are joined to form the
disaccharide maltose and water.
c. The combining of amino acids through the formation of
peptide bonds and water into polypeptides.
d. Water splitting adenosine triphosphate into adenosine
diphosphate and a phosphate group.
3. Which of the following statements is false?
a. Coenzymes are non-protein organic molecules required
for the activity of a particular enzyme.
b. Cofactors are small molecules or ions that must combine
with an enzyme for the enzyme to be active.
c. All cofactors are coenzymes, but not all coenzymes are
cofactors.
d. All coenzymes are cofactors, but not all cofactors are
coenzymes.
4. Individuals with Tay-Sachs disease are typically deficient in
functioning Hexosaminidase-A, which results in a buildup of
Ganglioside GM2 in the brain, causing neurological
deterioration. Ganglioside GM2 is most likely which part of a
metabolic pathway in nerve cells?
a. substrate 1
b. substrate 2
c. enzyme
d. catalyst
5. Using the terms hydrolysis and glycolysis as guides, which of
the following is most likely the meaning of the suffix -lysis?
a. breakdown, decompose
b. of or related to water
c. of or related to sugars
d. make, combine, compose
6. The increased surface area created by the folds of the
cristae within the mitochondria most likely
a. increase the rate of glycolysis.
b. increase electron transport chain production.
c. decrease the rate of glycolysis
d. decrease electron transport chain production.
7. ____________ sequencing is currently more cost-effective than
whole-genome sequencing because it only deals with the
genes that code for proteins, about 1.5% of the human
genome.
a. Chromosomal
b. Exome
c. Nitrogenous base
d. Replication
8. Which of the following anticodons is associated with the
tRNA holding the amino acid methionine?
a. TAC
b. UGU
c. UAC
d. ACA
Short Answer
1. What are enzymes?
Enzymes are proteins that help chemical reaction occur fast
enough to sustain the life of cells. They are called “biological
catalysts” and work by reducing the energy needed for a
reaction to occur.
2. What is a substrate? What is an active site?
The substrate is the chemical that an enzyme acts upon. The
active site is the part of the enzyme that physically interacts
with the substrate molecule.
3. Define metabolic pathway.
A metabolic pathway is a series of chemical reactions where
each product is needed for the next reaction in the pathway.
4. Define and describe a gene.
A gene is region of DNA on chromosome that codes for the
production of a protein.
5. Describe the structure of DNA.
DNA is composed of two strands of nucleotides held together
by. It is often referred to as a “double helix.” The backbone of
each strand is an alternating pattern of phosphate groups and
the 5-carbon ribose sugars. The inside of the strands contain
bases. The strands are held together by way of hydrogen
bonds between the bases. A and T will bond together, and C
and G will bond together.
6. What is a codon?
A codon, also called a triplet, is a series of 3 bases on a mRNA
molecule. Each codon codes for a specific amino acid during
protein synthesis
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7. Distinguish between transcription and translation.
Transcription is the first step in gene expression. The DNA,
which cannot leave the nucleus is used as template to
create mRNA. mRNA leaves the nucleus to take the
instructions into the cell. Translation is when the codons on
mRNA are used to code for the amino acids during protein
synthesis.
8. What is a co-enzyme?
A co-enzyme is a co-factor that aids in the function of an
enzyme. Often they are called vitamins.
9. Distinguish between anabolic and catabolic reactions.
Anabolic reactions unite small molecules to synthesize bigger
molecules. These reactions require an input of energy. Building
proteins from amino acids is an example of anabolic reaction.
Catabolic reactions break apart large molecules into smaller
molecules. These reactions release energy. Breaking glucose
into carbon dioxide and water during cellular respiration is an
example of a catabolic reaction.
10. Outline the process of glycolysis.
Glycolysis means “the breaking down of glucose”. It is the first
reaction in the process of cellular respiration, where glucose is
broken into the 3-carbon compound pyruvic acid.
11. Explain the differences between a genome and an exome.
A genome is the complete set of genetic instructions for an
organism. The small portion of the genome that actually codes
for proteins is called the exome.
12. Describe the relationship between adenine, thymine,
guanine, cytosine, and uracil.
These are the 5 bases found in the nucleic acids DNA and RNA.
A, T, C, and G are found in DNA. In a DNA molecule A and T are
paired and C and G are paired. RNA contains A, U, C, and G.
When using DNA as template to build RNA, U is paired with A.
13. Distinguish between aerobic and anaerobic.
Aerobic means in the presence of oxygen. Anaerobic means
without oxygen. The terms are used to describe metabolic
reactions.
Critical Thinking and Clinical Application
1. WRITING Connection It was once thought that “one gene
coded for one trait.” Discuss the evidence that proves this
wrong.
We now realize that one gene codes for a protein or a
polypeptide chain. Sometimes that translates to a physical
observable trait, but most often it does not.
2. CLINICAL Connection The drug methotrexate is used to
treat cancer and other diseases. It inhibits an enzyme needed
for folic acid production. Folic acid is necessary for nucleotide
production. What is the end result of the use of this drug?
Nucleotides are needed to build DNA. Without them a cell
cannot produce new DNA molecules and therefore cannot
engage in mitosis.
3. How can the same biochemical be both a reactant (a starting
material) and a product?
If a chemical is involved in a biochemical cycle, like the citric
acid cycle, it can be a reactant and also a product. This is
common in metabolic processes throughout the body, because
it allows materials to be continually reused.
4. After finishing a grueling marathon, a runner exclaims,
“Whew, I think I used up all my ATP!” Could this be possible?
No, this is never possible. Metabolic processes are continually
working to produce ATP through both aerobic and anaerobic
mechanisms. Fatigue can result due to a buildup of metabolic
waste products from ATP production, such as lactic acid or
hydrogen ions.
Lab Data Analysis: Measuring Enzyme Concentrations to Detect Heart Attacks
Think Critically
1. Describe the trend you see in the graph.
The cardiac troponin readings are all above the dashed line,
indicating a positive reading for myocardial cell damage. The
trend line shows a clear increasing slope over the first 24
hours, peaking near the final reading and then slowly trending
downward. This demonstrates that the level of the cardiac
troponin enzyme measurably increased in the patient’s blood
over 24 hours from onset of chest pain and then slowly
decreased over the next 2 days.
2. Why do you think the patient’s cTn level continues to
increase over the course of 24 hours, despite the patient
being treated immediately the ER?
If this patient arrived at the hospital with chest pain and one
positive cTn reading (the first red ring on the graph), they
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would be treated to restore normal blood flow to the heart
cells immediately. Nevertheless, damage has already been
done to a significant portion of cardiac myocytes. Those
damaged cells continue to break down over the first 24 hours,
releasing more and cTn into the bloodstream. Eventually all
the cTn from dead cells is released and the levels trend back
down toward normal.
3. If the patient’s chest pain was not the result of a heart attack,
what would you expect the cTn readings to show?
If the cause of the patient’s chest pain was non-cardiac in
origin (such as acid reflux), it is likely that the cTn levels in the
patient’s blood would remain low; i.e., the three red rings on
this graph would all fall below the dotted threshold line.
Additionally, sequential readings would not demonstrate such
a steep upward slope over the first 24 hours. Instead, they
would remain in a relatively straight line.
CHAPTER
5
Tissues
Section
Pacing
(class periods)
Learning Objectives
5.1Introduction
—
1.List the four major tissue types, and
indicate a function of each type.
5.2Epithelial Tissues
1
1.Describe the general characteristics
and functions of epithelial tissue.
2.Name the types of epithelium and
identify an organ in which each is
found.
3.Explain how glands are classified.
5.3Connective Tissues
1
1.Compare and contrast the ground
substance, cells, and fibers in different
types of connective tissue.
2.Describe the major functions of each
type of connective tissue.
3.Identify where each type of connective
tissue is found.
5.4Types of Membranes
2
1.Distinguish among the four major types
of membranes.
5.5Muscle Tissues
1
1.Distinguish among the three types of
muscle tissues.
5.6Nervous Tissues
1
1.Describe the general characteristics
and functions of nervous tissue.
Focus Activity Workbook
Focus Activities: Labeling (11)
Focus Activities: Vocabulary (5)
Chapter Resources
Extended Summary Review
Chapter 5 Test Bank
Chapter 5 Interactive Question Bank
Vocabulary Flashcards
APR Module 3: Tissues
Laboratory Exercise 6: Muscle and Nervous Tissue
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A Suggested Approach
An understanding of histology is important for anatomy and physiology. Being able to
compare and distinguish between normal and abnormal tissue samples is necessary
for the diagnosis of many diseases. Additionally, discerning the four major types of
tissue enables students to predict and understand organ behavior and function.
The first step in recognizing tissues is being able to identify normal histology
images. Either using posters, microscope slides, or internet-based images, students
should be exposed to normal histological images.
The majority of the names of the tissues are Latin roots that offer description. For
example, the epithelial tissues are classified according to the cell shape and cell
layer. Instructing students in the Latin roots of these terms will assist their
understanding of the various types of tissues. Additionally, if Latin roots are not
used in the name, typically tissues are names after a distinguishing characteristic or
function. For example, the distinction between the types of muscle is easily related
to their function.
Of course individual tissues rarely exist within in our body systems, rather it is a
combination of tissues. An example is that membranes are both epithelial and
connective. Guide students in a discussion of why both types of tissues are required
for the function of membranes. Further discuss other body systems or organs where
students could identify the types of tissue based on function.
This chapter is expected to take 6 class periods including Lab 6.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy used
to teach students how to construct explanations and craft scientific arguments.
A scientific claim answers a question or offers a solution to a problem. Give
students time to reflect and brainstorm, then have each student take a clear
stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is
information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support a
claim. Encourage students to return to their claims and add evidence at multiple
points in the chapter.
Additional information can be found in this article from Stanford: https://news.
stanford.edu/news/2004/august18/med-acupuncture-818.html
A possible extension activity: refer back to this case study throughout the
curriculum. For example, acupuncture is thought to promote local blood flow
through vasodilation, when studying the circulatory system, bring the
conversation back to acupuncture and investigate how that might work. During
the skeletal system, bring up acupuncture and ask the students if fibroblast
activation impact bone density. During the nervous system, investigate how
acupuncture may play a role in reducing pain.
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Introduction to the Theme
Theme: Patterns Cells in the human body are organized into tissues, which
exhibit distinct patterns. These patterns dictate the function of the tissues.
Theme Activity: Human Tissue Types
For this activity, students will relate properties of common items to the properties
and functions of tissue types.
Break students into small groups. Give each group a bag containing plastic blocks,
rubber bands, a sponge, a small radio Have the students determine how the
properties of each item are similar to the properties and functions of different
tissues. Note: students may determine that some items have properties that can be
classified as more than one tissue type; this is acceptable as long as they validate
their reasoning.
Section 5.1: Introduction
Learn
Classroom Activities
Section 5.1 sets the groundwork for activities in sections 5.2 and beyond.
Additional Discussion Questions
Ask students to develop a chart that summarizes information regarding the four
major types of tissue.
The chart should include information for epithelial tissue, connective tissue, muscle tissue, and
nervous tissue. Each tissue type can be summarized by locations within the body, the major
functions, and any distinguishing characteristics.
Provide microscope slides of various kinds of tissues. Ask students to ascertain
whether the sample is epithelial, connective, muscle, or nervous tissue based on
their knowledge of any distinguishing structural characteristics.
Samples will vary.
Practice
Practice Questions
1. What is a tissue?
Cells that are organized into groups composed of similar cells with a common function
are called tissues.
2. List the four major types of tissues.
The tissues of the human body are of four major types: epithelial, connective, muscle, and
nervous.
Use the Practice 5.1
Using Models Create a graphic organizer to differentiate among the four
major types of tissue: epithelial, connective, muscle, and nervous.
Answers will vary. Students might create a table, diagram, or outline.
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Section 5.2: Epithelial Tissues
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct students to write a paragraph describing the different
types of tissues. They should use the pictures in sections 5.2, 5.3, 5.5, 5.6 and
describe all parts of the tissue in their own words. Students may choose to
explain the functions, characteristics, and locations of the tissues. Ask for
volunteers to read their paragraphs.
Writing Connection: Flashcard Activity
Students should work in groups of three if possible. Provide students with a set of
large index cards or paper to make flashcards to study the different types of
epithelial tissue. Each student will be assigned a role. One student will be
responsible for drawing or inserting an image of a section of tissue onto the front of
the card. Another student will be responsible for writing the name and location of
the tissue on the back of the card. Another student will list the functions of the
tissue on the back of the card. Once students work as a team to complete all eight
variations of epithelial tissue identified in Table 5.2, they should quiz each other.
Differentiated Instruction
This activity may also be completed as a small group, but each individual would
make their own set of flashcards. The teacher should print out multiple images
of the different types of epithelial tissues as well as multiple copies of the
written functions and locations. Students can work together to tape or glue
the correct components together onto their index cards or papers. Students
may still practice quizzing each other but will now be able to take their own set
of cards home to continue working.
Additional Discussion Questions
Ask students to draw examples of various kinds of epithelia, and classify them based
on cell shape.
Student drawings should include examples of squamous, cuboidal, columnar, simple, and
stratified epithelial tissue.
Ask students to create a chart that depicts an illustration of the major types of
glands, and includes a description of each gland type’s secretion. Give examples of
locations within the human body where each type of gland would be found.
The charts should contain information regarding merocrine glands, apocrine glands, and
holocrine glands.
Develop a set of flash cards that contain the name of one type of epithelial tissue on
each card. Ask students to give examples of locations within the human body where
each type of tissue would be found.
Examples may include: simple squamous - walls of the alveoli in the lungs; simple cuboidal
- walls of the kidney tubules; simple columnar - lining of the digestive tract; pseudostratified
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columnar - lining of the respiratory tract; stratified squamous - outer layer of the skin; stratified
cuboidal - ducts of the salivary glands and sweat glands; stratified columnar - walls of the vas
deferens; transitional - urinary bladder.
Discuss the methods of secretion for merocrine, apocrine, and holocrine glands.
Merocrine glands release secretions without losing cytoplasm. Apocrine glands lose a small
part of their cell bodies during secretion. Holocrine glands release entire cells filled with
secretory products.
Practice
Practice Questions
1. List the general characteristics of epithelial tissue.
Epithelial tissues cover body surfaces and organs, form the inner lining of body cavities,
line hollow organs, and compose glands. They are anchored to connective tissue by a
basement membrane. They lack blood vessels and get nutrients from the connective
tissue via diffusion. Their cells readily divide, are tightly packed, and classified according
to their shape and number of cell layers.
2.Describe the classification of epithelium in terms of cell shape and number of
cell layers.
Epithelial tissues composed of thin, flattened cells are squamous epithelium; those with
cube-shaped cells are cuboidal epithelium; those with elongated cells are columnar
epithelium. Epithelium composed of only a single layer of cells is called simple, whereas
epithelium composed of two or more layers is called stratified.
3. Describe the special functions of each type of epithelium.
Simple squamous: substances can pass easily pass through, forms sites of diffusion or
filtration, like the lungs. Simple cuboidal: covers the ovaries, lines the kidney tubules and
ducts of glands. Simple columnar: can be ciliated or non-ciliated. Ciliated columnar:
propels the egg in the uterine tubes to the uterus. Simple columnar: specialized for
absorption. Pseudostratified columnar: appears stratified, but is not. Pseudostratified
columnar: lines the respiratory system and contains special mucus-secreting cells.
Stratified squamous: relatively thick, like the epidermis. Stratified squamous: accumulates
proteins called keratins that harden. Stratified cuboidal: lines the ducts of mammary
glands. Stratified columnar: the superficial layer is columnar and the basal layers consist
of cuboidal cells. Stratified columnar: found in the urethra. Transitional: specialized to
change in response to increased tension, such as in the urinary bladder. Glandular:
composed of cells specialized to secrete substances into ducts or into body fluids.
4. Distinguish between exocrine glands and endocrine glands.
Endocrine glands that secrete their products into tissue fluid or blood. Exocrine glands
that secrete their products into ducts that open onto surfaces.
5. Explain how exocrine glands are classified.
Merocrine and eccrine glands release fluid by exocytosis. Those that lose small
portions of their glandular cell bodies during secretion are apocrine glands. Holocrine
glands release entire cells that disintegrate to release secretions.
6. Distinguish between serous fluid and mucus.
Serous fluid is watery and slippery. Mucus fluid is thick and contains the glycoprotein mucin.
CHAPTER 5
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Use the Practices 5.2
Communicating Information As you read this section, make a table listing the
names of the different epithelial tissues, their characteristics, and their
locations in the body. What relationships can you see between the structures
and functions of these tissues?
Tissue Type
Characteristics
Location
Simple squamous
Thin, single-layer
Alveoli, capillaries
Simple cuboidal
Single layer of cube-shaped cells
Ovaries, kidney tubules
Simple columnar
Single layer of elongated cells
Uterus, digestive tract
Pseudostratified
columnar
Single layer of varyingly sized cells
Respiratory system
Stratified squamous Thick, many layers of cells
Skin, oral cavity
Stratified cuboidal
Two or three layers of cuboidal
cells
Mammary glands, sweat glands,
salivary glands
Stratified columnar
Columnar cells over multiple layers Urethra, exocrine glands
of cuboidal cells
Transitional
Several layers of irregularly
shaped cells
Urinary bladder, ureters
Glandular
Specialized secretion cells
Digestive, respiratory,
reproductive systems
Figure Questions
Figure 5.8, p. 139: In the micrograph (b), is this section through the urethra a cross
section or a longitudinal section?
Cross section
Section 5.3: Connective Tissues
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct student groups to write a paragraph describing the
different types of tissues (epithelial, connective, muscular, and nervous). They
should use the pictures in sections 5.2, 5.3, 5.5, 5.6 describe all parts of the tissue
in their own words. Students may choose to explain the functions, characteristics,
and locations of the tissues. Ask for volunteers to read their paragraphs.
Writing Connection: Compare & Contrast
Connective tissue is complex in that it contains other cells as well as the extracellular
matrix. Students should write a short compare and contrast composition highlighting
the major differences between connective tissue cellular components and extracellular
matrix. Key vocabulary students should include are listed below. After students finish
writing their compositions, pair students together to peer review each other’s work.
Encourage students to provide feedback including one way the composition supported
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the differences between connective tissue cellular components and extracellular
matrix and one way to improve the composition. Note: This activity could also be
completed with the types of connective tissue: loose, dense, and specialized.
Cellular Components
• Fibroblasts
• Macrophages
• Mast Cells
Extracellular (matrix)
• Collagen fibers
• Elastic fibers
• Reticular fibers
• Ground substance
Differentiated Instruction
Students could be paired together from the beginning and work as a team.
One student could write about the cellular components and the other student
write about the extracellular matrix. This would lighten the workload on the
initial writing portion. Next students would peer review each other’s work to
learn about the component they are peer reviewing. Students should still leave
the same feedback as in the regular activity.
Additional Discussion Questions
Ask students to describe the major types of connective tissue and give examples of
location of each type.
Possible examples include: hyaline cartilage - attaches ribs to sternum; bone - found
throughout the axial and appendicular skeletons; dense fibrous tissue - composes tendons
and ligaments; areolar tissue - composes part of the mucous membranes; adipose tissue located in hips and breasts in the subcutaneous layer; reticular tissue - found in the
spleen; blood - considered to be a connective tissue that is found throughout the
cardiovascular system.
Provide students with microscope slides of various types of connective tissues. Ask
them to comment on any distinguishing characteristics they observe.
Observations will vary. Distinctions can be made when viewing collagenous or elastic fibers.
Also, students will be able to differentiate characteristics among samples of loose fibrous
connective tissue, adipose tissue, ligaments, cartilage, bone, blood, etc.
Ask students to create a chart with the different types of connective tissue and give
examples of location of each.
Student charts will vary.
Why is blood considered to be a connective tissue?
Blood is considered to be a connective tissue because it is actually living cells surrounded by a
nonliving extracellular matrix (plasma).
Discuss the dangers of overexposure while basking in a tanning bed.
Connective tissue may lose its elasticity, thus causing the skin to become stiff and leathery.
The skin may eventually sag and wrinkle.
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Practice
Practice Questions
1. What are the general characteristics of connective tissues?
Connective tissues bind structures, provide support and protection, serve as frameworks,
fill spaces, store fat, produce blood cells, protect against infections, and help repair
tissue damage. Connective tissue cells are further apart than epithelial cells and have
abundant extracellular matrix between them, made of proteins and fluid. Most
connective tissue cells divide.
2. What are the characteristics of collagen and elastin?
Collagen is a protein that is grouped in long, parallel bundles, and is flexible but only
slightly elastic. Collagen has great tensile strength, meaning it resists pulling forces.
Elastin is a spring-like protein that branches and forms complex networks. Elastin is
weaker than collagen, but can be easily stretched and will return to its original shape
and length when the force acting on it is removed.
3. What feature distinguishes adipose tissue from other connective tissues?
Adipose tissue is distinguished from other connective tissues by its ability to store energy
in the form of fat molecules.
4. Explain the difference between loose and dense connective tissue.
Loose connective tissue includes areolar tissue, adipose tissue, and reticular connective
tissue. Areolar tissue forms delicate, thin membranes throughout the body. Adipose
tissue fills in spaces between muscles, surrounds organs, and insulates the skin. Reticular
connective tissues are also thin and form the framework that makes up certain organs.
Dense connective tissues consist of closely-packed, thick, collagen fibers and a fine
network of elastic fibers, with few cells.
5. Describe the general characteristics of cartilage.
Cartilage is a rigid connective tissue. It provides support, frameworks, and attachments;
protects underlying tissues; and forms structural models for many developing bones.
Cartilage extracellular matrix is abundant and largely composed of collagen fibers
embedded in a gel-like ground substance. Cartilage is enclosed in a covering of
connective tissue called a perichondrium. Nutrients diffuse to cartilage from blood
vessels in the perichondrium. Cartilage lacks a direct blood supply and thus healing
takes a long time. Chondrocytes do not divide frequently.
6. Explain why injured bone heals more rapidly than injured cartilage.
Bones have a very rich blood supply, whereas cartilage is dependent on the nutrients it
receives from the limited amount of blood vessels supplying the perichondrium. As a
result, materials can move rapidly between blood vessels and bone cells, allowing for
much more rapid healing than is observed in cartilage.
7. What are the major components of blood?
Blood is composed of formed elements suspended in a fluid extracellular matrix called
blood plasma. The formed elements are red blood cells, white blood cells, and platelets.
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Use the Practice 5.3
Asking Questions Develop a question you could ask about the extracellular
matrix of a sample of connective tissue that would allow you to determine the
source of that sample.
Answers will vary.
Figure Questions
Figure 5.21, p. 149: What is the consistency of the extracellular matrix of blood?
Fluid
Section 5.4: Types of Membranes
Learn
Classroom Activities
Group Activity: Detective Work
Put students in small groups for this activity. Provide each group of students with a
list of clues describing a specific type of membrane used in different parts of the
body. Students must use the clues to identify whether the description is describing
a serous membrane, mucous membrane, or cutaneous membrane and in which body
part. Provide students with an answer key at the end and have them check their
work and discuss the correct answers.
Example clues:
• This type of membrane lines the cavity used to detect different smells and filter
what we breathe.
Answer: The nasal cavity is lined with mucous membranes
• This type of membrane lines an area that houses the organs used in respiration.
Answer: The lungs are in the thorax and are covered by serous membranes.
Differentiated Instruction
Provide clues to students through visual examples instead of a written clue.
Use the figures from the book in Chapter 1-5 to create the visual images. To
challenge students further, each group could develop the clues as part of the
activity and then switch with another group to complete the original activity.
Additional Discussion Questions
Have students write a short report on pleurisy, an inflammation of the parietal
pleura of the lungs.
This report will provide students with an opportunity to learn more about membranes in detail.
The report should include information regarding the characteristics of the disease, common
causes, prognosis, and possible treatment modalities.
Ask students to describe each type of membrane and demonstrate on a wall chart
or overhead transparency examples of the location of each.
Examples may include the peritoneum, pericardium, pleura, walls of hollow organs, walls of
cavities, the skin etc.
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77
Practice
Practice Questions
1. Name the four types of membranes, and explain how they differ.
Epithelial membranes are composed of epithelium and underlying connective tissues. There are
three major types of epithelial membranes: serous, mucous, and cutaneous. Serous membranes
line body cavities that do not open to the outside of the body. Mucous membranes line
cavities and tubes that open to the outside of the body. Cutaneous membrane is another term
for skin. The fourth kind of membrane is a synovial membrane, which lines joints.
Use the Practice 5.4
Arguing from Evidence Membranes are a combination of epithelial and
connective tissues. Explain how both tissue types contribute to the functioning
of serous and mucous membranes.
Membranes are responsible for anchoring, secreting and absorbing. The role of
connective tissue allows membranes to anchor organs, while the epithelial tissue allows
for the absorption and secretion of mucus
Section 5.5: Muscle Tissues
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct student groups to write a paragraph describing the
different types of tissues (epithelial, connective, muscular, and nervous). They
should use the pictures in sections 5.2, 5.3, 5.5, 5.6 describe all parts of the tissue
in their own words. Students may choose to explain the functions, characteristics,
and locations of the tissues. Ask for volunteers to read their paragraphs.
Demonstration Activity: Muscle Mania
As a whole group, give students a few minutes to complete a few body stretches of
their choosing. Basic stretches may include standing up and stretching arms
overhead or touching toes. Remind students to only do a stretch they know is safe
and something they can do in their personal space. Encourage students to think
about which muscles they feel stretching or moving in their body as they stretch.
Put students in small groups and ask them to discuss their observations. Each group
should agree on one type of muscle to research. Provide students access to
research which type of muscle is in the location they choose (such as the back of the
lower leg). Students will identify the type of muscle in the area and add an image of
that type showing its specific features differentiating it from other muscle types.
Differentiated Instruction
Provide students a diagram of a human body displaying the different muscle tissues
throughout the body such as Figure 1.12. Students should view the image and try to
identify which type of muscle they can see. Students can refer to the figures in
chapter 5 to visually see differences between the three types of muscles and what
they may look like on the human body displaying the different muscle tissues.
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Additional Discussion Questions
Ask students to develop a chart that compares the location, function, and
characteristics of the three major types of muscle tissue.
Skeletal muscle - voluntary, striated, long, cylindrical, multinucleate, causes body movements
and changes in facial expression, located throughout body as attachments to bone and skin;
smooth muscle - no striations, uninucleate, spindle-shaped, located in the walls of hollow
internal organs, involuntary; cardiac muscle - found only in the heart, striated, cells are joined
end to end, uninucleate, contains intercalated disks, involuntary, pumps blood through the
heart chambers and into the blood vessels.
Explain the dire consequences of the healing process when part of the heart
muscle dies.
Unfortunately, the dying heart muscle is replaced with scar tissue. Cardiac muscle does not
regenerate.
Practice
Practice Questions
1. List the general characteristics of muscle tissues.
Muscle tissues are able to contract. As they contract, muscle fibers pull at their attached
ends which move body parts. There are three types tissue: skeletal, smooth, and cardiac.
2. Distinguish among skeletal, smooth, and cardiac muscle tissues.
Skeletal muscles typically attach to bones and can be controlled by conscious effort.
Skeletal muscles are striated, meaning they have alternating light and dark crossmarkings on their surface. Skeletal muscle cells also have many nuclei. Smooth muscle
cells do not have striations, and have a single, centrally-located nucleus. Cardiac muscle
is found only in the heart. Like skeletal muscle, it is also striated and like smooth muscle,
it is not under conscious control. Cardiac muscle cells have a single nucleus and are
connected by specialized intercellular junctions called intercalated discs.
Use the Practice 5.5
Communicating Information Make a chart to help your classmates identify
the three types of muscle tissue based on their microscopic structure.
Answers will vary.
Section 5.6: Nervous Tissues
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct student groups to write a paragraph describing the
different types of tissues (epithelial, connective, muscular, and nervous). They
should use the pictures in sections 5.2, 5.3, 5.5, 5.6 describe all parts of the tissue
in their own words. Students may choose to explain the functions, characteristics,
and locations of the tissues. Ask for volunteers to read their paragraphs.
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Writing Connection: Semantic Map Activity
Students can complete this individually or in pairs. Provide students with a list of
keywords about nervous tissue. Students should create a semantic map or a spider
map graphic organizer showing how the different concepts and words relate to
each other. Encourage students to write down brief notes or any quick memory tips
to be able to differentiate between the different key words.
Suggested Key Words:
• Nervous tissue
• Nerves
• Neurons
• Neuroglia
• Blood vessels
• Brain
• Dendrites
• Soma
• Axon
Differentiated Instruction
Students may prefer to practice vocabulary words and key concepts about
nerves in a different format. Students could choose from a variety of formats
such as making flash cards, creating word associations, or creating visual
images for each word. Provide students time to practice with other students in
pairs and to share the study strategy that works best for them.
Group Activity: Mapping Human Tissue
The human body contains four major tissue types that are localized to particular
regions of the human body. This activity allows students to draw and locate the
tissue types are found using life sized maps.
Break students into groups of at least two individuals. Each group will trace the
outline of one individual on a piece of large butcher paper. After they trace the
body, provide four different colored pencils or markers. Have the students use their
textbooks to create a map of where the different tissues are found. Encourage
students to use the tables in the textbook to create keys.
Writing Activity: Divide and Conquer
Break students in groups of six. Have each student pick one of the six sections in
the chapter. Each group member should read the selected section and teach the
group the materials presented in that section of the text.
Additional Discussion Questions
Students sometimes confuse the functions of neurons with those of neuroglial cells.
How are neurons different from neuroglial cells?
Neurons transmit nerve impulses along nerve fibers to other neurons, muscles, or glands.
Neuroglial cells support, insulate, and protect neurons. They also carry out phagocytosis and
help supply nutrients to neurons by connecting them to blood vessels.
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Ask students to create a chart that summarizes the major components of nervous
tissue. Comment on the structure and function of each component.
The chart should include information regarding a neuron, synapse, neurotransmitter, and
neuroglial cells.
Practice
Practice Questions
1. Describe the general characteristics of nervous tissue.
Nervous tissues are found in the brain, spinal cord, and peripheral nerves. The basic cells
are called neurons. Neurons interact closely with other neurons, muscle cells, and glands
to regulate and integrate many body functions. Neurons are unable to divide.
2. Distinguish between neurons and neuroglia.
Neuroglia are nervous cells that are crucial to the normal functioning of neurons. Neuroglia
support and bind the components of nervous tissue, carry on phagocytosis, and help supply
growth factors and nutrients to neurons by connecting them to blood vessels. Neuroglia
also play a role in cell-to-cell communication. Neuroglia, unlike neurons, can divide.
Use the Practice 5.6
Constructing Explanations Describe the structure of the cells that make up
the various types of tissues (muscle, epithelial, connective, nervous) and
explain how their structures relate to their functions.
Answers will vary. Students should identify that muscle cells tend to be long and
threadlike, allowing them to receive nerve impulses and contract. Epithelial cells have
a variety of shapes and characteristics depending on the type. Connective tissue cells
have an extracellular matrix to aid in their role as a support structure. Nervous cells
have extensions called axons to transmit nerve impulses.
Assess
Career Corner: Medical Transcriptionist
Consider This: It’s your first day as a medical transcriptionist working in a
busy office. You receive doctors’ reports full of abbreviations for common
medical conditions. Use your resources to interpret the following
abbreviations: HTN, CHF, DM, CAD, PE, DVT, SBO, HLD.
HTN- hypertension, CHF- congestive heart failure, DM- diabetes mellitus, CAD- coronary
artery disease, PE- pulmonary embolism, DVT- deep vein thrombosis, SBO- small bowel
obstruction, HLD- hyperlipidemia.
Genetic Engineering: The Body’s Glue:
The Extracellular Matrix (ECM)
1.Connective tissue is found in many parts of the body, fulfilling many roles. How
does the variety in the structure of ECM contribute to this versatility?
Connective tissue is found in bone, muscle, and epithelia. The ECM is a network of
proteins, other molecules, and fluids, meaning it can range from quite solid to quite liquid.
This allows connective tissue the flexibility to serve as rigid structures (such as bones) as
well as more compressible structures (fat cells, etc).
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2.Describe how fibrosis can be both a protective and a damaging mechanism in
organs such as the liver.
Limited fibrosis can keep an infectious or damaging agent from spreading if it is
localized and brief. However, if fibrosis continues, it can block the interaction between
organ cells and the blood stream, leading to scarring and loss of function.
Case Study Connection
p. 135: Acupuncture targets connective tissue. To reach connective tissue, will
the needle will pass through any other tissue types?
Yes – epithelial tissue
p. 144: If acupuncture could alter collagen release from fibroblasts, could the
basement membrane change? Could this impact the epithelium that rests on it?
Yes, collagen fibers are thick and relatively inflexible, which could make the
basement membrane more rigid and less elastic.
p. 145: In carcinogenesis, fibroblasts contract, however in acupuncture,
fibroblasts expand. Is it possible that acupuncture may play a role in reducing
the risk of some types of cancer? How would you begin to study that
question?
Answers will vary, accept all well-reasoned responses.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. HPV16, a type of Human papillomavirus, is linked to
oropharyngeal (throat) cancers that have risen in occurrence
over the past few decades, particularly in people under the
age of 55. Which of the following types of tissues are likely
the location for these HPV16-linked cancers?
a. simple cuboidal epithelium
b. stratified cuboidal epithelium
c. stratified squamous epithelium
d. transitional epithelium
2. People with acne can be found to produce more sebum, an
excretion filled with lipids that can coat the hair and skin
surface to provide enhanced barrier properties, than those
without acne. Sebum is released by sebaceous glands also
known as
a. glandular epithelium.
b. merocrine glands.
c. apocrine glands.
d. holocrine glands.
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3. Which of the following does not accurately describe
connective tissues?
a. good blood supply and well-nourished
b. tightly-packed cells form tight barriers
c. abundant extracellular matrix
d. widely distributed throughout the body
4. Cartilage cells that occupy small chambers and lie
completely within the extracellular matrix are
a. mast cells.
b. chondrocytes.
c. osteocytes.
d. platelets.
5. Which of the following best describes the synovial membrane?
a. This membrane forms the inner lining of the capsule of a
freely movable joint.
b. This membrane is an epithelial membrane known as skin.
c. This membrane lines tubes and body cavities that open to
the outside of the body.
d. This membrane lines a cavity without an opening to the
outside of the body.
6. All of the following are examples of membrane tissues except
a. mucous.
b. cutaneous.
c. blood.
d. serous.
7. Which of the following does not accurately describe muscle
tissues?
a. Muscle tissues are made up of fibers in place of cells.
b. Muscle tissues contract by shortening and thickening.
c. Muscle tissues comprise approximately 50% of the body,
by weight.
d. Muscle tissues can be controlled voluntarily and involuntarily.
8. About 200 known proteins are associated with the
intercellular junctions known as intercalated discs. Changes
in these proteins can lead to dysfunction of which associated
muscle tissue?
a. skeletal muscle tissue
b. smooth muscle tissue
c. cardiac muscle tissue
d. intercalated muscle tissue
9. Specialized cells of the nervous system that are able to
divide and, depending on the type, produce myelin, maintain
the ionic environment, provide growth factors and structural
support, and play a role in cell-to-cell communication
a. neurons
b. neuroglia
c. ipsilateral
d. proximal
10. Most of the following cells do not usually divide at all after
differentiating except
a. skeletal cells
b. cardiac muscle cells
c. nerve cells
d. connective tissue cells
only one layer reaches the free surface, it stratified epithelium.
The epidermis of the skin is stratified squamous epithelium.
The tubules in the kidneys are simple cuboidal epithelium.
5. What is a gland? What is the difference between exocrine
and endocrine glands?
A gland produces and secretes products. An endocrine gland
secretes it products (hormones) into the blood stream. An
exocrine gland, such secretes its product directly to the target.
6. Describe the general characteristics of connective tissues.
Connective tissues have at least two distinct cell types that are
separated by an extracellular matrix composed of protein fibers
and a ground substance. Connective tissues are highly
vascularized. Some, such as bone, are quite rigid. Loose
connective tissue and dense connective tissue are more flexible.
7. List and provide examples of the major cell types in
connective tissues.
Fibroblasts, mast cells, and macrophages
8. Describe the structure of compact bone.
Compact bone is organized into osteons (haversian systems),
which are osteocytes in concentric circles around a central
canal which contains blood vessels and nerves. Osteocytes are
fixed in a calcium phosphate matrix and communicate with the
central canals through little canals called canaliculi.
9. What is a membrane? Give an example.
Membranes are made of epithelial tissues fused to an
underlying connective tissue. Serous membranes line cavities
that do not open to the outside if the body.
10. What are the general characteristics of muscle tissue?
Muscle is a specialized tissue that generates a force when it is
stimulated. It constains contractile proteins, actin and myosin.
11. Describe the three types of muscle tissue.
Short Answer
1. Define tissue.
A group of similar cells that share a common function.
2. What are the four major tissue types?
Epithelial, connective, muscle, and nervous.
3. What are the characteristics of epithelial tissue?
Epithelial tissues line cavities and ducts and form glands. They
engage in secretion, absorption, and protection. The cells
attach to a basement membrane and are not vascularized.
4. How are epithelial tissues classified? Give examples.
They are classified based on cell shape and layering. The
shapes are squamous, cuboidal, and columnar. If only one
layer touches the basement membrane and reaches the free
surface, it is simple epithelium. If it has two or more layers and
only one layer is attached to the basement membrane and
Skeletal muscle is associated with bones for voluntary
movement. The cells are multi-nucleate. Cardiac muscle is only
in the heart, it pumps blood through the vessels. Smooth
muscle is in blood vessels and the digestive tract where it
pushes blood and food respectively.
12. Describe the structure of a neuron.
Neuron is a nerve cell. It has a spherical cell body that
appears much like most cells. However, it has extension called
dendrites on one side and an axon on the other.
13. What do muscle cells and neurons have in common?
Muscle cells and neurons both react rapidly to stimulation.
14. What can neurons do that no other cells can do?
Neurons can receive and send a stimulus.
15. What are neuroglial cells?
Neuroglial cells give support and protection to neurons.
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83
Critical Thinking and Clinical Applications
16. WRITING Connection Mitosis and a blood supply are
both needed for tissue repair. Explain how this affects the
rate of repair in epithelial tissue, bone, and cartilage.
Epithelial tissue cells are highly mitotic and bone is highly
vascularized. This allows them to repair much faster than
cartilage that is neither highly mitotic nor vascularized.
17. What would be the effects of replacing the bone in your
femur with fibrocartilage and the fibrocartilage in your
intervertebral discs with bone?
If a femur was made of fibrocartilage it would flexible but not
strong enough to support the weight of the body or allow
walking. If intervertebral discs were made of bone the torso
could not bend over or move easily.
18. CLINICAL Connection Smoking causes the ciliated
epithelium to be replaced with non-ciliated epithelium in the
respiratory tract. What effect will this have on the respiratory
system?
Loss of the cilia in the respiratory tract will reduce and maybe
even completely inhibit the ability to clear away debris and
foreign matter that enters with the inhaled air.
19. Joints such as the elbow, shoulder, and knee contain
considerable amounts of cartilage and dense connective
tissue. How does this composition explain why joint injuries
are often slow to heal?
A direct blood supply is important for quick healing from an
injury. Cartilage lacks a direct blood supply, and so injuries to
cartilage take longer to heal than other tissues.
20. There have been many scientific studies examining the
efficacy of acupuncture. What are the hallmarks of a good
study and how would you apply these to the question of
whether acupuncture is effective?
Answers will vary, but may include: sample size, reproducibility,
controlled variables, citation of other studies, etc.
Lab Data Analysis: The Strength of Human Connective Tissue
Think Critically
1. State, in your own words, what the two lines on the graph
represent.
The solid line represents normal human tissue that is being
assessed. The dashed line represents human tissue that has
been treated to remove collagen-producing cells to assess
whether or not these cells contribute to the tissue’s overall
maximal tensile strain.
2. Can you see a difference in the stress measurements
between the cellular and acellular cartilage? What
conclusions might researchers draw from these results?
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Yes. The cellular cartilage can withstand higher stress
with lower strain. This implies that the presence of
chondrocytes does contribute to the maximal tensile strain
of cartilage.
3. Suppose there were no experimental differences between
native and acellular cartilage. How would this appear
graphically?
Graphically, the two curves would follow the exact same
course, as if one were laid over the other. Their maximal
strain would occur at the exact same point along the
x-axis.
UNIT
Support and
Movement
Chapter
2
Pacing (class periods)
6 Integumentary System
8
7 Skeletal System
12
8 Muscular System
10
Unit 2 Resources
Unit Project Engineer a Healthier World—Engineering in Anatomy and Physiology
nit Project: Engineer a Healthier World—
U
Engineering in Anatomy and Physiology
Project 2: Mending a Broken Heart
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Stem Cells to Treat Diseases” (p. 191), and use this
to start their investigation into regenerative medicine.
A teacher guide for this project can be found online.
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85
CHAPTER
6
Integumentary System
Section
Pacing
(class periods)
Learning Objectives
6.1 Introduction
—
1. Describe what constitutes an organ, and
name the large organ of the integumentary
system.
6.2 Layers of the Skin
2
1. Describe the structure of the layers of the
skin.
2. Summarize the factors that determine skin
color.
6.3 Accessory Structures
of the Skin: Epidermal
Derivatives
2
1. Describe the accessory structures
associated with the skin.
6.4 Skin Function
1
1. List various skin functions and explain how
the skin helps regulate body temperature.
2. Describe wound healing.
Focus Activities Workbook
Focus Activities: Labeling (6)
Focus Activities: Vocabulary (4)
Chapter Resources
Extended Summary Review
Chapter 6 Test Bank
Chapter 6 Interactive Question Bank
Vocabulary Flashcards
APR Module 4: Integumentary System
Laboratory Exercise 7: Integumentary System
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A Suggested Approach
This chapter familiarizes students with the functions, anatomical features, and
accessory organs of the skin.
Emphasize the importance of both skin color and Vitamin D production for our
health with the following videos: TEDEd: Breaking the Illusion of Skin Color and
HHMI BioInteractive: The Biology of Skin Color.
Students can examine how the skin is responsible for maintaining the internal
temperature of the body regardless of the external temperature by observing
thermoregulation. Students can soak their hand and forearm in a bucket of ice water
for approximately 10 minutes and record changes in internal and external
temperatures. Students could also map their sweat glands on their palms using
cornstarch and iodine. These activities with the addition of reviewing the self—
care products and their effectiveness, will assist the students’ understanding of the
importance and functions of the accessory organs.
Lastly, students can investigate the variety of skin diseases and disorders by
researching a disorder that interest them, and writing a short magazine article about
the disease or disorder. Begin by asking students what skin diseases and disorders
they have heard about, and how they learned about them. Encourage students to
review magazine articles as a reference point for their own research and writing.
Have students share their written articles by reading them outloud or publishing
them on an online source such as Issuu or Flipboard.
This lesson is expected to take five class periods including Lab 7.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
For more information on Ozti, show students the following video:
https://www.smithsonianchannel.com/videos/
this-5300-year-old-corpse-was-found-by-accident/36308
This is a wonderful topic to explore the anatomy and physiology of tissues
(which can be preserved, which are more likely to disintegrate) as well as
explore various pathologies.
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87
Introduction to the Theme
Theme: Scale, Proportion, Quantity The level at which the integumentary
system protects the body from the environment is in proportion and quantity of
glands and bacteria which occupy the surface. This system is truly the largest
system in the body.
Theme Activity: The Role of the Integumentary System
The integumentary system is a large and complex system that affects all other
systems of the body. For this activity, students will play a matching game describing
how the integumentary system interacts with these other systems.
Print and cut out the following cards. One set provides the system that the
integumentary system affects and one set is how it interacts.
Shuffle the cards and have students play the matching game with one another.
When they have finished, go through the correct answers.
Vitamin D
Cardiovascular
System
regulate body
temperature
(blood vessels)
Muscular
System
controls body
temperature (shivering)
Lymphatic
System
first line of defense for
the immune system
Nervous System
provides information
about the outside world
Digestive System
stores excess
calories as fat
Urinary System
water and electrolyte
loss are compensated
by kidneys
Endocrine
System
increase skin blood flow
during exercise
Skeletal System
produces
Section 6.1: Introduction
Learn
Classroom Activities
Section 6.1 sets the groundwork for activities in sections 6.2 and beyond.
Additional Discussion Questions
Ask students to develop a chart that illustrates the levels of structural organization
in the human body.
The chart should include atoms, molecules, organelles, cells, tissues, organs, organ systems,
and organisms.
Ask students to discuss why the skin is vitally important to the functioning of all
other organs.
Responses will vary.
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Practice
Practice Questions
1. What constitutes an organ?
Two or more types of tissues structurally connected and performing shared, specialized
functions constitute an organ.
Use the Practices 6.1
Using Mathematics The skin is the largest organ in the body by weight,
making up approximately 16%. Calculate how much the skin of a 150-pound
person contributes to that person’s body weight .
150(0.16) = 24 pounds
Section 6.2: Skin and its Tissues
Learn
Classroom Activities
EL Strategy: Vocabulary Preteaching
Beginning Look at the Aid to Understanding Words at the beginning of the
chapter. Define the vocabulary in English and provide examples. Say the terms
out loud and have students repeat the words. The students should then go on
a “word scavenger hunt”, finding examples of words that use the roots in Aid
to Understanding Words. Students then write the word in their interactive
notebooks and the section where they found the word.
Writing Connection: Skin Cancer Research
Open the activity with a class discussion about skin cancer, and if students have
ever had it or know someone who is affected from skin cancer. Highlight for
students that ultraviolet radiation causes mutations that could cause skin cancer.
Put students into small groups and have them come up with five research questions
about skin cancer they are going to research based on information revealed in the
discussion. Students should write out their questions and where they’re going to go
to look for answers.
Differentiated Instruction
Instead of discussing skin cancers as a class, the teacher could focus the
discussion on careers and different occupations related to studying skin. See
the appendix for a list of common skin disorders. This could lead into different
repairs and types of skin disorders that affect different layers of skin. Students
could work on this research individually or in groups.
Demonstration Activity: Skin Deep Dessert
For this activity, students will try to design a layered dessert that best represents
the different layers of the skin. You may either bring ingredients in for students to
use, create the layered dessert as you lecture, or have students do this activity as
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89
either a take-home project or simply create the recipe. Students must label their
ingredients to correspond to the different layers and components of the skin. Refer
students to Figures 6.1 and 6.2.
Additional Discussion Questions
Ask students to bring in several photographs or pictures depicting a baby, a child,
an adolescent, a person in middle age, and an elder. Discuss these samples based on
comparisons of skin, nails, and hair.
Responses will vary.
What causes freckles?
Freckles are actually areas of the skin containing high concentrations of melanin. Exposure to
sunlight may increase the numbers of these locations.
Ask students to discuss the irony of the statement—Beauty is only skin deep in light
of the information learned by studying this chapter objective.
The statement is ironic in that, technically speaking, the stratum corneum, or outermost layer of
skin, is actually already dead and is waiting to be sloughed off and replaced by other skin cells
approximately once a month.
Explain the difference between a mole and a melanoma.
The common mole is a benign tumor called a nevus. It is sometimes referred to as a melanoma.
The nevus is congenital, but may change shape, size, or color later in life. This benign tumor
can convert into a malignant melanoma, the cancerous form of a mole.
Practice
Practice Questions
1. List the layers of the skin.
The skin includes two distinct layers. The outer layer, called the epidermis, and the inner
layer called the dermis.
2. Name the tissues in the outer and inner layers of the skin.
The epidermis is composed of stratified squamous epithelium. The dermis is composed of
collagen and elastic fibers, smooth muscle tissue, nervous tissue, and blood. The
epidermis is anchored to the dermis by a basement membrane.
3. Name the tissues in the subcutaneous layer beneath the skin.
Beneath the dermis are masses of areolar tissue and adipose tissue that bind the skin to
underlying organs. The collagen and elastic fibers of the subcutaneous layer are
continuous with those of the dermis.
4. What are the functions of the subcutaneous layer?
The adipose tissue of the subcutaneous layer insulates, helping to conserve body heat.
The subcutaneous layer also contains the major blood vessels that supply the skin and
underlying adipose tissue.
5. Explain how the epidermis is formed.
The deepest layer of epidermal cells is called the stratum basale and is nourished by
dermal blood vessels. As the basal cells divide and grow, the older epidermal cells
(keratinocytes) are pushed away from the dermis toward the skin surface. The further the
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cells move away from the dermis toward the skin surface, the poorer their nutrient supply
becomes, and in time they die.
6. Distinguish between the stratum basale and the stratum corneum.
The stratum basale is the deepest layer of the epidermis, close to the dermis and is
nourished by dermal blood vessels. Basal cells divide and grow. The stratum corneum is
the outermost layer of the epidermis. The cells in the stratum corneum are dead and are
continually shed.
7. What is the function of melanin?
Specialized cells in the epidermis called melanocytes produce melanin, a pigment that
provides skin color. The more melanin, the darker the skin. Without the protection of
melanin, UV radiation could cause mutations in the DNA of skin cells and other
damaging effects.
8. Which factors influence skin color?
All people have about the same number of melanocytes in their skin. Differences in skin
color result from differences in the amount of melanin that melanocytes produce and in
the distribution and size of the pigment granules. Skin color is mostly genetically
determined. If genes instruct melanocytes to produce abundant melanin, the skin is dark.
Sunlight and X rays darken existing melanin granules and stimulate production of more
melanin. Blood in the dermal vessels may affect skin color as physiological changes
occur. Diet and disease can also affect skin color.
9. Name and describe the functions of the tissues that make up the dermis.
The dermis binds the epidermis to underlying tissues. It is composed of areolar tissue
along with dense connective tissue that includes tough collagen fibers and elastic fibers
within a gel-like ground substance. Networks of these fibers give the skin toughness and
elasticity. Dermal blood vessels supply nutrients to all skin cells and help regulate body
temperature. Nerve cells are scattered throughout the dermis. Motor cell processes
conduct impulses out from the brain or spinal cord to dermal muscles and glands.
Sensory cell processes conduct impulses away from specialized sensory receptors, such
as touch receptors in the dermis, and into the brain or spinal cord. The dermis also
includes hair follicles, sebaceous glands and sweat glands.
Use the Practice 6.2
Using Models Sam says that a slice of cake is a good model for human skin,
because the epidermis is similar to frosting, while the deep layer of skin is
represented by the cake. Carlos argues that a chocolate chip cookie is a better
model, with the chips representing the accessory organs within the skin. Which
model is a better representation of the human integumentary system?
The model of a cake is a better representation, as the epidermis is the thin top layer of
the skin and the cake represents the larger area of the dermis
Figure Questions
Figure 6.2, page 166: Where is thick skin found on the body?
The palms and soles of the feet
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91
Section 6.3: Accessory Structures of
the Skin: Epidermal Derivatives
Learn
Classroom Activities
Visual Literacy: Structure & Function of Epidermal Derivatives
The body has many epidermal derivatives. This is an individual activity for students
to draw connections between the structure of the epidermal derivative related to
the function. Create a table for students to work from that includes the following
epidermal derivatives: nails, hair follicles, sebaceous gland, sweat gland. Create
a column for each epidermal derivative where they can identify the structure,
function, visual diagram, and one unique way they use to aid in retention of the
concepts. Students can share their completed tables in groups or pairs.
Differentiated Instruction
Provide students with the structure and function on moveable pieces of paper.
Students should align the correct structure and function on the table with the
correct epidermal derivative. Once students complete what they feel is
correct, have them switch with a partner and grade it. In the final steps, they
can work as a team to review and ensure everything is correct. While in pairs,
students can share different ways they study in order to retain the knowledge.
This promotes different learning styles and supporting each other in learning.
Group Activity: Your Skin—A Public Service Announcement
For this activity, students will create a public service announcement to explain a
disease that afflicts the skin and what can be done about it. Students can make either
a short video, a poster, a brochure, or a radio skit to perform to the rest of the class.
The PSA must include a scientific explanation of what the disease is and how it
affects the skin, what causes it, and how it can be prevented or managed. Chapter 6
offers many ideas through the text, including eczema, acne, and skin cancer.
Additional Discussion Questions
Ask students to develop a poster of a cross-section of skin that illustrates the
structure and location of several accessory organs of the skin.
The poster may depict a hair shaft, pore, basement membrane, sebaceous gland, arrector pili
muscle, hair follicle, keratinized cell, merocrine sweat gland, dermal blood vessels, etc.
What causes goose bumps?
If a person is emotionally upset or very cold, nerve impulses may stimulate the arrector pili
muscles to contract, causing this reaction.
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Practice
Practice Questions
1. Describe the structure of the nail bed.
Specialized epithelial cells continuous with the epithelium of the skin produce the nail
bed. The whitish, thickened, half-moon-shaped region at the base of a nail plate is the
most actively growing region. The epithelial cells here divide and become keratinized,
giving rise to tiny, keratinized, scales that become part of the nail plate, pushing it
forward over the nail bed. The nail plate extends beyond the end of the nail bed and
with normal use gradually wears away.
2. Explain how a hair forms.
Each hair develops from a group of stem cells at the base of a tubelike depression called
a hair follicle. These stem cells originate from a region near the bottom of the hair follicle
known as the hair bulge, and migrate downward. The follicle contains the hair root, which
can extend from the surface through the dermis into the subcutaneous layer. The
deepest portion of the hair root is the hair bulb, composed of epithelial cells that are
nourished from dermal blood vessels in a projection of connective tissue called the hair
papilla. As these epithelial cells divide and grow, they push older cells toward the
surface. The cells that move upward and away from their nutrient supply become
keratinized and die. Their remains constitute the structure of a developing hair shaft that
extends outward, away from the skin surface.
3. What is the function of the sebaceous gland?
Sebaceous glands produce globules of oily, fatty material called sebum. Sebum moves
through small ducts into the hair follicles and helps keep the hair and skin soft, pliable,
and waterproof.
4. Distinguish between merocrine sweat glands and apocrine sweat glands.
Merocrine glands are the most numerous and widespread sweat glands. They respond
throughout life to body temperature elevated by environmental heat or exercise. They
also release moisture on the palms and soles during stressful times. Merocrine glands are
found on the forehead, neck, and back as well. Apocrine glands are sweat glands that
become active at puberty and are found in the axilla and groin.
Use the Practice 6.3
Asking Questions Accessory structures of the skin (nails, hair, and glands) are
in the skin of all mammals. Develop a question to investigate the relationship
between the anatomy and physiology of a specific mammalian skin accessory.
Answers will vary. What would be a possible function of a cat’s longer claws? Why do we
refer to a cat’s nails as claws and a dog’s as toe nails?
Figure Questions
Figure 6.4, page 171: What is the most actively growing region of the nail?
The lunula, the whitish half-moon region at the base of the nail.
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Section 6.4: Skin Functions
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct students to write a paragraph describing what is
happening in Figure 6.8. Their paragraphs should describe all parts of the
diagram in their own words. They should describe the healing process and draw
a simple illustration to show understanding. Ask for volunteers to read their
paragraphs. Students can ask the volunteers clarifying questions as needed.
Writing Connection: Connecting to a Case
Explain to students or allow them to discuss what homeostasis is and why it is important.
Encourage discussion among the class about all the different ways skin can be affected
from sun burns to acne. Students may complete this activity in small groups. Provide
each group of students with the following three case studies. For each case study,
students should describe what evidence (symptoms) is presented and decide what type
of skin function is occurring and why. They will make a realistic prediction on what might
have occurred to cause the described issue in each case study.
Case Study A: A young student was unable to detect pressure or changes in
temperature when she touched a hot or cold surface. Which part of the skin
controls this function? Make a realistic prediction on what might have occurred to
cause this issue.
Case Study B: The doctor’s test found a build up of cholecalciferol in a patient’s
body and not enough calcitriol. How do these two substances play a role in
producing active Vitamin D? Make a realistic prediction on what might have
occurred to cause this issue.
Case Study C: A basketball player played three games in one day outside during the
summer. By the third game, the basketball player should have been sweating, but he
was not. What function does skin play in temperature regulation of the body? Make
a realistic prediction on what might have occurred to cause this issue.
Differentiated Instruction
Students may need additional support from the textbook or readings to make
a realistic prediction on what might have occurred to cause the described
issue in each case study. The teacher could invite a guest Dermatologist
speaker into the classroom or via a web seminar to provide guidance to
students. The teacher could assign each group only 1 case study to allow more
time for the guest speaker and group collaboration.
Additional Discussion Questions
What are the signs of and symptoms of heat exhaustion? What treatment would you
recommend?
Heat exhaustion may result in fatigue, dizziness, headache, muscle cramps, nausea, tachycardia,
agitation, intense thirst, profuse sweating, etc. Treatment should include rapid cooling of the
patient, fluid replacement (cool or cold clear liquids), and rest with the legs elevated.
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Discuss circumstances where hypothermia may be intentionally induced.
Hypothermia is sometimes induced during certain surgical procedures. For example, the
surgeon may slow a patient’s heart activity by applying a slushy ice and medications to the
heart so its activity will not interfere with the surgical repair. This procedure is sometimes
followed during repair of a mitral valve prolapse.
How can a bed-ridden patient reduce the probability of skin ulcerations?
Patients can reduce the probability of skin ulcerations by frequently changing positions,
maintaining proper hydration, avoiding contact with rough materials, applying lotion on
sensitive areas, and by using extra padding on bony projections when appropriate.
A patient has acquired a deep skin wound. Describe the phases of healing
for this patient.
Responses should include a discussion of the inflammatory phase and the formation of a blood
clot, the migratory phase and the development of a scab, the proliferation phase and the
growth of epithelium and blood vessels, and the maturation phase in which the scab
disappears and homeostasis is regained.
Practice
Practice Questions
1. List the functions of the skin.
The skin is vital in maintaining homeostasis. As a protective covering, the skin prevents
harmful substances and microorganisms from entering the body. Skin also slows water
loss by diffusion from deeper tissues, houses sensory receptors, and excretes small
amounts of wastes. The skin plays a role in the production of vitamin D.
2. How does the body lose excess heat?
Warmed blood reaches the hypothalamus in the brain, which then signals smooth muscle
in the walls of dermal blood vessels to relax. As these vessels dilate, some of the heat in
the blood is released to lower body temperature. The nervous system stimulates the
merocrine sweat glands to become active and release sweat onto the skin surface. As
this fluid evaporates, it carries heat away from the surface, cooling the skin.
3. Which actions help the body conserve heat?
When body temperature drops below the set point, the brain triggers smooth muscle in
the walls of dermal blood vessels to contract. This decreases the flow of heat-carrying
blood through the skin and helps reduce heat loss. Merocrine sweat glands are
inactivated, decreasing heat loss by evaporation. The nervous system may stimulate
skeletal muscle to contract slightly, releasing heat as a by-product. If this response does
not raise body temperature to normal, the muscles may contract with greater force,
causing shivering and generating more heat.
4. What is the tissue response to inflammation?
Blood vessels in affected tissues dilate and become more permeable, allowing fluids to
leak into the damaged tissues. Inflamed skin may become red, warm, swollen, and painful
to touch. The dilated blood vessels provide the tissues with more nutrients and oxygen,
which aids healing.
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5.Distinguish between the activities necessary to heal a wound in the epidermis
and those necessary to heal a wound in the dermis.
If a break in the skin is shallow, epithelial cells along its margin are stimulated to divide
more rapidly than usual, and the newly formed cells fill the gap. If the injury extends into
the dermis or subcutaneous layer, blood vessels break, and the released blood forms a
clot in the wound. The blood clot and dried tissue fluids form a scab that covers and
protects the underlying tissues. Fibroblasts migrate into the injured region and begin
secreting collagen fibers that bind the edges of the wound.
6. Explain the role of phagocytic cells in wound healing.
As healing continues, blood vessels extend into the area beneath the scab. Phagocytic
cells remove dead cells and other debris. Eventually the damaged cells are replaced,
and the scab sloughs off.
7. Define granulation.
In large, open wounds, healing may be accompanied by formation of small, rounded
masses called granulations that develop in the exposed tissues. A granulation consists of
a new branch of a blood vessel and a cluster of collagen-secreting fibroblasts that the
vessel nourishes.
Use the Practice 6.4
Arguing from Evidence If the skin around a cut is red and slightly swollen, is it
infected? Why or why not?
Part of wound healing is vasodilation, and increase in blood flow. This vasodilation
can lead to both redness in the area as well as slight swelling.
Assess
Career Corner: Massage Therapist
Consider This: Imagine you are a massage therapist talking with a new client.
The client mentions pain and tenderness in his shoulder. What kinds of
questions would you ask to assess whether or not massaging the injury is a
good idea?
Answers will vary, but students should indicate that they would ask questions to indicate
the type of injury and the tissues involved.
Diseases, Diagnosis, & Treatment:
Skin Cancer
1. Describe the role of melanin in the skin.
Melanin absorbs ultraviolet light and protects the skin from damage from UV rays.
2.Explain the characteristics looked for in trying to determine if a mole is a
melanoma.
The “ABCDE” rule provides a checklist for melanoma: A for asymmetry; B for border
(irregular); C for color (more than one); D for diameter (more than 6 millimeters); and E for
evolution or change.
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iseases, Diagnosis, and Treatment:
D
Burns
1.Describe the differences in wound healing between shallow and full-thickness
burns.
Third-degree burns are very serious because the skin provides a crucial barrier against
microorganisms (bacteria, fungi, etc.) that are present everywhere. Patients with thirddegree burns are very likely to develop sepsis, which can be deadly, as a result of
bacteria gaining entry to the bloodstream. To prevent this from occurring, patients with
third-degree burns are kept on special burn units with extremely strict sterilization
procedures.
2. Explain the “rule of nines.”
The rule of nines is used by physicians to subdivide the skin into regions, each accounting
for 9% (or multiples thereof) of the total surface area. This estimation of skin area is used
to plan for skin replacements or substitutes, and for replacing body fluids and
electrolytes to support repairing tissues.
Case Study Connection
age 164: Where are the tattoo pigments located, can you find the location
p
on this skin diagram? Think about the pathway of the tattooist’s needle as it
comes into the skin to deposit the pigment.
The pigment is located in the upper layer of the dermis. Students may recall from
the opening vignette that initially, the ink is injected between the dermis and the
epidermis.
age 165: Would you expect to find any of the tattoo pigment in the
p
subcutaneous layer?
No, the subcutaneous layer lies below the thick dermis and is unlikely to be pierced by
the needle.
age 166: As the tattooist’s needle is inserted, is it likely to cause much
p
bleeding? Why or why not? Will a tattooist require a different length of
needle when tattooing the bottom of a customer’s foot than they would
require when tattooing the skin of the forearm?
Some but not too much bleeding. Most of the blood vessels lie deeper in the dermis.
The skin of the foot is thicker than that of the forearm so it might require a longer
needle.
page 168: Eumelanin and phenomelanin are naturally occurring skin pigments.
Are they found in the same or different locations than the tattoo pigments?
No these pigments are produced by melanocytes in the epidermis.
age 170: The beau’s lines observed on Ozti are due to a temporary halt in
p
nail formation when he was seriously ill. Which part of the nail had stopped
functioning during the illness?
The lunula, or base of the nail plate where growth occurs.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. The largest organ in the body by weight is the
a. liver.
b. skin.
c. large intestine.
d. brain.
2. Which of the following is considered a true layer of skin?
a. epidermis (outer layer)
b. dermis (inner layer)
c. hypodermis (subcutaneous layer)
d. both a and b
3. Which of the following correctly matches skin tones to their
cause?
a. Bluish skin tone can be caused by a liver malfunction.
b. Orange-yellow skin tone can be caused by a diet high in
carrots and sweet potatoes.
c. Pinkish skin tone can be caused by oxygen-rich jaundice in
blood vessels.
d. Yellowish skin tone can be caused by cyanosis.
4. Which of the following statements is false regarding the
pigment melanin?
a. All people have the same number of melanocytes in their
skin.
b. Cytocrine secretion transfers melanin granules into cells
neighboring melanocytes.
c. Melanin protects nuclei from the sun’s UV radiation.
d. Melanocytes lie in the deepest portion of the dermis.
5. What causes some hair to appear gray in color?
a. mixture of pigmented and unpigmented hairs
b. a lack of melanin
c. an abundance of eumelanin
d. an abundance of pheomelanin
6. All of the following are components of sweat except —.
a. water
b. uric acid
c. kerotin
d. urea
9. Which of the following most closely lists the steps to healing
a skin wound in the correct chronological order?
a. fibroblasts produce collagen fibers; scar tissue develops; a
blood clot forms; a scab forms and protects
b. fibroblasts produce collagen fibers; a scab forms and
protects; a blood clot forms; scar tissue develops
c. a blood clot forms; fibroblasts produce collagen fibers; a
scab forms and protects; scar tissue develops
d. a blood clot forms; scar tissue develops; a scab forms and
protects; fibroblasts produce collagen fibers
10. Suturing (stitching) or otherwise closing a large break in the
skin speeds the process of
a. the provision of nutrients and oxygen to the wound
b. the extension of blood vessels into the area beneath the scab
c. the formation of scar tissue
d. collagen fibers binding the edges of the wound.
Short Answer
1. Explain why the skin is considered an organ system.
The skin is also known as the integumentary system because it
is comprised of several types of organs. First, the epidermis
and dermis together are an organ. Other organs include hair,
glands, muscles, and nails.
2. List and describe the functions of the skin.
The skin functions in protection, thermoregulation, the sense of
touch, excretion, and the production of vitamin D.
3. Describe the structure of the epidermis.
The epidermis is a stratified squamous epithelium. The
outermost layers are filled with the hard protective protein
keratin and are no longer alive. They are always shed. They
are replaced by the mitotically active stratum basal layer that
is next to the basement membrane.
4. Describe the structure of the dermis.
The dermis is a sea of loose connective tissue which houses
the blood vessels, hairs, glands, muscles and nerves.
5. Explain the role of melanocytes in the integumentary system.
7. All of the following describe functions of the integumentary
system except
a. Skin helps to increase water loss from deeper tissues.
b. Skin cells produce a vitamin D precursor.
c. Skin helps to regulate body temperature.
d. Skin prevents harmful substances from entering the body.
6. What effects do sunlight and carotene have on skin color?
8. What is the term used for the tissue’s response to stress that
includes pain, warmth, redness, and swelling?
a. Healing
b. Inflammation
c. Homeostasis
d. None of these
7. Describe the subcutaneous layer. Is it part of the skin?
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Melanocytes are the cells in the epidermis that produce the
pigment melanin that is responsible for skin color.
Sunlight activates melanocytes, resulting in the production of
more melanin, which makes skin darker. Carotene is yellow/
pigment found in certain foods. It will cause skin to have an
orange tint.
The subcutaneous layer lies beneath the dermis and is
comprised of collagen fibers, blood vessels, and adipose.
8. Describe the structure and function of a sebaceous gland.
A sebaceous gland is known as an epidermal derivative
because it is made from epithelial tissue. Its oily secretion is
called sebum and functions to keep hair soft and water proof.
9. What are the epidermal derivatives?
The epidermal derivatives are sebaceous glands, hair, sweat
glands, and nails.
10. What is jaundice?
Jaundice is a pathological condition where the skin turns
yellow. It often indicates a liver malfunction.
11. Describe the structure of a hair follicle.
A hair follicle contains the hair bulge which contains stem cells
to make new hair. The follicle also has root with a bulb that
pushes cells outward. The follicle is attached to a muscle and
a nerve.
12. Explain how body heat is produced.
Heat is produced during cellular metabolism, especially in the
skeletal and cardiac muscle cells and in organs such as the
liver. Thus, the more active a person is, the more heat is
produced.
13. How do sweat glands help regulate body temperature?
As heat builds to excess, the nerves sensitive to temperature
change stimulate the eccrine glands to secrete large amounts
of fluid onto the skin. As this fluid evaporates, it carries heat
away from the surface thus cooling the skin.
14. What is the function of the arrector pili muscle?
The arrector pili muscle raises a hair for insulation or when you
are frightened.
15. Describe the structure of a nail. How does the structure of a
nail relate to its function?
A nail has a cuticle where it meets the skin at a region called
the cuticle. The nail plate is the main part of the nail. The
lunula is the “moon-shaped” white region near the cuticle.
16. Distinguish between first, second, and third-degree burns.
A first degree burn only injures the epidermis. A second degree
burn injure the epidermis and some of the dermis. A third
degree burn injure the epidermis, dermis, and the skin organs
such as muscles, hair follicles, and glands.
17. What are the different types of skin cancer? What are their
characteristics?
Cutaneous carcinomas originate from epithelial cells and are
the most common type of skin cancer. They occur mainly in
light skinned people over the age of 40. They grow from hard
scaly skin with red coloration, and can be flat or raised.
Cutaneous melanomas are pigmented with melanin that arise
from melanocytes. They usually have irregular edges and may
feel bumpy.
Critical Thinking and Clinical Applications
1. WRITING Connection Explain why it is painful to pull a
hair out your head, but not when your hair is cut.
The root of a hair has an associated nerve, when it is pulled
out, it is painful. The hair that you see on your head is made of
dead cells with no nerve supply.
2. Acne is caused by a bacterium called P. acnes. What are
some potential treatment options?
Keep skin clean with soap and water is first defense.
Antibiotics can also be used in extreme cases.
3. If someone asked you if those with darker skin might have
more medical problems associated with lack of calcium, what
would be your answer and why?
Yes. Ultraviolet light from the sun is instrumental in activating
vitamin D in the skin. Vitamin D aids in the absorption of
calcium. Dark skin has more melanin which serves as a screen
to block ultraviolet radiation.
4. CLINICAL Connection Which of the following would
result in the more rapid absorption of a drug: a subcutaneous
injection or an intradermal injection? Why?
The skin is protected by a process called keratinization, in
which maturing cells undergo a hardening process and a
protein called keratin, secreted by these cells, forms a
waterproof cover on the skin. This protective layer cannot be
easily penetrated. A subcutaneous injection would go through
the skin and be injected into an area of greater blood supply
to be absorbed more rapidly.
5. As a rule, a superficial partial-thickness burn is more painful
than one involving deeper tissues. How would you explain
this observation?
Free nerve endings are located close to the surface of your
skin and can sense mild changes in heat and pain. Deep burns
actually destroy your nerves, so messages cannot be sent to
the brain to feel pain.
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99
Lab Data Analysis: Wound Healing Rates
Think Critically
1. Which HbA1c category of patients has the fastest wound
healing? The slowest?
The first group along the x-axis (HbA1c <7.0%) has the highest
‘mean change in wound area per day’, or in other words, their
wounds are shrinking the quickest. The third group (HbA1c ≥
8.0%) clearly demonstrates the slowest wound healing rates
among the three groups, with a considerable drop from the
middle range group (HbA1c 7.0-8.0%).
2. Which HbA1c category likely includes patients with severe
diabetes?
The third group along the x-axis (HbA1c ≥ 8.0%) includes the
patients with severe diabetes because they demonstrate the
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slowest wound healing among the three groups. We know that
diabetes slows wound healing, so it follows that the mean
change in wound area per day on the y-axis (aka, how much
the wound is shrinking per day) would be smallest in this
group.
3. Which group of patients would you most want to counsel on
the risks of eventually developing severe diabetes?
The first group along the x-axis is presumably in the normal
range, and the third group already has severe diabetes. So, it
would be most prudent to counsel the patients in the middle
group (HbA1c 7.0-8.0%) on the dangers of not controlling their
blood sugar and the effects that it could eventually have on
their wound healing capabilities if their HbA1c continues to
increase.
CHAPTER
7
Skeletal System
Section
Pacing
(class periods)
Learning Objectives
7.1 Introduction
—
1. List the active tissues found in a bone.
7.2 Bone Structure
½
1. Describe the macroscopic and microscopic
structure of a long bone, and list the
functions of these parts.
7.3 Bone Function
½
1. Discuss the major functions of bones.
7.4 Bone Development,
Growth, and Repair
½
1. Distinguish between intramembranous and
endochondral bones, and explain how such
bones develop and grow.
7.5 Skeletal Organization
2
1. Distinguish between the axial and
appendicular skeletons, and name the major
parts of each.
7.6 Skull
½
1. Locate and identify the bones and the major
features of the bones that compose the skull.
7.7 Vertebral Column
1
1. Locate and identify the bones and the
major features of the bones that compose
the vertebral column.
7.8 Thoracic Cage
½
1. Locate and identify the bones and the
major features of the bones that compose
the thoracic cage.
7.9 Pectoral Girdle
2
1. Locate and identify the bones and the
major features of the bones that compose
the pectoral girdle.
7.10 Upper Limb
½
1. Locate and identify the bones and the
major features of the bones that compose
the upper limb.
7.11 Pelvic Girdle
2
1. Locate and identify the bones and the
major features of the bones that compose
the pelvic girdle.
7.12 Lower Limb
1
1. Locate and identify the bones and the
major features of the bones that compose
the lower limb.
7.13 Joints
2
1. Classify joints according to the type of
tissue binding the bones, describe the
different joint characteristics, and name an
example of each joint type.
2. List six types of synovial joints, and describe
the actions of each.
3. Explain how skeletal muscles produce
movements at joints, and identify several
types of joint movements.
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101
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (12)
Chapter Resources
Extended Summary Review
Chapter 7 Test Bank
Chapter 7 Interactive Question Bank
Vocabulary Flashcards
APR Module 5: Skeletal System
Laboratory Exercise 8: Organization of the Skeleton
Laboratory Exercise 9: Vertebral Column and Thoracic Cage
Laboratory Exercise 10: Pectoral Girdle and Upper Limb
Laboratory Exercise 11: Pelvic Girdle and Lower Limb
A Suggested Approach
The majority of the chapter is focused on the skeletal organization of the major
bones of the skeletal system. Students become familiar with the classification of
joints and the actions of each joint which lead to specific movements.
Because students are used to seeing bones as skeletons at Halloween, or as part of
the food they eat, most do not associate their bones with living tissue. And yet,
bones are a very dynamic organ. Understanding the microscopic structure of bones,
not only allows students to understand bone development and growth, but also
lends to their understanding of bone fractures and bone healing. Since students
have already been introduced to bone tissue in Chapter 5, this chapter gives an
opportunity to further identify the cellular components of bone.
Students will likely know lay terms, such as knee cap for a number of bones in the
human body. If they use these terms, point to the skeleton’s skull and ask what that
bone is called. Students will most likely call it by the anatomically correct term, skull.
Agree that they wouldn’t call it the “head bone” and that similarly there are
anatomically correct terms for every other bone in the body. In addition, remind
students that just as the directional terminology helps health care professionals
communicate, it is important for anyone in the health care field to know the
anatomical names for body parts. Explain that through the study of the skeletal
system they will see how the anatomical terms convey more information than the lay
terminology. It is useful to have a full-size skeleton in order to assist students with
the memorization of the names of the bones. Additionally, there are a variety of
websites that can be used as tutorials for the skeletal system. (GetBodySmart.com)
In addition to the many labs provided in this chapter, it can also be helpful to have
students practice remembering the names of bones by playing a bingo game.
Lastly, the joints of the skeletal system allow the complex movements in response to
the contraction of the skeletal muscle. Demonstrate each of the joint movements by
using only the joint you are referring to. As this can be trickier than you think, you
may want to practice the movements beforehand. Additionally, you may want to
demonstrate the types of joint movements. Students can then describe the bones
involved in certain movements by using the appropriated anatomical language.
This chapter is expected to take 12 class periods including Lab 8, Lab 9, Lab 10, and Lab 11.
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Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
For an extension activity, explore with your students this huge dig that
uncovered over 40,000 skeletons. Think together and have students
generate questions you’d want to ask of these skeletons.
https://www.youtube.com/watch?v=mnQzuA4eOWk
Introduction to the Theme
Theme: Structure and Function Bones support, protect, store, and provide
movement for the body. Each of these functions is based on the specific structure
of bone and its location within the human body.
Theme Activity: Function and Construction
The purpose of this activity is to stress the importance of structure and function
using tools as a metaphor for different types of bones.
For this activity, you will need a series of tools, such as: pliers, hammers, salad tongs,
scissors, tape.
As you bring out each tool, ask the students to state the function of the tool. Then,
ask how the structure of the tool lends itself to its function.
To stress the importance of structure and function, you can further this exercise by
having the students brainstorm a construction project of some sort. Ask the
students to describe the structure of the tool they would need to perform the
project, rather than the name of the tool.
Example: To drive a nail into a piece of wood, I would need an object that has a
heavy end to strike the nail with and a handle for me to hold.
Section 7.1: Introduction
Learn
Classroom Activities
Section 7.1 sets the groundwork for activities in sections 7.2 and beyond.
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103
Additional Discussion Questions
Ask students to examine a variety of human bones.
should note the similarities and differences in structure, and then discuss the unique
relationship between structure and function.
Compare and contrast various microscopic structures of bones.
Supply students with a variety of prepared microscope slides. Assist them in the identification
of spongy bone, compact bone, osteocytes, etc. Reiterate the fact that bones are active, living
organs.
Practice
Practice Questions
1. Name the living tissues in bone.
Bones include active, living tissues: bone tissue, cartilage, dense connective tissue, blood,
and nervous tissue.
Use the Practice 7.1
Constructing Explanations At first glance, bone may appear to be non-living.
Explain why bone is a living tissue.
Bone is a connective tissue that also incorporates other types of tissue such as cartilage,
and blood.
Section 7.2: Bone Structure
Learn
Classroom Activities
Visual Literacy: Bone Matrix
Students may complete this in small groups or individually. The teacher will prepare
a matrix as in the example (see below) about the different kinds of bones. Students
will fill in information about each type of bone, including but not limited to the
structure, size, and location in the human body. Students can keep this matrix as a
reference as they learn about different bones in their body and categorize them.
Example matrix
Type of Bone
Unique Characteristics
Typical size of bone
Location in Body
Long Bone
Short Bone
Flat Bone
Irregular Bone
Differentiated Instruction
Students can still complete the same activity, but instead of building a matrix
and written descriptions, students may choose to create a visual manual where
they insert pictures of or draw the different types of bones and highlight key
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features on their paper. This would promote students to also think about which
format will help them to retain the information and study from later in the
course and science career.
Demonstration Activity: Use Your Noodle!
Provide students with different types of pasta in cups, such as: penne, spaghetti,
elbow noodles, and bowties. As you go through the different types of bones, have
students create the bone type with the pasta. Encourage the students to write the
type of pasta they chose down for the bone type and the function of that bone.
Examples: A lasagna noodle may represent a compact bone, as there are no gaps
and it is tightly packed. Pinwheel pasta may be similar to spongy bone as they have
numerous branches.
Additional Discussion Questions
Provide students with a variety of bones and ask them to identify at least twelve
different bone markings.
Students should be able to identify a condyle, crest, epicondyle, facet, fontanel, foramen, fossa,
fovea, head, meatus, process, sinus, spine, suture, trochanter, tubercle, and tuberosity.
Ask students to prepare a short report on a disease of the skeletal system.
Suggestions for topics include osteoporosis, osteopenia, rickets, osteomalacia, osteomyelitis,
tuberculosis, osteoma, osteogenic sarcoma, osteitis fibrosa cystica, osteoarthritis, and Paget’s
disease.
Practice
Practice Questions
1. Explain how bones are classified by shape.
Bones may be classified according to their shapes: long, short, flat, or irregular. Long
bones have longitudinal axes and expanded ends. Short bones have roughly equal
lengths and widths. Flat bones are platelike structures with broad surfaces. Irregular
bones have a variety of shapes and most are connected to several other bones.
2. List five major parts of a long bone.
The five major parts of a long bone are: the epiphysis, the diaphysis, compact/cortical
bone, spongy/cancellous bone, and the medullary cavity. At each of a long bone is an
expanded portion called an epiphysis, which articulates with another bone. The shaft of
the bone, between the epiphyses, is called the diaphysis. The wall of the diaphysis is
composed of tightly packed tissue called compact/cortical bone. Compact/cortical bone
has a continuous extracellular matrix with no gaps. The epiphyses are composed largely
of spongy/cancellous bone. Spongy/cancellous bone consists of numerous branching
bony plates called trabeculae. Compact/cortical bone in the diaphysis forms a tube with
a hollow chamber called the medullary cavity, which is filled with marrow.
3. How does compact and spongy bone differ in structure?
Compact bone has a continuous extracellular matrix with no gaps and is found in the
diaphysis of long bones. Spongy bone is found in the epiphysis of long bones and
consists of numerous branching bony plates called trabeculae. Spaces between the
trabeculae help reduce bone’s weight.
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105
4. Describe the microscopic structure of compact bone.
In compact bone, osteocytes and layers of extracellular matrix are concentrically
clustered around a central canal, forming a cylinder-shaped unit called an osteon. Many
osteons together make up the substance of compact bone. Each central canal contains
blood vessels and nerve fibers surrounded by loose connective tissue. Central canals are
connected to each other via transverse perforating canals. Perforating canals contain
larger blood vessels and nerves by which the smaller blood vessels and nerves in central
canals communicate with the surface of the bone and the medullary cavity.
Use the Practices 7.2
Analyzing Data Create a chart that could be used to classify bones as long,
short, flat, or irregular.
Answers will vary, look for the following characteristics used as differentiators:
Long bones- long longitudinal axis, expanded ends
Short bones- roughly equal length and width
Flat bones – Broad surfaces
Irregular bones –connected to several other bones
Section 7.3: Bone Function
Learn
Classroom Activities
Writing Connection: Vitamins and Bone Growth
Discuss with students what a daily vitamin is and their proposed medical benefits.
Also discuss daily diets and the types of foods which may be sources of vitamins.
Provide copies of the back label of an age-appropriate vitamin supplement. Put
students into small groups and have them make a list of the different elements in a
single vitamin dose. Students should discuss in their small groups which vitamins are
directly and indirectly related to bone function and structure.
Make sure the vitamin label includes the following elements essential to bones:
calcium, phosphorus, magnesium, sodium, potassium, carbonate ions.
Differentiated Instruction
The teacher could split the class in half and have half of the class complete the
activity above over the elements bones need, the other half of the class could
do the same activity but instead research elements that accidentally get into
our body system that could be harmful to bones. They could research types of
medical issues too much of these elements may cause. After all groups are
complete. Pair a group that researched essential elements with a group that
researched harmful elements to bones together and have them share what
they learned. Elements that may harm bones include: lead, strontium, and
radium.
Additional Discussion Questions
Ask students to create a chart that illustrates the major steps in the development of
an endochondral bone.
Students may use the figure provided in the chapter as a guide.
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A child sustained serious injuries in a recent automobile accident. Injury to the epiphyses
of various bones was discovered. Discuss why these injuries are of special concern.
If an epiphyseal disk is damaged before it ossifies, elongation of the long bone may cease
prematurely, or growth may be uneven.
Practice
Practice Questions
1. Name the major functions of bones.
Bones shape, support, and protect body structures. They also aid body movements,
house tissue that produces blood cells, and store inorganic salts.
2. Distinguish between the functions of red marrow and yellow marrow.
Red marrow functions in the formation of red blood cells, white blood cells, and blood
platelets. Yellow marrow stores fat and is not active in blood cell production. Most the
red marrow is replaced by yellow marrow over time. Yellow marrow can become red
marrow if necessary, and then reverts back to yellow marrow when blood cell production
is no longer deficient.
3. List the substances normally stored in bone tissue.
Bones store calcium, phosphorus, magnesium, sodium, potassium, and carbonate ions.
Use the Practice 7.3
Conducting Investigations Design an experiment to study how hormones
regulate bone calcium deposition.
Answer will vary, accept all that show an understanding of defining variables, setting
controls, and measuring results.
Figure Questions
Figure 7.4, page 191: What three components of a homeostatic mechanism are shown
in this figure?
receptors (detect changes in blood Ca2+ levels), control center (compares changes to set
point), effectors (glands secrete hormones to bring about responses)
Section 7.4: Bone Development,
Growth, and Repair
Learn
Classroom Activities
EL Strategy: Sequencing
Advanced High Using figure 7.6 as visual and contextual support, instruct
collaborative groups to create a pamphlet or poster illustrating the sequence
of events in the development of endochondral bones. The pamphlet or poster
should include information from the text and the graphic. Have students share
their pamphlets or posters with the class.
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Writing Connection: Bone Timeline
Use Figure 7.6 to create separate images of each major stage of bone development.
Put students in groups and provide each group a set of the pictures. Each group
must work to put the pictures in the correct chronological order. Once students
have done this, they should answer the following question about each represented
stage: What developmental features does the bone in this stage have or lack that
led your group to believe where you placed it on the timeline was correct?
Differentiated Instruction
Understanding bone development is important, but also understanding how a
bone repairs itself is also important. The activity above could be completed
with Figure7B (major steps in repair of a fracture). The activity would be the
same as above only with the different images. Some students who may have
broken a bone in the past may relate to this better. Students could be given
the chance to share their personal stories building social and emotional
support for each other.
Additional Discussion Questions
Ask students to develop a chart that compares various types of bone fractures. Ask
them to give an example of each type.
Responses should include a discussion of simple, compound, comminuted, compression,
depressed, impacted, spiral, and greenstick fractures.
Discuss why some people say they would rather break a bone than damage a
ligament or tendon.
Tendons and ligaments do not have an efficient blood supply of their own, resulting in a
healing process that is relatively slow. Bones are a special type of vascularized connective
tissue. This direct blood supply would increase the probability of healing relatively quickly.
Practice
Practice Questions
1. Describe the development of an intramembranous bone.
Intramembranous bones develop in the fetus from membranelike layers of unspecialized,
or relatively undifferentiated, connective tissues at the sites of future bones. Dense
networks of blood vessels are contained within these connective tissues. Some of the
partially differentiated progenitor cells enlarge and further differentiate into boneforming cells called osteoblasts. Osteoblasts deposit bony matrix around themselves,
forming spongy bone tissue. When extracellular matrix surrounds osteoblasts, they are
called osteocytes. Eventually, cells of the membranous tissues that persist outside the
developing bone give rise to the periosteum.
2. Explain how an endochondral bone develops.
Endochondral bones, which make up most of the skeleton, develop in the fetus from
masses of hyaline cartilage shaped like future bony structures. In a long bone, changes
begin in the center of the diaphysis, where the cartilage slowly breaks down and
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disappears. Blood vessels and osteoblasts from the periosteum invade the disintegrating
cartilage, and spongy bone forms in its place. This region of bone formation is called the
primary ossification center, and bone tissue develops from it toward the ends of the
cartilaginous structure. The epiphyses remain cartilaginous and continue to grow. Later,
secondary ossification centers appear in the epiphyses and spongy bone forms in all
directions from them. As spongy bone is deposited in the diaphysis and in the epiphysis,
a band of cartilage called the epiphyseal plate remains between these two ossification
centers. The cartilaginous tissue of the epiphyseal plate includes layers of young cells
that are producing new cells. As these cells enlarge and extracellular matrix forms
around them, the cartilaginous plate thickens, lengthening the bone. Calcium salts are
deposited in the extracellular matrix and as the extracellular matrix calcifies, the
cartilage cells begin to die.
3. Explain how osteoclasts and osteoblasts remodel bone.
Bone-resorbing cells called osteoclasts break down the calcified extracellular matrix.
Osteoclasts secrete an acid that dissolves the inorganic component of the calcified
matrix, and their lysosomal enzymes digest the organic components. After osteoclasts
remove the extracellular matrix, bone-building osteoblasts invade the region and deposit
new bone tissue in place of the calcified cartilage.
4.Explain how nutritional factors, hormones, and physical exercise affect bone
development and growth.
Vitamin D is necessary for absorption of calcium in the small intestine. In the absence of
this vitamin, dietary calcium is poorly absorbed, and the bone matrix will lack calcium,
softening and thereby deforming bones. Growth hormone stimulates division of cartilage
cells in the epiphyseal plates. Sex hormones stimulate ossification of the epiphyseal
plates. Physical exercise pulling on muscular attachments stresses the bones, stimulating
the bone tissue to thicken and strengthen.
Use the Practices 7.4
Arguing from Evidence Osteocytes and osteoblasts are incapable of dividing.
Provide evidence that bones are able to grow and explain how this happens
despite the fact that these cells don’t divide.
Osteoblasts are made from progenitor cells found within the bone. Once the osteoblasts
are trapped in the extracellular matrix they are referred to as osteocytes.
Section 7.5: Skeletal Organization
Learn
Classroom Activities
Group Activity: Pin the Term on the Skeleton
Use Figure 7.8 to create a larger replicate without the vocabulary terms. Put
students into small groups and have them use table 7.2 to create a set of sticky
notes with each term written on one stick note. Once each group creates their
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terms and has their larger skeleton replicate hung on the wall they may begin. Each
student in the group will take turns sticking the sticky note with the term in the
correct location identifying what each structure is in the skeleton. Students may
change their answers around until they have a final submission with all sticky notes
placed where they believe to be correct. Once all groups are finished, the teacher
will provide the answer key to groups. They will evaluate their skeleton on the wall
to determine if they labelled everything correctly. If there are errors, the group
should fix them. Repeat as many times as necessary to review.
Differentiated Instruction
Instead of using the name of the bone on the sticky notes, the definition or
example column from Table 7.2 could also be used. A different way to
complete this activity would be through a coloring activity using Table 7.1.
Provide each group with the same skeletal printout to hang on the wall.
Instead of adding sticky notes, students could use Table 7.1 to create color
coded categories on the skeletal picture. For example, all the middle ear bones
would be colored blue. Students would have to locate the middle ears bones
and color them on the skeletal picture on the wall. This would provide students
with a great visual of how the bones are related and their locations.
Demonstration Activity: Build-A-Bone
For this activity, students will pick three different bones from the chapter. Provide
the students with modeling clay. The students will need to fashion what each bone
looks like out of the modeling clay.
After the students have built their bone, ask them to describe to the class – or in a
short paragraph - where the bones are located, what the structure of the bones are,
and function of the bone they chose.
Additional Discussion Questions
Provide students with an unlabeled chart of the human skeleton and ask them to
label the major bones of the axial and appendicular skeleton.
Students should be able to label, at a minimum, the following bones: frontal, temporal, parietal,
occipital, cranium, skull, mandible, clavicle, scapula, sternum, hyoid, humerus, ribs, vertebrae,
ilium, ischium, pubis, ulna, sacrum, coccyx, radius, ulna, carpals, metacarpals, phalanges, femur,
patella, tibia, fibula, tarsals, and metatarsals.
Organize the students into groups of four. Ask them to examine each other by
identifying a variety of skeletal landmarks.
Students should be able to locate the bones listed earlier in this chapter objective, as well as
the mastoid process, olecranon process, iliac crest, lateral malleolus, medial malleolus,
calcaneous, glenoid cavity, acetabulum, and the heads of the metacarpals.
Practice
Practice Questions
1. Distinguish between the axial and appendicular skeletons.
The axial skeleton consists of the bony and cartilaginous parts that support and protect
the organs of the head, neck, and trunk. The appendicular skeleton consists of the bones
of the upper and lower limbs and the bones that anchor the limbs to the axial skeleton.
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2. List the bones of the axial skeleton and of the appendicular skeleton.
The axial skeleton is made of the skull (the cranium and facial bones), the hyoid bone,
the vertebral column (sacrum and coccyx), and the thoracic cage (ribs and sternum). The
appendicular skeleton is made of the pectoral girdle (scapula and clavicle), upper limbs
(humerus, radius, ulna, carpals, metacarpals, phalanges), the pelvic girdle (pelvis), and the
lower limbs (femur, tibia, fibula, patella, tarsals, metatarsals, phalanges).
Use the Practices 7.5
Using Mathematics Table 7.1 divides the bones of the body into axial and
appendicular skeletons. Calculate the percentage of bones in the axial
skeleton.
80 bones in the axial skeleton, 206 total bones. 80/206 = 38.8%
Section 7.6: Skull
Learn
Classroom Activities
Writing Connection: Skull Development
Discuss with the whole group the differences between an infant and an adult skull.
Students will point out they have different sizes and sometimes different shapes.
Ask students if they have ever heard of an infant’s “soft spot” or that an infant’s skull
is “soft”. Put students into pairs and have them further discuss these topics and
review the different structures of the skull and the stages of development the skull
goes through as it changes from and infant to and adult. Each student is to write a
written response comparing and contrasting bone development between an adult
and infantile skull. The teacher may create a rubric for specific content and written
organization components the student will be graded on.
Differentiated Instruction
Instead of students creating a written response of the comparison between
bone development between an adult and infantile skull, students could also
choose to create a presentation. Student could create a short PowerPoint slide
deck, speech, or possibly even a demonstration with a model they create or
already have at school. Give students the option on how they want to
communicate what they have learned.
Additional Discussion Questions
Additional discussion questions for sections 7.6-7.12 can be found in section 7.12
Practice
Practice Questions
1. Locate and name each of the bones of the cranium.
The cranium consists of eight bones: the frontal bone, two parietal bones, the occipital
bone, two temporal bones, the sphenoid bone, and the ethmoid bone. The frontal bone
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forms the anterior portion of the skull above the eyes. The parietal bones are located on
each side of the skull, just behind the frontal bone. The occipital bone joins the parietal
bones to form the back of the skull and the base of the cranium. The temporal bones are
located on each side of the skull and form parts of the sides and the base of the cranium.
The sphenoid bone is wedged between several other bones in the anterior cranium and
helps form the base of the cranium, the sides of the skull, and the floors and sides of the
orbits. The ethmoid bone is located in front of the sphenoid bone and forms part of the
roof of the nasal cavity.
2. Locate and name each of the facial bones.
The facial skeleton consists of thirteen immovable bones and a movable lower jawbone.
Those bones are: the maxilla, palatine bones, zygomatic bones, lacrimal bones, nasal
bones, vomer, inferior nasal conchae, and mandible. The maxillae form the upper jaw and
compose the anterior roof of the mouth, the floors of the orbits, and the sides and floor of
the nasal cavity. The palatine bones help to form the hard palate and floor of the nasal
cavity. The zygomatic bones form the prominences of the cheeks as well as the lateral
walls and floors of the orbits. The lacrimal bones are located in the medial walls of each
orbit between the ethmoid bone and maxillae. The nasal bones are side-by-side and
fused at the midline, forming the bridge of the nose. The vomer is located in the midline
in the nasal cavity and helps to form the nasal septum. The inferior nasal conchae are
attached to the lateral walls of nasal cavity and support mucous membranes in the nasal
cavity. The mandible is the lower jawbone.
3. Explain how an adult skull differs from that of an infant.
At birth, the skull is incompletely developed, with fibrous membranes connecting the
cranial bones. These membranous areas are called fontanels. Fontanels permit some
movement, allowing the skull to change shape slightly and be compressed, allowing for
easier passage through the birth canal. The infantile skull includes a relatively small face
with prominent forehead and large eyes. Sinuses are incompletely formed the frontal
bone is in two parts. Infantile skulls are also less-easily fractured than adult skulls.
Use the Practices 7.6
Constructing Explanations Early phrenologists identified 37 mental faculties
that they felt were represented in the exterior surface of the skull. Construct an
explanation based on reliable evidence that refutes the study of phrenology.
The cranium is composed of bones whose surfaces provide attachments for muscles.
These projections can be felt on the surface of the skull. These markings do not
correspond to mental faculties, but make head movement and chewing possible.
Section 7.7: Vertebral Column
Learn
Classroom Activities
Visual Literacy: Disorders of the Vertebral Column
Many pediatricians check for a vertebral column disorder called scoliosis, which
tends to more frequently affect adolescent females. Have students use the book
and online resources to research different vertebral column disorders. Students
should create a drawing of a normal vertebral column with labels as well as the
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different disorders they found in their research. Close the activity with discussion on
importance of health and getting wellness checks from the doctor for early diagnosis.
Differentiated Instruction
Instead of researching the vertebral disorders, the teacher could provide this
information to students and they could brainstorm in groups solutions to
correct the different curvatures. Once students make note of their ideas, have
them research how doctors could help correct the different positions and what
role a chiropractor plays in treating vertebral disorders.
Additional Discussion Questions
Additional discussion questions for sections 7.6–7.12 can be found in section 7.12
Practice
Practice Questions
1. Describe the structure of the vertebral column.
The vertebral column extends from the skull to the pelvis and forms the vertical axis of
the skeleton. It is composed of many bones called vertebrae, separated by intervertebral
discs and connected by ligaments.
2. Describe a typical vertebra.
A typical vertebra has a drum-shaped body, which forms the thick, anterior portion of the
bone. Projecting posteriorly from each vertebral body are two short stalks called
pedicles. Two plates called laminae arise from the pedicles and fuse in the back to
become spinous processes. The pedicles, laminae, and spinous process together form the
vertebral arch around the vertebral foramen. The bones of the vertebral column and
vertebral foramina form the vertebral canal, through which the spinal cord passes.
Between the pedicles and laminae are the transverse processes, projecting laterally and
posteriorly. Projecting upward and downward from each vertebral arch are superior and
inferior articular processes. The lower surfaces of the pedicles are notches that align to
form the intervertebral foramina, through which spinal nerves pass.
3.Explain how the structures of the cervical, thoracic, and lumbar vertebrae differ.
The transverse processes of the cervical vertebrae are the only ones with transverse
foramina, through which blood vessels pass. The spinous processes of the second
through the sixth cervical vertebrae are forked (bifid). The first vertebra (atlas) has no
body or spinous processes. The second vertebra (axis) bears a tooth like dens on its
body. Thoracic vertebrae are larger than the cervical vertebrae and all but T10-T12
articulate with ribs. The bodies of thoracic vertebrae increase in size as you travel
inferiorly along the vertebral column. Larger still than the thoracic vertebrae are the
lumbar vertebrae, owing to their need to support greater weight.
Use the Practice 7.7
Asking Questions Develop a question that addresses how the distinctive
characteristics of vertebrae in different regions of the vertebral column make
possible o their specific functions.
Answers will vary. Examples: Some of the vertebrae articulate with the ribs. What
structures allow for this articulation?
The lumbar vertebrae are responsible for the weight of the other vertebrae. How are
these vertebrae adapted for this function?
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Section 7.8: Thoracic Cage
Learn
Classroom Activities
Writing Connection: Rib T-chart
A typical rib has a long, slender shaft, which curves around the chest and slopes
downward. From this typical design there are three types of ribs that make up the
thoracic cage: true ribs, false ribs, and floating ribs. Have students create a T-chart
comparing all three types of ribs including their location in the thoracic cage,
cartilage attachments, and characteristics and number of each type.
Differentiated Instruction
Students may choose to create a drawing of the thoracic cage and label each
type of rib as well as the components they addressed in the original activity
above. A visual diagram may help students to build better relationships between
the type of rib and its characteristics and placement in the thoracic cage.
Additional Discussion Questions
Additional discussion questions for sections 7.6–7.12 can be found in section 7.12
Practice
Practice Questions
1. Which bones compose the thoracic cage?
The thoracic cage includes the ribs, the thoracic vertebrae, the sternum, and the costal
cartilages that attach the ribs to the sternum.
2. What are the differences among true, false, and floating ribs?
The first seven rib pairs are called true ribs because they join the sternum directly via
their costal cartilages. The remaining five ribs are called false ribs because their
cartilages do not reach the sternum directly and instead articulate with the cartilage of
the seventh rib. Floating ribs are the last two or three ribs and named because they do
not attach to the sternum at all.
3. Name the three parts of the sternum.
The three parts of the sternum are the manubrium, the body, and the xiphoid process.
Use the Practice 7.8
Conducting Investigations Unlike the cranium, which has fused bones, the
thoracic cage has an open structure. Plan an investigation that would
demonstrate how the thoracic cage structure allows for breathing.
Answers will vary. Example: Using a balloon and a couple of cardboard boxes. In one
box inflate the balloon until the balloon pushes on the sides of the box. Measure the
diameter of the balloon. In another cardboard box, cut the box in 1 inch strips. Inflate the
balloon again until the balloon pushes on the sides of box. Measure the diameter of the
balloon.
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Section 7.9: Pectoral Girdle
Learn
Classroom Activities
Demonstration Activity: Shoulder Movement
In this activity, put students together in pairs or small groups. Provide students with
a list of key vocabulary (structural) terms with definitions that make-up the pectoral
girdle. Ask students to move their arm and shoulder around. Each group will reflect
on the vocabulary terms and the movement they feel in their own shoulders and
attempt to draw a sketch of the pectoral girdle without previously looking at any
images in the book or from other resources. After students have completed their
sketch, tell them to compare what they drew to Figure 7.21 and 7.22.
Each student should complete the reflection questions:
• How was your sketch similar in structure to the book figure of the pectoral girdle?
• How was your sketch different in structure to the book figure of the pectoral
girdle?
• If you had some differences between your drawing and the figure in the book,
what movements or definitions led you to create your drawing? Explain how
you better understand the real configuration of the pectoral girdle related to
the movement in your own shoulder.
Differentiated Instruction
Some students may not be able to physically move their shoulders. The
teacher may provide a moveable doll to use or create a discussion about the
different rotations and special functions of the shoulder. Some groups may
choose to explore possible injuries such as a broken clavicle or rib bone and
how it would effect the movement of the pectoral girdle.
Additional Discussion Questions
Additional discussion questions for sections 7.6–7.12 can be found in section 7.12
Practice
Practice Questions
1. Which bones form the pectoral girdle?
The pectoral girdle is formed by two clavicles and two scapulae, which form an
incomplete ring, open in the back and separated by the sternum in the front.
2. What is the function of the pectoral girdle?
The pectoral girdle supports the upper limbs and is an attachment for several muscles
that move them.
Use the Practice 7.9
Using Models The word girdle suggests a ring-shaped structure. Develop a
model that predicts how the bones of the pectoral girdle would form a ringshaped structure to allow various movements to occur.
Answers will vary.
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Section 7.10: Upper Limb
Learn
Classroom Activities
Visual Literacy: Upper Limb Search and Find
Pairs students together and provide each pair a copy of a labeled skeleton of the
upper limb like in Figures 7.24 and 7.25. Let each of the partners in the group review
the labeled skeleton until they both feel like they could identify the different parts.
The first group member will hold the skeleton figure so only they can see it. They
are going to quiz the second student by calling out a bone name. The second
student must point to the correct location on their own finger, hand, or upper limb
that the first student called out. Students may keep score or just play for practice
and quiz each other.
Example: Student 1 states – identify the proximal phalanx, then Student 2 would
have to point to the region on their finger that represents this bone.
Differentiated Instruction
Students may associate the bones and their locations in the upper limb if they
get to move and build them. The teacher would provide a copy of the skeleton
upper limb. Students in their small pairs would cut out the different bones
from the paper so that each piece or bone is moveable like a puzzle. Student
pairs would mix up the different bones and try to build the hand and upper
arm together or taking turns.
Additional Discussion Questions
Additional discussion questions for sections 7.6–7.12 can be found in section 7.12
Practice
Practice Questions
1. Locate and name each of the bones of the upper limb.
The bones of the upper limb are: the humerus, the radius, the ulna, the carpals, the
metacarpals, and the phalanges. The humerus extends from the scapula to the elbow.
The radius is located on the thumb side of the forearm and extends from the elbow to
the wrist. The ulna is located laterally to the radius and extends from the elbow to the
wrist. The carpals are the wrist bones and articulate with the radius. The metacarpals
extend from the carpal bones and make up the knuckles. The phalanges extend from the
metacarpals and form the fingers.
2. Explain how the bones of the upper limb articulate.
The proximal end of the humerus has a rounded head that fits into the glenoid cavity of
the scapula. The distal end of the humerus has two smooth condyles, a lateral capitulum
that articulates with the proximal radius and a medial trochlea that articulates with the
promixal ulna. The distal ends of the radius and ulna have styloid processes that provide
attachments for the carpal bones. The carpal bones articulate with the head of the
radius. The metacarpals articulate with the carpal bones and the phalanges articulate
with the metacarpal bones.
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Use the Practice 7.10
Constructing Explanations Explain how the bones of the upper limb allow
you to rotate your palm.
The unique structure of the radius allows it to rotate around the ulna. When your palm is
face up, the bones are parallel. When you turn your hand over the bones radius crosses
over the ulna. You can even feel the bones moving in your forearm.
Section 7.11: Pelvic Girdle
Learn
Classroom Activities
Writing Connection: Symmetry
Provide students with the following scenario: The teacher overheard two students
discussing the structure and characteristics of the pelvic girdle. One student
described the pelvic girdle as having “bilateral symmetry”. Put students into small
groups and have them discuss the following questions about the scenario above.
• Is the student correct in stating that the pelvic girdle is bilateral? Support your
answer with evidence from the structure of the pelvic girdle.
• Why is the structure of the pelvic girdle as well as the sacrum and coccyx
important to the function it completes in humans?
• How are male and female pelvic girdles similar and how are they different?
Once all groups have completed their discussions, bring the class back together
and allow each group to report their main points they discussed and highlighted.
Differentiated Instruction
Instead of focusing on the structure of the pelvic girdle of just males and
females, the teacher could also have students research variations of the pelvis
between other groups (ages, geographical origin). Each group could discuss
how the structure of the pelvic girdle is similar and different between groups.
The teacher should highlight that even though humans have cultural
differences, our bone structures are very similar.
Additional Discussion Questions
Additional discussion questions for sections 7.6–7.12 can be found in section 7.12
Practice
Practice Questions
1. Locate and name each bone that forms the pelvis.
The pelvic girdle (illium, ischium, pubis), sacrum, and coccyx form the pelvis. The ilium is
the largest and most proximal portion of the hip bone. The ilium joins the sacrum at the
sacroiliac joint. The most distal portion of the hip bone is the ischium. The pubis is the
anterior portion of the hip bone. The sacrum is posterior and articulates with the hip
bones to complete the bowl-shape of the pelvis. The coccyx articulates with the sacrum
at its most distal point.
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2. Name the bones that fuse to form a hip bone.
The hip bones are formed by the fusion of three bones: the ilium, the ischium, and the pubis.
Use the Practice 7.11
Using Models In the same way as the pectoral girdle, the pelvic girdle also
forms a ring-shaped structure. Develop a model that predicts how the bones of
the pelvic girdle would form a ring-shaped structure to allow various
movements to occur.
Answers will vary
Figure Questions
Figure 7.28. p. 218: What are some of the specific differences between the female
and male pelves?
Female obturator foramen is more triangular; male is more oval. Female pubic arch is a wider
angle than the male pubic arch. Female ilia are more flared than those on the male hip bones.
Section 7.12: Lower Limb
Learn
Classroom Activities
Visual Literacy: Flow Chart
The lower limbs are comprised of the legs, ankle, and foot. These characteristics can
be easily followed externally from moving top to bottom from hip to toe. Identifying
the bones from hip to bone is a little more challenging. Put students into small
groups and provide them with a large piece of paper to create a flow chart showing
the order of how the bones connect starting from the hip pelvic girdle moving down
to the toes or phalanges. Encourage students to be creative and color code the
different areas similar bones would be found. Students may switch with other
groups to review and evaluate each other’s flow charts.
Differentiated Instruction
Flow charts create a great visual of how the information connects, but some
students may want to just use a skeleton printout to label and make visual
connections of location to the structure and function it has. Ask students to
think about how a particular bone would restrict movement if it was broken.
Emphasize that structure and function is vital to understand clear down to the
cellular level.
Additional Discussion Questions
Provide students with models or illustrations of the human male and female
skeletons, and ask them to identify as many differences as possible.
Students should comment on differences of the skull, pelvic girdle, pelvic cavity, sacrum, and
coccyx.
Discuss the distinguishing characteristics of four types of vertebrae.
Comments may include the following observations: the transverse foramen and bifurcated
spiny processes make cervical vertebrae unique, the thoracic vertebrae exhibit costal facets,
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and the lumbar vertebrae are the largest vertebrae. The sacrum is actually the result of the
fusion of five vertebrae.
Practice
Practice Questions
1. Locate and name each of the bones of the lower limb.
The bones of the lower limb are the femur, the patella, the tibia, the fibula, the tarsals,
the metatarsals, and the phalanges. The femur extends from the hip to the knee. The
patella is anterior and distal to the femur. The tibia and fibula are distal to the femur.
The tarsals are distal to the tibia and fibula. The metatarsals are distal to the tarsals and
the phalanges are distal to the metatarsals.
2. Explain how the bones of the lower limb articulate.
The head of the femur articulates with the acetabulum of the hip bone. The distal femur
has two condyles, medial and lateral, which articulate with the tibia. The tibia has medial
and lateral condyles that articulate with the femur proximally and with the fibula distally on
the lateral side. The tibial tuberosity provides an attachment for the patellar ligament and
patella to the tibia. The patella also articulates with the femur. The distal tibia articulates
with the talus. The fibula articulates with the tibia just below the lateral condyle. The
tarsals articulate with the lateral malleolus of the fibula and the medial malleolus of the
tibia. The metatarsals articulate with the tarsals proximally and the phalanges distally.
3. Describe how the foot is adapted to support the body.
The largest of the tarsal bones is the calcaneus forms the base of the heel. It helps
support body weight and provides an attachment for the muscles that move the foot.
The tarsals and metatarsals are bound by ligaments in a way that forms the arches of
the foot. These arches provide a stable, springy base for the body.
Use the Practice 7.12
Communicating Information Create an infographic to convey the strength
and size of the femur.
Answers will vary.
Section 7.13: Joints
Learn
Classroom Activities
EL Strategy: Making Connections
Beginning Help students access text by using a diagram or an illustration to
demonstrate key points. Have students look at figures 7.37–7.39. Before
reading, explain the diagram and labels to students using gestures and short
phrases. As you read, point out each labeled item on the diagram to show
students how the information in the diagram connects to information in the
text. Play “Joint Charades”. Have the students act out the joint movements for
each other and have students guess the movement based on the illustration.
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Writing Connection: Memory Match
Joints are essential for movements. Pairs students together and provide them with a
set of notecards. Student pairs will work together to put each of the following joint
types on individual cards. Repeat the steps and also make a notecard for each type
of possible joint movement. Below are the words that student pairs should have
created. Note: each notecard should have one list item.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fibrous
Cartilaginous
Synovial: ball-and-socket
Synovial: condylar
Synovial: plane
Synovial: hinge
Synovial: pivot
Synovial: saddle
None or slight twisting
Limited movement as when the back is bent
Movements in all planes including rotation
Variety of movement in two planes, but no rotation
Sliding or twisting
Flexion and extension
Rotation around a central axis
Variety of movements, mainly in two planes
Once students have created all the notecards, they will turn them face down and
space them equally to play a game of mix-n-match or memory. The first student will
go and turn over one card. They will then pick a second card. If the pair of cards
face up are the correct joint matching the correct movement, the students keeps
the cards and earns a point. They will get to go again until they don’t get a match or
unable to identify if the match is correct. The second student repeats the process.
Differentiated Instruction
The game above requires two steps, students must remember where the
matching pair is as well as identify if they are a correct match. To lower the
level and remove the memory step, the teacher could mix the joint list up one
side of the paper and list the movements on the other side of the paper.
Students would work in pairs to draw a line from the joint that matches the
correct movement. All words should be used one time. Student partners can
check each other’s work and remix the lists to play again.
Additional Discussion Questions
Ask students to demonstrate the movements of at least five different joints. The
demonstration should include the name of the type of joint, a description of the
joint, and a summary of its possible movements.
Demonstrations may include information regarding cartilaginous joints, ball-and-socket joints,
condyloid joints, gliding joints, hinge joints, pivot joints, and saddle joints.
Provide students with unlabeled diagrams of a knee joint, hip, shoulder joint, and
elbow. Ask them to correctly label each diagram as completely as possible.
The labeled diagrams should include the names of all bones, bone markings, cartilage,
membranes, bursae, capsules, etc.
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Ask students to demonstrate to a classmate each of the 17 types of joint movements
discussed in this chapter objective.
Demonstrations should include flexion, extension, dorsiflexion, plantar flexion, hyperextension,
abduction, adduction, rotation, circumduction, pronation, supination, eversion, inversion,
retraction, protraction, elevation, and depression.
Ask students to prepare a short report by comparing different forms of arthritis.
The reports may compare infectious/bacterial arthritis, juvenile rheumatoid arthritis,
osteoarthritis, psoriatic arthritis, and rheumatoid arthritis. Ask students to include a description
of the disease, signs and symptoms, causes, risk factors, diagnostic procedures, and possible
treatment modalities.
One form of chronic arthritis is known as synovioarthritis. Discuss why this name is
appropriate.
The synovial membrane of many joints is affected by swelling, formation of pulpy masses, and
eventual destruction of the articular cartilage. The joint surfaces may fuse causing stiffness and
immobility.
Discuss the advantages of arthroscopic knee surgery over conventional surgical
procedures in the past.
Discussions will vary, but should include emphasis on reduced recovery time, less invasive,
performed on an outpatient basis, nearly invisible scarring, etc.
Practice
Practice Questions
1. Describe the characteristics of the three major types of joints.
The three major types of joints are fibrous, cartilaginous, and synovial. Fibrous joints lie
between bones that closely contact one another and are held together by a thin layer of
dense connective tissue. Generally, no movement takes place at a fibrous joint.
Cartilaginous joints allow for limited movement. Synovial joints allow free movement and
are the most common joint type in the body, as well as the most complex. A joint capsule
holds the bones of a synovial joint together, each capsule having an outer fibrous layer
and inner synovial membrane, which secretes synovial fluid to lubricate the joint.
2. Name six types of synovial joints.
Six types of synovial joints are: ball-and-socket, condylar, plane, hinge, pivot, and saddle
joints.
3. What terms describe movements possible at synovial joints?
Synovial joints are freely movable. Flexion, extension, dorsiflexion, plantar flexion,
hyperextension, abduction, adduction, rotation, circumduction, pronation, supination,
eversion, inversion, retraction, protraction, elevation, and depression are all possible at
synovial joints.
Use the Practice 7.13
Communicating Information Construct a chart that explains the joint
movements in an everyday activity, such as swinging a baseball bat or playing a
video game.
Answers will vary depending on the action chosen.
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Assess
Career Corner: Radiology Technologist
Consider This: You are a radiologic technician in the midst of your licensing
exam. You encounter a question that asks you to distinguish a mature bone
from one that is still lengthening. How would you be able to tell?
A bone with an epiphyseal plate is still growing, while epiphyseal lines indicate that the
bone is mature and growth has stopped.
Diseases, Diagnosis, & Treatment: Bone Fractures
1. Describe the techniques used to help bone healing.
Various techniques are used, including casts, screws, plates, rods, wires and nails made
of titanium. Experimental approaches include cartilage grafts and stem cell infusions.
2.Explain some of the factors that contribute to the body’s ability to heal a
fracture.
Nutrition, hormonal secretions, vitamin D, physical exercise.
Case Study Connection
page 186: Where do you find some of these different types of bones? Do they
have different functions? Use examples of each type in your answer.
Long bones: long longitudinal axis, expanded ends. Found in thighs and forearms.
Used in support and movement. Short bones are equal in length and width, such
as wrist and ankle. Used for a lot of movement. Flat bones are platelike, such
as the ribs and skull. Used for protection. Irregular bones are not like any of
the previous categories, such as facial bones or vertebrae. Have very specialized
functions.
page 188: How is the epiphyseal plate related to the idea of bone fusion that
the forensic anthropologist was talking about?
The epiphyseal plate is in between the two ossification centers. Its presence indicates
that the bone is not done growing.
page 190: What types and shapes of bones are most well suited to protective
roles?
Flat bones are the types found in protective roles such as the skull or ribcage. They are
platelike and flattened.
page 193: Why do you think that the skeleton grows and elongates first as
cartilage, before becoming bone? Why might it be difficult to grow a bone
longer?
Cartilage is lighter and more flexible. Once bone is deposited it is difficult to stretch
or elongate.
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page 206: What changes occur in the skull across the lifespan that would be
useful in determining the age of a skeleton?
The skull starts incomplete, with membranes connecting the cranial bones of infants. In
adults, the cranial bones are firmly interlocked and do not move. The maxillae bones
grow and fuse together at the anterior of the hard palate.
page 210: Do you think that examining the sacrum could be important in
determining the age of a skeleton?
Student answers may vary, but should identify that the sacrum is not as likely as other
bones to demonstrate the wear and tear of aging.
page 223: Which types of joints do you think are more likely to fuse over the
lifespan? Which are less likely?
Fibrous joints already allow for very limited to no movement so should show no appreciable
change over time. Synovial joints are the most complex and therefore more likely to
suffer age-related symptoms.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Compact bone heals rapidly as a result of blood (nutrient
supply) having easy access to and between osteocytes
through the cellular processes passing through very small
tubes in the extracellular matrix called
a. periosteum.
b. trabeculae.
c. Medullary cavities.
d. canaliculi.
2. All of the following directly influence bone development,
growth, and repair except
a. deposition by osteoclasts and resorption by osteoblasts
b. a diet sufficient in vitamin D and calcium
c. the stimulation of processes by growth and sex
hormones
d. physical stress from exercise
3. Which of the following most correctly describes the
homeostatic response to levels of calcium that are too high in
the blood?
a. Parathyroid glands release parathyroid hormone, then
osteoclasts break down bone to release calcium.
b. The thyroid gland releases calcitonin, then osteoblasts
deposit calcium in bones.
c. Parathyroid glands release calcitonin, then osteoclasts
deposit calcium in bones.
d. The thyroid gland releases calcitonin, then osteoblasts
break down bone to release calcium.
4. The fourteen bones in the fingers and fourteen bones in the
toes are called
a. carpals and tarsals, respectively.
b. metacarpals and metatarsals, respectively.
c. phalanges.
d. clavicles.
5. All of the following describe functions of the paranasal
sinuses except
a. produce a mucus that moisturizes and protects the nose
b. form fibrous membranes connecting the cranial bones
c. decrease the relative weight of the skull
d. increase the resonance of the voice
6. A patient has dealt with years of back pain caused by
degenerative disc disease. After trying other routes of
treatment, a doctor decides to treat the patient through
spinal fusion surgery, fusing together the three vertebrae
closest to the sacrum. Which vertebrae are being fused?
a. C5, C6 and C7
b. T10, T11 and T12
c. L3, L4 and L5
d. S1, S2 and S3
7. Which structure of the thoracic cage functions in
compressing the heart during ideal cardiopulmonary
resuscitation (CPR) performed after cardiac arrest?
a. sternum
b. ribs
c. clavicle
d. scapulae
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8. Which lateral structures of the upper limbs provide
attachments for the muscles and ligaments of the elbow?
a. greater tubercles
b. epicondyles
c. styloid processes
d. lesser tubercles
9. The following are all functions of the pelvic girdle except
a. providing attachments for the lower limbs
b. supporting the body’s trunk
c. protecting the bladder and reproductive organs
d. providing space in back for the scapulae
10. Which type of joint allows for amphiarthrotic movement, as
seen in the vertebral column?
a. fibrous joint
b. cartilaginous joint
c. synovial joint
d. pivot joint
Short Answer
1. List all of the major functions of the skeletal system.
Support of body weight, protection of internal organs,
movement, blood cell formation, and storage of inorganic salts
2. Distinguish between diaphysis, epiphysis, and epiphyseal
plate.
The diaphysis is the shaft of the bone, the epiphyses are the
expanded ends of the bone which articulate with another
bone. The epiphyseal plate is between the epiphyses and
diaphysis and the area of active bone growth.
3. What is the connective covering of long bone called?
Periosteum
4. What are the protein fiber types found in the matrix in bone,
cartilage, and tendons?
Collagen
5. Distinguish between compact and spongy bone.
Compact bone is tightly packed tissue, with a continuous
extracellular matrix with no gaps. It is found in the diaphysis of
the long bones Spongy bone is formed from numerous
branching bony plates with irregular spacing in between.
Spongy bone makes up most of the epiphyses.
6. Describe intramembranous and endochondral ossification.
Intermembranous ossification occurs between flat bones like
those of the skull. These bones form from connective tissues at
the site of future bones. Progenitor cells from these tissues
develop into osteoblasts which deposit a bony matrix around
themselves. When the extracellular matrix completely
surrounds the osteoblasts, they are called osteocytes. In
endochondral ossification, the bones develop from hyaline
cartilage shaped like future bones. The changes begin in the
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center of the diaphysis, where the periosteum forms to protect
the developing bone while the cartilage slowly breaks down.
Osteoblasts from the periosteum move into the disintegrating
cartilage and begin to build spongy bone. Bone builds out
towards the epiphyses.
7. Distinguish between the axial and appendicular skeleton.
The axial skeleton consists of the bones and cartilage that
protect and support the head, neck, and trunk. The
appendicular skeleton includes the bones of the upper and
lower limbs.
8. List the bone of the cranium.
There are eight cranial bones: frontal, parietal, occipital, two
temporal bones, sphenoid, and ethmoid.
9. Which bone has the foramen magnum? What goes through
it?
The occipital bone has the foramen magnum, where nerves
from the brain enter the vertebral canal.
10. What is the formal name for “cheek” bone?
Zygomatic bones
11. What is a fontanel commonly called?
Soft spot
12. Distinguish between cervical, thoracic, and lumbar vertebrae.
Cervical vertebrae 2-6 have special spinous processes for
muscle attachment. The first vertebra is specifically for
supporting the head. The thoracic vertebrae are 12 in total,
and are larger than the cervical vertebrae. They have long,
pointed spinous prcesses. T1-T9 have facets that articulate
with the ribs. Lumbar vertebrae are again larger for supporting
more weight.
13. Which three bones fuse to make one coxal (hip) bone.
Ilium, ischium, pubis
14. List the carpal bones.
Scaphoid, capitate, trapezoid, trapezium, lunate, hamate,
triquetrum, pisiform
15. Distinguish between the femur and the humerus.
The femur is the large bone of the lower limb and the
humerus is the large bone of the upper limb. The femur is
the largest bone in the body and extends from hip to knee.
It has a large, round head and two rounded processes at
the distal end which articulate with the tibia. The humerus
extends from scapula to elbow, with a smooth upper head
and two condyles at the distal end which articulate with
the radius.
16. What is a synovial joint?
A synovial joint is a joint which allows for free movement, such
as a ball-and-socket, condylar, or hinge joint.
Critical Thinking and Clinical Applications
1. WRITING Connection Explain how exercise can slow the
progress of osteoporosis.
Weight-bearing exercises can improve bone density, and
muscle-strengthening exercises can protect bones as a person
grows older.
2. CLINICAL Connection A football player arrives to a
physical therapy appointment with an elbow injury. He says
that another player pulled on his elbow and the team doctor
said two bones separated. Is it more likely between the
humerus and ulna or the humerus and scapula?
3. When a child’s bone is fractured, growth may be stimulated
at the epiphyseal plate of that bone. What problems might
this extra growth cause in an upper or lower limb before the
growth of the other limb compensates for the difference in
length?
If an epiphyseal plate is damaged before it ossifies, long bone
growth may be uneven.
It is more likely to be between the humerus and the scapula.
Lab Data Analysis: Fracture Risk Assessment
Think Critically
1. How does the risk of hip fracture change with bone mineral
density?
As bone mineral density increases along the x-axis, the risk of
hip fracture decreases (as measured on the y-axis). This makes
sense given that less dense bone predisposes an individual to
fractures.
2. Which BMD quartile group do you suspect contains the
oldest individuals?
Quartile group 1, representative of the lowest bone mineral
density quartile, is likely composed of an elderly population.
Osteoporosis, a disease characterized by loss of bone density,
is especially common among postmenopausal women.
3. If you were a medical professional, how would you explain to
someone in BMD Quartile 1 or 2 that they were at risk for
severe injury?
When counseling an individual with low-density bones, it is
important to explain that less dense bones means more brittle
bones. As such, they are at a higher risk of developing
fractures. Hip fractures, especially among people over 70 years
of age, can often be devastating to their quality of life. Regular
check-ups and appropriate medication for low density bones is
advised.
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CHAPTER
8
Muscular System
Section
Pacing
(class periods)
Learning Outcomes
8.1 Introduction
—
1. List various outcomes of muscle actions.
8.2 Structure of a Skeletal
Muscle
2
1. Identify the structures that make up a
skeletal muscle.
2. Identify the major parts of a skeletal
muscle fiber, and the function of each.
3. Discuss nervous stimulation of a skeletal
muscle.
8.3 Skeletal Muscle
Contraction
3
1. Identify the major events of skeletal
muscle fiber contraction.
2. List the energy sources for muscle fiber
contraction.
3. Describe how oxygen debt develops.
4. Describe how a muscle may become
fatigued.
5. Distinguish between muscle fiber types.
6. Describe effects of skeletal muscle use
and disuse.
8.4 Muscular Responses
1
1. Distinguish among a twitch, recruitment,
and a sustained contraction.
2. Explain how muscular contractions move
body parts and help maintain posture.
3. Distinguish between the types of
contractions.
8.5 Smooth Muscle
1
1. Distinguish between the structures and
functions of multiunit smooth muscle and
visceral smooth muscle.
2. Compare the contraction mechanisms of
skeletal and smooth muscle.
8.6 Cardiac Muscle
1
1. Compare the contraction mechanisms of
cardiac and skeletal muscle.
8.7 Skeletal Muscle
Actions
2
1. Explain how the attachments, locations,
and interactions of skeletal muscles make
different movements possible.
8.8 Major Skeletal
Muscles
2
1. Identify and locate the major skeletal
muscles of each body region.
2. Identify the actions of the major skeletal
muscles of each body region.
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Focus Activity Workbook
Focus Activities: Labeling (9)
Focus Activities: Vocabulary (7)
Chapter Resources
Extended Summary Review
Chapter 8 Test Bank
Chapter 8 Interactive Question Bank
Vocabulary Flashcards
APR Module 6: Muscular System
Laboratory Exercise 12: Skeletal Muscle Structure and Function
Laboratory Exercise 13: Muscle Fatigue and Force Variance
Laboratory Exercise 14: Muscles of the Head and Neck
Laboratory Exercise 15: Muscles of the Chest, Shoulder, and Upper Limb
Laboratory Exercise 16: Muscles of the Hip and Lower Limb
A Suggested Approach
The three muscle types (skeletal, smooth, and cardiac) were introduced in Chapter 5.
In this chapter, students focus on skeletal muscle and learn about its microscopic
structure and how that structure allows for muscle contraction. Students are
introduced to the way the muscular and nervous systems are interrelated as they
study muscular responses. As with the prior chapter, the anatomically correct names
and functions of the major muscles of the body are presented.
In understanding the structure of the skeletal muscle, an orange is a good analogy.
Just as an orange is divided into many sections, each with their own covering, so is
skeletal muscle composed of both connective tissue and skeletal muscle tissue.
Additionally, students can build models of sarcomeres out of a variety of materials.
This modeling aids not only in the understanding of skeletal muscle structure, but
also provides a visual model for the sliding filament theory of muscle contraction.
There are also a variety of online tutorials to help students visualize the complex
process in which our muscles contract.
Although students have already learned about energy sources and cellular
respiration in cell (Chapter 4), the muscular system provides an opportunity to
review this material.
While muscle and bones are separate systems in the body, learning about muscles
draws on student knowledge of bones. Many of the muscles in our bodies are
named after the bones they are attached to, such as the frontalis and bicep femoris.
It is helpful to remind students of both the Latin roots of many of the anatomical
names. Additionally, many muscles in our bodies are actually groups of muscles. For
example, the hamstrings and quadriceps in our legs. In the same way knowing the
anatomical names of the bones is important to health care professions, so is
knowing the names of the muscles. Additionally, in order to understand the action
of the muscle, it is helpful to know the origin and insertion of the muscle. Again,
students can use an online resource to review the origin, insertion, and movement
made by the muscles they have learned about.
This chapter is expected to take 12 class periods including Lab 12, Lab 13, Lab 14,
Lab 15, and Lab 16.
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127
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
This mutation discussed in the case study is used to study muscle diseases, and
could possibly be used in agriculture as well. Here is a link to an open-source
article describing the induction of a myostatin mutation using the Crispr/CAS9
system to create lab animals: https://www.nature.com/articles/srep25029
Introduction to the Theme
Theme: Structure and Function The contraction and shorting of muscles is directly
a result of the unique structure that sets muscles apart of all other body tissues.
Theme Activity: The Sliding Filament Model
This activity focuses on how muscle is able to contract and shorten, allowing
muscles to move in the body. Begin by going over the sliding filament model with
students. How do muscles move? What is causing the pull and release of a muscle?
Be sure to go over what is actin and myosin.
Provide students with a variety of different model materials such as beads, rubber
bands, pipe cleaners, glue, etc. Have students create their own sliding filament
model. Be sure that they include a key with their model.
Section 8.1: Introduction
Learn
Classroom Activities
Section 8.1 sets the groundwork for activities in sections 8.2 and beyond.
Additional Discussion Questions
Ask students to develop a chart that compares and contrasts the structure and
function of various muscles.
Responses will vary, but should include a discussion of examples of skeletal, smooth, and
cardiac muscle.
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Compare and contrast various muscle actions.
Responses may include a discussion of muscle tone, the movement of nutrients and fluids, the
role of a heartbeat, and the production of heat through shivering.
Practice
Practice Questions
1. Name the three types of muscle tissue.
Muscle is of three types: skeletal, smooth, and cardiac.
Use the Practice 8.1
Analyzing Data Tissues are 3-D structures, but we often use the 2-D models
or tissue specimens to identify structures. Determine what a cross section of a
skeletal muscle fiber would look like. Identify three different places where a
fiber could be sectioned to reveal different structures.
Answers will vary.
Section 8.2: Structure of Skeletal
Muscle
Learn
Classroom Activities
EL Strategy: Summarizing
Beginning Review with students that a summary is a short explanation of a
longer work. Provide students with an example of a summary of one paragraph
of section 8.2. Have each student read a different paragraph and summarize
the paragraph. Give them a graphic organizer to provide a visual of the
skeletal muscle structure for their summary.
Writing Connection: Story Book Activity
Discuss with students how skeletal muscle is composed of a variety of fibers and
layers. Students will create a flip book that represents the five different layers of
skeletal muscle represented in Figure 8.1. Provide students with five sheets of paper,
organized from large size to small. Students will draw or create the outer most layer
of skeletal muscle on the largest paper. The should label the key components and
list any important characteristics at the bottom. The second page of the book is
smaller and represents the second internal layer of skeletal muscle. Repeat this until
all five layers are represented with the smallest layer in the center. The students will
have created a visual book of skeletal muscle that they can review when needed.
Differentiated Instruction
Student may prefer to make a digital presentation of the different layers of a
skeletal muscle. Students could also be given the chance to present their
illustrations to the class or to their families in an open house night.
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129
Demonstration: Muscle Layers
For this activity, you will either need a photo of a power cord that has been cut in
half or a power cord that you have cut in half. As you discuss the structure of
skeletal muscle, show the photo or past the cut cord around. Just like a power cord,
skeletal muscle is composed of different layers. Discuss the different functions of
the layers. The power cord has a protective sheath, followed by layers of insulation,
filler, and more PVC sheaths to protect the conductors within. Ask students what
the equivalents are within a skeletal muscle. It may be helpful to show Fig. 8.1 or 8.2
side by side with the power cord.
Additional Discussion Questions
Provide students with a variety of microscope slides applicable to this chapter
objective. Ask them to draw and label what they see.
The slides may illustrate myofibrils, sarcomeres, Z lines, actin, myosin, M lines, H zones, I bands,
A bands, and sarcoplasm.
Discuss the meaning of the presence or absence of striations by comparing skeletal
muscle, cardiac muscle, and smooth muscle.
The striated appearance of skeletal and cardiac muscle begins with an alternating
configuration of light and dark bands of myofibrils. The myofibrils are actually chains of
sarcomeres, which contain even smaller structures called myofilaments. It is the unique
banding pattern of the myofilaments that produces a striated appearance. This banding
pattern is absent in smooth muscle.
Practice
Practice Questions
1. Describe the general structure of a skeletal muscle fiber.
Each skeletal muscle fiber is a long, thin cylinder with rounded ends. Just beneath its cell
membrane (sarcolemma) the cytoplasm (sarcoplasm) of the fiber has many small, oval
nuclei and mitochondria. The sarcoplasm has myofibrils made of myosin and actin, which
give the skeletal muscle its striated appearance. Repeating patterns of units called
sarcomeres make up the functional units of skeletal muscle.
2. Explain why skeletal muscle fibers appear striated.
Myofibrils consist of two kinds of protein filaments, actin and myosin. The organization
of these filaments produces the characteristic alternating light and dark striations, or
bands, of a skeletal muscle fiber.
3. Which two structures approach each other at a neuromuscular junction?
Each skeletal muscle fiber is functionally (not physically) connected to the axon of a
motor neuron that passes outward from the brain or spinal cord. This functional
connection is called a synapse.
4. What is the function of a neurotransmitter?
Neurons communicate with the cells that they control by releasing chemicals called
neurotransmitters at synapses.
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Practice
Use the Practices 8.2
Using Models A skeletal muscle is composed of a variety of tissues that are
packaged together to make the organ. The structure of a muscle is similar to
an orange. Create a model that demonstrates how an orange depicts the
anatomy of a skeletal muscle.
Outside peel = muscular fascia (epimysium)
Orange sections = fascicles surrounded by perimysium
Individual orange cells = muscle fibers surrounded by the endomysium
Figure Questions
Figure 8.5, page 245: How does acetylcholine released into the synaptic cleft reach
the muscle fiber membrane?
Neurotransmitters cross the synaptic cleft by diffusion
Section 8.3: Skeletal Muscle
Contraction
Learn
Classroom Activities
Visual Literacy: Storyboard Activity
Muscle contractions and relaxations take place because of specific steps involving
molecules and organelles. Put students into groups and assign them an action in
skeletal muscle. Each group must break down the steps that occur to make the
action happen into storyboard boxes as if they were creating a step-by-step motion
film or flip book. Each storyboard box the group creates should explain one step.
Once each group completes their storyboard set, they should present it to the class
as if they were the teachers. Allow for questions from the student audience.
Example actions that can be assigned to groups: muscle fiber contraction, muscle
fiber relaxation, oxygen debt development, muscle fatigue.
Differentiated Instruction
Storyboard boxes can be created in different ways. Provide students options on
how their group chooses to complete the activity and present. Some groups may
need more guidance so the teacher should provide a storyboard template for the
assigned muscle action. Some of the storyboard boxes may be filled in to give the
students in the group more guidance.
Additional Discussion Questions
Application Questions
Ask students to develop a set of index cards, each of which has one or two key
words that represents a major event of muscle contraction. Develop a second set in
a similar manner for muscle relaxation. Have each student place the steps in the
correct order, and then briefly present the major steps to the class in more detail.
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Suggestions for key words in describing contraction are acetylcholine release, acetylcholine
diffuses, membrane stimulated, calcium diffusion, linkages, cross-bridges, and fiber shortens.
Suggestions for key words in describing relaxation are acetylcholinesterase, calcium transport,
linkages, sliding, and fiber relaxes.
What causes muscle cramping? What may be done to treat muscle cramps?
Cramps may occur anywhere in the body. They are a sharp, involuntary muscle contraction
that may be caused by fatigue, electrolyte imbalance, or dehydration. Muscle cramps are
usually treated with fluid intake and gradual stretching of the muscle.
Discuss the connection between anaerobic respiration and aerobic respiration when
describing how a muscle cell uses energy.
A muscle cell uses energy released in cellular respiration to synthesize ATP. ATP is then used
to power muscle contraction or to synthesize creatine phosphate. Later, creatine phosphate
may be used to synthesize ATP. The oxygen required to support aerobic respiration is carried
in the blood and stored in myoglobin. In the absence of sufficient oxygen, pyruvic acid is
converted to lactic acid. The maximum number of ATPs generated per glucose molecule varies
with cell type.
Distinguish between a strain and a sprain.
A muscle strain is sometimes referred to as a pulled muscle. It is caused by tearing of muscle
fibers or a tendon, resulting from an abnormally violent contraction. A sprain is caused by the
tearing of a ligament, resulting from a sudden force such as a violent twisting motion of the ankle.
Practice
Practice Questions
1. Explain how an impulse on a motor neuron can trigger a muscle contraction.
A skeletal muscle fiber normally does not contract until stimulated by acetylcholine. When
an impulse reaches the end of a motor neuron axon, some of the vesicles release their
acetylcholine into the synaptic cleft. Acetylcholine diffuses rapidly across the synaptic
cleft and binds to specific protein molecules in the muscle fiber membrane, increasing
membrane permeability to sodium ions. Entry of these ions into the muscle cell stimulates
an electrical impulse, which passes in all directions over the surface of the muscle fiber,
and travels through the transverse tubules until it reaches the sarcoplasmic reticulum. The
sarcoplasmic reticulum contains a high concentration of calcium ions, which diffuse into
the cytosol of the muscle fiber. When a high concentration of calcium ions is in the cytosol,
troponin and tropomyosin interact and the muscle fiber contracts.
2. Explain how the filaments of a myofibril interact during muscle contraction.
When a high concentration of calcium ions is in the cytosol, troponin and tropomyosin
interact and expose binding sites on actin where myosin heads can attach. Cross-bridge
linkages form between the thick and thin filaments and the muscle fiber contracts.
3. Which chemicals provide the energy to regenerate ATP?
Creatine phosphate, like ATP, it contains high-energy phosphate bonds.
4. What are the sources of oxygen for aerobic respiration?
The blood carries oxygen from the lungs to body cells to support aerobic respiration. Red
blood cells carry the oxygen bound to hemoglobin. Another protein, myoglobin, can also
combine with oxygen to assist in aerobic respiration.
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5. How are lactic acid and oxygen debt related?
During strenuous exercise, available oxygen is used primarily to synthesize the ATP the
muscle fiber requires to contract, rather than to make ATP for synthesizing glucose from
lactate. Consequently, as lactate accumulates, a person develops an oxygen debt.
Oxygen debt equals the amount of oxygen that liver cells require to convert the
accumulated lactate into glucose, plus the amount muscle cells require to restore ATP
and creatine phosphate to their original concentrations and to return blood and tissue
oxygen levels to normal.
6. What is the relationship between cellular respiration and heat production?
Less than half of the energy released in cellular respiration is transferred to ATP,
and the rest becomes heat. All active cells generate heat, with muscle tissue being
a major source.
Use the Practices 8.3
Arguing from Evidence In idiopathic dilated cardiomyopathy (a genetic
disorder) actin is unable to anchor to the Z lines in cardiac muscle cells.
Provide reasoning based on the mechanism of muscle contraction why this
results in heart failure.
The sarcomere is the functional unit of the muscle contraction. The interaction
between the myosin heads and the actin filament causes the shortening of the
muscle (or contraction). Without the actin molecules anchored to the Z-line the
movement would not shorten the muscle, and therefore no contraction. With no
contraction, no heartbeat.
Figure Questions
Figure 8.8, page 248: What happens to the length of the thick and thin filaments
during contraction?
Their lengths stay the same.
Section 8.4: Muscular Responses
Learn
Classroom Activities
Demonstration Activity: Lift it High
Divide students into small groups for discussion. Provide students with a picture of
an action of somebody doing something. Actions could be lifting a box from the
floor to the table or reaching up high to get something from the top shelf and set it
on the floor. Give each group a different motion. Each group then must analyze the
motion they are given and describe what muscular responses are occurring and in
what order as the action is completed. Encourage students to discuss the process of
summation including stimuli of the action that would increase frequency of muscle
fiber movements as well as cause periods of sustained contractions and muscle
tone. Groups could be paired together to collaborate on their action and their
answers to the activity.
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Differentiated Instruction
This could also be completed in a rotation activity where students move with a
small group through stations with different actions completing the same
activity above. Each station could have more guidance on the type of motions
occurring in muscle to complete the action with an answer key so each group
can check their understanding before moving onto the next station.
Additional Discussion Questions
Provide students with myogram printouts and ask them to identify peaks and troughs.
Students should be able to identify the period of contraction and the period of relaxation. A
variety of myograms may help the students to differentiate a series of twitches from a
summation or tetanic contraction.
Ask students to develop a list of excuses most commonly cited for not exercising
and strategies for dealing with these excuses.
Responses should address excuses relating to age, time availability, cost, hopelessness, stress,
attitude, etc.
Discuss hypoparathyroidism as it pertains to this chapter objective.
Responses should include a discussion of tetany, a sustained muscular contraction. Low levels
of calcium in the blood may result in overstimulation of certain skeletal muscles. Muscles of the
hands and feet, as well as the laryngeal muscles, are very susceptible to these spasms.
Discuss the health-related benefits associated with regular aerobic exercise.
Responses should include a discussion of reduction of the risk of cardiovascular disease, help
in controlling diabetes, development of stronger bones, promotion of joint stability, reduction in
lower back problems, improvement of self-image, etc.
Practice
Practice Questions
1. Define threshold stimulus.
Once threshold is reached, an electrical impulse is generated and the muscle fiber contracts.
2. What is a motor unit?
A motor neuron and the muscle fibers that it controls constitute a motor unit. A whole
muscle is composed of many motor units.
3. Distinguish between a twitch and a sustained contraction.
The contractile response of a single muscle fiber to a single impulse is a twitch. A twitch
consists of a period of contraction, during which pulling force increase, followed by a
period of relaxation, during which the pulling force declines. Summation and recruitment
together can produce a sustained contraction. Sustained contractions involve whole
muscles and enable us to perform everyday activities.
4. What is recruitment?
An increase in the number of motor units being activated during a contraction is called
recruitment. As the intensity of stimulation increases, recruitment of motor units continues
until maximal tension is reached.
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5. How is muscle tone maintained?
Muscle tone is a response to nervous stimulation that originates repeatedly from the
spinal cord and stimulates only a few muscle fibers at a time.
Use the Practices 8.4
Conducting Investigations Allison hypothesizes that the force generated by a
muscle is directly related to the number of muscle fibers contracting within the
muscle. Research whether or not there is evidence to support Allison’s hypothesis.
Answer will vary, accept those that show research
Section 8.5: Smooth Muscle
Learn
Classroom Activities
Group Activity: Make a Claim
Recall with students the different characteristics of skeletal muscle as well as
reviewing characteristics of smooth muscle. Split the class in half and assign the first
half smooth muscle and the other half skeletal muscle. Each side of the class will
debate which type of muscle is the most essential. Obviously there is no answer as
both are essential to human life. The goal is for students to be able to make a true
claim about their muscle type and support it with structural or function details. Each
student is to write down two claims about why their assigned muscle type is the
most essential. Allow students to debate in a teacher controlled respectful
environment. The teacher may choose to set requirements such as each student
must contribute by making a comment or defending.
Differentiated Instruction
Instead of the students debating with each other about which muscle type is the
most essential, they could work together to create a class presentation comparing
the two muscle types. The teacher can collaborate with the lower grade gym
classes and allow the students to teach the younger kids about the different
movements skeletal muscle helps with smooth muscle as well.
Additional Discussion Questions
Ask students to prepare a brief report that compares the structure and function of
multiunit and visceral smooth muscle, including examples of each.
Multiunit smooth muscle exhibits fibers that are well organized. The single fibers contract due
to motor nerve impulses or hormonal stimulation. The walls of blood vessels are examples of
this phenomenon. Visceral smooth muscles are sheets of spindle-shaped cells composed
of a longitudinal outer coat and a circular inner coat. Fibers stimulate each other during
rhythmicity. The urinary bladder is an example of visceral smooth muscle.
Peristalsis is the rhythmic contraction of smooth muscle that occurs in certain
tubular organs. Discuss examples of reverse peristalsis.
Examples may include the stimulation of the emetic center which induces vomiting, a back flow
of urine in the ureters from blockage, or a back flow of blood from an insufficient heart valve
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Practice
Practice Questions
1. Describe two major types of smooth muscle.
The two major types of smooth muscle are multiunit and visceral. Multiunit smooth muscle
cells are separated, rather than organized into sheets and contracts only in response to
stimulation by neurons or certain hormones. Visceral smooth muscle is composed of
sheets of spindle-shaped cells in close contact with one another. Visceral smooth muscle
is more common that multiunit and displays a pattern of rhythmic contractions.
2.What special characteristics of visceral smooth muscle make peristalsis
possible?
Rhythmicity and transmission of impulses from cell to cell are largely responsible for the
wavelike motion called peristalsis.
3. How does smooth muscle contraction differ from skeletal muscle contraction?
Two neurotransmitters commonly affect smooth muscle: acetylcholine and
norepinephrine. Smooth muscle is slower to contract and to relax than skeletal muscle,
and can maintain a forceful contraction longer with a given amount of ATP. Smooth
muscle cells can change length without changing tautness, allowing for constant
pressure inside organs.
Use the Practice 8.5
Asking Questions Develop a question about why peristalsis is found only in
smooth muscle.
Answers will vary. Example: What special characteristics of smooth muscle make
peristalsis possible?
Section 8.6: Cardiac Muscle
Learn
Classroom Activities
Writing Connection: Energy Transfer
Pair students in groups and give them the phrase “Cardiac muscle is self-exciting
and rhythmic”. Ask students to work together on an explanation of why this
statement is correct and use evidence to support their ideas.
Key points to ensure students discuss:
• Intercalated discs
• Actin and myosin
• Size of sarcoplasmic reticulum and transverse tubules
Differentiated Instruction
A more focused task for students would be to just explain the importance of
intercalated discs in cardiac muscle. Students could practice explaining this to
each other and then to a family member at home. Encourage EL students to
practice explaining in their native language as well as English.
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Additional Discussion Questions
Ask students to develop a chart that compares various characteristics among
skeletal, cardiac, and smooth muscles.
The chart should include information regarding location, appearance, presence or absence of
striations, control mechanisms, contraction speed, and functions.
Provide students with a variety of microscope slides of skeletal, cardiac, and smooth
muscle. Ask them to draw what they see and to comment on any similarities and
differences among the three types.
Responses should include a discussion of striations, nuclear configurations, transverse tubule
systems, and intercalated discs.
Practice
Practice Questions
1. How is cardiac muscle similar to smooth muscle?
Cardiac muscle and smooth muscle both have single nuclei in their cells. Cardiac and
smooth muscle cells both contract involuntarily. Cardiac and smooth muscle cells
contract rhythmically and are both self-exciting.
2. How is cardiac muscle similar to skeletal muscle?
Cardiac and skeletal muscle cells have actin and myosin filaments. Cardiac and skeletal
muscles are striated. Cardiac and skeletal muscles have a sarcoplasmic reticulum, many
mitochondria, and transverse tubules.
3. What is the function of intercalated discs?
Intercalated discs allow impulses to pass freely so that they travel rapidly from cell to
cell, triggering contraction.
4. What characteristic of cardiac muscle contracts the heart as a unit?
Intercalated discs help to join cells and to transmit the force of contraction from cell to
cell. Thus, when one portion of the cardiac muscle network is stimulated, the whole
structure contracts as a functional unit.
Use the Practice 8.6
Constructing Explanations Using what you have learned about muscle
contraction, describe how the structure of cardiac muscle allows it to produce
rhythmic, synchronized contractions.
Cardiac muscle releases a greater amount of calcium into the sarcoplasm resulting in a
longer twitch. Intercalated discs connect cell to cell and transmit the force on the
contraction from one cell to another. Together the slower twitch and the ability to pass
the impulse results in the rhythmic contraction of cardiac muscle.
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Section 8.7: Skeletal Muscle Actions
Learn
Classroom Activities
Hands-on Activity: Lever Challenge
Pairs students together. Give each pair of students the challenge to create or
design a lever that could be used in real-life that simulates the similar functions and
motions of the upper limb bending at the elbow and straightening. Each pair of
students will design one lever that functions this way. Students will present their
designed levers to the class and explain how it functions similar to the elbow.
Differentiated Instruction
Instead of students designing their own lever, the teacher should provide each
group of students with a picture of a lever. Some levers may be very similar,
and some levers may not be similar to an elbow. Each pair of students should
describe how the lever they were assigned is similar and different in terms of
structure and function to the movement at the elbow. Remind students to
include details on how the muscles affect the movement.
Additional Discussion Questions
Ask students to make a list of 25 muscles and determine by which criteria each
muscle derived its name.
Students should categorize the muscles they have chosen by size, location, number of origins,
shape, direction of the muscle fibers, action, and origin/insertion points.
Have classmates demonstrate various muscle movements to each other. The
classmates should identify the skeletal muscles involved, and determine which
muscles are contracting or relaxing during each demonstration.
Demonstrations will vary but should emphasize the concepts of prime movers, antagonists,
synergists, and fixators.
Practice
Practice Questions
1. Distinguish between the origin and the insertion of a muscle.
One end of a skeletal muscle usually attaches to a relatively immovable or fixed part on
one side of a movable joint, and the other end attaches to a movable part on the other
side of that joint, such that the muscle crosses the joint. The less movable end of the
muscle is called the origin and the more movable end is its insertion.
2. Define agonist.
An agonist, as it refers to muscles, helps the muscle perform a particular action. For
example, for the action of flexion of the elbow, biceps brachii would be the agonist.
3. What is the function of a synergist? An antagonist?
A synergist, as it refers to muscles, is a muscle that contributes to another muscle being able
to perform a particular action. For example, pectoralis major and latissimus dorsi are
synergistic for medial rotation of the arm. An antagonist, as it refers to muscles, is a muscle
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that works against a muscle being able to perform a particular action. For example, triceps
brachii is the antagonist for flexion of the elbow, since that muscle works to extend the elbow.
Use the Practice 8.7
Using Models In literature, the protagonist is the main character, and the
antagonist is the chief opponent. Use this structure to describe skeletal muscle
actions.
Skeletal muscles almost always function in groups. And although skeletal muscles do not
have a protagonist, they do have a prime mover or agonist. Working against this action,
is the antagonist. Together these muscles create movement.
Section 8.8: Major Skeletal Muscles
Learn
Classroom Activities
EL Strategy: Oral Language Development
Intermediate When discussing the name of skeletal muscles, instruct student
partners to make and use flashcards to check each other’s pronunciation and
understanding. Students should have two copies of figure 8.16 on paper. They
can label one and quiz each other with the unlabeled version. Have students
repeat each word and point to the visual representation as you review
vocabulary.
Visual Literacy: Muscle Scramble
Arrange students in small groups. The teacher should create a printout of the
different section of body. Each group is responsible for creating a game to help
other students remember the muscles in their assigned region, including the origins,
insertions, and actions. Depending on the length of the activity, groups could be
given time to bring in materials or create a game virtually. Once all games are
complete, rotate groups around the room so they have a chance to play every game
and practice with the different muscles in the human body.
Differentiated Instruction
Instead of students designing their own games, the teacher could assign each
group a game to create for their muscle type. This would ensure a variety of
games to engage students as well as reduce the amount of time required for
students to create the game. Pair groups of students together to practice their
games and help each other complete them.
Demonstration Activity: Muscle Shirt
For this activity, have students bring in a plain white t-shirt. Provide them with
permanent markers to draw the different types of muscles as you talk. You may
choose to do this activity by focusing on mainly the different types of skeletal
muscles, or you may decide to have the students draw the three different types of
muscles – skeletal, smooth, and cardiac, using different colors.
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Additional Discussion Questions
Ask students to locate on a wall chart or model as many superficial skeletal muscles
of the anterior and posterior aspects as possible. The name, origin, insertion, and
major actions should also be noted.
Students should be able to identify and discuss a minimum of 36 skeletal muscles.
Discuss the adverse effects of anabolic steroid use to build muscular strength and
endurance.
Responses should include the following possible side effects: increase in aggressive behavior,
addiction, psychosis, hair growth, sexual dysfunction, high blood pressure, atherosclerosis, liver
damage, cancer, etc.
Practice
Practice Questions
1. What information is imparted in a muscle’s name?
The name of a muscle may indicate its size, shape, location, action, number of attachments,
or direction of its fibers.
2. Which muscles provide facial expressions? Ability to chew? Head movements?
Facial expressions: epicranius, orbicularis oculi, orbicularis oris, buccinator, zygomaticus,
and platysma. Chewing: masseter and temporalis. Head movement: sternocleidomastoid,
splenius capitis, semispinalis capitis, and the scalenes.
3.Which muscles move the pectoral girdle? Abdominal wall? Pelvic outlet? The
arm, forearm, and hand? The thigh, leg, and foot?
Pectoral girdle: trapezius, rhomboid major, levator scapulae, serratus anterior, and
pectoralis minor. Abdominal wall: internal and external obliques, rectus abdominis, and
transversus abdominis. Pelvic outlet: levator ani, coccygeus, superficial transversus perinei,
bulbospongiosus and ischiocavernosus. Arm: coracobrachialis, pectoralis major, teres
major, latissimus dorsi, supraspinatus, deltoid, subscapularis, infraspinatus, and teres
minor. Forearm: biceps brachii, brachialis, brachiradialis, triceps brachii, supinator,
pronator teres, and pronator quadratus. Hand: flexor carpi radialis, flexor carpi ulnaris,
palmaris longus, flexor digitorum profundus, extensor carpi radialis longus, extensor carpi
radialis brevis, extensor carpi ulnaris, and extensor digitorum. Thigh: psoas major, iliacus,
gluteus maximus, gluteus medius, gluteus minimus, tensor fasciae latae, adductor longus,
adductor magnus, and gracilis. Leg: sartorius, biceps femoris, semitendinosus,
semimembranosus, rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius.
Foot: tibialis anterior, fibularis tertius, extensor digitorum longus, gastrocnemius, soleus,
flexor digitorum longus, tibialis posterior, fibularis longus, and fibularis brevis.
Use the Practice 8.8
Using Mathematics The human skeleton has 206 bones, but the muscular
system contains more than 600 muscles. Explain the benefit of having more
muscles than bones.
Muscles do more than move our bodies, they are responsible for pumping blood and
controlling digestion. In addition, muscles provide the tug on the bones to make them
move. But because muscles can only pull on bones, and not push on bones, for every
movement (or bone) we need at least two muscles.
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Assess
Career Corner: Physical Therapy Assistant
Consider This: Of the 3 muscle types, with which type do you think a physical
therapy assistant is most concerned?
A physical therapy assistant works primarily with skeletal muscles. Through exercise,
cardiac muscle also benefits, and healthy cardiac muscle ensures healthy smooth muscle.
Healthy Lifestyle Choices: Steroids and Athletes – An
Unhealthy Combination
1.Explain what happens to the levels of testosterone in a male athlete who
abuses steroids and how this explains the signs and symptoms of steroid abuse
(hint: think about negative feedback loops).
As mentioned in the excerpt, the levels of testosterone and estrogen are increased in a
male who abuses steroids. Since there are increased levels of testosterone in the blood
from the steroids, the testicles stop making their own testosterone and shrink. The
estrogen levels are increased due to the negative feedback the steroids have on the
testicles. The breast tissue is stimulated by the now excess estrogen.
2.Describe how the metabolic capacity of a muscle changes with physical exercise.
With high-intensity exercise, which depends more on glycolysis for ATP, a muscle
synthesizes more glycolytic enzymes, and its capacity for glycolysis increases. With
aerobic exercise, more capillaries and mitochondria form, and the muscle’s capacity for
aerobic respiration is greater.
Healthy Lifestyle Choices: Use and Disuse of Skeletal Muscles
1. Describe the difference between slow-twitch and fast-twitch muscle fibers.
Slow twitch fibers are used for endurance activities, like swimming or running. Increasing
the use of slow twitch fibers results in greater endurance, but not necessarily their size or
strength. Conversely, fast twitch fibers are used in forceful exercise. Increasing fast
twitch fibers can increase a muscle’s size and contraction strength, but not its endurance.
2.Muscles respond to increased use by hypertrophy, which is the enlargement of
the muscle fibers. Can you think of a part of the body where hypertrophy
could cause a problem?
Enlargement of cardiac muscle fibers is problematic and great pains are taken to
prevent this from occurring. The enlargement of the cardiac muscle, seen in conditions
like aortic stenosis, occurs when the left ventricle must pump blood against a narrowed
aortic valve. The left ventricle has to increase its pumping force in that situation, and
does so by enlargement of the cardiac myocytes. As time goes by, the heart loses its
ability to maintain these high pumping pressures and failure ensues.
Genetics Engineering: Inherited Diseases of Muscle
1.Describe how hereditary idiopathic dilated cardiomyopathy disrupts the
rhythm of cardiac muscle.
The condition is caused by a mutation in a gene that encodes a form of actin found only
in cardiac muscle. The mutation disturbs actin’s ability to anchor to the Z lines in heart
muscle cells, preventing actin from effectively transmitting the force of contraction.
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2.Describe how the protein dystrophin differs in Duchenne and Becker muscular
dystrophies, and why this difference results in one type being more severe
than the other.
In Duchenne muscular dystrophy (DMD), the protein dystrophin is severely shortened or
missing entirely. This produces symptoms that start in childhood. In Becker muscular
dystrophy, the correct form of dystrophin is produced but at extremely low levels.
Case Study Connection
page 241: If these facial muscles were all the same size, which would require
more caloric energy, smiling or frowning?
Frowning
page 242: Knowing that his muscles are functioning normally, will the child
with a myostatin mutation have the same ratio of myosin to actin as his
siblings without the mutation?
Yes – he will just have many more muscle cells
page 252: Because he has more muscle mass, will the child with the myostatin
mutation need more blood volume and more blood vessels?
More
page 252: This child has significantly more muscle mass than his peers. Last
week in his Kindergarten class, the school’s heat system broke and the
classroom was cold. How do you think this child felt in the cold room
compared to his classmates?
Since muscle produces so much body heat, the child with the myostatin mutation should
feel warmer
page 254: Muscle atrophy is common in AIDS and other diseases. What might
occur in AIDS patients if a myostatin inhibitor (a drug that could stop the
action of myostatin) was given?
Accept all answers which show sound reasoning
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Exercise that includes strength training offers all of the
following benefits except
a. increases the body’s energy efficiency
b. lowers blood pressure
c. decreases the risks of developing arthritis and osteoporosis
d. increases bone density and bone length
2. The sheet of dense connective tissue that separates
individual muscles and helps hold them in position is called
a. fascicles
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b. fascia
c. epimysium
d. endomysium
3. The cell membrane of a skeletal muscle fiber is called the
a. sarcolemma
b. sarcoplasm
c. sarcomere
d. sarcoplasmic reticulum
4. All of the following describe the sliding filament model of
muscle contraction except
a. ATPase catalyzes the breakdown of ATP to ADP and
phosphate inside myosin heads.
b. Calcium binds to troponin, pulling tropomyosin aside to
expose binding sites on actin.
c. The length of the thick myosin filaments shortens as thin
actin filaments slide past.
d. When ATP binds to myosin, the connection between the
two filaments is broken.
5. Which of the following muscle cell components aids in the
ability to store the oxygen required for energy muscle cells,
which utilize relatively large quantities of energy?
a. creatine phosphate
b. myoglobin
c. hemoglobin
d. lactic acid
6. Continuous, forceful muscular contraction without relaxation
is called
a. latency.
b. summation.
c. complete tetany.
d. partial tetany.
7. Fill in the blanks: Peristalsis describes the
waves of
smooth muscular contraction in the walls of certain
tubular organs such as the stomach intestines.
a. rhythmic; visceral
b. rhythmic; multiunit
c. random; visceral
d. random; multiunit
8. Which of the following descriptions truly applies to cardiac
muscle?
a. Cardiac muscle cells contain many nuclei.
b. Cardiac muscle cells contract and relax slowly.
c. Cardiac muscle cells lack transverse tubules.
d. Cardiac muscle cells junction at intercalated discs.
9. When a person extends their knee to straighten their leg,
three muscles work together as prime movers called the
rectus femoris, the vastus medialis, and the vastus lateralis
(all quadriceps). What is the best term for these three
muscles working together in leg extensions?
a. agonists
b. synergists
c. antagonists
d. origins
10. Which muscle functions to compress the cheeks with its
origin at the alveolar processes of maxilla and mandible?
a. epicranius
b. buccinator
c. masseter
d. temporalis
Short Answer
1. What are all of the functions of the muscular system?
Muscle provides body movement, heart beats, and digestive
tract movement. It also helps with thermoregulation.
2. What is fascia?
A dense connective tissue that separates individual muscles.
3. Describe a myofibril.
A myofibril is a tube of muscle cell. Within a myofibril there are
two contractile proteins, actin and myosin.
4. Distinguish between actin and myosin.
Actin is shaped like a long beaded necklace and is surrounded
by the regulatory proteins troponin and tropomyosin. Myosin
has extensions called heads.
5. Describe the unique structure of a muscle cell.
A muscle cell is a long tube. It is multinucleate for efficient
protein synthesis; to sustain the great energy demands it has a
high density of mitochondria. It has a unique ER called the
sarcoplasmic reticulum that is built to propagate a stimulus
rapidly throughout the entire cell.
6. What is a sarcomere?
Sarcomeres are the smallest functional units of contraction
that contribute to a muscle generating a force. Actin
and myosin are organized in an overlapping fashion for
contraction in sarcomere. Sarcomeres separated from each
by Z lines.
7. Describe the sliding filament model of muscle contraction.
When a muscle cell is stimulated the myosin heads attach to
the actin filaments, pulling them toward the middle, causing a
contraction of the sarcomere. This generates a force.
8. What is a motor unit?
A motor unit consists of a motor neuron and all of the muscle
cells it stimulates.
9. What is recruitment?
A muscle cell either contracts or it does not. If only a few
motor units fire off the force generated is small. If a larger
force is needed, more motor units will be recruited to help.
10. What is the neuromuscular junction?
The neuromuscular junction is the place where the motor
neuron meets the motor end plate of a muscle cells.
Neurotransmitters bind to receptors on the muscle cell here.
11. Distinguish between flexors and extensors.
Flexors are muscles that aid in closing an angle at a joint.
Extensors are muscles that aid in opening the angle at
a joint.
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12. Distinguish between origin and insertion.
The origin is the tendinous attachment to the less movable
end of a muscle. It is often attached to a bone that does not
move during the action. The insertion is the tendinous
attachment to the more movable end of a muscle. It is usually
attached to a bone that moves during the action.
13. What is the relationship between agonists, antagonists and
synergists?
An agonist is a muscle that brings about a desired action. An
antagonist is a muscle that opposed the action. A synergist is
a muscle that aids the agonist.
14. Distinguish between smooth muscle and cardiac muscle.
Smooth muscle is under involuntary control for digestion and
vasoconstriction. It contracts slowly and is non-striated. Cardiac
muscle is under involuntary control and found only in the heart.
It is striated and contracts/relaxes like skeletal muscle.
15. What is oxygen debt and fatigue?
Muscle fatigue is not fully understood but contributing to it
are, lack of energy and changes in pH.
Critical Thinking and Clinical Applications
1. WRITING Connection Discuss how connective tissue is
part of the muscular system.
Layers of fibrous connective tissue separate an individual
skeletal muscle from adjacent muscles and hold it in position.
Connective tissue also forms broad fibrous sheets which may
attach to bone or to the coverings of adjacent muscles.
2. All muscles contain fast and slow muscle fibers in various
ratios. This is controlled mostly genetically. What would be
the difference between these ratios in a marathon runner
and a sprinter?
In a world class marathon runner you would expect to find
muscles that had more than the average amount of slow fibers
for endurance. In a sprinter, you would find the opposite,
muscles with many fast fibers.
3. The drug neostigmine inhibits the function of
acetylcholinesterase. What do you predict will be the effects
of this drug?
Acetylcholinesterase degrades acetylcholine after muscle
contraction. Therefore, muscle cells would stay in state of
contraction longer than usual because of the abundance of
acetylcholine.
4. CLINICAL Connection The poison curare blocks Ach from
binding to receptors in the neuromuscular junction. What
would be the effects of this? How could this be used in a
clinical/medical setting?
Muscles would not be able to contract, thereby causing
paralysis. It could be used to treat muscle spasms and maybe
for localized temporary paralysis for medical procedures.
5. What steps might be taken to minimize atrophy of the
skeletal muscles in patients confined to bed for prolonged
times?
Passively moving or electrically stimulating the injured muscle
would help prevent muscle atrophy and contractures.
Lab Data Analysis: Mutations in a Giant Gene
Think Critically
1. Based on the chart, describe the various roles of the
dystrophin gene and protein.
Clearly, the dystrophin protein is essential in many different
intracellular processes. Among them, it is especially active in
the contractile function of the heart muscle cell (“Contractile
Apparatus”), as well as production of ATP as evidenced by its
role in the “Citric Acid Cycle” and “Oxidative Phosphorylation”.
2. Which cellular function is most dependent on the dystrophin
gene?
Given that the “contractile apparatus” constitutes 31% of all
dystrophin activity within the cell (more than any other cellular
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function), we can conclude that dystrophin is most vital to
helping the heart muscle cell contract.
3. Recall the Genetic Engineering feature “Inherited Diseases
of Muscles” (page 219). Describe how the role of dystrophin
in muscle cells explains some of the symptoms observed in
muscular dystrophy.
Many of the symptoms in muscular dystrophy relate to muscle
weakness and degeneration. Dystrophin holes skeletal muscle
cells together and also relates to their ability to contract.
Without dystrophin, muscle fibers cannot contract normally,
leading to weakness and eventual degeneration.
UNIT
Integration and
Coordination
Chapter
9 Nervous System
10 Senses
11 Endocrine System
3
Pacing (class periods)
19
10
7
Unit 3 Resources
Unit Project Engineer a Healthier World – Engineering in Anatomy and Physiology
nit Project: Engineer a Healthier World —
U
Engineering in Anatomy and Physiology
Project 3: Curing Diabetes
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Treating Diabetes” (p. 415), and use this to start
their investigation into bioengineering medicines.
A teacher guide for this project can be found online.
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CHAPTER
9
Nervous System
Section
9.1 Introduction
Pacing
(class periods)
—
Learning Outcomes
1. Distinguish between the two types of cells that
compose nervous tissue.
2. Name the two major groups of nervous system
organs.
9.2 Nervous System
Organization
1
1. Explain the general functions of the nervous
system.
9.3 Neurons
2
1. Describe the general structure of a neuron.
2. Explain how differences in structure and
function are used to classify neurons.
9.4 Neuroglia
1
1. State the functions of neuroglia in the central
nervous system.
2. Distinguish among the types of neuroglia in the
central nervous system.
3. Describe the Schwann cells of the peripheral
nervous system.
9.5 Charges Inside a
Cell
1
1. Explain how a membrane becomes polarized.
9.6 Impulse
Conduction
1
1. Explain how an impulse is conducted in
unmyelinated neurons; in myelinated neurons.
9.7 The Synapse
1
1. Explain how information passes from one
neuron to another.
9.8 Synaptic
Transmission
1
1. Locate and identify the bones and the major
features of the bones that compose the thoracic
cage.
2. Describe the events that lead to the generation
of an action potential.
2. Neurotransmitters have various effects when
they diffuse across the synaptic cleft and react
with specific receptor molecules in the
postsynaptic neuron membrane.
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9.9 Impulse
Processing
1
1. Describe the general ways in which the nervous
system processes information.
9.10 Types of Nerves
1
1. Describe how nerves are classified.
9.11 Neural Pathways
2
1. Describe the function of each part of a reflex
arc, and name two reflex examples.
9.12 Meninges
1
1. Describe the coverings of the brain and spinal
cord.
9.13 Spinal Cord
2
1. Describe the structure of the spinal cord and its
major functions.
9.14 Brain
2
1. Name the major parts of the brain and their
functions.
2. Distinguish among sensory, association, and
motor areas of the cerebral cortex.
3. Describe the location, formation, and function
of cerebrospinal fluid.
9.15 Peripheral
Nervous System
1
1. List the major parts of the peripheral nervous
system.
2. Name the cranial nerves, and list their major
functions.
3. Describe the structure of a spinal nerve.
9.16 Autonomic
Nervous System
1
1. Describe the functions of the autonomic
nervous system.
2. Distinguish between the sympathetic and
parasympathetic divisions of the autonomic
nervous system.
3. Describe a sympathetic and a parasympathetic
nerve pathway.
Focus Activity Workbook
Focus Activities: Labeling (14)
Focus Activities: Vocabulary (15)
Chapter Resources
Extended Summary Review
Chapter 9 Test Bank
Chapter 9 Interactive Question Bank
Vocabulary Flashcards
APR Module 7: Nervous System
Laboratory Exercise 17: Nervous Tissue and Nerves
Laboratory Exercise 18: Spinal Cord, Spinal Nerves, and Meninges
Laboratory Exercise 19: Reflex Arc and Reflexes
Laboratory Exercise 20: Reaction Rates and Practice
Laboratory Exercise 21: Brain and Cranial Nerves
A Suggested Approach
One of the densest chapters in the book, this chapter expands on the knowledge of
nervous tissue introduced in Chapter 5 and further familiarizes students with the
structure and functions of neurons and various divisions of the nervous system.
In order for students to understand the brain function, they must first learn the
normal function and structure of a neuron, the fundamental building block of the
nervous system. By discussing the versatile roles of the nervous system, students
can equate the anatomical structures and function of all neurons, as well as compare
the how neurons differ in structure and function. The anatomy of a neuron also
explains how neurons make excellent conductors of action potential, which enables
us to communicate, think, and move.
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Action potential, introduced in the muscular system chapter, is revisited as the way
impulses are propagated through neurons of the nervous system as well. Students
can develop a model of the propagation of the action potential by using dominos.
This activity can give students a sense of how impulse conduction is propagated
down an axon in an all or none response.
One way to understand neurotransmission, is to examine how different drugs of abuse
disrupt communication between neurons. There are many available online activities in
which students can further their knowledge about neurons and neurotransmission. For
example, NIH The Brain: Understanding Neurobiology Through the Study of Addiction
(found on the NIH website), Project Neuron: Why Dread a Bump on the Head (found
on the Project Neuron/University of Illinois website ), and Genetic Science Learning
Center The Science of Addiction (found on the University of Utah website) all lend
valuable lessons and insights to understanding how neurons communicate.
The routes impulses follow as they travel through the nervous system are call nerve
pathways. Students can demonstrate several different nervous system reflexes on
each other, make observations, and explain the path of the nerve impulse. In each
case, a specific receptor, nerve pathway, and muscles are involved.
Attention can be given to each of the brains functional regions through dissection of
a sheep brain. Students can identify the basic anatomy of the brain, as well as provide
an understanding of the function of each region. If students are not comfortable with
a physical dissection, an online version of the dissection can be used such as
Exploratorium: Sheep Brain Dissection (http://www.exploratorium.edu/memory/
braindissection/). Building on the effects of a drugs on neurons, students can also
study the effects of a specific drug on the brain, or further investigate brain function by
studying Traumatic Brain Injuries (TBI) using the aforementioned on – line resources.
This chapter is expected to take 19 class periods including Lab 17, Lab 18, Lab 19,
Lab 20, and Lab 21.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy used
to teach students how to construct explanations and craft scientific arguments.
A scientific claim answers a question or offers a solution to a problem. Give
students time to reflect and brainstorm, then have each student take a clear
stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is
information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support a
claim. Encourage students to return to their claims and add evidence at multiple
points in the chapter.
Students may be interested in the article linking CTE and TBI to football. The
article has a video with the senior author as well as all the data that support the
authors’ claim. It can be found in full online, at the JAMA network website. It is
from 2018, JAMA issue 318, volume 4, by Mez et al.
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Introduction to the Theme
Theme: Systems and Model Systems The maintaining of homeostasis through
electrical signal provides higher mental function and responses while activating
muscles and glands. This system helps us to understand the boundaries and
environment under which the human body operates.
Theme Activity: The Path of an Impulse
For this activity, students will trace the pathway of an electrochemical impulse and
the associated biochemical changes. Before you hand out the worksheet, you can
review the parts of a reflex arc.
Have students create a drawing of six boxes, connected by arrows. Fill in the boxes
to complete the reflex arc that occurs when someone steps on a tack.
Section 9.1: Introduction
Learn
Classroom Activities
Section 9.1 sets the groundwork for activities in sections 9.2 and beyond.
Additional Discussion Questions
Ask students to identify microscopic structures of the nervous system.
Provide students with prepared slides that exhibit dendrites, the cell body, an axon, and
neuroglial cells.
Compare and contrast various types of glial cells, based on structure and function.
Responses may include an analysis of microglial cells, oligodendrocytes, astrocytes, and
ependymal cells.
Practice
Practice Questions
1. What are the two major types of cells that form nervous tissue?
Nervous tissue consists of masses of neurons, or nerve cells and neuroglia that provide
physical support, insulation, and nutrients for neurons.
2. What are the two major subdivisions of the nervous system?
The nervous system is divided into the central nervous system (brain and spinal cord) and
the peripheral nervous system (cranial and spinal nerves).
Use the Practice 9.1
Communicating Information Summarize the general functional areas of a
typical neuron.
A typical neuron has a cell body, dendrites and an axon.
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Section 9.2: General Functions
of the Nervous System
Learn
Classroom Activities
Group Activity: Telephone
This is a whole class activity. Discuss with students the main differences between
the central nervous system and the peripheral nervous system. Split the class into
four groups, positioning one group in each corner or area of the room. Assign each
of the four groups a job: sensory division; motor division-somatic nervous system,
motor division-autonomic nervous system; and central nervous system. Allow
students to discuss in their small groups what their assigned group’s main job is in
relation to the nervous system. The teacher will provide students with a scenario
such as the boy picked up a piece of ice and was holding it in his palm. The group
that is responsible to first respond must create a note and deliver it to the next
group that would be in line to receive a direction or message. Each group as they
receive instructions, or a message must pass along the message with appropriate
directions leading the boy to have a reaction due to the ice being cold.
Differentiated Instruction
This activity could also be completed in small groups of four. Each student
would be assigned a role and they could take turns passing the message. To
help students understand the concept of the activity, the teacher could begin
the class with a fill in the blank game. The relation is that students are passing
along a message but adding to it or giving directions to get to a final end result
or action.
Additional Discussion Questions
Ask students to develop an organizational chart that illustrates the interrelationships
among the major divisions and subdivisions of the nervous system.
The chart should include the central nervous system, peripheral nervous system, sensory
division, motor division, autonomic nervous system, somatic nervous system, sympathetic
nervous system, and parasympathetic nervous system.
Divide the class into small groups and ask each group to define brain death. Discuss
their viewpoints.
Consider the moral, ethical, legal, medical, and financial implications of the definition.
Practice
Practice Questions
1. How do sensory receptors collect information?
Sensory receptors gather information by detecting changes inside and outside the body.
Sensory receptors monitor external environmental factors, such as light and sound
intensities, and conditions of the body’s internal environment, such as body temperature
and oxygen level.
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2. How does the central nervous system integrate incoming information?
Sensory receptors convert environmental information into impulses, which are then
conducted on peripheral nerves to the central nervous system. There, the signals are
integrated creating sensations, adding to memory, or helping produce thoughts that
translate sensations into perceptions.
3. What are the two types of motor functions of the nervous system?
The motor functions of the peripheral nervous system fall into two categories, voluntary
and involuntary. Those that are under voluntary (conscious) control involve the somatic
nervous system, which controls skeletal muscle. In contrast, the autonomic nervous
system controls effectors that are involuntary, such as cardiac muscle, smooth muscle,
and glands.
Use the Practices 9.2
Using Models Develop a model based on evidence to illustrate the
relationships among the components of the nervous system.
Answers will vary. Example: When you call a friend, the message is not going directly to
your friend’s phone. Similarly, when you sense something, it has traveled to your brain
through peripheral neurons to the central nervous system, where it is integrated.
Section 9.3: Neurons
Learn
Classroom Activities
Visual Literacy: Scaling Neurons
This is an individual or small group activity. Give students a piece of graph paper.
The reading describes the scale of the components of a neuron as a tennis ball and
one-mile length. Students should be given the tools to accurately measure a tennis
ball. Using the given 1-mile length and measured size of a tennis ball, students
should create a to-scale neuron on the piece of graph paper. The three parts
students should represent in a neuron are the cell body, dendrites, and axon.
Drawings should depict a very close image to how each part is structured.
Differentiated Instruction
To make this activity more challenging, students could depict the different
structural neurons instead of a generic neuron. Students could focus on
multipolar, unipolar, and bipolar neurons. All neurons should be drawn to scale
so students can see the relationship between the cell body, dendrites, and
axon.
Additional Discussion Questions
Provide students with an unlabeled diagram of a neuron and ask them to label it.
The labeled diagram should contain the cell body, dendrite, axon, nucleus, Nissl body,
neurilemma, node of Ranvier, Schwann cell, myelin sheath, axonal terminal, synapse, and
neurofibril.
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Distinguish among the major types of sensory receptors.
Students should be able to distinguish among Meissner’s corpuscle, Ruffini’s corpuscle,
Pacinian corpuscle, Golgi tendon organ, and Krause’s end bulb.
What do we call the portion of the neuron process that connects dendrites to the
axon?
The portion from dendrites to cell body, is called a peripheral process. The second portion,
from the cell body to the CNS, is referred to as the central process.
Practice
Practice Questions
1. Distinguish between a dendrite and an axon.
Dendrites are short and highly-branched processes that arise from the cell body and are
the neuron’s main receptive surface for impulses. The axon is a single extension from the
cell body that transmits impulses to other neurons away from the cell body.
2. Describe the components of a neuron.
Neurons have a cell body, dendrites, and an axon. The cell body contains a nucleus and
nucleolus, as well as the organelles found in other cells. In place of the rough ER, a
specialized structure called chromatophilic substance (Nissl bodies) exists to carry out
protein synthesis. Dendrites, which branch off the cell body, receive impulses from other
neurons and the signal is further propagated to other neurons via an axon, which is a
single process off the cell body.
3.Name three groups of neurons based on structure and three groups on
function.
Structural classifications of neurons include multipolar neurons, bipolar neurons, and
unipolar neurons. Functional classifications of neurons include sensory (afferent) neurons,
interneurons, and motor (efferent) neurons.
Use the Practices 9.3
Asking Questions Develop a question about how the structural differences
between the types of neurons relate to their differing functions.
Answers will vary. Example: Multipolar neurons have many dendrites arising from the cell
bodies, and are found primarily in the brain. What might the advantage be of having
multiple dendrites in the brain? ANSWER: To receive multiple signals.
Section 9.4: Neuroglia
Learn
Classroom Activities
Writing Connection: Neuroglia Creative Writing
Pose to students that glial cells are known as the “nerve glue” in the central nervous
system. Ask students to explain why this association makes sense. They must also
include the following words in their writing: microglial, oligodendrocytes, astrocytes,
Schwann cells, ependymal cells, and satellite cells. Review proper grammar and
writing style with students.
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Differentiated Instruction
Provide students the option to explain why the association of glial cells to
“nerve glue” makes sense in different formats. During the first part of the
class, the teacher should review different ways to express their thoughts
besides through writing. Some ideas are storyboard, speech, or digital
presentation.
Additional Discussion Questions
Ask the students to create a chart of the neuroglia including a drawing of the
neuroglia and describe the function.
The students’ chart should include all the neuroglia cells.
Ask students to devise a chart depicting various functions of each type of glial cell.
The students’ charts will include a comparison of microglial cells, oligodendrocytes, astrocytes,
and ependymal cells.
Ask students to research a disease that may result from malfunctioning accessory
cells in the nervous system.
An example is multiple sclerosis, which affects the myelin sheath formed by Schwann cells.
Practice
Practice Questions
1. Provide the functions of the glial cells that support the neurons in the CNS.
Microglia are phagocytes that remove bacterial cells and cellular debris from the central
nervous system. They also form scars in damaged areas. Oligodendrocytes produce
myelin, which insulates the axons of nerve cells in the central nervous system. Schwann
cells perform that function in the peripheral nervous system. Astrocytes provide structural
support, join other structures together, and regulate the concentrations of nutrients and
ions in nervous tissue. Ependymal cells line the spinal canal and ventricles of the brain.
2. Distinguish among the types of neuroglia in the central nervous system.
Microglia are phagocytes that remove bacterial cells and cellular debris from the CNS.
Oligodendrocytes produce myelin. Astrocytes provide structural support, join other
structures together, and regulate the concentrations of nutrients and ions in nervous
tissue. Ependymal cells line the spinal canal and ventricles of the brain.
3. What is the function of Schwann cells and satellite cells in the PNS?
Schwann cells in the PNS perform the same function as oligodendrocytes in the CNS,
that is, they produce myelin.
4.Explain why axons of peripheral nerves can regenerate, but axons of central
nervous system nerves cannot.
In the PNS, the Schwann cells that coat an axon do so in a way that allows for their
nuclei to remain outside the myelin sheath itself, and form a structure known as a
neurilemma, which surrounds the myelin sheath. The neurilemma is essential for the
ability of a neuron to repair itself and CNS neurons lack a neurilemma.
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Use the Practices 9.4
Arguing from Evidence You might have heard that you use “only 10%” of your
brain. Given that individuals use 100% of their neurons in their brains on any
given day, evaluate this claim based on what you know about the relative
number of neuroglia.
Our brain is not only made of neurons, rather it is primarily neuroglia. Neuroglia are cells
that fill spaces, and provide the structural framework for the working neurons of our brain.
Section 9.5: Charges Inside a Cell
Learn
Classroom Activities
Visual Literacy: Depolarization Game
The teacher will create the following game for each small group of students in the
class. Students will play the game to practice concepts related to action potential,
depolarization, and repolarization.
Game Materials
1 large 11 X 14 sheet of paper
1 regular 8 X 10 sheet of paper
6 large paperclips
Markers
1 pink and 1 purple sheet of construction paper (or two colors of choice)
Scissors
1 die (game dice) to roll
Game Setup
The teacher will create a cell membrane replica with three ion channels as shown in
Figure 9.9 on the large white paper. Pull the long end of each paper clip to a
90-degree angle and insert the point through the paper at the end of each ion
channel representing the gates (6 total). The bigger half of the paperclip should
be on the topside of the game sheet and be able to swivel. Create a set of K+ ions
and a set of Na+ ions from the pink and purple construction paper and label them. On
the regular white sheet of paper, create a voltage scale representing -70mV
resting potential up to +30 mV known as the action potential. Label the scale
between -70mV and -55mV in equal increments of 4 aligning to the die numbers
1–6.
Example Scale -70mV= 1, -67mV = 2, -64mV= 3, -61mV= 4, -58mV= 5,
-55mV= 6
Game Rules
The goal of the game is to get to -55mV which triggers the threshold potential
and earns +30 points equivalent to the action potential. The player with the most
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points at the end of regulated time wins. The first player will roll the die the first
time. Whatever number is on the die is the mV earned. The player now has the
option to stay at that mV and wait until next turns or by a second roll with 10mV. If
a player reaches six points either by adding the number of the die from two turns
or rolling a six, the player must simulate depolarization and collect their points
=+30. The next player to go is responsible for simulating repolarization and
resetting the ions for their turn. Keep score by adding the number of +30mV each
player earns or subtracting when a player purchases a second turn for a loss of
-10mV from their score.
Differentiated Instruction
Instead of playing this as a competitive game, the teacher would still create
the game pieces, but students would work in pairs and take turns drawing out
of the hat one of the mV values listed above. If a student draws anything below
-55mV they should explain why action potential didn’t occur. If a student
draws a -55mV, they will simulate depolarization and repolarization with the
game pieces. Students can take turns completing this task until both feel
comfortable with the process.
Additional Discussion Questions
Ask students to draw the membrane including the distribution of charges across the
membrane and arrows for the electrochemical gradient.
Answers will vary
Explain what happens when your arm falls asleep after awkwardly lying on it for an
extended period of time.
The pressure exerted on your arm by your body weight has a decrease in supply of oxygen and
nutrients to the neurons. When the pressure is alleviated, you feel a tingling in your arm due to
the return of nerve impulse transmission.
Practice
Practice Questions
1.Describe the ion distribution that creates the resting membrane potential in an
inactive neuron.
The cell membrane is more permeable to potassium ions than to sodium ions, so potassium
ions diffuse out of the cell more rapidly than sodium ions can diffuse in. The overall charge
on the isnide of a cell is due mainly to the negatively charged protiens and anions which
cannot cross the membrane.
2. List the major events of an action potential.
When threshold potential is reached, sodium channels, which are normally closed, open
and allow sodium from outside the cell to flow into the cell. This flow of positive charge
causes the inside of the cell, which is typically slightly negative, to become positively
charged. In response to this positive charge, potassium channels open allowing
potassium to flow out of the cell. Potassium flows out of the cell until the negative charge
of the cell’s interior present at rest is achieved once more.
3. Define all-or-none response as it relates to impulse conduction.
An action potential is an all-or-none response. If a neuron responds at all to stimulation,
it responds completely. An action potential will occur whenever a stimulus of threshold
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intensity or above is applied to an axon, and all action potentials occurring on that axon
are the same strength. A greater intensity of stimulation does not produce a stronger
action potential, but instead produces more action potentials.
Use the Practice 9.5
Analyzing Data Action potentials are measured as voltage changes. Using
Figure 9.13, determine the voltage range for the four phases of an action
potential.
Resting = -70 mV
Depolarization = -70 to +30 mV
Repolarization = +30 to -70 mV
Hyperpolarization = -70 to -100 mV
Section 9.6: Impulse Conduction
Learn
Classroom Activities
Group Activity: Metaphor Discussion
Discuss with the whole group what impulse conduction is and how it occurs. Pair
students together and ask them to create a metaphor that demonstrates the same
process. Student will need to present their metaphor and explain why it represents
impulse conduction. Encourage students to think about their own daily lives and to
create a metaphor that is not also a science concept.
Differentiated Instruction
Instead of students creating their own metaphor, the teacher would create a
set of metaphors where some are correct representations, and some are not.
Students would work in pairs to evaluate each metaphor and determine if it is
an accurate representation of impulse conduction.
Additional Discussion Questions
Have the students demonstrate an impulse conduction by performing the ‘wave’ in class.
Each student would be a section on the membrane. When the student stands up, it is
depolarization, and when the students sits down it is repolarization. As the result of one
students standing up and sitting down, it causes the next person to stand up and sit down. If
your classroom as an aisle between students, this would be the Nodes of Ranvier.
Explain the effect of lidocaine on impulse conduction.
Lidocaine blocks Na+ voltage channels from opening. As a result, a neuron is unable to send
an impulse conduction. If lidocaine was applied to a sensory neuron, the patient would be
unable to receive signals from that sensory neuron.
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Practice
Practice Questions
1. What is the relationship between action potentials and impulses?
An action potential is an impulse that has reached threshold potential. An impulse is
electrical stimulation which may or may not trigger an action potential (depends on strength).
2.Explain how impulse conduction differs in myelinated and unmyelinated nerve
fibers.
Impulse conduction along an unmyelinated axon is uninterrupted along its entire length.
An impulse traveling along a myelinated axon appears to jump from node to node. This
“jumping” of the impulse (saltatory conduction) makes the signal arrive at its destination
much faster.
3. What is the refractory period, and what purpose does it serve?
A refractory period is the short amount of time during which a threshold stimulus will not
trigger another action potention in that portion of the axon. This limits the frequency of
action potentials and ensures they only progress in one direction.
Use the Practice 9.6
Using Mathematics The speed of conduction an impulse is related to the
cross-sectional area of the axon. If an axon has a diameter of 0.1 μm and
conducts a nerve impulse at 30 m/s, calculate the speed of an impulse
conducted by an axon 1.0 μm in diameter.
0.1 um = 1.0 um × = 300 m/s
30 m/s ×
Figure Questions
Figure 9.12, page 304: Myelinated axons can be described as “functionally shorter”
axons compared to unmyelinated axons. Explain what is meant by “functionally shorter.”
The action potentials of myelinated axons occur only at the nodes of Ranvier
Section 9.7: The Synapse
Learn
Classroom Activities
Visual Literacy: Motion Map
Pair students together or individually and have them draw a motion map with vector
arrows to represent the motion of the impulse across a synapse. On the motion
map, students should identify where the impulse is moving on its own and where it
has to be transported.
Differentiated Instruction
Motion maps are a physical science concept that is built into this activity. The
teacher could remove the motion map piece and just have students draw out
the pathway the impulse would move highlighting the synapse,
neurotransmitters, and synaptic knobs in the drawing.
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Additional Discussion Questions
Ask the students to turn to another student and describe the process of synaptic
transmission. After doing so, as the students if they had any questions.
Answers will vary
Hypothesize the effect of a lack of neurotransmitter release at a synapse with a
motor neuron and skeletal muscle.
Without the release of a neurotransmitter from a motor neuron, the muscle would not receive
the signal to contract, and they muscle with be flaccid.
Practice
Practice Questions
1. Describe the events that occur at a synapse.
The distal ends of axons have extensions called synaptic knobs, which contain
membranous sacs called synaptic vesicles. When an impulse reaches the synaptic knob
of a presynaptic neuron, some of the synaptic vesicles release neurotransmitters by
exocytosis. The neurotransmitters diffuse across the synaptic cleft and react with specific
receptors on the membrane of the postsynaptic cell. Once the neurotransmitters bind to
receptors on a postsynaptic cell, the effect is either an excitatory or an inhibitory impulse.
Use the Practice 9.7
Conducting Investigations Design an experiment to investigate which
substances activate the brain’s reward pathways.
Answers will vary. Accept those that show a good understanding of the elements of an
experiment (question, control, variables, etc).
Section 9.8: Synaptic Transmission
Learn
Classroom Activities
Group Activity: Neurotransmitter Jeopardy
Put students in small groups and refer them to Table 9.2 Some Neurotransmitters
and Representative Actions. Students should use a presentation software or index
cards to create a review game over the type of neurotransmitter and its major
actions. Once students complete the game, they will trade their game with another
group and play the other group’s game. Students should keep score and play until
all questions have been answered.
Example: 50 pt. question — This type of neurotransmitter creates a sense of feeling
good. Answer — What is norepinephrine?
Differentiated Instruction
This game is modeled on an American game show. Not all students may be
familiar with this format. Many students may have other types of games similar
to this they play in their own homes or cultures. Encourage students to create
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their own game that still involves studying the type of neurotransmitter with
the major action. More time can be spent in class allowing different groups to
try out each other’s game and learn more about games from different cultures.
Demonstration: The Effect of Drugs on Neurotransmitters
Before you begin this lesson, be sure to review the neurotransmitters and their
actions as listed in Table 9.2 with your students. Next, have the students come up with
a list of common drugs. After the list has been generated, go through each drug with
your students and determine the effect of the drug on the brain’s neurotransmitters.
Example: Antidepressants or selective serotonin reuptake inhibitors (SSRIs) effect
neurotransmitters by retaining serotonin for longer within synapses.
If the drug is not described in the chapter, encourage students to research the
effect using primary sources.
Additional Discussion Questions
Have students research myasthenia gravis.
Myasthenia gravis is an automimmune disorder that results in muscle weakness and fatique.
Antibodies in the body block the acetylcholine receptors inhibiting the effects of acetylcholine
on the receptors located on muscle fiber membranes.
Practice
Practice Questions
1. Distinguish between the actions of excitatory and inhibitory neurotransmitters.
Neurotransmitters that increase postsynaptic membrane permeability to sodium ions will
bring the postsynaptic membrane closer to threshold and may trigger impulses. Such
neurotransmitters are excitatory. Neurotransmitters that make reaching threshold less
likely are called inhibitory because they decrease the chance that an impulse will occur.
2. What types of chemicals function as neurotransmitters?
Neurotransmitters can be monoamines, amino acids, neuropeptides, and even gases.
3. What are possible fates of neurotransmitters?
Released neurotransmitter is either decomposed or otherwise removed from the synaptic
cleft. Some neurotransmitters are decomposed by enzymes, others are transported back
into the synaptic knob that released them (reuptake) or into nearby neurons or neuroglia.
Use the Practice 9.8
Constructing Explanations Explain how inhibitory and excitatory
neurotransmitters impact postsynaptic membrane permeability.
Excitatory neurotransmitters increase postsynaptic membrane permeability, bringing the
membrane closer to the threshold to trigger impulses. Inhibitory neurotransmitters decrease
postsynaptic membrane permeability, decreasing the likelihood of triggering an impulse.
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Section 9.9: Impulse Processing
Learn
Classroom Activities
Demonstration Activity: Neuronal Pools
This is a demonstration activity that students can take part in to help them to
understand how each neuronal pool receives hundreds of inputs from neurons
which may be excitatory or inhibitory, but the neuron doesn’t reach threshold. The
teacher should first pose the questions to students: If the teacher mixes very hot
water with freezing cold water, what would the resulting water feel like? Most
student responses will be warm or room temperature. Discuss with students how
neuronal pools can have the same effect on the neuron resulting in it staying at
subthreshold. The teacher should provide each group with an ice cube and a heat
pack. Have the students take turns holding the ice cube and the heat pack such as
a handwarmer at the same time in the same hand. Students should document what
they feel. Provide students the following reflection questions:
1. Did your hand feel hot, cold, or neither? Why do you think this was?
2. Explain how your hand was like a neuron receiving different impulses.
3. Why can a neuron receive hundreds of impulses, yet the neuron may stay below
threshold?
4. What is one advantage to a neuron being able to receive many impulses all
at once?
Differentiated Instruction
Not every student will want to actually try this activity. Each student in the
group can be responsible for a job. Students who don’t want to hold the ice or
heat pack could be responsible for documenting observations or gathering
notes for answering the questions. Emphasize that teamwork is important, and
everyone should be playing a key role.
Additional Discussion Questions
Ask students to describe, in order, eight key events leading to the conduction of a
nerve impulse.
The steps include resting potential, threshold stimulus received, sodium channels open, sodium
ion diffusion, potassium channels open, potassium ion diffusion, stimulation of adjacent
portions, and a wave of action potentials.
Discuss factors that may influence the conduction of a nerve impulse.
Factors may include calcium deficiency, increases/decreases in extracellular potassium,
sedatives, pressure, cold, and anesthetics.
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Practice
Practice Questions
1. Define neuronal pool.
Neurons in the CNS are organized into neuronal pools, which are groups of neurons that
make hundreds of synaptic connections with each other and perform a common function.
Each pool receives input from neurons, which may be part of other pools. Each pool
generates output and can be excitatory or inhibitory on other pools or effectors.
2. Distinguish between convergence and divergence.
Axons originating from different parts of the nervous system and leading to the same
neuron exhibit convergence. Convergence makes it possible for impulses arriving from
different sources to have an additive effect on a neuron. Divergence is exhibited when a
neuron synapses with several other neurons. As a result of divergence, the effect of a
single neuron in the CNS may be amplified.
Use the Practice 9.9
Using Models Develop a model that illustrates the way the nervous system
processes impulses and initiate impulses in response.
See figure 9.17 (or any other model that displays concept).
Section 9.10: Types of Nerves
Learn
Classroom Activities
Visual Literacy: Layers of a Nerve
Discuss with students how some cakes has many layers and supports to keep those
layers in place. Nerves have connective tissues that protect the different layers just
like a cake. Provide students with Figure 9.18. Bakers have directions on how to put a
cake together. Have students create a step by step procedure describing how the
layers of the nerve are put together. Students may choose to work from within and
move outward or vice versa depending on how they like to picture things.
Differentiated Instruction
Pair students together and have one student write the directions first and have
the second student then attempt to draw a nerve based on the instructions.
They can discuss if the directions were an accurate depiction of the connective
tissue holding together the layers of the nerve or not. They should adjust the
directions based on their discussion.
Additional Discussion Questions
For each pair of the cranial nerves, what simple, but effective, clinical test could be
used to insure normal function?
Example: To test cranial nerve pair I, the patient could be asked to identify certain odors, such
as ammonia, oranges, or vanilla. To test cranial nerve pair VIII, the patient would respond to a
tuning fork, etc.
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Compare and contrast the somatic and autonomic nervous systems.
Responses should include a discussion of effector organs, types of neurotransmitters, and
construction of the efferent pathways.
Practice
Practice Questions
1. What is a nerve?
Nerves are bundles of axons that conduct impulses. They can be sensory, motor, or
mixed in function.
2. How does a mixed nerve differ from a sensory nerve? From a motor nerve?
Sensory nerves conduct impulses to the brain or spinal cord and mixed nerves are nerves
that have both sensory and motor axons. Motor nerves conduct impulses to muscles or
glands. In an up/down analogy, where the brain or spinal cord is considered up and the
periphery is down, sensory nerves conduct impulses in a down-up direction and motor
nerves conduct impulses in an up-down direction. Both sensory and motor nerves conduct
impulses in a one-way direction. Mixed nerves conduct impulses in a two-way direction.
Use the Practice 9.10
Communicating Information Understanding the terminology of the types
of nerve fibers can help in remembering the direction in which the nerve
carries information. Identify another word from the English language,
beginning with the same letter, to help communicate the direction of each
type of nerve fiber.
Answers will vary. Example: Afferent nerve fiber = Sensory fibers = affection (feeling);
Efferent nerve fiber = motor = cause and effect (doing something)
Section 9.11: Neural Pathways
Learn
Classroom Activities
Group Activity: Patellar Reflex
Discuss with students that sometimes at an annual doctor’s appointment, the doctor
may check a patient’s patellar reflex. Assign students to call their own family doctor
(or the teacher can provide a doctor's contact information) interview the them on
why this is tested. Provide students time in class in small groups to craft their
interview questions. Provide students time to practice interviewing each other with
good speaking and listening skills.
Differentiated Instruction
Some students may not have a family doctor. The teacher could instead bring
in a guest speaker in the medical field that can discuss why checking the
patellar reflex is important. The guest speaker could even demonstrate the
patellar reflex on students with parental approval.
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Additional Discussion Questions
Ask students to compare the parts of a reflex arc, in terms of description and function.
Responses should include an analysis of the receptor, sensory neuron, interneuron, motor
neuron, and effector.
Explain the knee-jerk reflex.
Striking the patellar region initiates the reflex. The quadriceps femoris stimulates stretch
receptors, which in turn, send a message to the spinal cord, where the sensory axon forms a
synapse with a motor neuron. The impulse travels back to the muscle, causing the leg to extend.
Practice
Practice Questions
1. What is a neural pathway?
The routes impulses follow as they travel through the nervous system are called neural
pathways.
2. List the parts of a reflex arc.
A reflex arc consists of a receptor, a sensory neuron, an interneuron, a motor neuron, and
an effector.
3. Define reflex.
Reflexes are involuntary actions resulting from nervous stimulation.
4. List the actions that occur during a withdrawal reflex.
Skin receptors become activated by some stimulus (heat, cold, pain, etc.) and send
impulses to the spinal cord. There, the impulse passes to the interneurons of a reflex
center and are directed to motor neurons. The motor neurons activate fibers in muscles,
which remove the body part from the stimulus.
Use the Practice 9.11
Arguing from Evidence Describe the supporting evidence needed to declare
a particular reaction a reflex.
Reflexes are simple neural pathways that involve only a few neurons, and provide the
structural and functional basis for involuntary actions.
Section 9.12: Meninges
Learn
Classroom Activities
Writing Connection: Word Search
The teacher will create a word search with words from figure 9.22 and 9.23. Put
students into small groups. The teacher will provide each group with the word
search puzzle as well as a picture of each figure without the words. Students in the
small group will begin to search for words. When someone finds a word, they must
circle it in the word search and then label it correctly in the figures. Once all words
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are found, each group will then go through and discuss what the function is of the
three membrane layers that make up the meninges.
• Dura mater
• Arachnoid mater
• Pia mater
Differentiated Instruction
Students could complete the puzzle individually at home as well as the
labelling activity. The teacher should create a key for students on how to
label the image. Students should choose a special individual at home that the
student could explain each word to and then find it on the image. Have the
individual (specially chosen by the student) sign puzzle sheet and return it
with the student to school. Each student could shortly present who they
chose to help them with their study sheet and why. Give students time in
groups to share with each other.
Additional Discussion Questions
Ask students to develop a flowchart depicting the location of formation, circulation,
and reabsorption of CSF.
Begin with a box labeled choroid plexuses of the lateral and third ventricle.
Meningitis is an acute inflammation of the meninges. Which meninges are most
likely affected?
Meningitis most often affects the pia mater and arachnoid mater.
Practice
Practice Questions
1. Describe the meninges.
The meninges are layered membranes that lie between the bony coverings and soft
tissues of the CNS and protect the brain and spinal cord. The outer layer is the dura
mater, composed of tough, fibrous connective tissue. Below the dura mater is the
arachnoid mater, a weblike membrane without blood vessels. Below the arachnoid mater
is the subarachnoid space, which is filled with cerebrospinal fluid. Resting directly on the
brain and spinal cord is the pia mater, a thin layer that contains many nerves and blood
vessels.
2. State the location of cerebrospinal fluid.
Cerebrospinal fluid is located in the subarachnoid space, which lies between the pia
mater and the arachnoid mater.
Use the Practices 9.12
Asking Questions Epidural and subdural hematomas are two common brain
injuries that result from trauma. Using your understanding of the meninges and
blood flow of the brain, develop a question that would distinguish an epidural
hematoma from a subdural hematoma.
Did the bleeding or pooling of blood, and therefore the symptoms happen quickly? If so,
then it is most likely an epidural hematoma as the bleeding is arterial, between the skull
and the dura mater.
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Section 9.13: Spinal Cord
Learn
Classroom Activities
EL Strategy: Practice Linguistic Patterns– Talking Stick
Beginning or Intermediate Students should work in small groups. This strategy
allows every student to have an opportunity to speak several times. Ask a question
(What is the structure of the spinal system?) Or give prompt (Describe the function
of the spinal cord. List one of the regions of the spinal cord.) and then pass a stick
or other object to the student. The student speaks, everyone listens, and then
passes the object to the next person. The next student speaks, everyone listens
then the student passes the object on until everyone has had one or two turns.
Visual Literacy: Puzzle Activity
The teacher should create a poster size print out of the spinal cord for each small
group of students. Each group of students should draw puzzles pieces of their
choice on the spinal cord picture. Next each group will take a picture of their puzzle
outline to document it as the answer key. Each group will cut out the puzzle pieces
of the spinal cord. Finally, have each group create one special bonus question that is
about the function of any part of the spinal cord. Have groups switch their puzzles
or rotate through so that each group of students gets to build 2-3 other puzzles and
answer their questions.
Differentiated Instruction
Instead of students creating puzzles pieces of the spinal cord, students may
choose to work more hands-on with a manikin with a spinal cord. The teacher
could purchase this and work it in as one of the final stations in a review about
the spinal cord structure and function. This would create a hands-on
experience where students could put what they have learned into action.
Additional Discussion Questions
What is spina bifida?
Spina bifida is a condition in which one or more of the vertebrae fail to fuse, leaving an
opening in the vertebral column. It may not be apparent at birth, but later manifestations
include hydrocephalus, cleft palate, club foot, strabismus, and muscular abnormalities.
What is a subdural hematoma?
A subdural hematoma occurs when blood collects in the space beneath the dura mater due to
trauma. This increases pressure between the skull bones and the soft brain tissue.
Practice
Practice Questions
1. Describe the structure of the spinal cord.
The spinal cord is a slender column of nervous tissue that passes downward from the
brain into the vertebral canal. In the neck, a thickening in the spinal cord called the
cervical enlargement gives rise to nerves to the upper limbs. A similar thickening in the
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lower back, the lumbar enlargement, gives rise to nerves to the lower limbs. The spinal
cord consists of 31 segments, each of which gives rise to a pair of spinal nerves and its
associated dorsal root ganglia. Two grooves, a deep anterior median fissure and a
shallow posterior median sulcus, extend the length of the spinal cord, dividing it into
halves. The core of the spinal cord is made of gray matter, surrounded by white matter.
The anterior and posterior wings of gray matter are called anterior and posterior horns.
Between the anterior and posterior horns, in the thoracic and upper lumbar segments is
the lateral horn. Gray matter divides the white matter into three regions on each side,
the anterior, lateral, and posterior funiculi made of longitudinal bundles of myelinated
axons. The wings of the gray and white matter on the right and left are connected by the
gray commissure in the middle of the spinal cord.
2. Describe the general functions of the spinal cord.
The tracts of the spinal cord provide a two-way communication system between the
brain and the body parts outside the nervous system.
3. Distinguish between an ascending and a descending tract.
The tracts that carry sensory information to the brain are called ascending tracts and
those that carry motor instructions from the brain to muscles and glands are called
descending tracts.
Use the Practice 9.13
Conducting Investigations Research the types of experiments used to
understand the function of a particular tract in the spinal cord.
Answers will vary. Accept all that show research was conducted.
Section 9.14: Brain
Learn
Classroom Activities
EL Strategy: Context Clues
Beginning Help students identify context-clued brain relate words in the text
they could use to understand vocabulary words. Have students circle the
words. Say the vocabulary words and context; clue words aloud. Have students
repeat them. Then have students copy the clue word into the appropriate
spaces of a three–column chart.
Three- column chart
Words
Context Clues
Meanings
suclus
A shallow groove
Structural organization of the
brain shows elevations
fissure
A deep groove
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Writing Connection: Four Corners
Assign each student to create a question about one of the categories below. The
answer to each student’s question must be one of the major portions of the brain:
the cerebrum, diencephalon, brainstem, and cerebellum. After questions are
created, the teacher will put a label in each of the four corners of the room
representing the four portions of the brain. The teacher will draw out a question
and students will have to choose a correct corner. Repeat this activity with as many
questions as the teacher chooses.
Categories for questions
• Structure of one of the four major portions
• Function of one of the four major portions
• Location of one of the four major portions or their subdivisions
Differentiated Instruction
An extension could be for the teacher to have students look up different type
of mammals and the structure of their brains compared to a human.
Additional Discussion Questions
Provide students with pictures of various views of the brain and have them label the
pictures.
Students should be able to label the major sections of the brain and various components.
Provide students with an anatomical model of the brain and ask them to identify the
major lobes and describe which functions are associated with each.
Students should be able to identify major motor, sensory, and association locations on the
model.
Provide a diagram of the human brain and ask students to trace the flow of
cerebrospinal fluid.
Discussion should begin with the two lateral ventricles and end with the return of CSF to the
blood in the dural sinuses.
Stroke victims are sometimes frustrated during recovery because they know what
they want to say, but cannot vocalize the words. What has most likely happened?
Responses should include a discussion of Broca’s area.
Why is it important that a patient remain in a horizontal position following a spinal
tap procedure?
CSF pressure is decreased following this procedure. It is recommended that the patient remain
in a horizontal position after the procedure to prevent a spinal headache.
Practice
Practice Questions
1. List the major divisions of the brain.
The brain can be divided into four major portions: the cerebrum, the diencephalon, the
brainstem, and the cerebellum.
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2. Describe the cerebral cortex.
The cerebral cortex is a thin layer of gray matter present on all lobes of the cerebrum. It
contains ~75% of all the neuron cell bodies in the nervous system.
3. Describe the major functions of the cerebrum.
The cerebrum provides higher brain functions like interpreting sensory impulses arriving
from sense organs and centers for initiating voluntary muscular movements, storing
information that constitutes memory and utilizing it to reason, as well as intelligence and
personality.
4. Locate the major functional areas of the cerebral cortex.
Specific regions of the cerebral cortex perform specific functions. Sensory areas (anterior
parietal lobes, base of lateral sulci, insula, temporal lobes, brainstem) interpret impulses
that arrive from sensory receptors, producing feelings or sensations. Association areas
(anterior frontal lobes, lateral parietal, temporal, and occipital lobes) connect with one
another and with other brain structures and analyze sensory experiences. Motor areas
(frontal lobes) send impulses downward through the brainstem into the spinal cord where
they synapse with lower motor neurons to reach skeletal muscles.
5. What is hemisphere dominance?
In most individuals, one side of the cerebrum is the dominant hemisphere, controlling the
ability to use and understand language.
6.What are the major functions of the dominant hemisphere? The nondominant
one?
In most people the left hemisphere is dominant for the language-related activities of
speech, writing, reading, and complex intellectual functions requiring verbal, analytical,
and computational skills. In others, the right hemisphere is dominant for these functions
or the hemispheres are equally dominant. The nondominant hemisphere specializes in
non-verbal functions, such as motor tasks that require orientation of the body in space,
understanding and interpreting music and nonverbal visual experiences. It also controls
emotional and intuitive thinking.
7. Where are the ventricles of the brain?
The lateral ventricles occupy parts of the frontal, temporal, and occipital lobes. The third
ventricle is in the midline of the brain, beneath the corpus callosum. The fourth ventricle
is in the brainstem, just anterior to the cerebellum and is connected to the third ventricle
via the cerebral aqueduct. The fourth ventricle is continuous with the central canal of the
spinal cord and also opens into the subarachnoid space.
8. Describe the circulation of cerebrospinal fluid.
Choroid plexuses secrete CSF. All four ventricles have choroid plexuses, but the lateral
ventricles produce most of the CSF. From the lateral ventricles, the CSF flows into the
third ventricle. From the third ventricle it flows through the cerebral aqueduct into the
fourth ventricle. From the fourth ventricle, CSF flows into the spinal canal and the
subarachnoid space. CSF is finally reabsorbed into the blood.
9. What are the major functions of the thalamus? The hypothalamus?
The thalamus is a selective gateway for sensory impulses ascending from other parts of
the nervous system to the cerebral cortex. It receives all sensory impulses except smell
and channels them to the appropriate regions of the cortex for interpretation. It
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produces general awareness of certain sensations and pinpoints the origin of sensory
stimulation. The hypothalamus helps maintain homeostasis by linking the endocrine and
nervous systems. The hypothalamus regulates heart rate and blood pressure, body
temperature, water and electrolyte balance, control of hunger and body weight, control
of movements and glandular secretions of the stomach and intestines, production of
hormones that stimulate the pituitary gland to secrete pituitary hormones, and sleep
and wakefulness.
10. How may the limbic system influence behavior?
The limbic system can modify the way a person acts by producing feelings such as fear,
anger, pleasure, and sorrow. It also recognizes upsets in a person’s physical or
psychological condition that might threaten life. By causing pleasant or unpleasant
feelings about experiences, the limbic system guides a person’s behavior.
11. List the structures of the brainstem.
The parts of the brainstem include the midbrain, pons, and medulla oblongata.
12. Which vital reflex centers are in the brainstem?
Nuclei in the pons may contribute to controlling the rhythm of breathing. The cardiac
center, which controls heart rate is in the medulla oblongata as is the vasomotor center,
which raises or lowers blood pressure and the respiratory center which adjusts rate and
depth of breathing.
13. What is the function of the reticular formation?
The reticular formation is a network of nerve fibers scattered throughout the medulla
oblongata, pons and midbrain. When sensory impulses reach the reticular formation, it
activates the cerebral cortex into a state of wakefulness. Decreased activity in the
reticular formation results in sleep. A nonfunctioning reticular formation results in coma.
14. Where is the cerebellum located?
The cerebellum is a large mass of tissue located below the occipital lobes of the
cerebrum and posterior to the pons and medulla oblongata.
15. What are the major functions of the cerebellum?
The cerebellum communicates with other parts of the CNS and is a reflex center for
integrating sensory information concerning the position of body parts and for
coordinating complex skeletal muscle movements and maintaining posture.
Use the Practice 9.14
Analyzing Data Humans are more reliant on vision than hearing; dogs are
more reliant on hearing than vision. With respect to these senses, which parts
of the brain would you expect to be more developed in each species?
The occipital lobe is responsible for processing visual information, so it would be
expected to be larger in humans. In humans and dogs, the temporal lobe is where
auditory information is processed. This area would be larger in dogs.
Figure Questions
Figure 9.33, page 329: What is the relative position of the fourth ventricle to the third
ventricle?
inferior
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Section 9.15: Peripheral Nervous
System
Learn
Classroom Activities
Visual Literacy: Color Coding
The brainstem has specific regions that can be identified by their structure. The
teacher should provide each student with a black and white outline of the brainstem
with a key identifying the four regions: diencephalon, midbrain, pons, and medulla
oblongata. Students will create a labelled color key code and then color each of the
correct areas on the brainstem. In the second half of the activity, the student will
color the brainstem again but in the view of being connected to the rest of the
brain. Use figure 9.34 and 9.35 to create these images. Students should take time to
label their own paper with important key terms and functions of the major regions.
Differentiated Instruction
Allow students to create a visual color-coded image with a computer program of
their choice. Some students may prefer to use paint or another 3D type of
program on the computer. Students can share their versions of the brainstem with
each other and practice studying the vocabulary words added to the diagram.
Additional Discussion Questions
Ask students to investigate the adverse effects of certain drugs on the nervous
system. Discuss their findings in the classroom.
Suggestions for topics to investigate include barbiturates, benzodiazepines, opiates,
cannabinoids, CNS stimulants, hallucinogens, and anabolic steroids.
Ask students to prepare a set of flash cards, each of which has a Roman numeral
(from I to XII) written on the front of the card.
By revealing the Roman numeral only, ask each student to identify the cranial nerve by name,
type (sensory, motor, or mixed), and function.
Ask students to trace which body areas are served by the cervical plexus, brachial
plexus, lumbar plexus, and sacral plexus.
Direct the students’ responses by offering the following guidelines: cervical plexus contains the
phrenic nerve, brachial plexus contains the axillary, radial, median, musculocutaneous, and
ulnar nerves, lumbar plexus contains the femoral and obturator nerves, and sacral plexus
contains the sciatic, common peroneal, and tibial nerves.
Provide students with an anatomical model of the human brain and ask them to
identify the approximate location of the origin of the twelve pairs of cranial nerves.
Reiterate the concept that the cranial nerves, except for the first pair, arise from the brain stem.
Discuss which bodily functions would be affected as each of the twelve cranial
nerves becomes injured.
Also, give examples of simple tests that could be performed to check the nerve’s function.
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Ask students to determine possible results of damage to the above-mentioned
nerves. Use previously learned body movement nomenclature, such as adduction,
extension, plantar flexion, etc.
Responses will vary.
Practice
Practice Questions
1. Define peripheral nervous system.
The PNS consists of nerves that branch from the CNS and connect it to other body parts.
The PNS includes the cranial nerves and the spinal nerves and is divided into somatic
and autonomic branches. The somatic branch connects to the skin and skeletal muscles
and the autonomic branch connects to viscera and glands.
2. Distinguish between somatic and autonomic nerve fibers.
Somatic nerve fibers of the PNS connect cranial and spinal nerves to skeletal muscles
and autonomic nerve fibers of the PNS connect cranial and spinal nerves to viscera and
glands. Somatic nerves are under conscious control, while autonomic nerves are not.
3. Name the cranial nerves, and list the major functions of each.
There are 12 sets of cranial nerves. The olfactory nerve (CN I) conduct impulses
associated with the sense of smell. The optic nerve (CN II) conduct impulses associated
with sight. The oculomotor nerve (CN III) controls most of the muscles that move the
eyes. The trochlear nerve (CN IV) conducts impulses to muscles that move the eyes. The
trigeminal nerve (CN V) has 3 branches, the ophthalmic (conducts sensations from the
upper eyelids, forehead, and scalp), maxillary (conducts sensations from the upper teeth,
gums, and lip), and mandibular branches (conducts sensations from the skin of the jaw,
lower teeth, and lower jaw and controls the muscles of mastication). The abducens nerve
(CN VI) conducts impulses to muscles that move the eyes. The facial nerve (CN VII)
conducts impulses to muscles of facial expression and from taste receptors in the
anterior tongue. The vestibulocochlear nerve (CN VIII) has two branches: the vestibular
branch (CN VIII1: conducts impulses associated with equilibrium) and the cochlear
branch (CN VIII2: conducts impulses associated with hearing). The glossopharyngeal
nerve (CN IX) conducts sensations from the pharynx, tonsils, posterior tongue and carotid
arteries and motor impulses to the pharynx used for swallowing. The vagus nerve (CN X)
conducts sensory and motor impulses to the mouth associated with speech and
swallowing, sensory impulses to the heart, and smooth muscles and glands in the
abdomen. The accessory nerve (CN XI) has two branches: the cranial branch (CN XI1:
conducts motor impulses to the soft palate, pharynx, and larynx) and the spinal branch
(CN XI2: conducts motor impulses to the tongue). The hypoglossal nerve (CN XII)
conducts motor impulses that move the tongue.
4. How are spinal nerves grouped?
31 pairs of spinal nerves originate from the spinal cord. The spinal nerves are named
according to the level from which they arise. Each pair of nerves is numbered in
sequence. Each spinal nerve, as it passes through the intervertebral foramen is
associated with the vertebra above it, with the exception of C1. Spinal nerve C1 passes
superior to spinal vertebra C1. There are 8 pairs of cervical nerves (C1-C8), 12 pairs of
thoracic nerves (T1-T12), 5 pairs of lumbar nerves (L1-L5), 5 pairs of sacral nerves (S1-S5),
and 1 pair of coccygeal nerves (Co).
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5. Describe how a spinal nerve joins the spinal cord.
Each spinal nerve emerges from the cord by two short branches, or roots (dorsal and
ventral), which lie in the vertebral canal. The ventral and dorsal roots unite to form a
spinal nerve, which extends outward from the vertebral canal through the intervertebral
foramen, beyond which the nerve divides into several parts.
6. Name and locate the major nerve plexuses.
The major nerve plexuses are the cervical, the brachial, and the lumbosacral. The
cervical plexuses lie deep in the neck. The brachial plexuses are deep within the
shoulders between the neck and axillae. The lumbosacral plexuses lie in the pelvic cavity.
Use the Practices 9.15
Using Mathematics Twelve numbered pairs of cranial nerves arise from the
ventral surface of the brain. What does the number assigned to each cranial
nerve pair represent?
The cranial nerves are numbered from the front side of the brain to the back side of the brain.
Section 9.16: Autonomic Nervous
System
Learn
Classroom Activities
Writing Connection: Pathways
Students can work in small groups. Provide students with a large white paper. Ask
students to create a T-chart comparing the two divisions of the autonomic nervous
system: sympathetic and parasympathetic. Once students complete their t-chart,
each group member must choose one organelle randomly from the list below and
identify how the different impulses either inhibit or activate an organ. Repeat the
process until all organs in the list below have been discussed.
•
•
•
•
•
•
•
eye
parotid gland
blood vessels
heart
trachea
lungs
liver
•
•
•
•
•
•
•
stomach
pancreas
small intestine
large intestine
adrenal gland
kidney
urinary bladder
Differentiated Instruction
Students could research the different control centers in the autonomic
nervous system. They could create a chart comparing what each control center
was in charge of and where it is located at. Students should be sure to include
controls of sympathetic and parasympathetic systems. This could be done in
small groups or individually.
Demonstration Activity: Neurons and Action Potentials
Supply each group with big and small marshmallows, licorice, and sharpies. They are
to build a neuron as you discuss it. Once students have made their models, have
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them draw their neuron model on a piece of paper and label the parts. Ask your
students to circle where a synaptic cleft is located on their neuron.
Next, provide students with smaller objects – such as different colored buttons or
chocolate candies- to model how a Na+/K+ pump drives an impulse or action
potential within their neuron.
Reminds to students to make a key of what each item represents.
After students build their models, go through the steps of an action potential in
relationship to where their ions are in their models.
Additional Discussion Questions
Compare the anatomy of the sympathetic and parasympathetic divisions of the
autonomic nervous system.
Discuss in terms of first and second neurons, collateral ganglion, and postganglionic axons.
Create a chart that compares and contrasts the functions of the parasympathetic
and sympathetic divisions of the autonomic nervous system.
The chart should include the same organs for both systems to illustrate the dual effect the
autonomic nervous system has.
Discuss the effects of neurotransmitter substances on visceral effectors or actions.
Compare the sympathetic and parasympathetic responses.
Ask students to compare these effects on the pupil of the eye, heart rate, bronchioles, blood
glucose levels, salivary glands, tear glands, and urinary bladder.
Describe the bodies response to exercise. Is this response controlled by
sympathetic or parasympathetic nervous system?
Exercise causes an increase in heart rate, dilation of bronchioles to increase breathing, increase
sweat gland activity, redistribution of blood to the muscles, decrease in digestive activity.
Compare the type of neurotransmitter employed in a sympathetic and
parasympathetic response.
Sympathetic fibers are adrenergic and secrete norepinephrine. Parasympathetic fibers are
cholinergic and secrete acetylcholine.
Practice
Practice Questions
1. Describe the parts of the autonomic nervous system.
The autonomic nervous system includes two divisions: the sympathetic and
parasympathetic.
2. Distinguish between the divisions of the autonomic nervous system.
The sympathetic division prepares the body for energy-expending, stressful, or
emergency situations, as part of the fight-or-flight response. The parasympathetic
division is most active under restful conditions, such as after a meal. The
parasympathetic division is responsible for restoring the body to a resting state after
activation of the sympathetic division. Preganglionic fibers of the sympathetic division
are typically short and postganglionic fibers are long, while in the parasympathetic
division, the preganglionic fibers are long, and the postganglionic fibers are short.
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3. Describe a sympathetic nerve pathway and a parasympathetic nerve pathway.
In the sympathetic division, the preganglionic fibers originate from neurons in the gray
matter of the spinal cord. Their axons leave the cord through the ventral roots of spinal
nerves in the first thoracic through second lumbar segments. These fibers extend a
short distance then leave the spinal nerves, and each enters a member of a chain of
sympathetic ganglia (paravertebral ganglia). In paravertebral ganglia, preganglionic
fibers form synapses with second neurons. The axons of these neurons, the
postganglionic fibers, extend to visceral effectors. The preganglionic fibers of the
parasympathetic division arise from the brainstem and sacral region of the spinal cord.
From there, they lead outward in cranial or sacral nerves to terminal ganglia located
near or in various viscera. The short postganglionic fibers continue from the ganglia to
specific muscles or glands.
4. Which neurotransmitters operate in the autonomic nervous system?
The preganglionic fibers of the sympathetic and parasympathetic divisions all secrete
acetylcholine and are called cholinergic fibers. The parasympathetic postganglionic
fibers are also cholinergic. Most sympathetic postganglionic fibers secrete
norepinephrine and are called adrenergic fibers.
5. How do the divisions of the autonomic nervous system regulate visceral activities?
Most organs receive innervation from both sympathetic and parasympathetic divisions,
usually with opposing actions. For example, parasympathetic activity increases activity of
the digestive system, whereas sympathetic activity decreases it. Some viscera are
controlled primarily by one division or the other and are not always actively antagonistic.
For example, the sympathetic division regulates the diameter of most blood vessels,
which lack parasympathetic innervation.
6. How are autonomic activities controlled?
The brain and spinal cord largely control the autonomic nervous system. For example,
control centers in the medulla oblongata for cardiac, vasomotor, and respiratory activities
receive sensory impulses from viscera on vagus nerve (CN X) fibers and use autonomic
nerve pathways to stimulate motor responses in the heart, blood vessels, and lungs.
Use the Practices 9.16
Constructing Explanations On your way to school, you almost hit a deer with
your car. Your heart begins to race, your blood pressure increases, your pupils
dilate, and you start sweating. Explain what is happening to you in terms of the
nervous system and various effector organs.
This is the fight or flight response. An impulse from the sympathetic nervous system
stimulates the release of acetylcholine and the production of norepinephrine. This results
in a dilation of the pupils, increase in heartrate, and other changes.
Assess
Career Corner: Occupational Therapist
Consider This: Your friend is considering going to school for physical therapy
or occupational therapy. What would you say to help your friend to compare
and contrast the two professions?
Answers will vary, but students should identify that both require specialized degrees and
extensive training. They both directly help patients overcome their deficits and are
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employed in similar settings. Differences include that an occupational therapist works with
a patient to help them regain independence with the use of aids, while a physical
therapist works to restore a patient to their original function without aids.
Genetic Engineering: Factors Affecting Synaptic Transmission
1. How does caffeine affect the nervous system?
Caffeine stimulates nervous system activity by lowering the thresholds at synapses.
As a result, postsynaptic neurons are more easily excited.
2.The Japanese delicacy “fugu” or pufferfish is famous for its danger. The
pufferfish has a potent neurotoxin called tetrodotoxin (TTX) that blocks
voltage-gated Na+ channels. If not prepared properly, the toxin can paralyze
the respiratory muscles, and the unfortunate diner can die. Using your
knowledge of the action potential, explain this action of the toxin.
Na+ channels are critical for the propagation of the action potential. If Na+ channels
are blocked, the neuron is not depolarized. Without depolarization, the electrical
signal stops, never reaching its endpoint, which in the case of pufferfish toxin is the
neuromuscular junction of the diaphragm. This leads to asphyxiation and death.
iseases, Diagnosis, and Treatment: Impared Cerebrospinal
D
Fluid Circulation
1. What can disrupt the fluid pressure in the ventricles?
Infection, tumor, or blood clots can disrupt the ventricle fluid pressure.
2.Describe a lumbar puncture.
A lumbar puncture, or spinal tap, can measure the pressure of the cerebrospinal fluid. A
clinician inserts a thin, hollow needle into the subarachnoid space between the lumbar
vertebrae while a manometer measures the pressure.
Healthy Lifestyle Choices: Substance Abuse Disorders
1. What is the difference between drug addiction and drug tolerance?
Drug addiction is a chronic disease resulting in compulsive drug seeking and use, despite
harmful consequences. Drug tolerance is the physiological affect where a drug’s impact
becomes less potent or effective due to prolonged use.
2.Barbiturates have a particularly strong impact on the reticular formation. What
is the role of the reticular formation?
The reticular formation is a network of nerve fibers and gray matter. It joins the
centers of the hypothalamus, basal nuclei, cerebellum, and cerebrum with the major
ascending and descending tracts. It is particularly involved in wakefulness and
consciousness.
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Case Study Connection
page 297: Which portions of the neuron are likely to be most vulnerable to
damage in traumatic brain injury? Which structural class of neurons is most
impacted in CTE? Which functional class of neurons is most impacted in CTE?
Dendrites and axons would be most vulnerable, since they are thin/delicate but
long. Multipolar neurons are most prevalent in the brain and would be vulnerable
to CTE. Interneurons, located within the brain and spinal cord, would be most
vulnerable to CTE.
page 306: In CTE a protein, Tau, accumulates outside the cells. How could this
accumulated protein interfere with synaptic function?
The protein could interfere with the sending or receiving of neurotransmitters.
page 311: Which of the major aspects of the nervous system, sensory input,
integration and processing or motor output would be directly impacted in CTE?
Accept all answers which demonstrate sound reasoning.
page 323: Compare and contrast a bleeding injury in the brain to a bleeding
injury that occurs if you cut or break the skin. Where does the blood go in each
case? How do these different injuries present different risks for the patient?
Students should identify that when you cut skin, the blood flows out of the body.
In the brain, the blood has nowhere to go and it increases the pressure inside the skull. The
increased pressure affects sensory and association areas.
page 324: The symptoms of CTE include personality changes and memory loss.
Which region(s) of the brain are primarily impacted?
Association areas for memory, reasoning, and emotion are in the anterior portions of the
frontal lobes and the lateral parts of the parietal, temporal, and occipital lobes.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. The motor portion of the peripheral nervous system that
controls the viscera and operates without conscious effort is
called the
nervous system.
a. autonomic
b. central
c. sensory
d. somatic
2. Oligodendrocytes align along nerve fibers, providing
insulating layers of myelin around axons within
.
a. scars in areas of damage
b. abundant cellular extensions
c. the brain and spinal cord
d. choroid plexuses
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3. Which of the following have a single process extending from
the cell body that divides into two branches that function as
a single axon.
a. Bipolar neurons
b. Multipolar neurons
c. Schwann cells
d. Unipolar neurons
4. The stimulation level (approximately -55 millivolts) that must
be achieved to elicit the sequence of electrical changes in
part of a nerve cell or muscle cell known as an impulse is
called the
a. polarized potential.
b. threshold potential.
c. resting potential.
d. action potential.
5. Select the option that lists select steps of impulse conduction
in chronological order once threshold stimulus is received.
a. axon membrane is depolarized; potassium ions diffuse
outward; potassium channels open; sodium channels open
b. sodium channels open; axon membrane is depolarized;
potassium channels open; potassium ions diffuse outward
c. axon membrane is depolarized; potassium channels open;
potassium ions diffuse outward; sodium channels open
d. sodium channels open; potassium channels open;
potassium ions diffuse outward; axon membrane is
depolarized
6. Acute hypocalcemia causes neurologic symptoms such as
tremors and seizures because of neuromuscular excitability
due to low blood concentrations of calcium. This has baffled
doctors since the increased presence of calcium ions would
be thought to cause excitability instead since their presence
causes
to fuse to the synaptic knob membrane.
a. neurotransmitters
b. acetylcholine
c. synaptic vesicles
d. postsynaptic neurons
7. Which part of a reflex arc is matched with its corresponding
function?
a. Interneuron; carries information from sensory neuron to
motor neuron
b. Receptor; responds to stimulation (or inhibition) by motor
neuron
c. Effector; senses specific type of internal or external
change
d. Motor neuron; carries information from receptor into brain
or spinal cord
8. First-year college students living in residence halls show
increased risk for contracting bacteria-caused infections
known as
. The first common symptoms include fever,
headache, and a stiff neck due to inflammation of the
protective membranes this disease is named for.
a. human papillomavirus
b. meningitis
c. mononucleosis
d. herpes simplex type 2
9. The primary motor areas of the cerebral cortex lie in which
portion of the human brain?
a. temporal lobe
b. parietal lobe
c. occipital lobe
d. frontal lobe
10. Any of several masses containing specialized capillaries that
secrete cerebrospinal fluid into a brain cavity is called a
a. choroid plexus
b. basal nuclei
c. diencephalon
d. ventricle
11. Some nuclei in the
portion of the brain are centers for
the reflexes associated with coughing, sneezing, swallowing,
and vomiting.
a. pons
b. midbrain
c. medulla oblongata
d. cerebellum
12. Sciatica describes a pain experienced by many people
caused by the sciatic nerve that travels from the brain down
the spinal cord to the legs. Which group of complex
networks is related to this condition?
a. brachial plexuses
b. cervical plexuses
c. intercostal nerves
d. lumbosacral plexuses
Short Answer
1. Distinguish between the CNS and PNS.
The CNS is comprised of the brain and spinal cord. The PNS is
all other neurons and nerves in the body.
2. Describe the structure of neuron, and the functions of its parts.
A neuron has three distinct regions. The cell body is much like
a generalized cell. It has several processes arising from it. The
dendrites on side provide the surface area to receive
information. The axon on the other side sends information to
other neurons, muscles, organs, and glands.
3. List the various glial cells and their functions.
Glial cells lend support to neurons. There are four types in the
CNS. Ependymal cells produce cerebrospinal fluid. Astrocytes
are instrumental in maintaining the blood brain barrier.
Oligodendroctyes produce myelin. Microglia are small cells that
serve as phagocytes. Schwann cells produce myelin in the PNS.
And satellite cells protect cell bodies of neurons in the PNS.
4. What are the three structural types of neurons?
Structurally neurons are classified based upon how many
processes extend from the cell body. The classes are:
multipolar, bipolar, or unipolar.
5. What is meant by resting membrane potential?
The resting membrane potential refers to the charge inside of
a neuron while it is at rest, which is about -70mV. Exhibiting a
charge gives the potential for the charges to move. When
charges move it is known as a current.
6. Describe the events of an action potential as shown on a graph.
When a neuron is sufficiently stimulated sodium channels
open, bringing in an initial flow of positive charges which will
take the membrane potential to -55mV. This is called the
“threshold” potential. At this point, voltage gated sodium
channels open. This rapidly take the potential to about +30mV.
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This is called the action potential. Changing the membrane
potential from -70mV to +30mV is called depolarization. To get
back to rest, sodium channels open and a flow of positive
charges leave the cell. This is called repolarization.
7. Why do myelinated axons transmit impulses faster than
non-myelinated axons?
Myelinated axons transmit faster because the myelin only
allows for action potentials at gaps called nodes. It then gives
the appearance that the action potential is jumping down the
axon. This is called saltatory conduction.
8. Describe the difference between an excitatory and an
inhibitory stimulus.
An excitatory stimulus is anything that can make the
membrane potential less negative, headed in the positive
direction. An inhibitory stimulus will prevent an action potential
by making the membrane potential more negative them
-70mV.
9. Describe the structure of the spinal cord.
The spinal cord exits the skull and runs through the vertebral
column. It exhibits a cervical and lumbar enlargement. It is
structured in an opposite fashion as the brain. The gray matter
(cell bodies and dendrites) is on the inside, surrounded by the
white matter (tracts of axons). Exiting along the length of the
spinal cord are spinal nerves that innervate the body, forming
the PNS.
10. List the lobes of the brain and their general functions.
The cerebral cortex is anatomically one huge structure but
various regions are recognized: the frontal lobe is the site of
complex intellectual processing, the temporal lobes are
instrumental in processing and housing visual and auditory
memories, the parietal lobes are involved general sensation,
and the occipital lobe is part of the visual processing pathway.
11. What are the functions of the medulla oblongata?
The medulla oblongata is part of the brainstem and is
somewhat of a switchboard that directs signals into and out of
the CNS. It houses regions that play roles in heart rate,
breathing rate, and control over vasoconstriction and
vasodilation.
12. List the cranial nerves by name and number.
Cranial nerves are: I-Olfactory, II-Optic, III-Oculomotor,
IV-Trochlear, V-Trigeminal, VI-Abducens, VII-Facial,
VIII-Vestibulocochlear, IX, Glossopharyngeal, X-Vagus,
XI-Accessory, XII-Hypoglossal.
13. What are the functions of cranial nerves V and X?
Cranial nerve V, the trigeminal nerve is a mixed nerve. That is,
it carries both sensory and motor neurons. It carries sensory
input from the eyes, teeth, face, gums, and forehead. It sends
motor output to the muscle in the mouth and jaw for chewing.
Cranial nerve X, the vagus nerve is also a mixed nerve. It
carries sensory and motor neurons to all of the viscera,
pharynx, and larynx.
14. Distinguish between the sympathetic and parasympathetic
portions of the autonomic nervous system.
The sympathetic system is often referred to as the “fight or
flight” system. It is responsible for an increase in heart rate,
breathing rate, and blood flow to the major skeletal muscles.
Anatomically, the sympathetic nerves arise from the thoracic
region of the spinal cord. Arising from the brainstem and sacral
region of the spinal cord, the parasympathetic nerves send
signals for “rest and digest” mode, lowering heart and
breathing rate and increasing blood flow to the digestive tract.
15. Compare and contrast the effects of dopamine and
substance P.
Dopamine has several action which include control over
muscle movements and serving as a natural anti-depressant.
Critical Thinking and Clinical Applications
1. CLINICAL Connection If an athlete sustained an injury to
the head resulting in brain damage, what would lead the
physicians to suspect that the cerebellum might be included
in the damaged area?
Loss of coordination and muscle control would be the primary
symptoms of damage to the cerebellum.
2. If a poison blocked only voltage-gated sodium channels, what
effect would this have on an action potential?
If voltage-gated sodium channels were blocked the membrane
potential could not get past -55mV. No action potential would
occur.
3. The basal nuclei are instrumental in initiating muscle
movements. If the neurons in this region become over active
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or under active muscle movements become abnormal. How
do they become abnormal and what are the names of the
associated diseases?
In Parkinson disease the neurons release less dopamine and
the basal nuclei become overactive, which inhibits movement.
In Huntington disease, the basal nuclei become inactive which
results in unrestrained movement.
4. WRITING Connection List four skills encountered in
everyday life that depend on nervous system function, and
list the part of the nervous system responsible for each.
Student responses will vary. Examples include vision (eyes,
occipital lobe), hearing (ears, temporal lobe), smell (nose,
temporal lobe), speech (mouth, temporal lobe).
Lab Data Analysis: The Effect of Hormones on Action Potentials
Think Critically
1. Does insulin change the frequency of the action potentials?
In what way?
The frequency, or rate, of the action potentials increases after
the neurons are exposed to insulin, shown by the action
potentials occurring closer together.
2. Does insulin change the intensity of the action potential? In
what way?
No, because the amplitude (or peak height) of each action
potential remains constant between the control and the
insulin-treated cells. Only the frequency of the action
potentials change (they occur more frequently with the same
intensity).
3. Insulin is a hormone that is released when blood glucose
increases after we eat. Why might olfactory neurons be
sensitive to insulin?
Insulin is an anabolic hormone released when we eat. The
olfactory (smell) sense is linked with our sense of taste, so it is
plausible that olfactory neurons are sensitive to the release
of insulin because of the need to better smell and taste what
we eat.
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CHAPTER
10
The Senses
Section
Pacing
(class periods)
Learning Objectives
10.1 Introduction
—
1. Distinguish between general senses and
special senses.
10.2 Receptors, Sensations,
and Perception
1
1. Name five kinds of receptors, and explain
their functions.
10.3 General Senses
2
2. Explain how a sensation arises.
1. Describe the receptors associated with
the senses of touch, pressure,
temperature, stretch, and pain.
2. Describe how the sense of pain is
produced.
10.4 Special Senses
1
1. Identify the locations of the receptors
associated with the special senses.
10.5 Sense of Smell
1
1. Compare the receptor cells involved with
the senses of smell and taste.
2. Explain the mechanism for smell.
10.6 Sense of Taste
1
1. Explain the mechanism for taste.
10.7 Sense of Hearing
1
1. Explain the function of each part of the
ear.
10.8 Sense of Equilibrium
2
1. Distinguish between static and dynamic
equilibrium.
10.9 Sense of Sight
1
1. Explain the function of each part of the
eye.
2. Explain how the eye refracts light.
3. Describe the visual nerve pathway.
Focus Activity Workbook
Focus Activities: Labeling (6)
Focus Activities: Vocabulary (8)
Chapter Resources
Extended Summary Review
Chapter 10 Test Bank
Chapter 10 Interactive Question Bank
Vocabulary Flashcards
APR Module 7: Nervous System
Laboratory Exercise 22: General Senses
Laboratory Exercise 23: Smell and Taste
Laboratory Exercise 24: Ear and Equilibrium
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A Suggested Approach
In this chapter students learn about our senses and how they shape our perception
of reality. Begin the chapter by displaying a series of optical illusions or a magic
illusion trick. Discuss with the students what is real and what is the illusion. As they
study the anatomy of their sense organs, they will determine if their senses can
grow sharper and detect illusions.
The senses of smell and the sense of taste are intricately linked in our perception.
Often what we perceive as taste, is actually smell. Students can understand this
concept by imagining they are eating a warm chocolate chip cookie. Additionally,
students can trick their perception, by limiting their sense of smell and observing
the effect on their sense of taste.
Our senses of hearing and equilibrium are found in the same organ — the ear.
Students may be unaware of the types of hearing loss, especially from listening to
music with ear buds. After watching the video at Ted Ed: Can Earbuds Lead to
Hearing Loss?, generate a brief discussion about hearing loss, and ask if knowing this
type of hearing loss is permanent affects the loudness at which they listen to music.
The sense of sight might be the most familiar sense to students. The structure of
the eye, and its basic anatomy can be determined by dissecting a cow’s eye. If
students are not comfortable with a physical dissection, an on — line version of the
dissection can be used such as Exploratorium: Cow’s Eye Dissection.
The chapter can be concluded by revisiting the concept of perception and reality.
Ask students to think back to the way their senses were tricked at the beginning of
the chapter, and how their understanding of anatomy and function of their sense
organs alters their view of optical illusions or the magician’s illusion.
This chapter is expected to take 10 class periods including Lab 22, Lab 23, and Lab 24.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
The website for the National Insititute on Deafness and Other Communication
Disorders has a useful overview on how cochlear implants work.
One extension activity could be to get the students into groups and have
them compare and contrast sound perception and the hearing pathway with
touch sensation.
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Introduction to the Theme
Theme: Cause and Effect Humans, by nature, are responsive beings. Using the
five senses, the human body determines the specific action from a direct
environmental cause.
Theme Activity: Ted Radio Hour: The Five Senses
For this activity, students need access to NPR’s podcast Ted Radio Hour: The Five
Senses (January 20, 2017): www.npr.org/programs/ted-radio-hour/archive. Have
students pick and listen to one of the five stories that they find interesting. After
listening to the story, ask students to write two paragraphs on the story.
Encourage students to write more than a condensed version of the story by asking
them to address questions such as: What sense(s) is(are) explored in the Ted talk?
How does this sense affect our reality? How does this sense help us perceive our
environment? Is this sense necessary for survival?
Section 10.1: Introduction
Learn
Classroom Activities
Section 10.1 sets the groundwork for activities in sections 10.2 and beyond.
Additional Discussion Questions
Ask students to develop a chart that illustrates the location of various somatic and
special receptors.
Responses will vary.
Ask students to interview an elderly person and analyze the effects of aging on
various somatic and sensory receptors.
Responses should include a discussion of touch, pain, temperature, smell, taste, hearing, etc.
Practice
Practice Questions
1.How special senses different from general senses?
Receptors associated with the general senses are widely distributed throughout the skin
and deeper tissues, and are structurally simple. Receptors for special senses are parts of
complex sensory organs.
Use the Practices 10.1
Asking Questions Propose a question that will help you investigate why
receptors for the general senses are more widely distributed than receptors
for the special senses.
Answers will vary
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Section 10.2: Receptors, Sensations,
and Perception
Learn
Classroom Activities
EL Strategy: Listening and Speaking
Intermediate Slowly read aloud a paragraph. After each sentence or two,
pause and ask volunteers to identify an important idea in the text. Have
students write the important idea in the left column of their Table Notes and
write a phrase or short sentence restating what they heard about the ideas in
the right column. Students will then record their responses on a class version
of Table Notes on the board. Review the Table Notes to ensure every student
has information in their chart.
Table Notes
Important Idea
What I learned
Sensation
Sensory receptors are send information to the brain.
Receptors
Many types of receptors that allow people to feel pain,
temperature, pressure.
Projection
Allows a person to know the area of sensation
Writing Connection: Sensations vs Perceptions
The teacher should create five mystery brown bags all with different items for
students to reach in and touch. Put students into small groups. Pass out one bag per
group. Remind students they can’t look into the bags. Ask each group member to
reach in the bag and feel the object. Remind them to write down all observations
made by the group including temperature, smells, pressure, hearing, or anything
else they can observe besides looking at the item. After students have recorded all
their observations and labeled which kind they are, allow students to look inside the
bag. Have students briefly discuss if their prediction was accurate or not. Rotate the
brown bags so that each group can repeat the activity multiple times. Ask students
to think about which types of senses and receptors were easier to recognize begin
utilized and which ones were more natural and went unnoticed.
Differentiated Instruction
Students may feel anxiety to reach into the bag and feel something they can’t
see. Rather than forcing students to reach into the bags, allow students to use
their other sense to complete this activity, or to be the group recorder for
observations. Alternatively, the teacher may also provide students with a
substance that is unknown, but they can see. This would also reduce anxiety
for students.
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183
Additional Discussion Questions
Conduct visual examinations on each student in the class by using a Snellen eye chart.
Also, conduct simple tests for peripheral vision, color blindness, and depth perception.
An emphasis should be placed on the mechanisms of photoreceptors. Students are always
interested in these types of self-tests and the discussions sometimes reveal previously
undetected visual problems, such as near- or farsightedness.
Why can we sometimes detect a particular perfume or cologne long after the
person wearing it has left the room?
This application provides an opportunity to reinforce the principles of diffusion, and the concept
that molecules of solute seek to migrate from an area of higher concentration to an area of
lower solute concentration. Apply this phenomenon to the mechanisms of olfactory receptors.
Discuss the interrelationships between the sense of taste, sight, and smell. Provide
students with a variety of samples and test their ability to identify each item when
they smell the item but can’t taste it, and vice versa. Try similar tests utilizing a
blindfold.
Discussion should emphasize the interdependency of the special senses of the human body.
Give several examples of the stimulation of chemoreceptors and photoreceptors. Discuss how
food tastes when a student has a sinus cold, discuss how a particular food tastes when we are
not allowed to see it, discuss the fact that we can —almost// taste food just by looking at it or
smelling it, etc.
Discuss examples of how the sensations of smell and hearing may become
desensitized after adaptation to a particular stimulus.
Examples may include a woman who know longer smells her own perfume, even though she
has applied twice as much as normal, a construction worker who has adapted to loud
machinery noises that he hears every day, or a mother who may seemingly ignore continuous
cries from her baby, even though everyone around her is annoyed.
Practice
Practice Questions
1. List five general types of sensory receptors.
Sensory receptors are categorized into five types: chemoreceptors, pain receptors,
thermoreceptors, mechanoreceptors, and photoreceptors.
2. Explain how a perception is different from a sensation.
A sensation occurs when sensory receptors reach threshold and the resulting action
potentials cause the brain to become aware of the stimulus. A perception occurs when
the brain interprets those sensory impulses.
3. What is sensory adaptation?
The ability of the nervous system to become less responsive to a maintained stimulus is
called sensory adaptation.
Use the Practices 10.2
Communicating Information Differentiate between sensation and perception.
A sensation happens when the threshold of a receptor is reached and an action potential
is generated. Perception occurs when the brain interprets those sensory impulses.
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Section 10.3: General Senses
Learn
Classroom Activities
Group Activity: What would you do?
Put students in pairs and present them with the following scenario:
A woman is running in the park at a pretty steady pace. Her right ankle is starting to
ache every time she steps. Finally, the woman stops and checks out her ankle. It feels
warm and definitely hurts.
Students should read and discuss the scenario above and then answer the following
questions.
1.Describe in general which body movement and stretch receptors are involved
to allow the woman to run.
2.Explain one positive indicator and one negative indicator of the resulting pain
in the woman’s ankle.
3.Could the pain the woman be feeling be a type of visceral pain? Explain.
Differentiated Instruction
The teacher could find a video of a person running and allow students to
observe the runner. The same scenario could be completed. Having the visual
aid for students will help them to perceive the situation and better analyze
what might be happening with the movement and stretch receptors.
Additional Discussion Questions
What is meant by referred pain? Give an example.
Referred pain is pain felt in one area of the body but caused in another. Examples include pain
felt in the left arm during a heart attack, pain felt in the leg during a lower back spasm, or pain
in the chest during a gall bladder attack.
What are the warning signs of a heart attack and what should you do if these signs
are present?
Signs of a heart attack include pain that spreads to the shoulders, arms, or neck, dizziness,
sweating, nausea, shortness of breath, and tightness in the chest. If you experience these signs,
seek medical attention immediately, take aspirin, and do not deny what may be occurring.
Ask students to prepare a short report on the causes of lower back pain.
The reports should include comments on the relatively high incidence of lower back pain,
mechanical factors that contribute to lower back pain, including excess weight, poor posture,
lack of exercise, etc., the effects of emotional stress on lower back pain, and possible
preventative and treatment modalities. According to some researchers, approximately ninety
percent of all back problems occur in the lumbar region.
Ask students to prepare a short report on migraine headaches.
The report should include a discussion of a description of the disease, signs and symptoms,
causes, risk factors, diagnostic procedures, treatment, and medications. An interesting sideline
to this report is a discussion of various analgesics currently available over-the-counter and by
prescription.
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Practice
Practice Questions
1. Describe the three types of touch and pressure receptors.
Touch and pressure receptors include three types: free nerve endings, tactile (Meissner’s)
corpuscles, and lamellated (Pacinian) corpuscles. Free nerve endings are common in
epithelial tissues and responsible for sensations like itching. Tactile (Meissner’s)
corpuscles are oval masses of flattened tissue with two or more sensory nerve fibers
found in hairless areas of skin and are responsible for the sensations of light touch.
Lamellated (Pacinian) corpuscles are large and connected to a single sensory nerve fiber.
Lamellated (Pacinian) corpuscles are responsible for the sensation of heavy pressure and
are located in the deep dermal and subcutaneous tissues.
2. Describe the receptors that sense temperature.
Temperature sensation depends on two types of free nerve endings, those that respond
to warm temperatures (warm receptors) and those that respond to cold temperatures
(cold receptors). Warm receptors are most sensitive to temperatures above 25˚C (77˚F)
and become unresponsive at temperatures above 45˚C (113˚F). Cold receptors are most
sensitive to temperatures between 10˚C (50˚F) and 20˚C (68˚F). Within about a minute
of continuous stimulation, the sensation of warmth or cold begins to fade.
3. Explain the function muscle spindles and Golgi tendon organs.
Muscle spindles are specialized fibers in skeletal muscle that monitor the state of
contraction. Golgi tendon organs detect how much a tendon is stretched during muscle
contraction.
4. What types of stimuli excite pain receptors?
Injuries likely promote the release of certain chemicals that build and stimulate pain
receptors. A deficiency of oxygen-rich blood (hypoxia) or disruption of blood flow (ischemia)
in a tissue triggers pain sensations. Extremes of hot or cold stimulate pain receptors.
5. Describe how pain can be pharmacologically controlled.
Drugs mimic the functions of natural endorphins and enkephalins, which inhibit the
release of substance P. Narcotics bind to the same opiate receptors in the spinal cord.
6. What is referred pain?
Visceral pain may feel as if it is coming from a part of the body other than the part being
stimulated, a phenomenon called referred pain.
7. Describe two types of pain fibers.
There are two main types of pain fibers: fast pain fibers and slow pain fibers. Fast pain
fibers are myelinated, conduct impulses rapidly, and are associated with immediate
sharp pain that usually does not continue once the pain stimulus is removed. Slow pain
fibers are unmyelinated, conduct impulses slowly, and are associated with delayed or
dull pain that can continue after the initial stimulus is removed.
8. How do acute pain and chronic pain differ?
Acute pain and chronic pain differ by the length of time of which they are felt, as well as
in their typical locations. Acute pain is most often located on the skin’s surface, while
chronic pain tends to be felt more deeply.
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9. What parts of the brain interpret pain impulses?
Most pain fibers terminate in the thalamus, the reticular formation, or the limbic system.
From there, other neurons conduct impulses to the hypothalamus and cerebral cortex.
The cerebral cortex determines pain intensity, locates the pain source, and carries out
motor responses to the pain. The emotional response to pain involves the limbic system.
Use the Practices 10.3
Arguing from Evidence Leprosy is a chronic bacterial infection, and many
people associate it with missing extremities. However, the tissue damage is
actually a secondary symptom caused by loss of sensory receptors in the skin
of the hands and feet. Construct an argument to explain how the loss of
sensory receptors could lead to tissue damage.
Leprosy is a peripheral neuropathy resulting in the loss of pain receptors (corpuscles)
primarily in the hands and feet which results in numbness. This loss of pain receptors
results in the inability to respond to painful stimuli, and therefore allows the damage of
tissue resulting in skin lesions.
Section 10.4: Special Senses
Learn
Classroom Activities
Group Activity: Special Sense Challenge
This is a whole class activity. Students should be very familiar with their special
senses in everyday use. This is a unique activity that will challenge students to
reflect on how their special sense work together to provide a whole picture. In the
front of the class, the teacher will complete the following demonstrations. After
each demonstration, ask students to reflect on how well they are able to interpret
information.
Demo 1a: The teacher plays a clip of music (school appropriate but associated to the
likes and culture of the students)
Question Set: What type of music is it? Does the beat go fast or slow? Are their any
harmonies in the song?
Demo 1b: The teacher plays a music video of the same clip of music with the
movement of the sound waves of the music possibly with color stimulants.
Question Set: Ask students if seeing and hearing the beat of the music helped them
to feel the music better? Were they able to pick up on the rhythm better?
Demo 2: Ask students to close their eyes and bring in a type of food for them to
smell such as pizza or another type of food with distinct smells. (Note any food
allergies) Allow students to taste it if approved with parent / guardians.
Question Set: What type of food do you smell? Does it smell hot or cold?
How do you know?
Reflection Question: Explain how utilizing more than 1 sense at a time helps you
interpret information. Describe a scenario when all senses picking up information
could be an information overload.
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Differentiated Instruction
Instead of the teacher bringing items in items for the demo, each student
could bring in one item, or play a clip of music with which they connect. This
would give students an opportunity to share a little more about themselves as
well as complete the activity. They could do this in small groups so each
student would have time to share and ask each other questions. Groups could
answer the demo questions and reflection question together.
Demonstration: Sense Charades
After you go over the different senses, divide students into small groups. Assign
each student group one of the five sense without letting the other groups know
who has what sense.
Next, instruct students that they have ten minutes to come up with a way to act out
the biochemical process their sense.
Students will perform their charade in front of the class. Students will have to guess
what sense they are performing. Students who guess the process must have a
reason for their guess.
Practice
Practice Questions
1. Where in the body are the sensory organs of the special senses located?
The olfactory organs are located in the nasal passages. Taste is located in the taste
buds of the tongue. Hearing and equilibrium are located in the outer, middle, and inner
ear. Sight is located in the eyes.
Use the Practices 10.4
Using Models Create a graphic organizer that displays the special senses. As
you read the subsequent chapter sections, fill your organizer with information
about the receptors, pathways, and organs involved in each sense.
Answers will vary.
Figure Questions
Figure 10.6, page 369: Which cranial bone is shown in this figure?
temporal bone
Section 10.5: Sense of Smell
Learn
Classroom Activities
Writing Connection: Debunking Smells
Discuss with the whole group things they may have smelled before but didn’t eat but
could still “taste” it. Also discuss the reverse of when a student maybe tasted something
and could smell it. Let students discuss their past experiences and share with other. The
following activity could be completed in pairs or individually. Provide students with
the following scenario. Students will read each scenario and use the resources from
the book to explain if the process does work like that or if it is now different.
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Scenario: A father asked his five-year old child to eat her green beans at the dinner
table. The child dislikes the taste of green beans and is putting up a fight. The father
tells the child to hold her nose while she eats the green beans, so she won’t taste them.
Question: Will holding the child’s nose allow her to not taste the green beans?
Explain your answer and include the structure or relationship between taste
receptors and olfactory receptors to support your response.
Differentiated Instruction
Instead of using the scenario above, have students attempt to eat a safe, but
generally disliked, food without being able to smell it. Have them record if they
were successful or not and why using support from the book on the
relationship between taste receptors and olfactory receptors. Students will
experience the scenario and make their own observations.
Practice
Practice Questions
1. Where are olfactory receptors located?
Olfactory receptors are located in the olfactory organs, which are in the upper parts of
the nasal cavity, the superior nasal conchae, and a part of the nasal septum.
2. Trace the pathway of an olfactory impulse from a receptor to the cerebrum.
Stimulated olfactory receptor cells send impulses along their axons and synapse with
neurons in the olfactory bulbs in the skull. The impulses are processed in the olfactory
bulbs and further conducted along olfactory tracts, where they are interpreted in the
temporal and frontal lobes, as well as the limbic system.
Use the Practices 10.5
Communicating Information You might have heard people say that smell is
the sense most connected with memory. Explain a physiological mechanism
that accounts for the strong connection between scent and memory.
Unlike taste, we can distinguish between 2000 – 4000 olfactory stimuli. The ability to
smell is the only sensory information that reaches the cerebral cortex without passing
through the cortex. Additionally, the limbic system connects smell with emotions.
Section 10.6: Sense of Taste
Learn
Classroom Activities
EL Strategy: Making Connections
Advanced/Advanced High After reading Section 10.6: Sense of Taste as partners.
Ask students to make connections between the text and their prior knowledge
using a Think/Pair/ Share activity. Ask students to complete the following
statement: This text reminds me of __________ because __________. Have ELL students and
English proficient students pair up to share their connections. Students should
record a few main ideas and be prepared to share one connection with the class.
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Writing Connection: Debunking Taste
Discuss with the whole group things they may have eaten before and feel they
could taste sometimes in one area of the tongue, but not in the other. Let students
discuss their past experiences and share with other. The following activity could be
completed in pairs or individually. Provide students with the following scenario.
Students will read each scenario and use the resources from the book to explain if
the process does work like that or if it is now different.
Scenario: A woman was very ill and read online that lemon juice could help her
improve her cold. She dislikes lemon juice very much. She has heard before that the
tongue had certain sections that responded to different tastes such as sweet or sour.
She is hoping that if she drinks the sour lemon juice away from that section of the
tongue that she won’t taste the lemon.
Question: Is the information the woman found about the tongue being associated with
certain sections of taste still accurate? Explain your answer. What can the woman do
to help reduce the amount of taste she will perceive when drinking the lemon juice?
Differentiated Instruction
The teacher should research to ensure any allergies that exist in the classroom.
Pick a typical and safe food or candy that most students may find sweet, sour,
or salty such as limes, candy, pretzels. Have students eat the different types to
investigate if they do in fact have different areas of the tongue that pick up
different tastes or not. Students will experience the scenario and make their
own observations.
Additional Discussion Questions
Provide students with a variety of common edible food samples and ask them to
draw a taste map that illustrates the location of taste buds on the tongue
corresponding to the four basic taste sensations.
Comment on the interrelationships between the sense of smell and taste. Ask students to
discuss which foods tasted —better// because they were able to smell them simultaneously.
Discuss examples of drugs that alter our sense of taste and smell.
Responses may include a discussion of acetazolamide (taken to prevent mountain sickness),
penicillamine (anti-inflammatory), nitroglycerin (transdermal patch used to treat chest pain),
tetracycline (antibiotic), certain cancer chemotherapies and radiation treatments.
Practice
Practice Questions
1. Why is saliva necessary for the sense of taste?
The taste buds are surrounded by saliva, a watery fluid produced from the salivary
glands. A particular chemical must be dissolved in the saliva in order for it to be tasted.
2. Name the five primary taste sensations.
The five primary taste sensations are: sweet, sour, salty, bitter, and umami.
3. Trace a sensory impulse from a taste receptor to the cerebral cortex.
Sensory impulses from taste receptor cells in the tongue travel on fibers of the facial,
glossopharyngeal, and vagus nerves into the medulla oblongata. From there, the
impulses ascend to the thalamus and are directed to the gustatory cortex, in the parietal
lobe of the cerebrum.
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Use the Practice 10.6
Conducting Investigations Design an experiment to discover which part of
the tongue contains the most receptors responsible for each of the five
primary taste sensations.
Answers will vary, accept those that show a solid understanding of experimental design.
Section 10.7: Sense of Hearing
Learn
Classroom Activities
Writing Connection: Sensory Impulses
This activity can be completed in small groups. The teacher should provide students
with a copy of Figure 10.6 showing the major parts of the ear. Students should be
provided the steps involved in generation of sensory impulses from the ear from
Table 10.1, but the steps should be mixed up and not labelled 1-11. Students in their
groups must discuss and order the steps from beginning with sound waves entering
the ear to the impulses being interpreted. Once students believe they have the
steps in the correct order, pair two groups together. Each group will present the
order of the steps using the visual diagram of figure 10.6 to explain where each step
occurs on the diagram.
Have the two groups discuss any differences and agree on the correct order.
Students may check their answers with the book table 10.1.
Differentiated Instruction
Eleven steps may be a lot for students to process in one sitting. Pair two
groups together: give one group steps that cover movement of sound through
the outer and middle ear, and the other group steps of the inner ear. This will
reduce the workload and also allow groups to collaborate and learn something
new when they present their steps together to the teacher or each other.
Additional Discussion Questions
Ask students to create a set of index cards, each of which contains one or two key
words describing a major step in the generation of sensory impulses from the ear.
Shuffle the cards and allow students to place them in the correct sequence while
providing a brief description of each step.
Suggestions for the key words include sound waves, tympanic membrane, auditory ossicles,
stapes movement, cochlear duct, basilar membrane, depolarization, neurotransmitter release,
neuron stimulation, vestibulocochlear nerve, temporal interpretation.
Describe two tests used to diagnose conductive deafness.
Two common tests used to detect conductive deafness are the Weber test and the Rinne test.
In the Weber test, a tuning fork is activated and placed against the forehead. With normal
hearing, the sound will seem to approach from directly in front of the patient. In the Rinne test,
a tuning fork is held against the bone behind the ear. A normal ear will continue to hear its
tone, even after the tuning fork is removed from the bone and placed at the opening of the
external auditory meatus.
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Practice
Practice Questions
1.How are sound waves transmitted through the outer, middle, and inner ears?
Outer ear: the auricle of the ear collects sound waves traveling through the air and
directs them into the external acoustic meatus. At the end of the meatus, the sound
waves reach the eardrum. Sound waves change the pressure on the eardrum, which
vibrates in response and thus reproduces the vibrations of the sound wave source.
Middle ear: The malleus attaches to the eardrum and vibrates when the eardrum
vibrates. Vibrations are passed to incus and stapes. The stapes is held to the wall of the
tympanic cavity by the oval ligament and a hole in the tympanic cavity called the oval
window leads to the inner ear, where the vibrations are transferred.
Inner ear: Sound vibrations entering the perilymph at the oval window travel along
the scala vestibuli and pass through the vestibular membrane into the endolymph of
the cochlear duct, where they move the basilar membrane. The basilar membrane
has many thousands of elastic fibers, which move in response to sound vibrations.
After passing through the basilar membrane, the vibrations enter the perilymph of
the scala tympani. As sound vibrations move the basilar membrane, hair cells of the
spiral organ contact the tectorial membrane above and are stimulated. Different hair
cells respond to different frequencies of sound. Hair cells then release
neurotransmitter-containing vesicles, stimulating nearby neurons, which fire sensory
impulses along the vestibulocochlear nerve (CN VIII) to the auditory cortex.
2. Distinguish between the osseous and membranous labyrinths.
The bony (osseous) labyrinth is a cavity within the temporal bone of the skull. Within the
bony (osseous) labyrinth is the membranous labyrinth, a tube of similar shape.
3. Describe the spiral organ.
The spiral organ is located on the upper surface of the basilar membrane and stretches
from the apex to the base of the cochlea. The spiral organ contains hair cells organized
into rows and whose processes project into the endolymph of the cochlear duct. Above
the hair cells is the tectorial membrane, which is attached to the bony shelf of the
cochlea and contacts the tips of the hair cells.
4. Distinguish between conductive and sensorineural hearing loss.
Conductive hearing loss usually occurs in the middle ear and can be caused by cerumen
impaction, eardrum perforation, temporal bone fracture, or acute otitis media.
Sensorineural hearing loss occurs in the inner ear and is nerve-related. It may be noise
induced, hereditary, congenital, or may be caused by an acoustic tumor or autoimmune
disease.
Use the Practices 10.7
Using Mathematics You attended a concert last night where the music was
played at 100 dB. Your ears are still ringing, and you are having a hard time
hearing. How many times louder was the music compared to a normal
conversation (approximately 30dB)?
The decibel scale is a logarithmic scale and increase 10X. Normal whispers are
measured at 0 dB, and a normal conversation of 30 dB would be 1000 times louder
than the whisper. A concert of 100 dB would be 1000000000 times as loud, and likely
to cause damage.
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Section 10.8: Sense of Equilibrium
Learn
Classroom Activities
Group Activity: Energy Transfer
The teacher should find a series of videos of people losing balance. Examples include
the game played at baseball games where people bend over and spin around in
circles with their head bent of on the bat. When they stand up to run, they are dizzy
and lack balance. After watching the short series of videos, discuss with the class
the different positions of the head and motion of the body that could have caused
the person to be dizzy or lose balance.
Ask students to pick one of the scenarios or videos to evaluate and explain what
happened to the static equilibrium and dynamic equilibrium to actually cause the
resulted dizziness, loss of balance, or nausea. Students can write their responses or
discuss in small groups.
Differentiated Instruction
Instead of analyzing videos situations, the teacher can provide students with a
bank of different scenarios such as riding in the car and reading, riding on a
boat in the sea, head bent down to the floor, or walking with your eyes closed.
Student groups should analyze each scenario and describe what is occurring in
the static equilibrium organs and dynamic equilibrium organs to actually cause
the resulted dizziness, loss of balance, or nausea. Students can write their
responses or discuss in small groups.
Additional Discussion Questions
What is motion sickness? Explain in terms appropriate for this chapter objective.
Motion sickness is a normal response to abnormal and irregular body motions that disturb the
organs of equilibrium. A sensory conflict exists among the visual receptors, vestibular receptors,
and certain proprioreceptors. Symptoms include nausea, vomiting, pallor, hypersalivation,
anxiety, panic, fatigue, confusion, weakness, etc.
Practice
Practice Questions
1. Distinguish between static and dynamic equilibrium.
The sense of equilibrium is two senses: static equilibrium and dynamic equilibrium, each
with their own separate organs. The organs of static equilibrium (utricle and saccule,
maculae) sense the position of the head and maintain balance, stability and posture
when the head and body are still. When the head and body suddenly move or rotate, the
organs of dynamic equilibrium (semicircular canals, ampullae, crista ampullaris, cupolae)
detect such motion and aid in maintaining balance.
2.Which structures provide the sense of static equilibrium? Of dynamic equilibrium?
The organs of static equilibrium are in the vestibule, a bony chamber between the
semicircular canals and the cochlea. The membranous labyrinth inside the vestibule
consists of a utricle and saccule. The utricle and saccule each have maculae. Maculae
have hair cells which project into a mass of gelatinous material with otoliths embedded
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in it. Bending the head forward, backward, or to either side tilts the gelatinous masses of
the maculae, and as they sag in response to gravity, the hairs projecting into them bend.
This causes the hair cells to signal the sensory neurons associated with them to send
impulses into the CNS informing the brain of the head’s new position. The brain responds
by adjusting the pattern of motor impulses to skeletal muscles, which contract or relax to
maintain balance. The organs of dynamic equilibrium are the semicircular canals in the
labyrinth. Suspended in the perilymph of the bony portion of the each semicircular canal
is a membranous semicircular duct that ends in a swelling called an ampulla. The
ampulla houses the sensory organs of the semicircular canals, called cristae ampullaris.
The hair cells of the cristae ampullaris extend upward into a gelatinous mass called the
cupola. Rapid movement of the head or body stimulates the hair cells of the cristae
ampullaris and the semicircular canals move with the head or body, but the fluid inside
the membranous ducts remains stationary. The cupola bends in a direction opposite that
of the head or body and the hairs embedded inside it also bend. The stimulated hair
cells signal their associated neurons, which conduct impulses to the brain, namely the
cerebellum, which then modifies signals to skeletal muscles to maintain balance.
3. How does sensory information from other receptors help maintain equilibrium?
Certain mechanoreceptors in the joints of the neck inform the brain about the position of
body parts. The eyes detect changes in position that result from body movements.
Use the Practice 10.8
Constructing Explanations Each of the semicircular canals in your inner ear is
oriented in one of three planes of space. Explain how the receptors in the
semicircular canals respond to dynamic movements such as twirling in a chair
or doing a headstand.
Because each of the semicircular canals align to the three spatial planes, when the head
moves in any direction, the cupula inside the canals move in opposite direction. This
allows rotational movement in any direction.
Section 10.9: Sense of Sight
Learn
Classroom Activities
Demonstration Activity: Eye Muscle Movements
Pair students together and have them review Table 10.2 providing an overview of
muscles associated with the eyelids and eyes. Have student practice together. One
student will go first and make an eye movement such as rotating eyes upward and
toward the midline. The second student will observe the movement and have to
identify which muscle was used to create that movement. Have the student then
point on a diagram of the eye where the muscle is located at in the eye. The partners
should take turns practicing back and forth until both feel confident in identifying the
type of eye movement with the correct muscle and location in the eye.
Differentiated Instruction
Some students may feel uncomfortable looking directly at another student.
Allow students to draw the different eye movements or print out a paper that
demonstrates different eye movements. The review activity can still be
completed using these alternative resources.
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Visual Literacy: Sense Organ
Ask the students to design one organ that would work to control all five senses. This
activity is helpful in showing students the uniqueness of the human body.
Challenge students by asking them to draw the organ as anatomically correct
possible – does it have optical nerves? taste receptors?
Additional Discussion Questions
Provide students with an unlabeled drawing of the human eye and ask them to label
it with the names of the six extrinsic muscles of the eye.
Students should label the drawing with the superior rectus, inferior rectus, medial rectus, lateral
rectus, superior oblique, and inferior oblique muscles. Have students describe each muscle in
terms of innervation and function.
Apply the concepts learned in this chapter objective to describe color blindness.
Color blindness results from the lack of certain photoreceptors on the retina. If an individual
lacks the receptors that respond to green light, then the individual may interpret green objects
as being red. If the individual lacks the receptors that respond to red light, the individual will
interpret red objects as being green. Red/green color blindness is the most common type and
occurs almost exclusively in males, since color blindness is a sex-linked condition.
What kind of lens would be used to correct myopia? Hyperopia? Astigmatism?
Myopic vision may be corrected by the use of concave lenses. Hyperopic vision may be
corrected by the use of convex lenses. Astigmatism may be corrected using special cylindershaped lenses. Of course, it may be possible to experience more than one abnormality
simultaneously. In these cases, more complex lenses may be required.
Practice
Practice Questions
1. Explain how the eyelid moves.
The eyelids are moved by orbicularis oculi muscles, which act as a sphincter and close
the lids when they contract, and by the levator palpebrae superioris muscles, which raise
the upper lid to help with opening the eyes.
2. Describe the conjunctiva.
The conjunctiva is a mucous membrane that lines the inner surfaces of the eyelids and folds
back to cover the anterior surface of the eyeball, except for the central portion (cornea).
3. What is the function of the lacrimal apparatus?
The lacrimal apparatus consists of the lacrimal gland, which secretes tears, and a series
of ducts that carry tears into the nasal cavity. Two small ducts (the superior and inferior
canaliculi) collect tears, which then flow into the lacrimal sac. From there the tears flow
into the nasolacrimal duct, which empties into the nasal cavity. Secretion by the lacrimal
gland moistens and lubricates the surface of the eye and the lining of the lids. Tears also
have enzymes that kill bacteria, reducing the risk of eye infection.
4. Describe the outer and middle layers of the eye.
The anterior sixth of the outer layer bulges forward as the transparent cornea. The cornea
helps focus entering light rays. It is composed largely of connective tissue with a thin
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surface layer of epithelium. It is transparent because it contains few cells and no blood
vessels. The cornea is continuous with the sclera, the white portion of the eye. The sclera
makes up the posterior five-sixths of the outer layer of the wall of the eye. It is opaque due
to many large, disorganized, collagenous fibers and elastic fibers. The sclera protects the
eye and serves as an attachment for the extrinsic muscles. The sclera is pierced by blood
vessels and the optic nerve in the back of the eye. The middle layer of the eye includes the
choroid coat, ciliary body, and iris. The choroid coat in the posterior five-sixths is loosely
joined to the sclera and is honeycombed with blood vessels. It also has pigment-producing
melanocytes, which absorb excess light and help keep the inside of the eye dark. The
ciliary body is the thickest part of the middle layer and extends forward and inward from
the choroid coat to form a ring inside the front of the eye. Within the ciliary body are
radiating folds called ciliary processes and groups of smooth muscle cells that constitute
the ciliary muscle. Suspensory ligaments extend inward from the ciliary processes and hold
the transparent lens in position. The iris, the colored part of the eye, is a thin diaphragm
composed mostly of connective tissue and smooth muscle fibers. The iris extends forward
from the periphery of the ciliary body and lies between the lens and cornea.
5. What factors contribute to the transparency of the cornea?
The cornea is transparent because it contains few cells and no blood vessels, and the
cells and collagenous fibers form unusually regular patterns.
6. How does the shape of the lens change during accommodation?
The lens is enclosed by a clear capsule composed largely of elastic fibers, keeping the
lens under constant tension and allowing it to assume a globular shape. The suspensory
ligaments attached to the margin of the capsule are also under tension and when they
pull outward, flatten the capsule and lens, which brings distant objects into focus. If the
tension on the suspensory ligaments relaxes, the lens becomes more convex, bringing
closer objects into focus. The ciliary muscle controls the actions of the suspensory
ligaments. When the muscle contracts, the suspensory ligaments relax and the lens
thickens. When the ciliary muscle relaxes, tension on the suspensory ligaments increases
and the lens becomes thinner.
7.Why would reading for a long time cause eye fatigue, while looking at a distant
scene is restful?
In order to focus on near objects, like a book for reading, the tension on the suspensory
ligaments must relax. In order for the suspensory ligaments to relax, the ciliary muscles
must contract, which thickens the lens and allows for focusing on near objects. Eye fatigue
results from prolonged contraction of the ciliary muscles. By looking at a distant scene, the
suspensory ligaments must contract. In order for the suspensory ligaments to contract, the
ciliary muscles must relax which makes the lens become thin and allows for focusing on
far away objects.
8. Explain the source of aqueous humor, and trace its path through the eye.
The epithelium on the inner surface of the ciliary body secretes aqueous humor. Aqueous
humor is secreted into the posterior chamber and then flows through the pupil into the
anterior chamber. Aqueous humor leaves the anterior chamber through veins and a
drainage canal known as the scleral venous sinus (canal of Schlemm).
9. How does the pupil respond to changes in light intensity?
The iris controls the size of the pupil in response to varying intensities of light. The contractile
cells of the iris are organized into two groups: the radial set (made of myoepithelial cells) and
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the circular set (made of smooth muscle). When the radial set cells contract, the pupil’s
diameter increases and more light enters. The radial set cells are stimulated to contract when
light is dim. When the circular set cells contract, the pupil’s diameter decreases and less light
enters. The circular set cells are stimulated to contract by bright light.
10. Describe the structure of the retina.
The inner layer of the wall of the eye is the retina. The retina contains photoreceptors, is
nearly transparent, is continuous with the optic nerve (CN II) in the back of the eye, and
extends forward as the inner lining of the eye. The retina is thin and delicate with several
layers. The layers are as follows from superficial to deep: nerve fiber layer, ganglion cell
layer, bipolar neurons, photoreceptors, retinal pigment epithelium, and the choroid coat. In
the central region is a yellow spot called the macula lutea. A depression in its center is
called the fovea centralis. Medial to the fovea centralis is the optic disc where nerve fibers
from the retina leave the eye and form the optic nerve (CN II). A central artery and vein
also pass through the optic disc, supplying blood to the cells in the inner layer of the eye.
11. What is refraction?
Refraction is the term that is used when light rays are bent and is the result of the
focusing of the light rays.
12. What parts of the eye provide refracting surfaces?
The cornea, the lens, and fluids in the chambers of the eye provide refracting surfaces.
13. Distinguish between the rods and cones of the retina.
Photoreceptors in the retina are of two distinct kinds: rods and cones. Rods have long,
thin projections at their ends, and provide vision without color. Cones have short, blunt
projections, and provide color vision.
14. Explain the roles of visual pigments.
Rods and cones both contain light-sensitive pigments that decompose when they absorb
light energy. Rhodopsin (in rods) is broken down by light into opsin and retinal. In bright
light, nearly all the rhodopsin is broken down; but in dim light, the regeneration of
rhodopsin from combining opsin and retinal is faster than its decomposition, allowing for
better vision in the dark. The light-sensitive pigments in cones are retinal and three types
of opsin proteins, which respond to various wavelengths of light. Erythrolabe is most
sensitive to red, chlorolabe is most sensitive to green, and cyanolabe is most sensitive to
blue. The color a person perceives depends on which cones the light in a given image
stimulates. If all three are stimulated with equal intensity, the person senses the light as
white and if none are stimulated, the person senses the light as black.
15. Trace an impulse from the retina to the visual cortex.
Axons of retinal neurons leave the eyes to form the optic nerves (CN II). Just anterior
to the pituitary gland, the nerves form the x-shaped optic chiasm. Within the optic
chiasm the medial (nasal) nerve fibers cross over, while the lateral (temporal) fibers do
not. Fibers from the nasal half of the left eye and the temporal half of the right form
the right optic tract and fibers from the nasal half of the right eye and the temporal
half of the left eye form the left optic tract. The right and left optic tracts reach the
thalamus and synapse in a region called the lateral geniculate body (LGN). From the
LGN, visual impulses travel along the optic radiations to the visual cortex of the
occipital lobes.
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Use the Practices 10.9
Using Models Develop a model that depicts how a lens correctly focuses light
on the retina.
See figure 10.24 (or any other model that displays concept).
Figure Questions
Figure 10.16, page 378: Are the extrinsic muscles of the eye under voluntary
control?
Yes, they are skeletal muscles. Look up at the ceiling without moving your head if you have a
question about this!
Assess
Career Corner: Optometrist
Consider This: Optometrists and ophthalmologists are eye specialists, and
they can work together in the same practices. Some procedures are more
likely to be performed by one over the other. Would the following
procedures be more likely to be performed by an optometrist or an
ophthalmologist: annual eye exams, cataract surgery, contact lenses fitting,
laser eye surgery?
1: annual eye exams are typically performed by optometrists, however there are
instances where ophthalmologists may see patients for their annual eye exams if they
have comorbid medical issues, like advanced diabetes or cancers of the eye. 2:
cataract surgery is performed by an ophthalmologist. 3: being fitted for contact lenses
or glasses is performed by an optometrist. 4: laser eye surgery is performed by an
ophthalmologist.
Genetic Engineering: Synesthesia: Connected Senses
1.Describe the hypothesis researchers have developed to explain synesthesia
in adults.
Researchers hypothesize that mixed senses are present in all babies, but synesthesia
develops in individuals who do not “prune” as many synapses as others as they age.
(A loss of 20 billion synapses a day is normal for adults.)
2. Define the special senses.
The special senses are smell, taste, hearing, equilibrium, and sight. Special senses are
those whose sensory receptors are in large, complex sensory organs in the head.
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Case Study Connection
page 369: How could changes in the anatomy of the outer ear change the
quality or acuity of sound perception? Which parts of the outer ear might be
most critical to sound reception?
Answers will vary and may focus on the auricle, external acoustic meatus, or eardrum.
Students might identify any of these structures as critical for receiving sound.
page 370: What issues might result if bone spurs (bone growths) occurred on
the ossicles?
Students should note that the ossicles direct sound vibrations to specific structures, so bone
spurs might misdirect the vibrations.
page 373: The number and elasticity of elastic fibers decrease all over the body
as we age (this is one of the reasons we get skin wrinkles). What are the
consequences when the basilar membrane loses elasticity?
The basilar membrane moves in response to vibrations. If it lost elasticity, it would
not respond as readily to sound waves and be less efficient at propagating the
sound wave.
page 378: If the auditory tube was filled with mucus, would this impact the sense
of equilibrium? Hearing? Why or why not?
Accept all answers that demonstrate solid reasoning.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. All of the following are special senses, as opposed to general
senses, except.
a. sight
b. hearing
c. taste
d. touch
2. A sensation is
a. the ability of the nervous system to become less
responsive to a maintained stimulus.
b. a specialized structure associated with the peripheral end
of a sensory neuron specific to detecting a particular
stimulus and triggering an impulse in response.
c. an awareness that impulses associated with a sensory
event have reached the brain.
d. a neuron that conducts impulses from sensory receptors
to the central nervous system.
3. Responding to the motion of objects that barely contact the
skin, these small masses of connective tissue cells known as
________ are abundant in hairless areas of skin, such as the palms
of the hands and soles of the feet.
a.
b.
c.
d.
free nerve endings
tactile corpuscles
lamellated corpuscles
Pacinian corpuscles
4. The phenomena where a headache (or “brain freeze”) is
caused after quick consumption of a cold food or beverage,
even though it is not the head but the roof of the mouth and
back of the throat that are stimulated, is called
a. referred pain.
b. visceral pain.
c. adaptive pain.
d. misguided pain.
5. If the binding of an odorant molecule to an olfactory
receptor cell is the cause, what is the resulting effect?
a. An impulse travels from the brain, resulting in the
contraction of throat muscles.
b. An impulse travels from the brain, telling the nose to sniff
and smell.
c. An impulse travels to the olfactory bulbs in the brain which
then codes for a smell.
d. An impulse travels to the cilia of the olfactory receptor
cells, resulting in a trapping of smell in the nose.
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6. Which of the following statements related to the sense of
taste is true?
a. Taste buds are only found on the surface of the tongue,
associated with papillae.
b. Each taste bud includes gustatory cells and exhibits a
taste pore at its free surface.
c. Each taste cell experiences five sensations: sweet, sour,
salty, bitter, and umami.
d. Taste does not experience sensory adaptation, but smell
does.
7. Vibrations from the eardrum are amplified by auditory
ossicles – first the malleus, then the incus, and then the
stapes and the oval window. All of this occurs in which
portion of the ear structure?
a. auricle
b. eustachian tube
c. middle ear
d. cochlea
8. Otoliths collected from fish can help scientists estimate the
age of fish because they increase incrementally in size with
age. The otoliths of fish share a number of similarities in
structure and function with those of humans. Which of the
following best describes human otoliths?
a. An otolith is a bony chamber between the semicircular
canals of the inner ear and the cochlea.
b. Otoliths are sensory organs in a semicircular canal that
function to maintain balance when the head and body are
suddenly rotated or otherwise moved.
c. An otolith maintains the body’s balance when the head
and body are motionless.
d. Otoliths are calcareous grains that add weight to the
gelatinous material of the inner ear that moves in response
to gravitational force.
9. “Pink eye” is the common term for the contagious inflammation
of the thin mucus membrane that lines the inner surface of the
eyelid and covers the white part of the eye that is commonly
suffered by children. “Pink eye” is the infection of what eye
structure?
a. lacrimal apparatus
b. conjunctiva
c. cornea
d. aqueous humor
10. If all three types of cones in an eye are stimulated with equal
intensity, what color is sensed by the brain?
a. white
b. black
c. red and green
d. red, green, and blue
Short Answer
1. List the five classes of sensory receptors.
Chemoreceptors, pain receptors, mechanoreceptors,
thermoreceptors, and photoreceptors.
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2. Explain the difference between a general sense and a special
sense.
General senses are often widespread throughout the body
and are associated with receptors in the skin for senses of
touch, pressure, temperature, and pain. Special senses are
those associated with complex organs found in the head. They
include vision, hearing, balance (equilibrium), smell, and taste.
3. What is proprioception?
Proprioception is the sense of where your body is in space and
time and the sense of the position of body parts relative to
other parts.
4. Distinguish between muscle spindles and golgi tendon organs.
The muscle spindles send signals to the CNS regarding the
state of contraction in a given muscle. The golgi organ detects
the amount of stretch on a tendon. If it is too great the golgi
organ will inform the CNS to stop stimulation for contraction.
5. What is anosmia and what can cause it?
Anosmia is the partial or complete loss of the sense of smell.
It can be caused by respiratory infections, tobacco use, and
drug use.
6. What are the five basic taste sensations?
The five basic taste sensations are: sweet, sour, salty, bitter,
and Umami (savory).
7. Distinguish between Meissners and Pacinian corpuscles.
Meissners corpuscles connective tissue cells innervated by nerves.
They are found in the skin and detect light touch. Pacinian
corpuscles are found deeper in the skin and can sense pressure.
8. What are two types of thermoreceptors? How do they differ?
Warm receptors are most sensitive to temperatures above
25 °C (77 °F). Cold receptors are most sensitive to temperatures
between 10 and 20 °C (50-68 °F). Temperatures above 45 and
below 10 °C will stimulate pain receptors for a burning or
freezing sensation respectively.
9. What are the three auditory ossicles? What is their function?
The auditory ossicles are part of the middle ear. They include
the stapes, malleus, and incus. They transfer the vibrations of
sound to the eardrum.
10. What are the semi-circular canals?
The semi-circular canals are part of the inner ear. They are
filled with fluid called endolymph. They are instrumental in the
sense of balance and equilibrium.
11. Distinguish between static and dynamic equilibrium.
Static equilibrium refers to the sense of balance when the
head moves while the rest of the body stays in one position.
It is associated with vestibule. Dynamic equilibrium refers to
keeping the heads in position and balance during sudden
body movements. It is associated with the ampulla.
12. Distinguish between rods and cones.
Rods and cones are both photoreceptors found in the retina.
Rods are very sensitive to low levels of light but can only
provide outlines and shapes of objects. Cones are responsible
for color vision, but need high levels of light for their activation.
13. What is the iris?
The iris is the pigmented portion of the eye, responsible for eye
“color”. It contains smooth muscle that controls the size of the
pupil based upon the intensity of light.
14. Trace the visual processing pathway from the time light rays
enter the eye until an image is perceived.
Light passes though the pupil and then the lens. From there
the image is formed on the retina. The signal is sent into the
optic nerves, past the optic chiasma and into the optic tracts.
It passes through the thalamus and then to the primary visual
cortex in the occipital lobe. From there it goes to the
association areas of the cortex.
15. What visual problem is associated with a lack of vitamin A?
Night blindness.
Critical Thinking and Clinical Applications
1. WRITING Connection At a baseball game, you are
watching the players on the field about 75 feet away. You
turn to look at your friend sitting next to you. Describe what
changes occur in your eyes as you move your focus from far
away to close up.
The lenses in your eyes will accommodate, they will become
shorter and broader because you are now focusing on a closer
image. More than likely there will also be a change in the
intensity of light, so your pupils will either dilate or constrict.
2. At the age of 60, a woman got an eye check-up. After a
lifetime of never needing corrective lenses, the optometrist
gave her a week prescription using a convex lens. What has
happened to her vision?
She has become farsighted. The convex lens will converge the
light rays so that the retina will receive a sharp image.
3. CLINICAL Connection A couple decided to have their
newborn daughter screened for any potential genetic issues.
It was found that she had a mutation in the gene called
PIEZO2. Should the parents be concerned? Why?
Yes. PIEZO2 is instrumental in normal proprioception. Without
normal proprioception their daughter will find it difficult to
engage in the simplest movements such as walking or talking.
Lab Data Analysis: Seeing Different Colors
Think Critically
1. How do just three types of cones absorb the broad spectrum
of wavelengths?
As depicted in the graph, each cone cell type has a distinct
range of wavelengths that it can best absorb. The strength of
each cell type is spread across the spectrum, allowing the
human eye to perceive a broad range of wavelengths of light,
rather than just the narrow range that would be provided by a
single type of cone cell.
3. If the human retina were able to respond to infrared light
(wavelength > 700 nm), how would this appear graphically?
The retina would have to contain a new type of cone cell that
could perceive light beyond 700 nanometers. Graphically,
this would represent a new color of curve to the right of the
red cone curve, with a peak absorbance spanning beyond
700 nanometers.
2. According to the graph, to what range of wavelengths of
light can the human retina respond?
The perceived wavelengths span from ~300 nanometers on
the low end (perceived best by blue cones) to ~700
nanometers on the high end (perceived best by red cones).
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CHAPTER
11
Endocrine System
Section
11.1 Introduction
Pacing
(class periods)
—
Learning Objectives
1. Describe the secretions of the endocrine
system.
2. Compare the nervous system and endocrine
system in maintaining homeostasis.
11.2 Hormone Action
1
11.3 Control of Hormonal
Secretions
2
11.4 Pituitary Gland
1/2
3. Distinguish between endocrine, autocrine,
and paracrine secretions.
1. Explain how steroid and nonsteroid
hormones affect target cells.
1. Discuss how negative feedback mechanisms
regulate hormonal secretions.
2. Explain how the nervous system controls
secretion of hormones.
1. Describe the locations of the anterior and
posterior lobes of the pituitary gland, and list
the hormones they secrete.
2. Describe the functions of the hormones that
the pituitary gland secretes.
11.5 Thyroid Gland
1/2
3. Explain how the secretion of each pituitary
hormone is regulated.
1. Describe the location of the thyroid gland,
and list the hormones it secretes.
2. Describe the functions of the hormones that
the thyroid gland secretes.
11.6 Parathyroid Gland
1/2
3. Explain how the secretion of each thyroid
hormone is regulated.
1. Describe the locations of the parathyroid
glands, and identify the hormone they
secrete.
2. Describe the functions of the hormone that
the parathyroid glands secrete.
11.7 Adrenal Glands
1/2
3. Explain how the secretion of parathyroid
hormone is regulated.
1. Describe the locations of the adrenal glands,
and list the hormones they secrete.
2. Describe the functions of the hormones that
the adrenal glands secrete.
3. Explain how the secretion of each adrenal
hormone is regulated.
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11.8 Pancreas
1
1. Describe the location of the pancreas, and list
the hormones it secretes.
2. Describe the functions of the hormones that
the pancreas secretes.
11.9 Pineal, Thymus, and
Other Glands
3. Explain how the secretion of each pancreatic
hormone is regulated.
1. Describe the locations of the pineal, thymus,
and other endocrine glands covered in this
section, and list the hormones they secrete.
1
2. Describe the functions of the hormones that
the glands covered in this section secrete.
11.10 Stress and Health
3. Explain how the secretion of each of the
hormones described in this section is regulated.
1. Describe how the body responds to stress.
1
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (10)
Chapter Resources
Extended Summary Review
Chapter 11 Test Bank
Chapter 11 Interactive Question Bank
Vocabulary Flashcards
APR Module 8: Endocrine System
Laboratory Exercise 25: Endocrine Structure and Function
A Suggested Approach
In this chapter, students learn the major glands and hormones in the body, known as
the endocrine system. Since the main function of the endocrine system is maintaining
homeostasis, this chapter serves as a review of positive and negative feedback loops.
Introduced in Chapter 3, students gain a more in-depth understanding of how
cell-to-cell communication within the body is achieved.
Both the endocrine system and the nervous system oversee cell-to-cell communication
and allow our responses to outside stimulus. To introduce the endocrine system,
students can experience the response of both systems as they are startled, and their
adrenal glands respond. Ask the students to sit quietly, with their eyes closed imagining
a peaceful scene. You may even choose to read a relaxing script such as the Beach
Relaxation found at http://www.innerhealthstudio.com/visualization-relaxation.html.
After a minute or so of silence, pop a balloon. Generate a brief discussion with the
students what occurred when they are surprised. Explain that the endocrine system
plays a role in the adrenaline rush they just experienced.
There are many available online activities in which students can further their knowledge
about the endocrine system. For example, Project Neuron: Food for Thought: What
Fuels Us (https://neuron.illinois.edu/units/food-for-thought-what-fuels-us) focuses on
glucose and the endocrine systems ability to maintain homeostasis as well as
prevent type II diabetes.
This chapter is expected to take 8 class periods including Lab 25.
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Case Study
After reading the case study, students should access their online Claim, Evidence,
Reasoning (CER) chart and make their claim. CER is a strategy used to teach
students how to construct explanations and craft scientific arguments. A scientific
claim answers a question or offers a solution to a problem. Give students time to
reflect and brainstorm, then have each student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is information
that supports or contradicts a claim. This information can come from a variety of
sources, such as research, experimentation, or data interpretation. It is important
to have multiple pieces of evidence to support a claim. Encourage students to
return to their claims and add evidence at multiple points in the chapter.
Here is a nice summary of the work that has been done looking at pheromone
signaling in human mate choice: https://www.nytimes.com/1998/06/09/science/
studies-explore-love-and-the-sweaty-t-shirt.html
Some pheromones stimulate learning of smell profiles. A recently discovered
pheromone, darcin, creates long-lasting smell memories:
https://www.sciencedaily.com/releases/2010/06/100602193316.htm
Introduction to the Theme
Theme: Stability and Change The endocrine systems has the ability to release
chemicals called hormones in order to maintain homeostasis. This helps to keep
organisms stable in an ever changing environment.
Theme Activity: Fight or Flight
This is a fun exercise that is a great way to introduce the endocrine systems to students.
Ask students sit quietly for five minutes with lights off. You may choose to play relaxing
music during this time. Without warning, flick lights on and yell "WAKE UP" very loudly.
Go around the room, and have the students discuss their feelings. Did they notice
any physical changes before and after you surprised them?
Tie this activity back into the different hormones of the adrenal medulla. Which
hormones did they experience a surge in during which times and why?
Section 11.1: Introduction
Learn
Classroom Activities
Section 11.1 sets the groundwork for activities in sections 11.2 and beyond.
Additional Discussion Questions
Ask students to devise a chart that illustrates the location of various glands that
secrete hormones.
Answers will vary
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Provide students with an unlabeled diagram of the human body and ask them to
locate the major endocrine glands.
The diagrams should include, at a minimum, the location of the pineal gland, parathyroid
gland, hypothalamus, pituitary gland, thyroid gland, thymus, adrenal gland, kidney, pancreas,
ovaries, and testes. Students should include a brief description of the functions of each of
these glands.
Discuss how glands that secrete hormones affect cells, tissues, organs, and organ
systems.
Responses should include a discussion of the reproductive system, skeletal system, respiratory
system, urinary system, etc.
Discuss and compare the functions of each of the exocrine and endocrine glands.
Develop a poster that illustrates an example of each. The students may prepare a
short presentation to the class.
Presentations will vary.
Practice
Practice Questions
1. What are the components of the endocrine system?
The endocrine system includes cells, tissues, and organs, collectively called endocrine
glands that secrete substances called hormones into the internal environment. The
hormones diffuse into the blood and eventually act on target cells.
2. State some general functions of hormones
Hormone actions include regulating metabolism, water balance, and growth.
3. What determines whether a cell is a target cell for a particular hormone?
Target cells have a receptor for a particular hormone.
4. Explain how the nervous and endocrine systems are alike and how they differ.
Both are systems of communication and both maintain homeostasis. The endocrine
system is able to communicate across long distances by releasing hormones into the
blood stream.
5.How do paracrine and autocrine secretions function differently than
traditionally defined hormones?
Paracrine secretions affect only neighboring cells and autocrine secretions affect only
the cell secreting the substance. Paracrine and autocrine secretions do not reach the
bloodstream, making them different from “traditional” hormones.
Use the Practices 11.1
Analyzing Data The nervous system acts with immediacy, but the processes
controlled by the endocrine system take time. Identify some processes in your
body that take place over different time frames such as minutes, hours, or days.
Answers will vary; digestion and metabolism are processes that occur over several hours.
Growth and development are processes that occur over several years. All of these types
of processes are most likely controlled by the endocrine system.
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Figure Questions
Figure 11.2, p. 393: What do postsynaptic cells and target cells have in common that
allow them to respond to secreted chemicals?
specific receptors for the chemicals to which they respond
Section 11.2: Hormone Action
Learn
Classroom Activities
Writing Connection: Types of Hormones
Students can work in small groups together, but each individual should complete
the work, so they have something to study later. The teacher should provide
students with some recent articles about common hormones students may
recognize from table 11.2.
Students should circle key words they find that have to do with a type of compound,
what it is formed from, or examples. Students should compose a written response
summary about their article and information they gathered about the specific
hormone they learned about. Encourage students to share any current relevant
information they may find that would be of interest to their peers.
Differentiated Instruction
The free resource Science News for Students allows the teacher to search for
articles based on standards for writing, math, or science as well as readability
score range. The teacher could assign students articles that align to their
reading and writing abilities as well as interests.
Additional Discussion Questions
Ask students to develop a set of index cards, each of which summarizes a step in the
sequence of steroid hormone action. Shuffle the cards and ask students to place
them in the correct sequence while briefly explaining each step in the process.
The index cards should include the following information: steroid hormone secreted, diffusion
into target cell, combines with receptor, DNA binding, synthesis of messenger RNA, messenger
RNA directs protein synthesis, new proteins produce desired effects.
Discuss the adverse effects of steroid abuse.
Responses should include a discussion of the hastening of adulthood, stunting height, causing
early hair loss, possible heart, kidney, and liver damage, etc.
Practice
Practice Questions
1.How does a steroid hormone promote cellular changes? How does a nonsteroid
hormone do the same?
Steroids diffuse into target cells and bind to their receptors (specific protein
molecules). The resulting hormone-receptor complex binds to specific sequences of
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DNA in the cell’s nucleus and activates transcription into mRNA. The mRNA leaves
the nucleus and enters the cytoplasm, where translation of specific proteins occurs.
Those proteins then leave the cell. Nonsteroid hormones bind receptors in target cell
membranes. The receptors are proteins with binding and activity sites. Nonsteroid
hormones bind to the binding site, which stimulates the activity site to interact with
other membrane proteins. Nonsteroid hormone binding activates adenylate cyclase,
catalyzing conversion of ATP into cAMP. cAMP activates existing proteins, causing a
series of reactions leading to cellular changes associated with the hormone’s action.
2. What is a second messenger?
Chemicals that induce changes in response to the hormone’s binding are called second
messengers. Examples of second messengers are cAMP, DAG, and IP3.
3. What are prostaglandins?
Prostaglandins are lipids that regulate cells and are synthesized from fatty acids in cell
membranes. Prostaglandins usually act more locally than hormones, often affecting only
the organ where they are produced.
4. What are the effects of prostaglandins?
Prostaglandins produce diverse effects. They can relax smooth muscle in the airways and
blood vessels, contract smooth muscle in the uterus and intestines, stimulate hormone
secretion from the adrenal gland, inhibit secretion of stomach acid, influence movement
of sodium ions and water in the kidneys, regulate blood pressure, and effect both male
and female reproduction.
Use the Practices 11.2
Asking Questions Develop a question you might use to investigate the
similarities and differences between the endocrine and nervous systems.
What would the advantage be of the chemical signal being secreted into the blood
stream versus directly released onto the target cell?
Section 11.3: Control of Hormone
Secretions
Learn
Classroom Activities
Visual Literacy: Flow Chart
Students may work in small groups. The teacher will provide students a copy of
Figure 11.5. Students will cut out the brown boxes representing each step of the
three different cycles. Once students have cut out all of the steps, the teach will
provide each group a blank copy of the flow chart from the figure.
Students will practice arranging the pieces they cut out into the correct order Once
students are finished and ready to check their answers, have them refer to the
Figure 11.5 in the book and check their answers. Encourage students to discuss if
they missed any or had any arranged wrong and why they had thought that and
what the correct order is.
Reflection Question: Why is hormone secretion said to be a negative feedback loop?
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Differentiated Instruction
This activity could be completed individually. Instead of students creating a
flow chart and cutting and arranging the boxes, students could create a
mixed-up line maze with the different words scattered throughout the maze.
Students would then challenge each other and family members to complete
the mazes which means they would have to put the order of each system of
control together correctly.
Additional Discussion Questions
How does negative feedback regulate cortisol secretion?
This negative feedback mechanism involves the hypothalamus, anterior pituitary gland, and
adrenal cortex. Under certain conditions, such as stress, injury, disease, extreme temperature
or emotional upset, nerve impulses send the brain information concerning the stressful
condition. In response, brain centers signal the hypothalamus to release more corticotropinreleasing hormone, leading to a higher concentration of cortisol until the stress subsides.
Discuss the relationship between insulin and glucagon in the regulation of serum
glucose levels.
A low concentration of blood glucose stimulates release of glucagon from the alpha cells
located in the pancreas. When blood glucose concentration returns to normal, glucagon
secretion decreases. This mechanism prevents hypoglycemia from occurring at times when
glucose concentration is relatively low, such as between meals, or when glucose is being used
rapidly, as during periods of exercise. Insulin’s main effect is exactly opposite of glucagon.
Insulin decreases the concentration of blood glucose, promotes transport of amino acids into
cells, increases protein synthesis, and stimulates adipose cells to synthesize and store fat.
Practice
Practice Questions
1. Explain three examples of control of hormonal secretion.
The hypothalamus regulates the anterior pituitary gland’s release of hormones. The
nervous system stimulates some glands directly. Another group of glands respond
directly to changes in the composition of the internal environment. In each of these
cases, as hormone levels rise in the blood and the hormone exerts its effects, negative
feedback inhibits the system, and hormone secretion decreases. As hormone levels in
the blood decrease and the effects of the hormone are no longer taking place,
inhibition of the system is lifted and secretion of the hormone starts again.
2. Describe a negative feedback system that controls hormone secretion.
When the blood glucose level rises, the pancreas secretes insulin, and when the blood
glucose level falls, it secretes glucagon, etc.
Use the Practices 11.3
Using Models Develop a model that illustrates the mechanisms of action for
steroid and nonsteroid hormones.
See Figure 11.3 and Figure 11.4 (sample)
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Section 11.4: Pituitary Gland
Learn
Classroom Activities
Demonstration: Be the Teacher
Discuss with the whole class briefly what the pituitary does, its structure, and where
it is located. Pair students together and assign each student one section of the
pituitary gland: the anterior pituitary hormone and the anterior pituitary hormone.
Challenge them to design a creative way to teach each other about their assigned
part of the gland.
Rubric of information that should be included in the presentation
•
•
•
•
Location of gland
Structure of gland
Which hormones are secreted and their actions
How hormones are regulated
Differentiated Instruction
Instead of pairing students together, create groups of four students. Assign two
students to work on one part of the pituitary gland. This will promote collaboration
and allow students to brainstorm on how to best teach the other partners in their
group. Encourage students to think about ways to best reach their partners such
as language of presentation, visual aids, or type of learning styles of their partners.
Additional Discussion Questions
Application questions for sections 11.4-11.9 can be found in section 11.9
Practice
Practice Questions
1. Where is the pituitary gland located?
The pituitary gland is located at the base of the brain, where a pituitary stalk attaches it
to the hypothalamus.
2.Explain how the hypothalamus controls the secretory activity of the posterior
and anterior lobes of the pituitary gland.
Neurons whose cell bodies are in the hypothalamus have axons that extend down into
the posterior pituitary gland. Impulses on their axons trigger the secretion of chemicals
from their axon terminals, which enter the blood as posterior pituitary hormones. Axon
terminals of another population of neurons in the hypothalamus secrete hormones called
releasing hormones (and some release-inhibiting hormones) into a capillary network
associated with the hypothalamus, which forms the hypophyseal portal veins and
connects to the anterior pituitary. Upon reaching the anterior pituitary, the hormones act
on specific populations of target cells.
3. How does growth hormone affect protein synthesis?
Growth hormone (GH) enhances the movement of amino acids across cell membranes
and speeds the rate at which cells utilize carbohydrates and fats, thus GH increases
protein synthesis.
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4. What is the function of prolactin?
Prolactin (PRL) stimulates and sustains a woman’s milk production following the birth of
an infant. No role for PRL has been found for males, but elevated levels of PRL can
disrupt sexual function in both males and females.
5. How is secretion of thyroid-stimulating hormone regulated?
The hypothalamus stimulates TSH secretion from the anterior pituitary by secreting
thyrotropin- releasing hormone (TRH). Circulating thyroid hormones inhibit release of
TRH and TSH. As the blood concentration of thyroid hormones increases, secretion of
TRH and TSH decreases.
6. What is the function of adrenocorticotropic hormone?
Adrenocorticotropic hormone (ACTH) controls the manufacture and secretion of
hormones from the outer layer of the adrenal gland, the adrenal cortex.
7. What is a gonadotropin?
Gonadotropins exert their actions on the gonads; the testes in males and the ovaries in
females. The anterior pituitary gonadotropins are LH and FSH.
8. What is the function of antidiuretic hormone?
ADH produces an antidiuretic effect by reducing the volume of water the kidneys
excrete, which regulates the concentration of body fluids. Dehydration due to loss of
water increasingly concentrates blood solutes. Osmoreceptors sense the resulting
increase in osmotic pressure and signal the posterior pituitary to release ADH which
acts on target cells in the kidney. As a result, the kidneys produce less urine,
conserving water.
9. How is secretion of antidiuretic hormone controlled?
The hypothalamus controls ADH secretion. Dehydration due to loss of water increasingly
concentrates blood solutes. Osmoreceptors sense the resulting increase in osmotic
pressure and signal the posterior pituitary to release ADH which acts on target cells in
the kidney. As a result, the kidneys produce less urine, conserving water. On the other
hand, drinking excess water dilutes body fluids, inhibiting ADH release. In response, the
kidneys excrete a larger volume of dilute urine.
10. What effects does oxytocin produce in females?
In females, OT contracts smooth muscle in the uterine wall and stimulates uterine
contractions in the later stages of childbirth. OT stimulates contraction of specialized
cells associated with milk-producing glands and their ducts. In lactating breasts, this
action forces liquid from the milk glands into the milk ducts and ejects the milk from the
breasts for breast-feeding. OT also plays a role in bonding between mother and infant as
well as between sexual partners.
Use the Practice 11.4
Communicating Information Explain how the pituitary gland contributes to
maintaining proper hydration of the body.
The hypothalamus controls ADH secretion. which in turns causes the kidneys to conserve
water. When you drink water, ADH secretion is turned down, in order for your kidneys to
excrete more urine.
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Section 11.5: Thyroid Gland
Learn
Classroom Activities
Small Group Discussion: The Three Hormones
Discuss with students that the thyroid gland produces three main hormones. There
are also many ions that are important to the proper functioning of the thyroid gland.
In pairs, have students discuss which ions affect which hormone and what would
happen if that ion wasn’t available. Students may need to research on the internet
or the library.
Example: Calcium controls calcitonin release which stimulates bone forming activity.
If the release of calcitonin is not regular, issues in bone development could occur.
Differentiated Instruction
Instead of students researching how ions affect the different hormones,
students could research diseases that have been connected back to the
thyroid gland. Have students complete their research in groups and create a
short presentation on their findings to the class.
Additional Discussion Questions
Application questions for sections 11.4-11.9 can be found in section 11.9
Practice
Practice Questions
1. Where is the thyroid gland located?
The thyroid gland consists of two large lobes connected by a broad isthmus. The lobes
are just inferior to the larynx and anterior and lateral to the trachea.
2.Which hormones of the thyroid gland affect carbohydrate metabolism and
protein synthesis?
The thyroid produces thyroxine and triiodothyronine, which collectively are known as
thyroid hormone. Thyroid hormone helps regulate the metabolism of carbohydrates,
lipids, and proteins. It increases the rate at which cells release energy from
carbohydrates, increases the rate of protein synthesis, and stimulates breakdown and
mobilization of lipids.
3.How does the thyroid gland influence the concentrations of blood calcium and
phosphate ions?
The thyroid produces calcitonin, which regulates the concentration of blood calcium and
phosphate ions. The blood concentration of calcium ions controls calcitonin release. As
the blood calcium concentration increases, so does calcitonin secretion.
Use the Practice 11.5
Constructing Explanations Explain why hypothyroidism is normally marked
by high levels of TSH and why it could be an indication that the thyroid gland is
failing.
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A low level of T3 indicates to the hypothalamus to secrete TRH to trigger the pituitary
gland to secrete TSH, which in turn triggers the thyroid gland to secrete T4. T4 travels in
the blood stream to the liver, where it is converted into T3 to be used by the cells. In
hypothyroidism, low levels of T3 and T4 cause the pituitary gland to continue releasing
TSH even though the thyroid gland is not able to secrete enough T4.
Section 11.6: Parathyroid Gland
Learn
Classroom Activities
Visual Literacy: PTH Secretion Color Code
This is an individual activity where students can physically color the different
secretion pathway of PTH as well as the movement of Ca+ ions. Provide students a
copy of Figure 11.12, but remove the color codes on the arrows. Students should
color and label what is flowing at each arrow in and out of the different areas in the
diagram. Leave the color code key in the top hand corner so students know which
colors to use. Students should use their diagram to practice explaining the process
of PTH stimulating ion movement.
Differentiated Instruction
Instead of students coloring the arrows, the teacher can print Figure 11.12 with
the colored arrows and remove the labels of PTH and Ca+2 throughout the
diagram. Students should label the diagram instead of coloring it. Students
should use their diagram to practice explaining the process of PTH stimulating
ion movement.
Additional Discussion Questions
Application questions for sections 11.4-11.9 can be found in section 11.9
Practice
Practice Questions
1. Where are the parathyroid glands?
The parathyroid glands are on the posterior surface of the thyroid gland. Most
individuals have four parathyroid glands, a superior and an inferior gland associated
with each of the thyroid’s bilateral lobes.
2.How does parathyroid hormone help regulate concentrations of blood calcium
and phosphate ions?
PTH increases the blood calcium ion concentration and decreases blood phosphate ion
concentration. PTH inhibits the activity of osteoblasts and increases the activity of
osteoclasts to resorb bone and release calcium and phosphate ions into the blood. At
the same time, PTH causes the kidneys to conserve blood calcium and to excrete more
phosphate ions in the urine. It also causes the kidneys to activate vitamin D, which
stimulates calcium absorption from food in the intestine, further increasing the blood
calcium concentration. As the blood calcium concentration drops, more PTH is secreted
and as the blood calcium concentration rises, less PTH is secreted.
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Use the Practice 11.6
Arguing from Evidence In one study, researchers argued that inappropriate
regulation of the bone resorption and bone formation processes, which are
normal parts of bone remodeling, can lead to net bone loss. Evaluate this
hypothesis based on your knowledge of the function of parathyroid hormone
and calcitonin.
The parathyroid glands secrete PTH which increases blood calcium concentration. PTH
inhibits the activity of osteoblasts, the cells that build bone, and stimulates osteoclasts to
break down bone and release calcium into the blood. Calcitonin, from the thyroid gland,
also regulates the blood calcium levels, but in the opposite way as PTH by decreasing
above – normal blood calcium levels. If there is an imbalance in either of these hormones,
bone loss may occur.
Section 11.7: Adrenal Glands
Learn
Classroom Activities
EL Strategy: Comprehension Skills
Beginning Ask questions about the lesson content to elicit yes/no answers:
“Are adrenal glands associated with the kidneys?” yes “Do hormones influence
metabolism?” yes “Is the adrenal system the only system that produces
hormones?” no
Writing Connection: EpiPens and Cortisol Research
Discuss with the whole group the structure of the adrenal gland and the hormones
both parts of the adrenal gland secrete. Arrange students into small groups of four.
Half the groups will explore their library and internet resources about EpiPen pens
and how they relate to epinephrine. They will work together write an explanation of
why a student who is having an allergic reaction should use an EpiPen.
The other groups will explore their library and internet resources about reducing
stress and how that relates to cortisol. They will work together to write an explanation
of why cortisol and other stress hormones can negatively affect the body.
At the end of the activity, students should share their explanations with the class.
Differentiated Instruction
Instead of students researching and debating these topics, students could
recreate Table 11.5 and 11.6 in order to practice the same concepts. Once
students review these concepts, take an in-school field trip to the nurse’s
office to view an EpiPen and receive training on it. Many students carry
EpiPen’s in the school or with the appropriate professional. Discuss with
students the importance of being aware of allergies among their classmates
and how they can all raise awareness to help avoid allergic reactions.
Additional Discussion Questions
Application questions for sections 11.4-11.9 can be found in section 11.9
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Practice
Practice Questions
1. Where are the adrenal glands?
The adrenal glands sit atop each kidney like a cap and are embedded in the mass of
adipose tissue that encloses the kidney.
2. Describe the two portions of an adrenal gland.
The adrenal glands consist of two parts: the central portion (medulla) and the outer portion
(cortex). The two regions are functionally distinct and secrete different hormones. The
medulla consists of irregularly shaped cells organized in groups around blood vessels.
Adrenal medullary cells are actually modified postganglionic neurons and intimately
connected with the sympathetic division of the autonomic nervous system. The adrenal
cortex is composed of packed masses of epithelial cells, organized in layers: the outer layer
(zona glomerulosa), the middle layer (zona fasciculata), and the inner layer (zona reticularis).
3. Name the hormones the adrenal medulla secretes.
The adrenal medulla secretes two hormones: epinephrine and norepinephrine.
4. What effects do hormones from the adrenal medulla produce?
Epinephrine and norepinephrine increase heart rate, the force of cardiac contraction,
and blood glucose levels. They also dilate airways, elevate blood pressure, and decrease
digestive activity.
5. What stimulates release of hormones from the adrenal medulla?
Sympathetic impulses originate in the hypothalamus in response to stress. Impulses
arriving on sympathetic preganglionic nerve fibers stimulate the adrenal medulla to
release its hormones.
6. Name the most important hormones of the adrenal cortex.
The adrenal cortex secretes aldosterone, cortisol, and adrenal androgens.
7. What is the function of aldosterone?
Aldosterone is a mineralocorticoid and helps regulate the concentrations of mineral
electrolytes. Aldosterone causes the kidney to conserve sodium ions and excrete
potassium ions. By conserving sodium ions, aldosterone stimulates water retention
indirectly by osmosis, helping to maintain blood volume and blood pressure.
8. What actions does cortisol produce?
Cortisol is a glucocorticoid hormone, which means it affects glucose metabolism. Cortisol
inhibits protein synthesis in tissues and increases blood concentrations of amino acids.
Cortisol promotes fatty acid release from adipose tissue, increasing utilization of fatty
acids and decreasing glucose use. Cortisol stimulates liver cells to synthesize glucose,
which increases blood glucose concentration.
9. How are the blood concentrations of aldosterone and cortisol regulated?
An increase in blood concentration of potassium ions stimulates aldosterone release. The
kidneys also indirectly stimulate aldosterone secretion if blood pressure falls or if blood
sodium ion concentrations decrease. Negative feedback controls cortisol release. The
hypothalamus secretes corticotropin-releasing hormone (CRH) which stimulates the
anterior pituitary to release ACTH. ACTH then stimulates the adrenal cortex to release
cortisol. Cortisol inhibits the release of CRH and ACTH, and as concentrations of these
fall, cortisol production drops.
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Use the Practices 11.7
Constructing Explanations Explain the mechanisms that cause your heart to
race when you hear a loud, unexpected noise such as a car backfiring.
When you hear a loud, unexpected noise, a series of events are triggered that ultimately
increase your heart rate. It starts as sound enters your ear, which triggers the temporal lobe.
Your brain receives the information as an “unknown threat,” and sends the information to the
hypothalamus. Your hypothalamus sends a directly signal, through the spinal cord along
the sympathetic nervous system to the adrenal glands. The adrenal glands secrete
epinephrine in response and your heart rate increases, maintaining your “fight or flight” state.
Section 11.8: Pancreas
Learn
Classroom Activities
Group Presentation: Diabetes
Discuss with students what it means to be diabetic. Diabetes affects many people in
different ways. Split students into groups of six with subgroups of three. Each subgroup
will research one of the types of diabetes: type I or type II. Each of the subgroups
will present to the other on the type they researched. Presentations can be done in
any format the students choose. Encourage student to be creative and to incorporate
the relationship between insulin, glycogen, and glucose in their presentation.
Differentiated Instruction
The teacher may want to assign students a part of the presentation to ensure
that all students are involved. There could be jobs for the presentation each
student must accomplish. Encourage students to create a testimonial section
where they can discuss if they have someone in their life that is diabetic or
even one of the students. Students may wish to discuss their findings within
the large group instead of presenting it.
Writing Connection: Genetic Engineering of Insulin
For this activity, have students read page 352 “Disease, Diagnosis & Treatment:
Treating Diabetes.” Then, have students write a PSA on what diabetes is, why insulin
is needed to treat this disease, and how genetic engineering helped create a form
of insulin usable by humans.
Extension topics: Is this the only type of treatment available for diabetes? What are
the pros and cons of the use of this biotechnology?
Additional Discussion Questions
Application questions for sections 11.4-11.9 can be found in section 11.9
Practice
Practice Questions
1. What is the endocrine portion of the pancreas called?
The endocrine portion of the pancreas consists of groups of cells that are closely
associated with blood vessels and form “islands” of cells called pancreatic islets. The
pancreatic islets include distinct cells: alpha cells and beta cells.
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2. What is the function of glucagon? Of insulin?
Glucagon raises the blood sugar concentration by stimulating the liver to break down
glycogen and convert amino acids into glucose. The main effect of insulin is to lower the
blood glucose level, exactly the opposite of glucagon. Insulin promotes facilitated
diffusion of glucose into cells that have insulin receptors (adipose, liver, skeletal muscle).
Insulin also stimulates the liver to form glycogen from glucose and inhibits conversion of
noncarbohydrates to glucose. Insulin also promotes transport of amino acids into cells,
increasing protein synthesis, and stimulates adipose cells to synthesize and store fat.
3. How are glucagon and insulin secretion controlled?
A negative feedback system sensitive to the blood glucose concentration regulates
insulin secretion. When the blood glucose concentration is high, beta cells release insulin.
When glucose concentration falls, insulin secretion decreases. As insulin secretion
decreases, glucagon secretion increases. Insulin and glucagon are coordinated to
maintain a relatively stable blood glucose concentration.
4.Why are nerve cells particularly sensitive to changes in blood glucose
concentration?
Nerve cells obtain glucose by facilitated diffusion and do not require insulin, but depend
on the blood glucose concentration alone for their glucose needs. This makes nerve cells
particularly sensitive to blood glucose levels.
Use the Practice 11.8
Using Mathematics Create a graph showing a typical pattern of changing
blood sugar and insulin levels over the course of a day. Add labels to your
graph indicating when meals are eaten.
The graph should show periodic spikes and dips in blood sugar throughout the day. you
have eaten, your blood sugar levels increase, as the food is broken down through your
digestive system and travels in the blood stream. This increase in glucose levels in the
blood, trigger the release of insulin from the pancreas. Insulin allows glucose to enter
your cells, which in turn decreases the blood sugar levels. When the blood sugar levels
fall below normal, it triggers the release of glucagon from the pancreas.
Figure Questions
Figure 11.15, p. 413: What term describes the secretions that enter the pancreatic ducts?
exocrine
Section 11.9: Pineal, Thymus,
and Other Glands
Learn
Classroom Activities
Visual Literacy: Trace the Hormones
Provide students with a picture of the human body and colored pencils.
As you lecture, ask students to create maps of the hormones. Where do the
hormones start? What is their final destination?
Have the students create pathways of the hormones using different colors.
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Writing Connection: The Extras
Individually have students list as many hormones they can, where they are
produced, and what the purpose is for the hormone. Once students have their list,
have them switch papers with a partner and peer review. The editing partner can
correct anything and add to the list.
Differentiated Instruction
Artificial versions of some of the hormones produced by the pineal gland and
the thymus gland are used in controversial ways. Melatonin is used in multiple
ways that some believe are unethical. Discuss with students what ethics of
science is, and research different ways melatonin is used.
Additional Discussion Questions
What is the interrelationship between calcitonin and parathormone?
Calcitonin is a hormone secreted by the thyroid gland, parathormone is a hormone secreted by
the parathyroid gland. Both hormones help regulate calcium levels in the bloodstream.
Calcitonin decreases calcium levels in the blood by causing an increase in its absorption into
bone. Parathormone stimulates bone to release calcium back into the bloodstream.
List each hormone, location of production, function and the controls of secretion of
the hormone.
Students should create a chart with the hormones
Briefly describe the interaction between a nonsteroid hormone molecule and its
target cell.
Nonsteroid hormone molecules are carried via body fluids to the target cell, where they
combine with receptor sites on the cell membrane. The activation of adenylate cyclase may
follow, which catalyzes the conversion of ATP into cyclic AMP. This initiates a series of
reactions that promote hormonal action.
Have students research different disorders that affect the endocrine system.
Disorders could include acromegaly, diabetes, Cushing syndrome, or Addison’s disease.
Discuss the mechanism by which the hypothalamus, in conjunction with the pituitary
gland, controls secretion of a peripheral endocrine gland.
An example of this mechanism would be thyrotropin-releasing hormone, secreted by the
hypothalamus, which initiates the release of thyroid-stimulating hormone from the anterior
pituitary gland, which then stimulates the thyroid gland to release its secretions to target cells.
Practice
Practice Questions
1. Where is the pineal gland located?
The pineal gland is a small structure located deep between the cerebral hemispheres,
where it is attached to the upper part of the thalamus near the roof of the third ventricle.
2. What is the function of the pineal gland?
The pineal gland secretes melatonin in response to changing light conditions outside the
body. Melatonin may regulate circadian rhythms, patterns of repeated activity
associated with environmental cycles of day and night.
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3. Where is the thymus located?
The thymus lies in the mediastinum, posterior to the sternum and between the lungs.
4. Which reproductive organs secrete hormones?
The reproductive organs that secrete hormones are the testes (males) and ovaries (females).
5. Which other organs secrete hormones?
The digestive glands secrete hormones associated with the linings of the stomach and
small intestine. The heart produces atrial natriuretic peptide and the kidneys and liver
secrete erythropoietin.
Use the Practice 11.9
Conducting Investigations Identify what type of data—qualitative,
quantitative, or both—would need to be collected to understand the various
circadian rhythms of an individual.
In order to understand circadian rhythms of an individual, we would need both
qualitative observations such as how sleepy they feel, or when they are most alert, as
well as quantitative observations such as how long they sleep, what time they are
sleeping, the amount of melatonin secreted, and how long the day light persists.
Section 11.10: Stress and Health
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct a small group of students to write a paragraph
describing what is happening in Figure 11.18. In addition to the description of
steps, students should have an example of physical or psychological stress to
show their understanding. Their paragraphs should describe all parts of the
diagram in their own words. Ask for volunteers to read their paragraphs. Have
students ask others for clarification as needed.
Writing Connection: Can stress make you sick?
Discuss with the whole class what stress is and what stresses they have in their life.
Stresses could be at school, work, or home. Encourage students to share only if they
are comfortable. Present students with the statement: “Stress can make you sick.”
Ask students to write scientific evidence of how the body responds to stress and if
it is true or not that stress can make an individual sick. Students can work in pairs or
individually.
Differentiated Instruction
Instead of students researching and finding evidence about the how the body
fights stress, ask students to create a survey for adults in their life over how stress
affects them. Encourage students to follow the scientific method and to present
their findings to the group or class. Highlight to students that different people and
cultures have different stressors depending on their past and experiences.
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Additional Discussion Questions
Ask students to establish personal guidelines for dealing with stress and present
their ideas to the class.
Techniques that work for one student will not necessarily work for another. However, the
discussion should revolve around some basic concepts in stress management, such as
scheduling time effectively, setting priorities, establishing realistic goals, perceiving oneself as
an achiever of goals, and allowing oneself time to relax, exercise, and enjoy life every day.
Discuss the physiological responses to stress.
Responses should include a discussion of the limbic system, the role of the hypothalamus, the
role of the pituitary gland and its release of ACTH, the fight-or-flight reaction, effects on blood
pressure, release of epinephrine and norepinephrine, release of endorphins, effects on the
heart, lungs, metabolism, skeletal muscles, etc.
Practice
Practice Questions
1. What is stress?
Stress is a condition in the body that results from stimulation by internal or external
factors called stressors.
2. Distinguish between physical stress and psychological stress.
Examples of physical stress are conditions such as extreme temperatures, decreased
oxygen concentration, infection, injury, etc. Examples of psychological stress include
feelings such as anger, grief, anxiety, sexual arousal, etc.
3. Describe the stress response.
The stress response can be divided into two stages: the alarm stage and the resistance
stage. In the alarm stage, the hypothalamus activates the fight-or-flight response. This
includes raising blood glucose concentrations, increasing heart rate and blood pressure,
dilating air passages, shunting blood away from digestive organs, etc. In the resistance
stage, the hypothalamus releases CRH, which stimulates the anterior pituitary to release
ACTH. ACTH stimulates the adrenal cortex and increases blood cortisol levels. Cortisol
increases blood concentrations of amino and fatty acids, and increases glucose
synthesis.
Use the Practices 11.11
Communicating Information Anxiety and weight gain often occur together.
Propose a process that would explain how high levels of long term stress
result in weight gain.
See Figure 11.18
Assess
Career Corner: Licensed Practical Nurse
Consider This: Research the difference in the training and responsibilities of
a licensed practical nurse and a registered nurse.
Answers will vary somewhat. Both LPNs and RNs are involved directly in patient care
and both are vital members of the healthcare team. The primary difference between an
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219
LPN and RN is the educational and training requirements. While LPNs have a highschool diploma and vocational training, RNs complete a 4-year degree and attend
nursing school. Both RNs and LPNs are employed in similar locations.
Diseases, Diagnosis, and Treatment: Hypo- and Hypersecretion
of Adrenal Cortical Hormones
1.What are the symptoms of Cushing syndrome?
Puffy skin and masculinizing effects in females, such as beard growth or a deep voice.
2.Differentiate between mineralocorticoids and glucocorticoids.
Mineralocorticoids help regulate the concentration of mineral electrolytes. An example is
aldosterone, which causes the kidneys to conserve sodium and excrete potassium.
Glucocorticoids affect glucose metabolism. An example is cortisol, which affects glucose
metabolism as well as influences protien and fat metabolism.
Healthy Lifestyle Choices: Biological Rhythms
1.What might be the consequences of disrupting normal biological rhythms by
taking hormonal supplements?
Answers will vary
2.If someone works a night shift job, and thus must sleep during the day, what
behaviors might they adopt to help their biological rhythms adjust?
Since your friend is tasked with falling asleep in the morning and waking in the evening,
the most important step in achieving this is to trick his body into thinking it is nighttime.
You could suggest that he buy special curtains for his bedroom window that block out
the sun. You could suggest that he avoid “screens” (tablets, smartphones, etc.) that emit
blue light and decrease melatonin, increasing wakefulness. You could suggest your friend
wear a sleeping mask to further block light.
Case Study Connection
page 393: Would pheromones be considered endocrine or exocrine molecules?
Exocrine
page 394: Where would you expect to find pheromone receptors? Would
pheromones fit the definition of paracrine or autocrine signaling molecules?
Answers may vary but will probably include the nose or mouth (respiratory system).
Pheromones would better fit the description of a paracrine signaling molecule.
page 395: Many human pheromones are steroid molecules that are found in
sweat. Axillary and inguinal sweat has a higher concentration of lipids than
eccrine sweat found over the surface of the body such as the forearms. Would
you expect there to be a difference in the solubility of pheromones in eccrine
versus axillary sweat?
Yes, the presence of lipids would affect the solubility of a pheromone.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Biochemicals that send messages within the body are called
a. pheromones.
b. exocrine.
c. hormones.
d. the nervous system.
2. Which is not true about steroid hormones?
a. they consist of complex rings of carbon and hydrogen
b. they are highly soluble in water
c. they can diffuse into cells fairly easily
d. they may enter any cell in the body
3. Releasing hormones come from which one of the following?
a. thyroid gland
b. anterior pituitary gland
c. posterior pituitary gland
d. hypothalamus
4. Prolactin does which of the following?
a. stimulates breast milk secretion
b. stimulates breast milk production
c. inhibits breast milk secretion
d. inhibits breast milk production
5. Under which of the following conditions would you expect an
increase in antidiuretic hormone secretion?
a. An individual ingests excess water.
b. The posterior pituitary is removed from an individual
because of a tumor.
c. An individual has spent three days in the desert without
food or water.
d. An individual with normal kidneys is producing a large
volume of urine.
6. If an adult had their thyroid removed, which hormone
supplement would they least likely need to take?
a. thyroxine
b. triiodothyroxine
c. calcitonin
d. melatonin
7. Which hormone is incorrectly matched with its source and
actions?
a. cortisol – adrenal gland; sodium retention
b. insulin – posterior pituitary; glucose production
c. epinephrine – adrenal gland; fight-or-flight response
d. calcitonin – thyroid; decreases blood calcium level
8. Fight-or-flight hormones come from where?
a. adrenal glands
b. pituitary gland
c. ovaries
d. hypothalamus
9. Match the following hormones with their actions. More than
one hormone can correspond to the same function.
(1) growth hormone
A. milk production
(2) thyroid-stimulating hormone
B. cell division
(3) prolactin
C. metabolic rate
(4) adrenocorticotropic hormone
D. exerts action on
gonads
(5) follicle-stimulating hormone
E. controls secretion of
adrenal hormones
(6) luteinizing hormone
(1)B, C; (2)C; (3)A; (4)E; (5)D;
(6)D
10. Match the hormones from the thyroid gland with their
descriptions.
(1) thyroxine
A. most potent at controlling
metabolism
(2) triiodothyronine
B. regulates blood calcium
(3) calcitonin
C. has four iodine atoms
(1)A, (2)C, (3)B
Short Answer
1. What are the functional differences between the nervous
and endocrine systems?
The nervous system employs neurotransmitters that are
released directly to the target and the effects are immediate
and short-lived. The endocrine system produces hormones that
are released into the blood for delivery to the intended target.
The effects can last hours to days.
2. What is the major function of the endocrine system?
Overall the hormones produced by the endocrine system help
regulate all metabolic process. They are instrumental in
maintaining homeostasis.
3. List the major endocrine organs.
The major endocrine organs are: hypothalamus, pituitary
gland, thyroid gland, parathyroid glands, adrenal glands,
pancreas, ovaries, and testes.
4. Describe a steroid hormone.
Steroid hormones are built from rings of carbon and hydrogen
atoms, with some oxygen atoms.
5. What are the classes of non-steroid hormones?
Non-steroid hormones are amines, peptides, and proteins.
6. What are the anterior pituitary hormones?
The anterior pituitary hormones are: growth hormone,
prolactin, thyroid stimulating hormone, adrenocorticotropic
hormone, and follicle-stimulating hormone.
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7. How do hormones ultimately affect cAMP action?
A hormone binds to a receptor and that activates G proteins.
G proteins activate adenylate cyclase. This enzyme converts
ATP into cAMP. cAMP then activates enzymes in the cell.
8. What is the action of ADH?
ADH (antidiuretic hormone) causes the kidneys to hold onto to
water. It also is a vasoconstrictor. ADH therefore is
instrumental and controlling blood pressure.
9. What is the action of prolactin?
In females, prolactin sustains milk production after birth.
10. What are the two cell types in the pancreatic islets? What do
they produce?
Alpha and beta cells. Alpha cells produce and secrete
glucagon and beta cells produce and secrete insulin.
11. What is the action of insulin?
Insulin promotes the movement of glucose into cells and the
formation of glycogen from glucose.
12. What does the pineal gland produce? What is its action?
The pineal gland produces melatonin. It induces sleep.
13. What hormones does the thyroid gland produce?
The thyroid gland produces thyroxine and triiodinethyronine.
Together they are referred to as thyroid hormone. The thyroid
gland also produces calcitonin.
14. Distinguish between calcitonin and PTH.
Both blood calcium levels. Calcitonin is released from the
thyroid gland in response to elevated blood calcium levels.
PTH is released from the parathyroid glands in response to a
drop in blood calcium levels.
15. Describe the structure of the adrenal gland. What hormones
does it produce?
The adrenal gland is composed of an inner medulla and an
outer layer called the cortex. The medulla produces
epinephrine and norepinephrine. The cortex produces
aldosterone, cortisol, and adrenal sex hormones.
Critical Thinking and Clinical Applications
1. A 45-year-old man had his yearly physical, which included a
blood work up. His blood pressure is a bit too high and the
levels of potassium and sodium ions are out balance. Which
endocrine organ does the physician suspect of
malfunctioning?
The physician probably suspects the adrenal glands because
aldosterone plays a role in blood pressure and sodium and
potassium balance.
2. CLINICAL Connection Amy noticed a slight enlargement
in the anterior portion of her neck. Her doctor suspected a
goiter, so she ordered some tests to try to determine the
cause. The results showed that Amy’s TRH levels were low,
TSH levels were high, and T3 and T4 levels were high. Given
these results, which endocrine organ is the problem? Is this
condition an example of hypersecretion or hyposecretion?
Why was Amy’s neck enlarged?
The hypothalamus releases TRH, which stimulates the anterior
pituitary to release TSH. TSH stimulates the thyroid to release
T3 and T4. If TRH and TSH are not oversecreted, the issue is
hypersecretion from the thyroid. The enlargement is a goiter,
which can be caused by both hyper- and hypothyroidism.
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3. An athlete takes a great deal of vitamin supplements,
including large amounts of vitamin D. How will this affect
calcium levels? Which hormones will be secreted in response
to this?
Vitamin D facilitates calcium absorption into the blood. This
will increase blood calcium levels. Calcitonin will be released
from the thyroid gland to help decrease calcium levels.
4. A young man was involved in an automobile accident which
resulted in a head injury that included a fracture to the
sphenoid bone. Why might this cause some hormone
imbalances?
The pituitary gland is housed in the sphenoid bone and the
hypothalamus is very close to it. These two glands are the
regulators of hormone production and release.
5. WRITING Connection Growth hormone is administered
to people who have pituitary dwarfism. Parents wanting their
normal children to be taller have requested the treatment for
them. Do you think this is a wise request? Why or why not?
Answers will vary
Lab Data Analysis: Glycemic Index and Diabetes
Think Critically
1. How do the insulin and blood glucose curves compare
between low- and high-glycemic index foods?
With low-glycemic foods, the blood glucose and insulin curves
mirror each other. This is similar to the curves with highglycemic foods, except that the increase in blood levels is
approximately twice as much. Additionally, there is a dip in
insulin below baseline at four hours that does not exist with
low-glycemic foods.
2. Keeping in mind the normal actions of insulin, which group of
patients do you think would store more sugar after a meal?
Thus, the high-glycemic diet (which promotes increased insulin
release) would result in more sugar storage.
3. The central issue in type 2 diabetes is insulin resistance due
to excessive insulin release into the bloodstream. Based on
the graphs, which diet seems better for a patient who has
type 2 diabetes?
Low-glycemic-index diet. The central issue in type 2 diabetes is
insulin resistance due to excessive insulin release into the
bloodstream. A low-glycemic diet is advisable to decrease
insulin levels and promote weight loss.
High-glycemic-index group. Insulin is an anabolic hormone,
meaning that it promotes storage of sugars for future use.
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UNIT
4
Transport
Chapter
Pacing (class periods)
12 Blood
8
13 Cardiovascular System
14 Lymphatic System and Immunity
10
8
Unit 4 Resources
Unit Project Engineer a Healthier World – Engineering in Anatomy and Physiology
nit Project: Engineer a Healthier World—
U
Engineering in Anatomy and Physiology
Project 4: Are you positive?
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Blood Typing: from Serology to DNA Chips”
(p. 454), and use this to start their investigation into technologies that can improve
blood typing for emergency or remote situations.
A teacher guide for this project can be found online.
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CHAPTER
12
Blood
Section
Pacing
(class periods)
12.1 Introduction
—
Learning Objectives
1. Describe the general characteristics of blood,
and discuss its major functions.
2. Distinguish between the formed elements and
the liquid portion of blood.
12.2 Formed
Elements
2
1. Explain the significance of red blood cell counts.
2. Summarize the control of red blood cell
production.
3. Distinguish among the five types of white blood
cells, and give the function(s) of each type.
4. Explain the significance of platelet counts.
12.3 Plasma
2
1. Describe the functions of each of the major
components of plasma.
12.4 Hemostasis
2
1. Define hemostasis, and explain the mechanisms
that help achieve it.
2. Review the major steps in blood coagulation.
12.5 Blood Groups
and Transfusions
2
1. Explain blood typing and how it is used to avoid
adverse reactions following blood transfusions.
2. Describe how blood reactions may occur
between fetal and maternal tissues.
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (4)
Chapter Resources
Extended Summary Review
Chapter 12 Test Bank
Chapter 12 Interactive Question Bank
Vocabulary Flashcards
APR Module 9: Cardiovascular System
Laboratory Exercise 26: Blood Cells
Laboratory Exercise 27: Blood Typing
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A Suggested Approach
To begin this chapter, ask students, “What do a mosquito, a leech and a vampire bat
have in common?” Students will probably quickly answer that all three drink blood.
Then ask the students, “What do you think is in blood that these animals would use
blood as their source of nutrients?” Inform students that during the study of this
chapter, they will learn why blood signifies life, and the complex mixture of cells, cell
fragments, and dissolved biochemicals that make up our blood.
All of the cellular components of blood can be seen by viewing a blood smear under
a microscope. This provides an opportunity for students to become familiar with
each of the formed elements found in blood, and the role they play in our bodies.
There are a variety of lessons available online to supplement the teaching of
Chapter 12. For an overview of blood, as well as lessons on the cardiovascular
system, America’s Blood Center has developed a high school curriculum and videos.
The America Society of Hematology has developed student worksheets, lessons,
and laboratory activities to accompany the Blood Detectives video. The lessons
build on themes from the study of specific blood disorders and help students
understand how the components of blood are necessary for life.
In addition to the blood typing lab provided, students may practice their knowledge
of blood typing by solving a crime or mystery. Or students could research blood
banks and participate in a community blood drive.
This chapter is expected to take 8 class periods including Lab 26 and Lab 27.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
At this juncture in your course it might be interesting to have a discussion or
case studies about different ways that physiology can be manipulated. Here
are two articles to get your discussion going about different manipulations of
physiology that might be on the rise in sports.
https://www.washingtonpost.com/news/early-lead/wp/2017/06/20/moveover-blood-doping-cyclists-might-be-poop-doping-soon/?noredirect=
on&utm_term=.9b33680f5c3c
https://www.nature.com/scitable/topicpage/sports-gene-doping-and-wada-764
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Introduction to the Theme
Theme: Energy and Matter Blood is mechanism for distributing heat energy and
transporting nutrient matter and many other substances throughout the body.
Theme Activity: Recipe Card
Blood contains all the necessary nutrients and elements to sustain life. Start this
lecture by passing out index cards to students. As you lecture, have students write
down a recipe for blood. What are its ingredients (components)? In what amounts
are these ingredients found? And, lastly, are these ingredients mixed in a certain way?
You may find it helpful to show Figure 12.2 as you lecture during this activity
Section 12.1: Introduction
Learn
Classroom Activities
Modeling Activity: Blood Model
This activity pairs well with the theme activity but it can also be done separately.
Once students have created a “recipe” for blood, pass out 100 mL graduated
cylinders and bowls of different model components. Components can be tiny
household items such as: rice, red hot candies, tictacs, popcorn kernels, beads, etc.
Ask the students to create their blood in a 100 mL graduated cylinder, using the
gradations to make the correct proportions of their ingredients. As with all models,
ask the students to make a key to show which component illustrates which element
they are representing.
Additional Discussion Questions
When a patient is tested for a complete blood count, what characteristics of blood
are being measured?
A complete blood count is a measure of the number of white blood cells, red blood cells, and
platelets contained in a specified volume of blood. The patient’s hemoglobin, hematocrit, and
other red cell parameters are also measured. Then, an estimate is made of the percent of each
type of white blood cell present, based on a microscopic examination of 100 cells. Finally, red
blood cell morphology is visually examined.
Ask students to develop a master chart that traces the pathway of development of
each type of blood cell from stem cell to its mature form.
The chart should contain information regarding stem cells, proerythroblasts, erythroblasts,
normoblasts, reticulocytes, erythrocytes, megakaryoblasts, megakaryocytes, thrombocytes,
myeloblasts, progranulocytes, band cells, neutrophils, eosinophils, basophils, monoblasts,
monocytes, macrophages, lymphoblasts, T lymphocytes, B lymphocytes, and plasma cells.
Discuss various causes of anemia.
Anemia is a general term meaning a decrease in hemoglobin in the blood to levels below the
normal range. There are several types of anemia, named primarily on the basis of the direct
cause. Causes include hemorrhage, bacterial infections, lack of certain vitamins, lack of
intrinsic factor, bone marrow destruction, lack of iron, prolonged bleeding, or a genetic defect.
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Practice
Practice Questions
1. What are the major components of blood?
The major components of blood are red blood cells, white blood cells, and platelets.
These are considered the “formed elements” of blood and are suspended in the liquid
portion of blood, called plasma.
2. What factors affect blood volume?
Blood volume varies with body size, percent adipose tissue, and changes in fluid and
electrolyte concentrations.
3. What might cause abnormal hematocrit values?
Anemia, nutritional deficiencies, abnormal blood cell production, or dehydration.
Use the Practices 12.1
Using Mathematics Red blood cells usually make up 45% of a blood sample
(by volume). If an average blood sample consists of 15 mL of red blood cells,
what is the volume of the full sample?
15 = 0.45(x)
x = 15/0.45
= 33.3 repeating
Around 33 mL
Figure Questions
Figure 12.2, page 431: How would the percentage of red blood cells (hematocrit)
change in a person who is dehydrated? Would the actual number of red blood cells
be affected?
With the loss of water, hematocrit will increase. The actual number of RBCs would be unaffected
Section 12.2: Blood Cells
Learn
Classroom Activities
Visual Literacy: Visualizing Blood Cells
Discuss with students that blood consists of plasma with formed elements. The main
formed elements are platelets, red blood cells, and white blood cells. Pair students
together and assign them the task to visually represent the following information.
Task 1 — Create a series of pie charts to visually represent the percentages of
formed elements in blood as well as the types of white blood cells we have.
Task 2 — Create your drawings with a description. Create a drawing of what each of
the formed elements would look like under a microscope. Label any identifying
characteristics and provide a brief description of the job of that formed element.
Finally have groups exchange their microscopic drawings and practice identifying
the different formed elements based on the drawings and key characteristics.
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Differentiated Instruction
Students may not want to create the drawings and diagrams on their own.
The teacher could provide a mixed-up container of all the different formed
elements including types of white blood cells and blood cell formation
(Figure 12.5). Students would work together in pairs to identify what each
picture represented and write down what identifying characteristics lead them
to that answer. The teacher could also have students pick a few blood cells to
then provide a brief description of the job of that formed element or stage.
Additional Discussion Questions
Apply the information learned in this chapter objective to describe the role of
erythropoietin.
Low oxygen pressure causes the kidneys and liver to release erythropoietin, which stimulates
production of red blood cells that carry oxygen to tissues.
Provide students with various samples of patient blood smears and ask them to
perform a white blood cell differential count on at least ten samples. Note any
abnormalities.
Discussion should emphasize the normal ranges for each type of white blood cell. (Try to
include a few slides indicative of leukemia, infectious mononucleosis, allergic reaction or
parasite, aplasia, and examples of immature white blood cells.
Describe the role of erythropoietin in terms of a negative feedback mechanism at
high altitudes.
Erythropoietin is released in response to prolonged oxygen deficiency. It travels through the
blood to the red bone marrow to stimulate red blood cell production. This process continues
until the red blood cells in the circulation supply enough oxygen to the liver and kidneys, thus
signaling the decrease in erythropoietin’s activity.
Compare the five major kinds of white blood cells in terms of size, shape, color,
normal ranges per cubic millimeter, and function.
One way to approach this is to use slides projected on a screen. Allow the students to identify
a variety of cells together as a class, and then reiterate the distinct features of each.
Practice
Practice Questions
1. Describe a red blood cell.
Red blood cells (erythrocytes) are biconcave discs. This shape is adapted for
transporting oxygen by its binding to hemoglobin and carbon dioxide. Hemoglobin is
responsible also for the red color of blood.
2. What is the function of hemoglobin?
Hemoglobin is a protein in red blood cells that binds oxygen and carbon dioxide
molecules. The bound oxygen is delivered to the tissues, and the carbon dioxide is
delivered to the lungs for excretion into the air.
3.What is the significance of the organelles that are lacking in a mature red
blood cell?
Mature red blood cells lack nuclei and mitochondria. This means they do not use any
oxygen they carry, and they are unable to divide.
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4. What is the typical red blood cell count for an adult male? For an adult female?
The typical range for adult males is 4.7 million-6.1 million cells/microliter and the typical
range for adult females is 4.2 million-5.4 million cells/microliter.
5. Where are red blood cells produced?
Red blood cell formation occurs in the yolk sac, liver, and spleen during fetal
development. After birth, RBCs are produced in the red bone marrow.
6. How does a red blood cell change as it matures?
Red blood cells have nuclei during their early stages of development but lose their nuclei
as the cells mature, which provides more space for hemoglobin. Mature RBCs also do
not have mitochondria, which means they use none of the oxygen they carry, and rely
solely on glycolysis for their metabolism. The loss of nuclei means mature red blood cells
are unable to divide.
7. How is red blood cell production controlled?
The hormone erythropoietin controls the rate of red blood cell formation through
negative feedback. The kidneys, and to a lesser extent, the liver release erythropoietin in
response to prolonged oxygen deficiency. When the availability of oxygen returns to
normal, erythropoietin release decreases, and RBC production decreases as well.
8. Which vitamins are necessary for red blood cell production?
The B-complex vitamins B12 and folic acid (vitamin B9) significantly influence red blood
cell production. These vitamins are necessary for DNA synthesis and DNA synthesis
occurs frequently in erythropoietic tissues.
9. Why is iron required for the formation of red blood cells?
Normal production of RBCs and hemoglobin synthesis both require iron. Iron deficiency
can lead to decreased production of RBCs and/or hemoglobin, resulting in anemia.
10. What happens to damaged red blood cells?
Damaged red blood cells are phagocytized by macrophages in the liver and spleen.
11. What are the products of hemoglobin breakdown?
Hemoglobin molecules are liberated from RBCs and broken into their component parts,
four globin chains surrounded by a heme group. The heme is decomposed into iron and
biliverdin. Biliverdin is converted to bilirubin and both are secreted in the bile.
12.How do white blood cells reach microorganisms that are outside blood vessels?
WBCs are capable of squeezing between the cells that form blood vessel walls in a
movement called diapedesis. Diapedesis allows the WBCs to leave the circulation to
enter tissues where microorganisms can then be attacked.
13.Which hormones are necessary for differentiation of white blood cells from
hematopoietic stem cells in the red bone marrow?
The hormones necessary for differentiation of WBCs fall into two groups: interleukins
and colony-stimulating factors (CSFs). Interleukins are numbered, while most CSFs are
named for the cell population they stimulate.
14. Distinguish between granulocytes and agranulocytes.
Leukocytes with granular cytoplasm are called granulocytes, whereas those without
cytoplasmic granules are called agranulocytes. The granulocytes are: neutrophils,
eosinophils, and basophils. The agranulocytes are monocytes and lymphocytes.
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15.List the five types of white blood cells, and explain how they differ from one
another.
The five types of white blood cells are: neutrophils, eosinophils, basophils, monocytes,
and lymphocytes. Neutrophils have lobed nuclei in two-to-five segments and stain light
purple due to their cytoplasmic granules. Neutrophils make up 54-62% of WBCs in an
adult sample. Eosinophils have two-lobed nuclei and stain red due to their cytoplasmic
granules . They make up 1-3% of WBCs in an adult sample. Basophils have similar size
and in the nucleus shape to eosinophils. They stain blue due to their cytoplasmic
granules and account for <1% of WBCs in an adult sample. Monocytes are the largest of
the WBCs. Nuclei can be round, kidney-shaped, oval, or lobed. Monocytes make up 3-9%
of WBCs in an adult sample. Lymphocytes have large, round nuclei surrounded by a thin
rim of cytoplasm. Lymphocytes account for 25-33% of WBCs in an adult sample.
16. How do white blood cells fight infection?
Monocytes leave the bloodstream and specialize further to become macrophages that
phagocytize bacteria, dead cells, and other debris in tissues. Neutrophils phagocytize
bacteria, but cannot engulf large particles like a monocyte. Eosinophils can also
phagocytize bacteria, but more commonly kill certain parasites. They control inflammation
and allergic reactions by removing biochemicals associated with these reactions
Basophils migrate to damaged tissues to promote inflammation and healing. Lymphocytes
like B-cells produce antibodies to proteins found on invading bacteria and lymphocytes
like T-cells assist in the killing of viruses.
17. Which white blood cells are the most active phagocytes?
The most mobile and active phagocytic leukocytes are neutrophils and monocytes.
18. What is the normal human white blood cell count?
The normal WBC count is 3,500-10,500 cells/microliter.
19. Distinguish between leukocytosis and leukopenia.
A total number of WBCs >10,500 cells/microliter constitutes a leukocytosis. A total
number of WBCs <3,500 cells/microliter constitutes a leukopenia.
20. What is a differential white blood cell count?
A differential white blood cell count lists percentages of the various types of leukocytes in
a blood sample. The relative proportions of white blood cells can be used in diagnostics.
21. What is the normal blood platelet count?
Normally, the platelet count varies between 150,000-350,000 platelets/microliter.
22. What is the function of blood platelets?
Platelets help close breaks in damaged blood vessels
23. What is the risk of high platelet count? what is the risk of low platelet count?
Risks of a high platelet count include blood clots and bleeding; risks of a low platelet
count include internal bleeding.
Use the Practices 12.2
Arguing from Evidence Some endurance athletes use (often against the
rules) recombinant erythropoietin to artificially increase their red blood cell
count. Explain the potential risks and benefits of this practice.
Benefit: More erythropoietin results in an increase in red blood cells, which directly
stimulates more red blood cell production to increase oxygen transport.
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Risks: More red blood cell production can result in slow, sluggish blood that could form
dangerous clots in the lungs or brain.
Figure Questions
Figure 12.6, page 435: How might kidney disease affect red blood cell production and
oxygen-carrying capacity?
RBC production and oxygen-carrying capacity will be decreased if the kidneys are unable to
efficiently produce erythropoietin
Section 12.3: Blood Plasma
Learn
Classroom Activities
EL Strategy: Sequencing
Advanced High Using figure 12.7 as visual and contextual support, instruct
collaborative groups to create a pamphlet illustrating the life, death, and
destruction of a red blood cell. Create a “gallery” to display the pamphlets and
have the class walk through the gallery examining their peers’ work.
Writing Connection: Plasma Highway
Pair students up and provide them the following challenge:
Our blood is composed of plasma and formed elements. Besides the formed
elements, plasma carries a lot of other items with many functions. Explain the
metaphor that blood is the body’s highway. Use specific example following the
rubric or provided list of plasma components.
Students can be given a rubric to ensure their answer is in depth and includes the
following components of plasma
•
•
•
•
•
Plasma proteins (albumins, globulins, fibrinogens)
Gases (oxygen and carbon dioxide)
Nutrients (amino acids, simple sugars, nucleotides, vitamins, minerals, and lipids
Nonprotein nitrogenous substances
Electrolytes
Differentiated Instruction
Metaphors can be sometimes misinterpreted depending on cultures and
students’ past experiences. Encourage students to create their own metaphor
that aligns best to how they understand it in their mind.
Additional Discussion Questions
Apply the concepts of this chapter objective to distinguish between good
lipoproteins and bad lipoproteins.
Responses should include a comparison of HDL and LDL lipoprotein molecules. HDL molecules
carry chylomicron remnants away from artery walls to the liver to be decomposed, and are thus
referred to as good. LDL molecules contain a relatively high concentration of cholesterol that
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they deliver to cells, and are thus referred to as bad. Individuals should try to maintain a
relatively high HDL/LDL ratio.
Discuss various blood components and products that are commercially available.
Give examples of when they may be used.
Responses should include a discussion of whole blood, packed cells, platelets, fresh frozen
plasma, coagulation factors, gamma globulin, and various irradiated products.
Practice
Practice Questions
1. List three types of plasma proteins.
The three main types of plasma proteins are albumins, globulins, and fibrinogen.
2.How do albumins help maintain water balance between the blood and the
tissues?
Plasma proteins like albumin are too large to pass through capillary walls and create an
osmotic pressure (termed a colloid osmotic pressure) that holds water in the capillaries,
counteracting the blood pressure which forces water outside of the blood vessel by
filtration. By maintaining the colloid osmotic pressure of plasma, albumins help regulate
water movement between the blood and the tissues.
3. What are the functions of the globulins?
Globulins transport lipids and fat-soluble vitamins, and can also function as antibodies in
fighting infection.
4. What is the role of fibrinogen?
Fibrinogen functions in blood coagulation (clotting).
5. Which gases are in plasma?
Oxygen, carbon dioxide, and dissolved nitrogen are present in blood plasma.
6. Which nutrients are in plasma?
Plasma nutrients include amino acids, simple sugars, nucleotides, and lipids (fats,
phospholipids, cholesterol).
7. What is a nonprotein nitrogenous substance?
Molecules that contain nitrogen atoms but are not proteins are called nonprotein
nitrogenous substances. This includes urea, uric acid, creatine, and creatinine all of which
are carried in the plasma.
8. What are the sources of plasma electrolytes?
Plasma electrolytes are absorbed from the intestine or released as a by-product of
cellular metabolism.
Use the Practices 12.3
Asking Questions Propose a question about the physiological effect of
altering the concentration of a specific biochemical within the blood plasma.
If albumins are no longer synthesized by the liver, and therefore no longer found in the
blood plasma, how would osmotic pressure be affected?
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Section 12.4: Hemostasis
Learn
Classroom Activities
EL Strategy: Using Visual and Contextual Support
Intermediate Before reading, have students take a close look at the visual
support. Have them use the image as they work in pairs to form questions
about the selection. After reading, have partners compare their original
predictions with questions they answered no. Have them discuss how their
ideas changed or stayed the same. Move around the room to monitor
progress.
Writing Connection: Pulmonary Embolism
Students will work in pairs or small groups. Describe to students that they are going
to role-play a scenario. They must create a script for the scenario to show how the
conversation might go. Below are the roles:
• A 40-year-old woman recently had pelvic surgery and must take a long drive
home in a car. She doesn’t want to waste time staying in the hospital and thinks
the doctor is being over worrisome.
• The doctor is worried about a pulmonary embolism in the patient because she
just recently had pelvic surgery and is not giving enough time before riding in a
car a long distance.
The script students create must include an explanation for why the doctor is
worried about the pulmonary embolism. The woman should be responding and
asking questions about what the doctor is describing could happen in her body.
Students may choose to be elaborate as they wish with the role-play by including
props or technology.
Differentiated Instruction
Students may feel uncomfortable role-playing in front of their peers. Instead of
students role-playing, the teacher could have some groups reviewing case
studies and presenting a summary of the case study. This could be done before
other groups who want to role-play to provide them with ideas for their scripts
from real-life cases. Another options would be for the teacher to provide
students each a job in the group. Not all students will be the actor in the
role-play. Some students could be the record keeper or fact checker.
Additional Discussion Questions
Ask students to create poster that illustrates the intrinsic and extrinsic pathways of
the coagulation cascade.
The intrinsic pathway includes Factors XII, XI, VIII, IX, X, prothrombin, thrombin, fibrinogen, and
fibrin in the formation of a clot. The extrinsic pathway includes tissue thromboplastin, and
Factors VII, V, X, prothrombin, thrombin, fibrinogen, and fibrin in the formation of a clot. The
cascade should also include mention of calcium ions and platelets.
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Describe hemostasis in terms of a positive feedback mechanism.
Once a blood clot begins to form, it promotes still more clotting, as thrombin also acts directly
on blood clotting factors other than fibrinogen, causing prothrombin to form still more thrombin.
Practice
Practice Questions
1. What is hemostasis?
Hemostasis is the process that stops bleeding when blood vessels are damaged. It
encompasses actions such as vascular spasm, platelet plug formation, and blood
coagulation.
2. How does a vascular spasm help control bleeding?
Cutting or breaking a small blood vessel stimulates vascular spasm, the contraction of
smooth muscle in the wall of the blood vessel. Blood loss lessens almost immediately,
and the ends of the severed vessel may close completely.
3. Describe the formation of a platelet plug.
When a blood vessel breaks, platelets adhere to the collagen underlying the endothelium
lining blood vessels. Platelets also adhere to each other, forming a platelet plug in the
vascular break. A plug may control blood loss from a small break, but a larger break may
require a blood clot to halt bleeding.
4. In order, what are the major steps in coagulation?
Blood clots form through a process known as the coagulation cascade. Damaged tissue
releases tissue thromboplastin, initiating a series of reactions that results in prothrombin
activator. Prothrombin activator works to convert prothrombin to thrombin. By the
actions of thrombin, soluble plasma protein fibrinogen is converted into fibrin. Once fibrin
threads form, they stick to the exposed surfaces of damaged blood vessels, creating a
meshwork that traps blood cells and platelets. The resulting mass is a blood clot.
5.What prevents the formation of massive clots throughout the cardiovascular
system?
Normally, blood flow throughout the body prevents formation of a massive clot in the
cardiovascular system by rapidly carrying excess thrombin away, keeping its
concentration too low in any one place to promote further clotting. Coagulation usually
only occurs only in blood that is moving slow or stagnant.
6. Distinguish between a thrombus and an embolus.
A blood clot abnormally forming in a vessel is a thrombus. A clot that dislodges, or a
fragment of a clot that breaks loose and is carried away by the blood flow is an embolus.
Use the Practice 12.4
Using Models Develop a model to illustrate the steps of blood coagulation.
See Figure 12.16 for a sample; accept any illustration to depict a process.
Figure Questions
Figure 12.15, page 447: What is the major event in blood clot formation? How might the
blood clotting mechanism be affected if a person has hypocalcemia (low blood Ca2+)?
The conversion of soluble fibrinogen into insoluble fibrin. A person with hypocalcemia may
have difficulty forming a blood clot if injured because Ca2+ is required for blood coagulation.
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Section 12.5: Blood Groups and
Transfusions
Learn
Classroom Activities
Visual Literacy: Blood Function
This activity can also be an extension of the theme activity, or it can stand alone.
Students will focus on the purpose of each component of blood.
Students will make a concept map of the different components of blood and then
describe the function of each component.
If students have trouble with the outline of a concept map for this activity, Figure 12.2
is a great place to start as it outlines the different components. However, students
may choose to build their concept map around function, rather than composition.
You can have students do this activity as you lecture or work independently before
discussing their maps.
Writing Connection: Blood Types
Discuss with students the different types of ABO blood groups and the antigens
and antibodies that exist in the different types. Each pair of students should
research about blood donations and types of blood that are in need.
After students have completed their research, have them create a free reflection
writing discussing if they believe donating blood is important or not and why. Have
students also address that blood donations are not for everyone and they should be
aware of who can and can’t donate blood. Encourage students to discuss their own
blood type if known and what they have learned about their own blood type.
Differentiated Instruction
Donating blood can be very personal for students. Instead of students researching
the red cross website, the teacher should call the Red Cross and see if a
volunteer can come to the school. The red cross volunteer can share
information about donating blood and who can or can’t. After listening to the
presentation, students should write a reflection about having a blood drive at
their school or in their community and why.
Additional Discussion Questions
Which blood type is considered to be the universal donor? Universal recipient?
Which Rh type could an Rh positive individual receive?
Type O blood is regarded as the universal donor, which means a person with type O blood
could donate blood to a type A, type B, type AB, or type O recipient. Packed red blood cells
are usually donated, as opposed to whole blood. Type AB individuals may receive blood from
any of the four types, if based solely on ABO compatibility. An Rh positive individual may
receive blood from either an Rh negative or Rh positive donor.
In what cases should the administration of RhoGam be considered?
RhoGam is administered in certain clinical situations in which an Rh negative individual may
have developed anti-Rh antibodies in the bloodstream. The presence of these antibodies
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increases the possibility of an adverse reaction in the future. Situations may include giving
birth, pregnancy termination, miscarriage, or amniocentesis.
How could you determine if a blood transfusion reaction has taken place?
The patient may shake, experience nausea, or exhibit signs of shock. The transfusion should be
immediately discontinued, the blood type and crossmatch reconfirmed for accuracy, and a
urine sample from the patient should be analyzed for the presence of hemoglobin.
Provide students with several examples of actual incidents in which a transfusion
reaction was suspected. Ask the students to determine, based on the information
provided, if they feel an error had been made in the blood typing and cross
matching procedures.
Examples will vary, but the discussion should emphasize the importance of correct ABO and
Rh blood typing.
Practice
Practice Questions
1. Distinguish between antigens and antibodies.
An antigen is any molecule that triggers an immune response. When the immune system
encounters an antigen not found on the body’s own cells, it will attack, producing
antibodies specific to the antigen to remove it from the body.
2.What is the main concern when blood is transfused from one individual to
another?
The major concern in a blood transfusion procedure is that the cells in the donated blood
not clump (agglutinate) due to antibodies in the recipient’s plasma. A mismatched blood
transfusion quickly produces telltale signs of agglutination: anxiety, breathing difficulty,
facial flushing, headache, and severe pain in the neck, chest, and lumbar area. RBCs
burst, releasing free hemoglobin that is toxic to the kidney resulting in kidney failure.
3. Why is an individual with type AB blood called a universal recipient?
Type AB blood does not have anti-A or anti-B antibodies, so an AB person can receive a
transfusion of blood of any type.
4. Why is an individual with type O blood called a universal donor?
Type O blood has neither antigen A nor antigen B. Therefore, this type could be
transfused into persons with blood of any other type.
5. What is the Rh blood group?
The Rh blood group was named after the rhesus monkey in which it was first studied. In
humans, this group includes several Rh antigens (factors). The most prevalent of these is
antigen D. If the Rh antigens are present on the RBC cell membranes, the blood is said
to be Rh-positive. Conversely, if the RBC cell membranes do not have Rh antigens, the
blood is called Rh-negative. The presence or absence of Rh antigens is an inherited trait.
6. What are two ways that Rh incompatibility can arise?
If an individual with Rh-negative blood receives a transfusion of Rh-positive blood, the Rh
antigens stimulate the recipient to begin producing anti-Rh antibodies. The initial
transfusion has no serious consequences, but if an individual with Rh-negative blood who
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is now sensitized to attack Rh-positive blood receives another transfusion of Rh-positive
blood, the donated cells are likely to agglutinate. Similarly, if an Rh-negative woman is
pregnant with an Rh-positive fetus, the first pregnancy will likely have no problems;
however, if the infant’s Rh-positive blood cells enter the maternal circulation (as can
happen with birth, miscarriage, etc.), the mother will form anti-Rh antibodies. A second
pregnancy with an Rh-positive fetus will result in the mother’s anti-Rh antibodies
attacking the fetus’ Rh-positive blood cells and destroying them.
Use the Practice 12.5
Analyzing Data If someone has blood type O, Rh-positive, to which blood
types can this person donate? From which blood types can this person receive
a transfusion?
Donate: A, B, AB, O, all Rh +
Receive: O, Rh+ or –
Assess
Career Corner: Phlebotomy Technician
Consider This: Phlebotomy technicians, like many healthcare professionals,
wear protective equipment such as gloves while doing their jobs. Explain why
this is an important precaution for both the technician and the patient. Why is
it important to put on new gloves for each patient?
Blood-borne pathogens are many. Protective clothing and gear protect both the
technician and patient from contamination and disease.
Diseases, Diagnosis, and Treatment: Bone Marrow and
Stem Cell Transplants
1. What is anemia? Why is sickle cell disease classified as a type of anemia?
Anemia is a deficiency of red blood cells or a reduction in the amount of hemoglobin.
Sickle cell disease reduces the amount of hemoglobin the blood stream can carry.
2. What are the risks and benefits associated with a bone marrow transplant?
Bone marrow transplants can increase tolerance of chemotherapy drugs, and can cure
sickle cell disease. Bone marrow transplants can trigger a fatal immune response in a
small percentage of patients.
Diseases, Diagnosis, and Treatment: Leukemia
1.How do white blood cell counts differ between a patient who has leukemia and
a patient who has leukocytosis brought on by infection?
In leukemia, WBC counts are more than 10x normal levels. In leukocytosis, counts are
elevated (maybe 10,500 or more), but not nearly as much as in leukemia.
2. What is the difference between acute and chronic leukemia?
Chronic leukemia moves more slowly. It often goes undetected for months or years.
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Case Study Connection
page 431: Would an athlete who had been doping have a higher or lower
hematocrit than an average person?
higher
page 435: What can you tell your friend about the risks of EPO abuse?
EPO abuse could result in polycythemia, which would increase blood viscosity, slow blood
flow, and impair circulation.
page 436: Could EPO be a treatment for anemia?
It depends on the type of anemia. If the anemia was a result of a low RBC count, maybe. If
the anemia was due to low hemoglobin, no.
page 437: Would blood doping with EPO have any effect on white blood cells?
no
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Major functions of blood include:
a. nutrient, hormone, and oxygen transport
b. helping maintain the stability of interstitial fluid
c. heat distribution
d. all of the above
2. Where do blood cells form?
a. red bone marrow
b. pancreas
c. heart
d. thyroid
3. Which function can red blood cells NOT perform?
a. glycolysis
b. oxygen diffusion
c. cellular division
d. carbon dioxide transport
4. Which of the following is not a leukocyte?
a. lymphocytes
b. hemophils
c. neutrophils
d. monocytes
5. Which line of defense would you rely on if you contracted a
blood parasite?
a. eosinophils
b. heparin
c. megakaryocytes
d. erythrocytes
6. The most abundant component of plasma is
a. waste.
b. oxygen.
c. proteins.
d. water.
7. Which answer below does not induce hemostasis?
a. platelet plug formation
b. blood coagulation
c. embolus
d. vascular spasm
8. An individual with B antigens and anti-A antibodies is ABO
blood type
a. A.
b. B.
c. AB.
d. O.
9. Which type of white blood cell have three-to-five lobed
nuclei and are phagocytes?
a. basophils
b. eosinophils
c. neutrophils
d. all of the above
10. Which factors may cause platelet counts to change?
a. infection
b. genetic mutation
c. viruses
d. all of the above
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Short Answer
1. What are the functions of blood?
Blood functions for transport of red and white blood cells,
platelets, gases (oxygen and carbon dioxide), hormones,
nutrients, and waste. It also helps regulate body temperature.
2. What are the materials found in plasma?
Plasma is mostly water. It contains proteins, nutrients, wastes,
vitamins, hormones, and electrolytes.
3. List the formed elements.
red blood cells, white blood cells, and platelets
4. Describe the structure of a red blood cell. How does its
structure contribute to its function?
Red blood cells are biconcave disks. During development they
lose mitochondria and nuclei. This makes room for hemoglobin
which transports oxygen.
5. Distinguish between albumins, globulins, and fibrinogen.
They are all plasma proteins. Albumins give viscosity to blood.
Fibrinogens are instrumental in blood clotting. Globulins are
antibodies and function in protection from foreign invaders.
6. Starting with a stem cell, what are steps involved in making a
neutrophil?
Stem cell to myeloid stem cell to myeloblast to neutrophil.
7. Describe the structure of hemoglobin.
Hemoglobin is comprised of two main parts. Globin the protein
portion. It is made up of four polypeptide chains: two alpha
chains and two beta chains. This portion serves as a platform
for four heme groups. Each heme contains iron that can bond
to oxygen molecules.
9. How does low blood oxygen levels stimulate erythrocyte
(RBC) production?
A drop in blood oxygen levels stimulates the kidneys and liver
to release erythropoietin, which travels to the red bone
marrow and triggers red blood cell production.
10. What big cells give rise to platelets?
megakaryoblasts
11. What is the universal donor blood type? Why?
Type O is the universal donor because it has no antigens on
the red blood cells that can be detected as foreign invaders.
12. With regards to blood typing, distinguish between “antigen”
and “antibody.”
An antigen is usually a protein on a cell membrane that
serves as an identifying marker. An antibody is a protein
that is found in the plasma that seeks out foreign invaders.
They will respond to antigens found on cells that do not
belong there.
13. What is the function of prothrombin?
Prothrombin is an important part of the biochemical pathway
to produce fibrin for blood clotting. It is converted to thrombin
by prothrombin activator and calcium.
14. Why can a person with type AB blood receive a transfusion
from any blood type?
AB type red blood cells have no antibodies in the plasma.
Therefore, nothing is detected as a foreign invader.
15. What is a vascular spasm?
A vascular spasm is the constriction of a damaged blood
vessel to prevent blood loss.
8. Differentiate between the functions of monocytes, basophils,
and lymphocytes.
Monocytes are phagocytes. They engulf bacterial cells and
other foreign materials. Monocytes can even leave the blood
stream. Basophils release heparin which inhibits blood clotting
and histamine for vasodilation and inflammation. Lymphocytes
produce antibodies for immunity.
Critical Thinking and Clinical Applications
1. Certain drugs depress the respiratory system, causing
hypoventilation (slow breathing rate). What effect will this
have on red blood cell production? Why?
This will increase red blood cell production. A lowered
breathing rate results in less oxygen in the blood. The kidneys
and liver respond to low oxygen levels by releasing the
hormone erythropoietin which stimulate the red bone marrow
to produce red blood cells.
2. CLINICAL Connection A woman with Rh negative blood
has two children, both of whom are Rh positive. The pregnancy
with her first child would pose no problem. But, why might
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her second pregnancy be potentially dangerous? What can
be done about this?
During her first pregnancy with an Rh positive baby she
produced antibodies to the Rh positive antigen. So, with her
second pregnancy the antibodies will attack the Rh positive
red blood cells. She can be given an injection of a drug called
RhoGAM which inhibits the antibodies.
3. Cirrhosis of the liver can reduce the number of plasma
proteins, including albumins and clotting factors. What would
be the effects of these reduced proteins?
Reducing albumins will change the viscosity of the blood by
making it to thin. If clotting factors are adversely affected, the
ability to stop bleeding wil be impaired. This together with
blood that is to thin could result in rapid bleeding.
4. WRITING Connection How would you explain to a patient
with leukemia, who has a greatly elevated white blood cell
count, the importance of avoiding bacterial infections?
A person suffering from leukemia has an excessive amount of
non-functioning WBC’s. If they had a bacterial infection, they
would not have adequate working WBC’s to fight it off.
5. Why can an individual receive platelets from any donor, but
whole blood only from a matched donor?
platelets can be given to anyone, unlike whole blood. Whole
blood contains antigens and must be given to certain
individuals.
6. If, a few weeks before the race, an athlete had erythrocytes
removed from the blood, would there be an increase in EPO
release from his kidney? If the removed red blood cells were
added back just before the race, what would we expect of his
hematocrit values?
Yes, low RBC count triggers EPO production. The hematocrit
values would rise sharply if the cells were added back.
Antigens are markers on the outside of red blood cells. These
markers are not found on the outside of platelets. Therefore,
Lab Data Analysis: Anemia and Oxygen
1. Describe the general trend of oxygen-carrying capacity at
different partial pressures of oxygen.
In general, oxygen-carrying capacity increases with partial
pressure of O2.
2. How does the oxygen-carrying capacity of the anemic
patient compare to the non-anemic patient?
As evidenced graphically, at any given partial pressure of
oxygen the anemic patient is able to carry less oxygen in their
blood (along y-axis) than the normal patient.
3. Carbon monoxide is dangerous because it binds to
hemoglobin in a way that prevents hemoglobin from carrying
oxygen. If a person were suffering from carbon monoxide
poisoning, would this person’s oxygen-carrying capacity
resemble the anemic or non-anemic curve?
The anemic curve. Hemoglobin exists to carry oxygen in the
blood. If all of the hemoglobin becomes loaded with carbon
monoxide instead of oxygen, the oxygen-carrying capacity of
the blood will decrease. Effectively, these patients become
acutely anemic.
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CHAPTER
13
Cardiovascular System
Section
Pacing
Learning Objectives
13.1 Introduction
—
13.2 Structure of the
Heart
2
1. Discuss the functions of the organs of the
cardiovascular system.
1. Distinguish between the coverings of the heart
and the layers that compose the wall of the
heart.
2. Identify and locate the major parts of the heart,
and discuss the functions of each part.
13.3 Heart Actions
3. Trace the pathway of blood through the heart
and the vessels of coronary circulation.
1. Describe the cardiac conduction system and
the cardiac cycle.
2
2. Identify the parts of a normal ECG pattern, and
discuss the significance of this pattern.
13.4 Blood Vessels
13.5 Blood Pressure
13.6 Arterial System
13.7 Venous System
3. Explain control of the cardiac cycle.
1. Compare the structures and functions of the
major types of blood vessels.
2
2. Describe how substances are exchanged
between blood in the capillaries and the tissue
fluid surrounding body cells.
1. Explain how blood pressure is produced and
controlled.
2
2. Describe the mechanisms that aid in returning
venous blood to the heart.
1. Identify and locate the major arteries.
1. Identify and locate the major veins.
1
1
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (6)
Chapter Resources
Extended Summary Review
Chapter 13 Test Bank
Chapter 13 Interactive Question Bank
Vocabulary Flashcards
APR Module 8: Cells & Chemistry
Laboratory Exercise 28: Cardiac Cycle
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A Suggested Approach
In this chapter, students learn about the heart and blood vessels, the structures of
the cardiovascular system. This includes the structure and action of the heart, types
of blood vessels, paths of circulation, and ability to identify major arteries and veins.
After presenting the structure of the heart, students can dissect a sheep heart to
identify its parts. Because heart diagrams are drawn with color-coding to show the
flow of blood, students often have a hard time recognizing structures on a real heart.
In addition to identifying the main vessels and chambers of the heart, a dissection can
be used to study heart valves. This activity allows students the opportunity to not only
identify major internal heart structures, but also instructs them in suturing techniques.
Lastly, students could watch a video of a heart transplant surgery on ORLive.com.
The coordinating action of the cardiac cycle can be both viewed through an ECG
and heard through heart sounds. Students can have the opportunity to use a
stethoscope to listen to specific valves of the heart. If stethoscopes are not
available, or students have a difficult time identifying heart sounds, many online
resources allow students to listen to both normal and abnormal heart sounds in
order to provide information about the condition of the heart (such as Medical
Multimedia Laboratories: Heart Sounds Tutorial).
The difference between arteries which are under high pressure and the other blood
vessels can be demonstrated by having students take each other’s blood pressure.
Begin by asking students if they have ever had their blood pressure taken. Invite a
few of those students to share what they remember about the process. Students
will be taking each other’s blood pressure using a stethoscope and blood pressure
cuff (sphygmomanometer). If stethoscopes and blood pressure cuffs are not
available, the American Heart Association Watch, Learn and Live: Interactive
Cardiovascular Library allows students to understand the anatomy of blood vessels,
as well as take a virtual blood pressure.
This chapter is expected to take 10 class periods including Lab 28.
Case Study
After reading the case study, students should access their online Claim, Evidence,
Reasoning (CER) chart and make their claim. CER is a strategy used to teach
students how to construct explanations and craft scientific arguments. A scientific
claim answers a question or offers a solution to a problem. Give students time to
reflect and brainstorm, then have each student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is information
that supports or contradicts a claim. This information can come from a variety of
sources, such as research, experimentation, or data interpretation. It is important
to have multiple pieces of evidence to support a claim. Encourage students to
return to their claims and add evidence at multiple points in the chapter.
The case study describes the use of an external defibrillator. Some individuals
who are very prone to fibrillation event can get an implanted defibrillator known
as an implanted cardioverter defibrillator. Here is some more information about
these devices: https://www.heart.org/en/health-topics/arrhythmia/prevention–
treatment-of-arrhythmia/implantable-cardioverter-defibrillator-icd
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One extension activity for this chapter is to dive into the ECG. While ECGs are
complex, it can be approachable to ask the students to predict how different
cardiopathologies might show up on an ECG. Ask the students to think about
changes to each of the waves, or the length of time between the waves, known
as the interval.
Introduction to the Theme
Theme: Systems and Model Systems The boundaries of the cardiovascular
system are the heart, blood vessels, and blood. Each of these is a system in itself
but working together to provide key nutrients and gases to the entire body.
Theme Activity: The Sticky Note Game
For this theme activity, you will need a few stacks of sticky notes pre-written with
parts of each cardiovascular system: the heart and blood vessels. Each student
gets a sticky note with a part written on it, such as aorta, arteries, etc. You can
either assign a student to represent the heart or blood vessels, or make a
designated spot for each of these. Next, call each part out. As the part is called,
the student who has the part has to figure out where the part belongs in the
cardiovascular system. Once they have this figured out, they need to place the
sticky note in the correct place. After you have called out all the parts, go over the
completed cardiovascular systems.
Section 13.1: Introduction
Learn
Classroom Activities
Section 13.1 sets the groundwork for activities in sections 13.2 and beyond.
Additional Discussion Questions
Ask students to develop a diagram that illustrates the flow of blood from the
systemic circuit, through the heart, to the lungs, back to the heart, and out once
again to the systemic circuit.
The diagram should illustrate flow to the vena cavae, right atrium, right ventricle, pulmonary
trunk, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle, aorta, to the
systemic circuit.
How does a stroke differ from a heart attack in terms of the location of arterial
blockage?
A stroke is the result of a blockage of blood flow to the brain, whereas a heart attack may
result from the blockage of blood flow through the coronary arteries.
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Practice
Practice Questions
1. Name the parts of the cardiovascular system.
The heart, arterioles, capillaries, venules, and veins comprise the cardiovascular system.
2.Distinguish between the pulmonary and systemic circuits of the cardiovascular
system.
The pulmonary circuit carries blood from the heart to the lungs and back to the heart.
The systemic circuit carries blood from the heart to all other parts of the body and back.
Use the Practice 13.1
Arguing from Evidence The cardiovascular system is often illustrated in red
and blue structures, to indicate the location of oxygen-rich and oxygen-poor
blood. You may also have heard people say that your oxygen-poor blood is
blue—is this correct? Provide evidence for your response.
Although we use red structures to indicated those that are carrying oxygenated blood,
and blue structures to indicated those carrying deoxygenated blood, our blood is never
blue. Rather, our blood just changes from a shade of bright red when oxygenated to dark
red when deoxygenated. The illustrations help our understanding of the flow of blood,
but do not depict the actual color of blood
Section 13.2: Structure of the Heart
Learn
Classroom Activities
EL Strategy: Using Visual and Contextual Support
Advanced Before reading, have students take a close look at Figure 13.6.
Have them use the image as they work in pairs to form questions and make
predictions about pulmonary and systemic circuits. Have student pairs take
turns reading the text to one another. Remind that they are reading for an
audience, and that they need to maintain the audience’s interest with their
voices. Move around the room, correcting pronunciation as necessary. Have
pairs discuss their questions and predictions. Then have them share their
thoughts with the class. Record their contributions on the board.
Visual Literacy: Pulmonary and Systemic Circuits
Students need to be able to recognize the flow of blood through the heart and
lungs as well as be able to identify the different components of the heart. Put
students in pairs and provide them with a color copy of Figure 13.6 (a and b).
Students will use a large sheet of paper or poster board to recreate these images
with the color. Students will create their own flowchart spaces and then colored and
labelled cutouts for each block in (b). Students will mix up the answer choices for
the boxes and practice putting them into the correct location.
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Students will also create their own vocabulary words to place on the blank diagram
of the heart. The teacher may choose to print the heart Figure instead of trying to
draw it. See the example below. Students should continue to practice their games
until they have reached mastery.
Differentiated Instruction
If students are visual and kinesthetic learners, the teacher could have students
color the blood pathways on both diagrams with red or blue as well as label
the different locations and structure. Students who like to write could describe
the pathways instead of labeling or coloring it.
Additional Discussion Questions
Use the information presented in this chapter objective to explain the process of
mitral valve prolapse.
One or both of the cusps on the mitral valve stretches and bulges into the left atrium during
ventricular contraction. Sometimes blood will back flow into the left atrium.
In physiological terms, what is the meaning of lub and dup?
—Lub occurs during ventricular contraction when the atrioventricular valve is closing. —Dup
occurs during ventricular relaxation when the semilunar valves are closing.
Discuss the effect of aortic stenosis on the body.
Aortic stenosis is a narrowing of the aortic valve. As a result not all the blood is able to be
pumped out of the body in a normal heart beat. As such, the blood is back up into the left
ventricle, potentially causing an enlargement of the heart.
What is meant by the skeleton of the heart? Compare this role to the function of
the human skeleton.
Responses should include a discussion of the roles of providing structure and a framework,
protection, and attachment points for muscle fibers.
Describe what happens when increasing blood volume stretches muscle cells
associated with the atria, in terms of ANP.
Atrial natriuretic peptide inhibits release of renin from the kidneys and of aldosterone from the
adrenal cortex. The overall result is a decrease in blood pressure and volume.
Practice
Practice Questions
1. Where is the heart located?
The heart is in the mediastinum, superior to the diaphragm. It is bordered laterally by the
lungs, posteriorly by the vertebral column, and anteriorly by the sternum.
2. Distinguish between the visceral pericardium and the parietal pericardium.
The pericardium is a membranous sac that encloses the heart and the proximal ends of
the large blood vessels to which it attaches. The innermost layer is the visceral
pericardium and covers the heart. At the base of the heart, the visceral pericardium turns
back upon itself to become the parietal pericardium.
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3. Describe the layers of the heart wall.
The wall of the heart is composed of three distinct layers: an outer epicardium, a middle
myocardium, and an inner endocardium. The epicardium is a serous membrane that
consists of connective tissue covered by epithelium. Its deeper portion contains adipose
tissue. The myocardium consists of cardiac muscle tissue that pumps blood out of the
heart chambers. The endocardium is made of epithelial and connective tissues, as well
as muscle fibers called Purkinje fibers.
4. Name and locate the four chambers of the heart.
The heart is divided into four chambers, two upper and two lower, left and right. They are the
left and right atria, and the left and right ventricles. The right atrium is on the right upper side
of the heart and the right ventricle is on the right lower side of the heart. The left atrium is on
the left upper side of the heart and the left ventricle is on the left lower side of the heart.
5. Describe the function of each heart valve.
The heart has four valves: the tricuspid, the pulmonic, the mitral, and the aortic. The
tricuspid valve connects the right atrium with the right ventricle and allows blood from
the right atrium to enter the right ventricle. The pulmonic valve connects the right
ventricle with the lungs and allows blood from the right ventricle to enter the pulmonary
arteries and lungs. The pulmonary veins drain newly-oxygenated blood from the lungs
into the left atrium. The left atrium is connected to the left ventricle via the mitral valve
and allows blood from the left atrium to enter the left ventricle. The left ventricle is
connected to the aorta and the aortic valve allows blood to flow from the left ventricle
into the aorta and to the rest of the body.
6. Trace the path of blood through the heart.
Blood enters the heart from the superior and inferior vena cavae and flows into the right
atrium. From the right atrium, blood flows into the right ventricle. From the right ventricle,
blood flows into the lungs via the pulmonary arteries. From the lungs, blood leaves via
the pulmonary veins and flows into the left atrium. From the left atrium blood enters the
left ventricle. From the left ventricle, blood flows through the aortic valve to the aorta
and the rest of the body.
7. Which vessels supply blood to the myocardium?
The right and left coronary arteries supply blood to the myocardium.
8. How does blood return from the cardiac tissues to the right atrium?
The coronary veins drain blood that has flowed through the coronary arteries (to supply
the cardiac tissues) into the right atrium via the coronary sinus.
Use the Practices 13.2
Using Models Create an illustration of the heart that shows the flow of blood
from the systemic circuit to the pulmonary circuit and back to the systemic
circuit. Indicate where the blood is oxygen-rich and oxygen-poor.
See Figure 13.1 as a sample
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Section 13.3: Heart Actions
Learn
Classroom Activities
Writing Connection: Deciphering an ECG
Discuss with students what an electrocardiogram is and how it is used in the medical
field. Provide groups of students the cardiograms from Figure 13.12. After students
feel confident in reading an ECG, ask students to describe what the ECG would
look like if the heart was out of rhythm. If possible, the local doctors’ office or care
clinic may loan the school a few stethoscopes for students to listen to their own
hearts. Ask students to research how a pacemaker works and to include how the
electrical impulses of the pacemaker are similar to the impulses of the heart.
Differentiated Instruction
Students could investigate the cardiac cycle that is represented on an ECG as
the movement through the actual heart. Students would research in pairs how
the heart actually pumps and how the valves work together to move the blood.
Additional Discussion Questions
Provide students with several examples of ECG patterns. Ask them to discern a
normal pattern from an abnormal one.
An emphasis should be placed on the analysis of a QRS complex, T wave, and P wave.
Have the students take their heart rate before and after exercise. Then ask them to
describe the results and what occurred in the body.
After exercise the heart rate should increase due to sympathetic stimulation on the SA node.
Discuss the use of magnetic resonance imaging in diagnosing cardiovascular
problems. Compare this procedure to a conventional methodology.
An MRI can non-invasively image coronary arteries. Coronary angiography involves the
invasive snaking of a catheter into a blood vessel, providing a passageway for contrast media.
Practice
Practice Questions
1. What series of events constitutes a single complete heart beat?
A complete heartbeat or cardiac cycle consists of the contraction and relaxation of all
four heart chambers.
2. What is a functional syncytium?
A mass of merging cells that act as a unit is called a functional syncytium. In the heart,
the atrial and ventricular walls fit this definition.
3. What types of tissues make up the cardiac conduction system?
Specialized cardiac tissues that initiate and distribute impulses throughout the
myocardium form the cardiac conduction system. A portion of the cardiac conduction
system is the sinoatrial node (muscle tissue). Another example is the atrioventricular
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node (muscle tissue). The last two components are the AV bundle and the Purkinje fibers
(muscle tissues).
4. How is a cardiac impulse initiated?
The cells of the SA node can reach threshold on their own, and their cell membranes
contact one another. Without stimulation from nerve fibers or any other outside agents,
the nodal cells initiate cardiac impulses that spread into the surrounding myocardium
and stimulate cardiac muscle cells to contract.
5.How is a cardiac impulse conducted from the right atrium to the other heart
chambers?
An impulse generated from the SA node in the right atrium travels to the AV node, which
then can pass the impulse to the AV bundle, and finally to the Purkinje fibers. The electrical
stimulation then travels from the apex of the heart to the base where it repeats.
6. What is an electrocardiogram?
An electrocardiogram is a recording of the electrical changes in the myocardium during
the cardiac cycle.
7. Which cardiac events do the P wave, QRS complex, and T wave represent?
The P wave on the electrocardiogram represents atrial depolarization. The QRS complex
represents ventricular depolarization and the T wave represents ventricular
repolarization.
8. How do parasympathetic and sympathetic impulses help control heart rate?
Parasympathetic impulses slow the heart rate; decreased parasympathetic impulses can
increase heart rate. Sympathetic impulses increase the heart rate.
9. How do changes in body temperature affect heart rate?
Rising body temperature increases heart rate and decreasing body temperature
decreases heart rate.
10.Describe the effects on the heart of abnormal concentrations of potassium and
calcium ions.
An excess of potassium ions in the blood decreases the rate and force of myocardial
contractions, while a low amount of potassium in the blood can result in arrhythmias.
Excess calcium in the blood increases heart action and low calcium in the blood
depresses heart action.
Use the Practices 13.3
Analyzing Data An electrocardiogram (EKG) records the electrical changes in
a heart during the cardiac cycle. Turn to figure 13.12 to see the characteristics
of a normal EKG. What changes would you expect to see if it were an EKG for
a heart that was beating faster than the heart represented in the figure?
If the heart was beating faster, the peaks would be closer together (not necessarily have
a different amplitude).
Figure Questions
Figure 13.12, page 475: Which two electrical events occur during the QRS complex?
ventricular depolarization and atrial repolarization
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Section 13.4: Blood Vessels
Learn
Classroom Activities
Hands-on Activity: Build-a-Spinner
Provide students the following supplies to make their own game spinner: one gold
head fastener, one piece of cardboard, and one sheet of paper. Students should
create the following categories on the paper:
•
•
•
•
•
•
•
Vein
Artery
Capillary
Atherosclerosis
Lumen
Valve
Endothelium
The first student will go and spin the spinner. Whichever category above the student
lands on, they must describe what the component is and how it relates to blood
vessels. Students should continue to play the review game until both partners can
explain each vocabulary word.
Differentiated Instruction
Instead of students creating the spinner, allow students to choose the strategy
that will best allow them to remember the components of blood vessels.
Students can present their review tool to the class since other students may
find their method useful.
Additional Discussion Questions
Provide students with microscope slides of an arterial wall and a venous wall.
Compare the structure of each.
Students should be able to locate the endothelium of tunica interna, connective tissue, tunica
media, and tunica externa.
Distinguish among ischemia, necrosis, arteriosclerosis, and atherosclerosis.
Ischemia results from blood insufficiency to a tissue, finally resulting in tissue death (necrosis).
Arteriosclerosis (hardening of the arteries) is the end-stage of a process that begins with the
buildup of plaque on the arterial wall (atherosclerosis).
How does water enter and leave a capillary?
Water leaves a capillary due to a net outward filtration pressure at the capillaries’ arteriolar
ends. Water enters a capillary at the venule end due to a net inward force of osmotic pressure.
Practice
Practice Questions
1. Describe the wall of an artery.
The wall of an artery consists of three layers. The innermost layer is simple squamous
epithelium that rests on a connective tissue membrane rich in elastic and collagen fibers.
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The middle layer makes up the bulk of the arterial wall. It includes smooth muscle cells
and thick elastic connective tissue. The outer layer is thin and consists of connective
tissue with irregular elastic and collagen fibers. The outer layer attaches the artery to
surrounding tissues.
2. What is the function of smooth muscle in the arterial wall?
The smooth muscle is responsive to signals from the sympathetic autonomic nervous
system. Vasomotor fibers stimulate the smooth muscle to contract, reducing the diameter
of the vessel, lessening blood flow. If vasomotor impulses are inhibited, the smooth
muscle cells relax and the diameter of the vessel increases, allowing greater blood flow.
3. How is the structure of an arteriole different from that of an artery?
Larger arterioles have three layers, like arteries; however, small arterioles consist of a
single, endothelial lining and some smooth muscle cells.
4. Describe a capillary wall.
Capillaries have thin walls, with slits between the endothelial cells that vary in size
depending on their location in the body.
5. What is the function of a capillary?
Capillaries form a semipermeable membrane through which substances in the blood are
exchanged for substances in the tissues. Capillaries can also shunt blood away from or
to areas where nutrients are plentiful or scarce.
6. What controls blood flow into capillaries?
The smooth muscle surrounding a capillary (pre-capillary sphincters) where it branches
from an arteriole contracts and relaxes in direct response to the metabolic needs of the
tissue for which the capillary supplies. This contraction or relaxation determines the
blood flow through the capillary.
7.Which forces affect the exchange of substances between blood and tissue fluid?
Forces include diffusion, filtration, and osmosis. Diffusion is based on concentration
gradients between the blood and tissue fluid. Filtration occurs as a result of the blood
pressure generated by the heart. Osmosis results from the pressure between the blood
(colloid osmotic pressure) and tissue due to the semipermeable nature of membranes.
8.Why is the fluid movement out of a capillary greater at its arteriolar end than
at its venular end?
The effect of the blood pressure is felt greatest at the arteriolar end of the capillary, thus
favoring filtration and fluid movement out of the capillary. At the venular end, the blood
pressure is decreased and the colloid osmotic pressure predominates, favoring reabsorption
of fluid from the tissues, or holding fluid inside the capillary.
9. How does the structure of a vein differ from that of an artery?
The middle layer of the venous wall is much thinner than the arterial wall and thus, veins
have much less smooth muscle and elastic connective tissues than do arteries. The
diameter of a venous lumen is also larger than that of an artery. Veins have valves to
prevent backflow of blood, also not present in arteries.
10.How does venous circulation help maintain blood pressure when hemorrhaging
causes blood loss?
Veins function as blood reservoirs. In hemorrhage, sympathetic impulses reflexively
stimulate the muscular walls of the veins, constricting them and returning blood stored in
them to the systemic circulation to restore blood pressure.
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Use the Practice 13.4
Asking Questions Develop a question about the effects of aerobic exercise
on blood vessels.
Answers will vary. Example: As you exercise, your heart pumps quicker and with more
force, increasing the blood flow, and thereby dilating arteries. What happens to the
venules upon exercise?
Figure Questions
Figure 13.21, page 485: Which substances do not leave the blood at the arteriolar end
of the capillary and draw water by osmosis back into the capillary at the venular end
of the capillary?
plasma proteins
Section 13.5: Blood Pressure
Learn
Classroom Activities
Visual Literacy: Hypertension Poster
For this activity, students will research and then make posters describing hypertension
or high blood pressure. Posters should include a brief description of the disease, what
causes it, and the problems it causes. Students should also include how the disease is
treated. Be sure students add references to their posters. Diagrams or illustrations are
also great to include.
Writing Connection: Blood Pressure Brochure
High and low blood pressure are medical issues many people face. Students are
assigned to assume the role of a practitioner speaking to a room of individuals
effected by changes in blood pressure. Create a brochure or hand-out for the
crowd that will provide them the following information about blood pressure.
Students may present their brochures or do a rotation, so everyone has a chance
to view each other’s handouts.
•
•
•
•
•
•
Characteristics of blood vessels
Diastolic pressure vs. systolic pressure
Pulse
Sphygmomanometer (blood pressure cuff)
Blood volume & viscosity
Control of blood pressure
Differentiated Instruction
Instead of students creating a brochure or handout, students may choose to
make an online survey, Prezi, or other type of program or technology.
Students may want to work in groups to reduce workload.
Additional Discussion Questions
Explain Starling’s law of the heart.
The greater the length of the myocardial fibers in the ventricular wall, the greater the force
with which they contract.
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Apply the information learned in this chapter objective to compare the structure
and function of a vein to that of a lymphatic vessel.
Responses should include a discussion of pressure within the vessel, the presence of valves,
direction of flow, thinness of vessel walls, and the action of smooth muscle in circulation.
Practice
Practice Questions
1. What is blood pressure?
Blood pressure is the force blood exerts against the inner walls of the blood vessels
(usually arteries).
2. Distinguish between systolic and diastolic pressure.
The maximum pressure during ventricular contraction is called the systolic pressure.
When the ventricles relax, the arterial pressure drops, and the lowest pressure that
remains in the arteries before the next ventricular contraction is the diastolic pressure.
3. What causes a pulse in an artery?
The surge of blood entering the arterial system during a ventricular contractions distends
the elastic arterial walls, but the pressure begins to drop almost immediately as the
contraction ends, and the arterial walls recoil. This alternate expanding and recoiling of
the arterial wall can be felt as a pulse in an artery that runs close to the body surface.
4. How are cardiac output and blood pressure related?
If either the stroke volume or the heart rate increases, so does the cardiac output, and
blood pressure increases. Conversely, if the stroke volume or the heart rate decreases,
the cardiac output decreases, and blood pressure decreases.
5. How does blood volume affect blood pressure?
Normally blood pressure is directly proportional to blood volume in the cardiovascular
system. Thus, any changes in blood volume can initially alter the blood pressure. Blood
volume can also fall if the fluid balance is upset.
6.What is the relationship between peripheral resistance and blood pressure?
Between blood viscosity and blood pressure?
Blood pressure must overcome peripheral resistance if the blood is to continue flowing.
As peripheral resistance increases, the blood flow decreases, but blood pressure is
increased. As peripheral resistance decreases, blood flow increases, but pressure
decreases. When the viscosity of the blood increases, the resistance to flow also
increases. When the resistance to flow is high, the pressure required to move the blood
must also be high. Blood pressure increases with increased blood viscosity.
7.Describe how the volume of blood returning to the heart and entering the
ventricles affects cardiac output.
Entering blood mechanically stretches myocardial cells in the ventricular walls. Within
limits, the greater the length of these cells prior to contraction, the greater the force with
which they contract. The more blood that enters the heart from the veins, the greater the
ventricular distention, the stronger the contraction, the greater the amount of blood
pumped in a single beat, and the greater the cardiac output.
8. What is the function of baroreceptors in the aortic arch and carotid arteries?
Baroreceptors in the aortic arch and carotid arteries sense changes in blood pressure. If
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arterial pressure increases, impulses travel from the baroreceptors to the cardiac center
of the medulla oblongata. This center relays parasympathetic impulses to the SA node
and decreases heart rate, which decreases cardiac output and blood pressure.
Decreasing arterial blood pressure initiates the cardioaccelerator reflex, sending
sympathetic impulses to the SA node and increasing heart rate, which also increases
cardiac output and blood pressure.
9. How does the vasomotor center control peripheral resistance?
The vasomotor center continually sends sympathetic impulses to smooth muscle in the
arteriole walls, keeping them in a state of tonic contraction. This maintains the peripheral
resistance associated with normal blood pressure. The vasomotor center can increase
peripheral resistance by increasing its outflow of sympathetic impulses, or it can
decrease peripheral resistance by decreasing its sympathetic outflow.
10. What is the function of venous valves?
Venous valves close to prevent backflow of blood.
11.How do skeletal muscles and respiratory movements affect venous blood
flow?
Contracting skeletal muscles press on veins, moving blood from one valve section to
another, and eventually back to the heart. During inspiration, the pressure within the
thoracic cavity is reduced as the diaphragm contracts and the rib cage moves. At the
same time, the pressure within the abdominal cavity is increased as the diaphragm
presses downward. Consequently, blood is squeezed out of the abdominal veins and
forced into thoracic veins.
12. What factors stimulate venoconstriction?
If blood is lost and blood pressure falls, venoconstriction can force blood out of the veins
and into the systemic circulation. Venoconstriction also occurs when the venous pressure
is low, as a result of sympathetic stimulation of the smooth muscle in the walls of veins.
Use the Practice 13.5
Using Mathematics Cardiac output is calculated by multiplying the stroke
volume by the heart rate. If a patient has a heart rate of 60 beats/min, and a
cardiac output of 4800 mL/min, what is the patient’s stroke volume?
80 mL/beats
Section 13.6: Arterial System
Learn
Classroom Activities
EL Strategy: Context Clues
Beginning Help students identify context-clue words they could use to
understand vocabulary words in the Arterial System section. Students
should circle the words and use both the visual and written clues to
determine meaning. Say the vocabulary words and context-clue words aloud.
Have students repeat them. Then have students copy the clue word into the
appropriate spaces of a three–column chart.
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Three-column chart
Words
Context Clues
Meanings
aorta
Extends upwards
Largest diameter artery in the
body
Vertebral arteries
Pass upward through the
cervical vertebrae
Vessels that supply blood to
the brain stem, vertebrae
Carotid arteries
Branches off to structures One of the major arteries
in the neck, face, and jaw. supplying blood to structures
in the head, neck and brain.
Visual Literacy: Drawing the Arteries
This is an individual activity, but students can work together in groups on their own
projects to collaborate and ensure they are drawing correctly. The teacher should
provide students with a large piece of paper such as the size of a small poster board.
Students will trace the outline of a body figure onto their paper or the teacher can
print one. Students will label major organs involved in blood flow such as the lungs
and the heart. Next students should label all the major vessels of the arterial system.
Students should color the arteries red and ensure they are placing them in the
correct location. Students may refer to Figure 13.31 for help.
Differentiated Instruction
Instead of students creating their own drawing, students can work as a group
and divide up the different sections of the body by each group member. This
would lighten the work each individual would have to do. Students could also
present their body sections individually through a program instead of the body
as a whole.
Additional Discussion Questions
Discussion questions for sections 13.6 and 13.7 can be found in section 13.7.
Practice
Practice Questions
1. Name the parts of the aorta.
The aorta is divided into an ascending portion, an arch, a descending portion, a thoracic
portion, and an abdominal portion.
2. Name the vessels that arise from the aortic arch.
The brachiocephalic trunk, left common carotid, and left subclavian arteries arise from
the aortic arch.
3. Name the branches of the thoracic and abdominal aorta.
The bronchial, pericardial, esophageal, mediastinal, and posterior intercostal arteries
arise from the thoracic aorta. The celiac, phrenic, superior mesenteric, suprarenal, renal,
gonadal, inferior mesenteric, lumbar, middle sacral, and common iliac arteries arise from
the abdominal aorta.
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4.Which vessels supply blood to the head? to the upper limb? to the abdominal
wall? to the lower limb?
The brachiocephalic trunk and left common carotid artery supply the head. The external
carotid artery and its branches: lingual, facial, occipital, posterior auricular, maxillary,
and superficial temporal arteries supply the head. The internal carotid artery and its
branches: vertebral, ophthalmic, anterior choroid, anterior cerebral and middle cerebral
arteries supply the head. The arch of the aorta and its branches: brachiocephalic trunk
and left subclavian arteries supply the upper limbs. The subclavian and its branches:
axillary, brachial, deep brachial, ulnar, and radial arteries supply the upper limbs.
Branches of the internal thoracic and external iliac arteries provide blood to the anterior
abdominal wall. The phrenic and lumbar arteries supply blood to the posterior
abdominal wall. The abdominal aorta and its branches: common iliac, internal iliac,
external iliac, femoral, popliteal, anterior, and posterior tibial, and dorsalis pedis arteries
supply the lower limbs.
Use the Practice 13.6
Conducting Investigations Plan an experiment to investigate whether the
efficiency of blood flow varies with increasing age (consider both arterial and
venous blood flow).
Answers will vary. Accept those that propose a testable question and show an
understanding of experimental design.
Figure Questions
Figure 13.30, page 497: Blood from the brachial artery flows into which artery (arteries)
in the forearm?
radial artery and ulnar artery
Section 13.7: Venous System
Learn
Classroom Activities
Visual Literacy: Drawing the Veins
This is an individual continuation activity of the body drawing with arteries, but
students can work together in groups on their own projects to collaborate and
ensure they are drawing correctly. The teacher should provide students with the
large piece of paper such as the size of a small poster board that they started
already with the arteries. Students already have labelled all the major organs
involved in blood flow such as the lungs and the heart. Next students should label
all the major vessels of the venous system. Students should color the veins blue and
ensure they are placing them in the correct location. The completed drawing will
represent veins and arteries. Students may refer to Figure 13.35 for help.
Differentiated Instruction
Instead of students creating their own drawing, students can work as a group
and divide up the different sections of the body by each group member. This
would lighten the work each individual would have to do. Students could also
present their body sections individually through a program instead of the body
as a whole.
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Additional Discussion Questions
Provide students with a drawing of the human body and ask them to label the
principal branches of the aorta.
The diagram should include the major branches that arise from the ascending aorta, aortic
arch, descending aorta, thoracic aorta, and abdominal aorta.
Discuss various common sites of venipuncture.
The vein of choice, if appropriate, is the median cubital vein. However, circumstances may
mandate that the phlebotomist procure the blood sample from a vein in the back of the hand
or ankle. Newborns are often stuck in the heel. Arterial blood samples are usually taken from
the radial artery.
Practice
Practice Questions
1. Name the veins that return blood to the right atrium.
The veins that return blood to the right atrium are the superior and inferior vena cavae.
2.Which major veins drain blood from the head? From the upper limbs?
From the abdominal viscera? From the lower limbs?
The internal and external jugular veins are the major veins that drain blood from the
head. The upper limbs are drained by deep and superficial veins. The major superficial
veins are the basilic and cephalic. The major deep veins are the radial, ulnar, brachial,
axillary, and subclavian veins. The abdominal viscera are drained via the hepatic portal
system, including the right and left gastric, superior and inferior mesenteric and splenic
veins. The lower limbs are drained by deep and superficial networks of veins. The deep
veins are the anterior and posterior tibial, popliteal, femoral, and external iliac. The
superficial veins are the small and great saphenous veins.
Use the Practices 13.7
Constructing Explanations Explain why veins are often named after arteries.
Unlike arteries, veins form an irregular network, in which many unnamed tributaries join
to form a large vein. But the pathway of large veins typically run parallel to the arties.
Because of this, may veins bear the names of their arterial counterparts.
Figure Questions
Figure 13.33, page 501: Blood from the brachial vein and basilic vein drains into which
vein(s)?
axillary vein
Assess
Career Corner: Surgical Technician
Consider This: Surgical technicians are routinely in charge of preparing
operating rooms, including making sure the operating table and its surroundings
remain uncontaminated. What do you think uncontaminated means in this
context, and why is it important?
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Infection is a major risk of any surgical procedure. Keeping the operating room
uncontaminated means reducing the introduction of any bacteria through sterilization,
PPE, and other procedures.
Diseases, Diagnosis, and Treatment: Vavular Disease, Heart
Transplant, Angina Pectoris, Myocardial Infarction
1. Describe the function of an LVAD.
An LVAD, or left ventricular assist device, allows people to survive while waiting for a
heart transplant.
2. Explain why physical activity may trigger angina pectoris.
During exercise, oxygen demand may exceed oxygen supply.
Diseases, Diagnosis, and Treatment: Atherosclerosis
1.Describe the characteristics of arteries that generally prevent blockage of
blood flow.
The connective tissue of arteries is rich in elastic and collagen fibers. In addition, the
endothelium helps prevent blood clotting by providing a smooth surface that allows blood
cells and platelets to flow through the vessel without being damaged and by secreting
biochemicals that inhibit platelet aggregation. Endothelium also may help regulate local
blood flow by secreting substances that dilate or constrict blood vessels. For example,
endothelium releases the gas nitric oxide, which relaxes the smooth muscle of the vessel.
2.What are the risk factors for developing atherosclerosis? How can behavior
modify the risk of developing atherosclerosis, and what types of treatments
are available if the condition develops?
Risk factors for developing atherosclerosis include a fatty diet, elevated blood pressure,
tobacco smoking, obesity, and lack of physical exercise. Genetic factors may also
increase the risk of developing atherosclerosis. Behavioral changes like diet and exercise
can modify the risk of developing the condition. Treatments include drugs called statins
to reduce LDL cholesterol and regulate triglyceride levels. More invasive treatments
include percutaneous transluminal angioplasty, lasers, and bypass graft surgery.
Healthy Lifestyle Choices: Exercise and the
Cardiovascular System
1.Cardiac output increases by as much as seven fold during strenuous exercise,
yet blood pressure only increases about 10%-15%. What must be happening to
the blood vessels to account for this? Which blood vessels do you predict
would be involved?
If cardiac output increases but blood pressure remains relatively stable, peripheral
resistance must decrease. Peripheral resistance is controlled by arteriole diameter,
meaning vessels dilate.
2. Calculate your beneficial heart rate range (70–85% of theoretical maximum).
Answers will vary, but students should find this by subtracting their age from 220.
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Case Study Connection
page 468: Atria and ventricles both can have rhythm issues known as fibrillation,
but ventricular fibrillation is much more serious. Why is ventricular fibrillation so
much more dangerous for health than atrial fibrillation?
The ventricle is responsible for pumping blood to the lungs and to the body.
page 472: If the ventricles both experience fibrillation, will the pulmonary circuit
or systemic be affected? Will they be affected equally? Will blood supply to the
heart be compromised during the ventricular fibrillation event? What could be
the long-term consequences to heart tissue, if any?
Both circuits will be affected, as the right ventricle pumps blood to the lungs and the left
ventricle pumps blood into the systemic loop. Since blood returns to the atria from both
loops, ventricular fibrillation would also affect blood supply to the heart. Lack of oxygenated
blood to the heart could result in tissue death.
page 475: Would you be able to detect ventricular fibrillation on an EKG? If so,
what parts of the EKG might look different?
Students should identify that the QRS complex shows the depolarization of the ventricle
which might look different during ventricular fibrillation.
page 477: How would the aortic pressure graph change in ventricular
fibrillation? How might the ventricular volume graph change in ventricular
fibrillation? Would heart sounds change during a ventricular fibrillation event?
Answers will vary somewhat; accept all sound reasoning.
page 489: What changes to cardiac output would you expect during a ventricular
fibrillation event? Could this help explain the man’s collapse at the airport?
Ventricular fibrillation could reduce cardiac output. Accept all student answers that identify
this and link it to collapse.
page 497: Which arteries are especially important to maintain blood pressure in
order to prevent interruptions in brain function?
The main arteries to the brain come from the subclavian and carotid arteries.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. The cardiovascular system includes
a. the heart.
b. the arteries and veins.
c. the capillaries.
d. all of the above.
2. How many layers make up the heart’s wall, and how many
chambers does a human heart have, respectively?
a. two; two
b. three; two
c. three; four
d. four; three
3. Blood flows through the vena cavae and coronary sinus into
the right atrium, through the to the right ventricle, then
through the pulmonary valve to the pulmonary trunk and its
branches. From there, blood enters the associated with the
alveoli of the lungs.
a. tricuspid valve; alveolar capillaries
b. aortic valve; systemic capillaries
c. mitral valve; systemic capillaries
d. mitral valve; alveolar capillaries
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4. When atria or ventricles relax, it is called
a. systole.
b. diastole.
c. functional syncytium.
d. myocardium.
5. Which is not part of an ECG pattern?
a. P wave
b. U wave
c. A and B
d. None of the above.
6.
carry oxygen-rich blood away from the heart, and
carry oxygen-depleted blood to the heart.
a. Arteries; arterioles
b. Arteries; veins
c. Veins; arterioles
d. Veins; venules
7. How does CO2 enter capillaries from tissues?
a. diffusion
b. osmosis
c. active transport
d. it cannot enter capillaries
8. If a patient develops a blood clot in the femoral vein of the
left lower limb and a portion of the clot breaks loose, where
is the blood flow likely to carry the embolus?
a. aorta
b. superior vena cava
c. inferior vena cava
d. left pulmonary veins
Short Answer
1. Describe the anatomical position, size, structure, and shape
of the heart.
The heart is located between the lungs and behind the
sternum. It varies in size based upon body size (average is 14
cm long by 9 cm wide). Comprised of cardiac muscle, it is
mostly hollow with four chambers. The heart is an upside down
cone with the apex at the bottom and the base at the top.
2. What is the pericardium?
The pericardium is fibrous connective tissue sac that encloses
the heart. It contains a pericardial cavity with fluid that
reduces friction during heart beats.
3. Starting at the right atrium, trace the blood flow through the
heart, lungs, and tissues.
Blood low in oxygen enters the right atrium from the inferior
and superior vena cavae, from there here is the pathway:
triscupsid valve, right ventricle, pulmonary valve, pulmonary
trunk, pulmonary arteries, lungs (where oxygen is picked up
and carbon dioxide unloaded), pulmonary veins, left atrium,
bicuspid (mitral) valve, left ventricle, aortic valve, aorta, all
body tissue (where oxygen is delivered and carbon dioxide is
picked up), then back to the superior and inferior vena cavae.
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4. What is an ECG? Describe the three waves associated with it.
An ECG is a graphic representation of the electrical activity in
the cardiac muscle in the chambers of the heart during a
heartbeat, or cardiac cycle. The P wave represents atrial
contraction (systole). The QRS wave represents ventricular
contraction (systole). The T wave formally represents
ventricular repolarization, but also is a time during which all
chambers are in a state of relaxation (diastole).
5. Distinguish between heart rate, stroke volume, and cardiac
output.
Heart rate (HR) is the number of heart beats per minute. Stroke
volume (SV) is the amount of blood ejected by the left ventricle
per beat. Cardiac output (CO) is the amount of blood ejected
by the left ventricle per minute. It is calculated by multiplying
heart rate by stroke volume: CO = SV X HR.
6. Name the three layers of a blood vessel.
A blood vessel has an inner layer of simple squamous
epithelial tissue called the tunica interna. The middle layer, the
tunica media, is made of smooth muscle. Connective tissue
makes up the tunica externa, the outer most layer.
7. Describe a capillary network.
A capillary network is where gas exchange occurs. It lies
between the arterial side and the venous side of blood flow.
Capillaries are the smallest vessels, only one cell layer thick to
facilitate rapid, efficient diffusion. On the arterial side, precapillary sphincters regulate blood flow into the network.
8. Which vessels have valves? Why?
Veins in the extremities (arms and legs) have valves to prevent
back flow of blood due to the low pressure on the venous side
of blood flow.
9. What causes the lubb dupp sounds of a heart beat?
The sounds of a heartbeat are caused by the closing of the
valves. The first heart sound, the lubb, corresponds to the
closing of the AV (tricuspid and bicuspid) valves. The second
sound, the dupp, corresponds to the closing of the pulmonary
and aortic valves.
10. All vessels have a certain amount of pressure exerted on
their walls. What is meant by clinical blood pressure? How is
it measured?
Clinical blood pressure refers to the pressure on the wall of
the aorta during systole and diastole. It is expressed as
systole/diastole. Using a blood pressure cuff, it is usually
measured on the brachial artery in the left arm because of the
easy access and it is close to the aorta so the measurement is
an accurate reading. Example: 120/80.
11. What is an average heart rate? Define tachycardia and
bradycardia.
An average resting heart rate is 70-75 beats per minute, with a
normal range of 60 to 100 beats per minute. Bradycardia is
the condition when resting heart rate is below 60. Tachycardia
is the condition when resting heart rate is above 100.
12. Distinguish between the SA and AV nodes.
The SA node is the “pacemaker”. It initiates every heart beat
by sending signals to the atria. It also sends signals to the AV
node. The AV node then sends signals to the ventricles by way
of the Purkinje fibers.
13. What are intercalated disks? What effect do they have on
cardiac muscle cell contraction?
Intercalated disks are gap junctions between cardiac muscle
cells. They facilitate rapid communication between all cardiac
muscle cells. This allows the cells in the chambers to contract
as one unit.
14. What is the function of barorecpetors?
Baroreceptors are stretch receptors. In this capacity they can
monitor blood pressure in the walls of the aorta and carotid
arteries. Signals are then sent to the medulla to either increase
or decrease heart rate.
15. What is atherosclerosis?
Atherosclerosis is the condition where fatty and cholesterol
deposits build up in blood vessels, most often in arterial walls.
This constricts the vessel and restricts blood flow and makes
the vessels less elastic or, “hardened.”
Critical Thinking and Clinical Applications
1. A colonoscopy revealed a small tumor in the colon of a
60-year-old man. His physician ordered a liver scan out of
concern that the cancer might have spread. Using your
knowledge of blood vessels, why is the physician concerned?
The hepatic portal vein carries blood from the digestive tract
to the liver to be filtered. Therefore, the possibility exists that
the cancer cells can migrate from the colon into the liver
through the hepatic portal vein.
2. CLINICAL Connection An overweight 45-year-old woman
who has smoked for over 20 years had an annual physical.
Diagnosed with hypertension and a slightly elevated heart
rate her physician prescribed her medication and urged her
to make lifestyle changes. How are her conditions and
lifestyle related? What type of medications might the
physician have prescribed?
Hypertension can result from a lack of physical exercise or a
higher body weight. The doctor may have prescribed her
diuretics or sympathetic nerve inhibitors.
3. WRITING Connection A heart attack (myocardial infarction)
left a man with a failing left ventricle. Pulmonary edema
(fluid build-up in the lungs) was detected. Explain this.
The heart has to pump same volume of blood out that flows in.
And blood flow into and out the right side of the heart has to
equal blood flow into and out of the left side. Therefore, if the
left ventricle is weakened or fails blood will back up into the
lungs causing a pulmonary edema.
Lab Data Analysis: Cardiac Stress Test
1. What is the patient’s resting heart rate?
The patient’s resting heart rate — that is, heart rate when the
body is not undergoing any stress from exercise — is
approximately 80 beats per minute. This is shown along the
y-axis at time t=0s.
resting heart rate at time t=0s would be lower, perhaps
50 bpm. The rate at which the athlete’s heart rate increased
over time would be slower, and the maximal HR at t=400s
would be lower.
2. Suppose this graph represents an 80-year-old patient with
heart disease. What differences would you expect to see in a
graph showing data from a 25-year-old elite athlete?
We can assume that the cardiac conditioning of an athlete
55 years younger would be considerably better. As such, the
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CHAPTER
14
Lymphatic System
and Immunity
Section
Pacing
(class periods)
Learning Objectives
14.1 Introduction
—
1. Describe the general functions of the
lymphatic system.
14.2 Lymphatic
Pathways
1
1. Identify the locations of the major lymphatic
pathways.
14.3 Tissue Fluid and
Lymph
1
1. Describe how tissue fluid and lymph form,
and explain the function of lymph.
2. Explain how lymphatic circulation is
maintained.
14.4 Lymphatic Tissues
and Organs
1
1. Describe a lymph node and its major functions.
14.5 Body Defenses
Against Infection
1
1. Distinguish between innate (nonspecific) and
adaptive (specific) defenses.
14.6 Innate (Nonspecific)
Defenses
2
1. List seven innate body defense mechanisms,
and describe the action of each mechanism.
14.7 Immunity: Adaptive
(Specific) Defenses
2
1. Explain how two major types of lymphocytes
are formed and activated, and how they
function in immune mechanisms.
2. Discuss the location and function of the
thymus and the spleen.
2. Discuss the actions of the five types of
antibodies.
3. Distinguish between primary and secondary
immune responses.
4. Distinguish between active and passive
immunity.
5. Explain how allergic reactions, tissue rejection
reactions, and autoimmunity arise from
immune mechanisms.
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (6)
Chapter Resources
Extended Summary Review
Chapter 14 Test Bank
Chapter 14 Interactive Question Bank
Vocabulary Flashcards
APR Module 10: Lymphatic System
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A Suggested Approach
The majority of high school students enrolled in Anatomy and Physiology have already
been exposed to immunity in their introductory biology or health course, this chapter
is a good review of the lymphatic system and the importance of our immunity.
A good way to begin the study of the lymphatic system and immunity is to
determine the prevalence of pathogens in the environment. There are many ways to
demonstrate this concept, from using Glo Germ powder, which is not visible to the
naked eye, but illuminates under black light, or using a vial of potassium hydroxide
solution and an indicator to demonstrate the transmission of unseen pathogens. If
these sources are unavailable, students can also demonstrate transmission of
pathogens using printed cards. After demonstrating the prevalence of pathogens,
have a classroom discussion on the best ways to avoid transmission.
There are several good videos available online to review the functions of lymphatic
system, such as TED Ed: The Immune System Explained. Generate a discussion
about the students’ knowledge of innate and adaptive defenses and how these
function to give us immunity. Students can then learn the anatomy of the lymphatic
system, and add to their knowledge of innate immune defenses, and acquired
immune defenses, including vaccination.
This chapter is expected to take 8 class periods.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is information
that supports or contradicts a claim. This information can come from a variety of
sources, such as research, experimentation, or data interpretation. It is important
to have multiple pieces of evidence to support a claim. Encourage students to
return to their claims and add evidence at multiple points in the chapter.
The immune system has affects all over the body. In this case study, the young
woman experiences symptoms in her skin (the flushed face), the digestive system
(vomiting) and the respiratory system (difficulty breathing). In these types of
reactions, the circulatory system is involved in distributing the cytokine signaling
molecules. A fun exercise for your students can be to explore how the immune
system can have anatomical links to these three disparate anatomical systems.
Another fun link for students is to talk about stress and the immune system.
The most common drugs we use to suppress immune responses (prednisone,
epi-pens, and hydrocortisone creams) are all using synthetic forms of our
body’s own stress hormones epinephrine and cortisol. This helps us to
understand the role that stress plays in depressing our own immune responses.
A review article that can help in this discussion can be found in Volume 9, Issue
3 of Pathophysiology: Stress and the immune system by Stephen B. Pruett.
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Introduction to the Theme
Theme: Cause and Effect The cause of most human illness is due to a bacterium
or virus. It is the effectiveness of the lymphatic system in filtering those pathogens
to the immune system that has allows us to stay health human beings.
Theme Activity: Innate and Adaptive Defenses Crossword Puzzle
As you go through Section 14.7 and 14.8, your students will be inundated with many
new terms that are specific to the immune system. To help students grasp the many
different parts of the innate and adaptive defenses, have students create crossword
puzzles with all of the different types of cells and molecules. Pass out pieces of
graph paper and instruct students that their clues must highlight the action or
effect of the defense mechanism.
An example would be:
Clue: A mechanical barrier that blocks the entrance of some pathogens
Answer: Skin
After students have created their puzzle, have them hand their puzzle to another
student to complete.
Section 14.1: Introduction
Learn
Classroom Activities
Section 14.1 sets the groundwork for activities in sections 14.2 and beyond.
Additional Discussion Questions
Ask students to create a diagram that illustrates how lymphatic vessels transport
fluid from interstitial spaces to the bloodstream.
The diagram should include information about lymphatic capillaries, pulmonary capillary network,
systemic capillary network, lymphatic capillaries, lymph nodes, and lymphatic vessels.
Practice
Practice Questions
1. What the general functions of the lymphatic system?
Lymphatic vessels transport excess fluids away from interstitial spaces in most tissues and
return it to the bloodstream, preventing its accumulation in the interstitium. Cells of the
lymphatic system launch generalized and targeted attacks against “foreign” particles also.
Use the Practices 14.1
Asking Questions Develop a question about how the lymphatic system works
with other body systems to maintain homeostasis.
Answers will vary. Some examples include:
Some of the immune cells mature in the bone marrow. What body system would be
necessary for the maturation of B cells?
Similar to the cardiovascular system, the lymphatic system is made up of a series of
vessels. What is another similarity to the cardiovascular system?
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Section 14.2: Lymphatic Pathways
Learn
Classroom Activities
Visual Literacy: Lymphatic Art
Students will work individually on this activity to create their own art piece of the
lymphatic trunk and collecting ducts. The teacher will provide students with a blank
white sheet of paper, glue, scissors, markers, and colored yarns (blue, red, purple,
and green). Students will recreate Figure 14.2 on their own paper and label it. They
can be creative in how they use the yarn to recreate the trunks, ducts, capillaries,
and arteries. Once students complete their artwork and it dries, students will
present their artwork to a person at home or involved in their learning.
Differentiated Instruction
Students may need an outline of the different ducts, trunks, capillaries, and
arteries instead of generating the terms on their own. This guidance will
support the non-artistic kinesthetic learners. Student should also work on their
presentation of their artwork with a peer and possibly write out their description
instead of presenting it to a person at home.
Additional Discussion Questions
Ask students to label a diagram of the human body with the locations of the major
lymphatic trunks and collecting ducts.
The diagram should include the jugular trunk, subclavian trunk, bronchomediastinal trunk,
intercostal trunk, intestinal trunk, lumbar trunk, right lymphatic duct, and the thoracic duct.
Discuss the causes of tonsillitis.
Frequently, streptococcal organisms may cause the tonsils to become infected and irritated.
This may lead to a narrowing of the passageway for swallowing, fever, and leukocytosis.
Practice
Practice Questions
1. Compare the structure of lymphatic vessels and veins.
Lymphatic vessels are similar to veins but with thinner walls. Line veins, some lymphatic
vessels have valves to prevent backflow.
2. Distinguish between the thoracic duct and the right lymphatic duct.
The right lymphatic duct receives lymph from the right side of the head and neck, right
upper limb, and right thorax and empties into the right subclavian vein. The thoracic duct
is wider and longer than the right lymphatic duct. It receives lymph from the lower limbs
and abdominal regions, left upper limb, and left side of the thorax, head, and neck. It
empties into the left subclavian vein.
Use the Practices 14.2
Using Models Draw a diagram showing the lymphatic and cardiovascular
pathways. Highlight the similarities in the pathways, and use notes to indicate
the direction of flow for blood and lymph.
See Figure 14.1 as a sample
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Figure Questions
Figure 14.4, page 515: Which lymphatic duct drains lymph from the right lower limb?
thoracic duct
Section 14.3: Tissue Fluid and Lymph
Learn
Classroom Activities
Writing Connection: Edema Scenario
Discuss with students as a whole group how tissue fluid is related to lymph. Provide
students with the following scenario:
A surgeon is going to perform surgery on a breast cancer patient and may have to
remove nearby axillary lymph nodes. The doctor advised the patient there may be
swelling afterwards.
Ask students to discuss the following questions in pairs. After the discussion, they
should each write their own constructed response in their own notebooks.
Question 1: What role do the axillary lymph nodes play? Why would their function
make the doctor worried about leaving them and thus opt to remove them?
Question 2: The doctor said the patient may experience swelling afterwards. Explain
why is swelling most likely to occur.
Differentiated Instruction
Instead of students answering the scenario questions, students could draw or
describe how lymph movement occurs, and how transport through the lymph
system could be positive or negative for the body.
Additional Discussion Questions
Provide students with microscope slides of a lymphatic vessel and ask them to
comment on what they see.
Discuss the similarities in lymphatic vessel and venous structure. Include comments on the
function of valves.
Discuss the causes of elephantiasis.
Elephantiasis is caused by blockage of a lymphatic vessel, resulting in severe edema, etc. It is
often caused by a parasite.
Practice
Practice Questions
1. What is the relationship between tissue fluid and lymph?
Tissue fluid is composed of water and dissolved substances that leave blood capillaries
by filtration. Filtration from the plasma normally exceeds reabsorption, leading to the net
formation of tissue fluid. The accumulation of tissue fluid increases the tissue fluid
hydrostatic pressure, which moves tissue fluid into lymphatic capillaries, forming lymph.
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2. How do plasma proteins in blood capillaries affect lymph formation?
The osmotic effect of the plasma proteins (plasma colloid osmotic pressure) helps draw
fluid back into the blood capillaries, as most plasma proteins are too large to be filtered
out of the capillaries. Since plasma proteins are not filtered, they would draw fluid back
into the blood capillaries, ultimately decreasing lymph formation.
3. What are the major functions of lymph?
Lymph returns those plasma proteins that are filtered to the bloodstream as well as
transports foreign particles like bacteria and viruses to lymph nodes.
4. What factors promote lymph flow?
Lymph within lymphatic vessels is under relatively low hydrostatic pressure and may not
flow readily through the lymphatic vessels without help from contraction of skeletal and
smooth muscles, as well as the pressure changes generated with breathing.
5. What is the consequence of lymphatic obstruction?
Conditions that interfere with lymph movement cause tissue fluid to accumulate within
the interstitial spaces, producing edema, or swelling.
Use the Practices 14.3
Communicating Information Create a graphic organizer that demonstrates
the relationships among blood plasma, tissue fluid, and lymph.
Answers will vary. Accept all graphic organizers that show understanding of body fluids.
Section 14.4: Lymphatic Tissue
and Organs
Learn
Classroom Activities
EL Strategy: Vocabulary Preteaching
Beginning For the section 14.4, define the vocabulary words in English and
provide examples and explanations. Use Appendix A to find the complete Aids
to Understanding Words. Show the students the related root words. Say the
terms out loud and have students repeat the words. Then have students write
the word in their interactive notebooks.
Writing Connection: True or False
Pair students together to work on this activity. Each student will create a set of true
statements and a set of false statements about the lymph nodes, thymus, and
spleen. Students should create at least three true and false statements. After
students have both created their statements, they will take turns reading them to
their partner one at a time. The partner who is listening at the time will have to
determine if the statement is true or false. If the statement is false, the student who
wrote it should explain what the correct statement would be. Take turns back and
forth until they have discussed all statements.
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Differentiated Instruction
Students can work together in small pairs to create the sets of true and false
statements Then they will switch papers with another group. The partner pair
will work together going through the statements the other group wrote and
deciding if they are true or false. If they find a false statement, they should
correct it. Once complete, they should return the paper to the original group
and receive their own question set back and grade it.
Visual Literacy: Life-Sized Lymph
You may do this activity as a continuation from the drawings created in Chapter 13:
Life-Sized Cardio, or have students create a new outline on butcher paper. Provide
markers or colored pencils. Students will then draw the lymphatic system on the
life-sized outline. You may also provide the students cotton balls and glue if you
would like to have the students make the lymph nodes 3D.
Additional Discussion Questions
Provide students with an unlabeled diagram of a lymph node and ask them to
correctly label its structures.
The diagram should include the hilum, medulla, sinus, capsule, nodule, germinal center, and
trabecula.
Compare the structure of a spleen and a lymph node.
The structures are somewhat similar. Discussion should emphasize the venous sinus, white pulp,
red pulp, capsule, and connective tissue.
Discuss what is meant by swollen glands.
This phrase actually refers to enlarged cervical lymph nodes associated with throat or
respiratory infection.
Examine microscopic slides of the spleen and comment on any observations.
Emphasis should be placed on the identification of red pulp, white pulp, and the capsule.
Reiterate the functions of each structure.
Practice
Practice Questions
1. What is the size and shape of a lymph node?
Lymph nodes vary in size and shape, but are usually 2.5 cm long and somewhat
bean-shaped.
2. Where are lymph nodes located and what are their functions?
Lymph nodes are generally in groups or chains along the paths of the larger lymphatic
vessels throughout the body, but absent in the central nervous system. Lymph nodes
have two primary functions: filtering potentially harmful particles from lymph before
returning it to the bloodstream, and monitoring body fluids (immune surveillance).
3. Why are the thymus and spleen considered organs of the lymphatic system?
The lobules of the thymus house lymphocytes that mature into T lymphocytes and leave
the thymus to provide immunity. The spleen itself resembles a large lymph node and is
separated into red pulp (housing blood cells) and white pulp (housing lymphocytes).
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4. What are the major functions of the thymus and the spleen?
The thymus produces T cells which help in immunity. The spleen serves as a filter for the
blood, as well as producing lymphocytes to help in immunity.
Use the Practices 14.4
Constructing Explanations Explain why the spleen is considered to be an
organ of the lymphatic system rather than an organ of the cardiovascular system.
The spleen contains blood rather than lymph, but is still composed of encapsulated
lymphatic tissue.
Section 14.5: Body Defenses Against
Infection
Learn
Classroom Activities
Writing Connection: Disease-Causing Agents
This is a short research project where students will investigate a disease of their
choice. This can be done individually or in small groups. Each group will discuss
different diseases they know of or have been affected by (examples include the
common cold). A disease that we get vaccinated against is another good option.
Once each group chooses a disease, they will research how the disease infects or
invades the body. Is it through a virus, bacteria, fungi, or protozoan? Students
should also research history of the disease, how it is treated, and if it is
communicable. The teacher may want to provide research sites for students and
review an example disease first. The Center for Disease Control and Prevention is a
great starting place. Students may present their findings to the class or the teacher
could have each group create a one-page report of the information to combine into
a class disease information book.
Differentiated Instruction
Instead of students choosing any disease, the teacher could create a list of
diseases that students would be familiar with and are easy to research. The
teacher should provide an outline to students for their research to support data
collection. Students in the group could each take a role in the research such as an
image of the disease infecting agent, treatment, communicable, and more so that
everyone is completing a small job instead of the entire research project together.
Practice
Practice Questions
1. What may cause an infection?
The presence and multiplication of a disease-causing agent (pathogen) if left unchecked
may cause an infection. Pathogens include viruses, bacteria, fungi, and protozoa.
2. In general, how do innate and adaptive defenses differ?
Innate defenses are general and defend against many types of pathogens. Adaptive
defenses are precise and target specific pathogens.
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Use the Practices 14.5
Conducting Investigations Outline a plan to determine the classification
(as virus, bacterium, fungus, or protozoan) of a disease-causing agent.
Answers will vary. Many students will suggest viewing the organisms under a microscope.
Viruses will be considerably smaller and have a unique morphology. Eukaryote cell
structures will distinguish a fungus from a bacterium.
Section 14.6: Innate (Nonspecific)
Defenses
Learn
Classroom Activities
Writing Connection: Innate Body Defenses
Pair students together and ask them to create a worksheet to review the innate
body defenses. They should design a worksheet with matching activities. Encourage
students to be creative. Below are the innate body defenses they should include.
They should include these terms along with examples or definitions.
•
•
•
•
•
•
•
Species resistance
Mechanical barriers
Inflammation
Chemical barriers
Natural Killer (NK) cells
Phagocytosis
Fever
Once students complete their worksheet, the teacher will collect them and make
a copy of each group’s worksheet enough to pass out a copy of everyone’s
worksheet to each group. The students will then complete all of the other
groups’ worksheets.
Differentiated Instruction
Instead of giving each group a copy of every worksheet, have groups switch
with each other and only complete 1 other worksheet. Students can complete
the worksheet and then also evaluate it to ensure that it is correct.
Additional Discussion Questions
Ask students to prepare a poster that lists the major actions that may occur during
an inflammation response. Explain the poster to the class.
The poster should contain information about the effects on blood vessels, white blood cells,
body fluids, fibroblasts, phagocytes, and cellular reproduction.
Give specific examples of different types of nonspecific defenses. Make a list on the
board based on student input.
Examples should address species resistance, mechanical barriers, chemical barriers, fever,
inflammation, and phagocytosis.
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Practice
Practice Questions
1. What is considered a first line of defense? Provide examples.
The mechanical barriers are the first line of defense. These include skin and mucous
membranes, which many pathogens are unable to penetrate them.
2. Explain seven innate (nonspecific) defense mechanisms.
Seven innate defense mechanisms are: species resistance, mechanical barriers,
inflammation, chemical barriers, natural killer cells, phagocytosis, and fever. Species
resistance refers to the fact that a given species may be resistant to infections that affect
other species. The basis of species resistance is that cells of a resistant species do not have
receptors for the pathogen, or do not provide the proper environment for a pathogen to
flourish. Mechanical barriers prevent the entrance of some infectious agents as long as
they’re intact. Inflammation produces a localized swelling and increases blood flow to the
area, which carries WBCs to the area to respond to the invader/damage. Chemical
barriers, like gastric juice, have enzymes that split proteins and can kill some bacteria.
Natural killer (NK) cells are nonspecific immune cells that kill viruses and cancer cells.
Phagocytosis removes foreign particles from lymph and blood. Fever works to increase the
body’s temperature to make the internal environment inhospitable to invaders.
Use the Practices 14.6
Communicating Information The human body’s innate immunity is often
referred to as our first line of defense against pathogens. Explain this statement.
The innate immune system is both a physical and chemical barrier to any pathogen you
are exposed to. Mechanical barriers, like your skin and mucus, keep pathogens from
entering your body. But in case some break through the surface, a range of chemicals
and cells serve as a safeguard to destroy the pathogen.
Section 14.7: Immunity: Adaptive
(Specific) Defenses
Learn
Classroom Activities
EL Strategy: Making Connections
Intermediate Paraphrase content to make it accessible to all students.
Paraphrasing helps students make connections more easily. Encourage
students to make connections to the text after each paragraph.
Writing Connection: T and B Cells
Provide students the steps in antibody production from Table 14.2. Have students
work individually and cut out each step on its own slips of paper. Have students
shuffle the B Cell Activities steps together, and separately shuffle the T Cell
Activities steps. Students must then reorganize the steps into the correct order.
Once students have them organized back into the correct order they can trade with
another student to grade their work.
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Differentiated Instruction
Instead of students rearranging the steps of antibody protection, provide
students Figure 14.14 showing T and B Cell activation. Print out the figure
without the labels. Provide students the list of labels and have them practice
with a partner labeling the different steps of the figure. Ask students to write a
reflection describing the difference between activation of a T cell and a B cell.
Visual Literacy: Your Body’s Super Heroes
For this activity, you will need to supply your students with colored pencils or
markers and paper. You will ask your students to make a storybook including
common super heroes as parts of the immune system. Your students can work in
pairs or individually for this activity. This activity hinges more on the action of the
“super heroes” rather than the artistic rendering in the book. Therefore, explain to
students that their “super heroes” can be stick figures if they are concerned about
their ability to draw.
Additional Discussion Questions
Ask students to perform a white blood cell differential count and comment on the
number of lymphocytes observed.
Attempt to include a variety of normal and abnormal blood smears that the students examine.
Give the normal ranges for lymphocyte counts and then comment on possible diseases
represented by the abnormal counts.
Ask students to create a chart of the characteristics of the major immunoglobulins.
The chart should include information on IgG, IgA, IgM, IgD, and IgE.
What are the common actions of the complement system?
Some actions include activation of complement proteins, altering the structure of viruses,
clumping of antigens, lysis, chemotaxis, and opsonization.
Discuss examples of various types of active, passive, naturally-acquired, and
artificially-acquired immunity.
Examples may include a discussion of vaccines, snake bites, maternal antibodies, booster
shots, bee stings, injections of gamma globulin, etc.
Give examples of tissue transplantation attempts and discuss why they have
succeeded or failed.
Responses should include a discussion of liver, kidney, heart, heart valve, cornea, lung, etc.
Create a diagram that will effectively illustrate the release of lymphocytes from the
bone marrow that eventually become B cells or T cells.
The diagram should include the following steps: stem cells in red bone marrow give rise to
undifferentiated lymphocytes, undifferentiated lymphocytes enter blood, some lymphocytes
are processed in thymus gland to become T cells, other lymphocytes are processed in bone
marrow to become B cells, and T cells and B cells are transported to lymphatic organs by
blood.
Discuss the steps in antibody production. Compare the steps regarding B cell
activity and T cell activity.
The B cell activity includes a discussion of B cell receptors, activated B cells, plasma cells, and
antigen-antibody combinations. T cell activity includes a discussion of macrophages, antigen
presentation, phagocytosis, helper T cells, and cytokines.
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Compare the direct attack forms of antibody actions.
Agglutination results in antigen clumping, precipitation results in antigens becoming insoluble,
and neutralization results in antigens becoming less toxic.
Discuss ways in which AIDS may be transmitted.
Responses should include a discussion of sexual contact, contaminated needles, maternal
infection, blood transfusions, etc.
Compare examples of immediate-reaction and delayed-reaction allergies.
The discussion may include information regarding contact dermatitis, hay fever, asthma, hives,
eczema, and allergies to cosmetics.
Practice
Practice Questions
1. What is immunity?
Immunity is resistance to specific pathogens or to their toxins or metabolic by-products.
Lymphocytes and macrophages (cellular immunity) are cells that recognize specific
foreign molecules. Humoral immunity refers to the production of specific antibodies
against specific antigens found on invaders.
2. What is the difference between an antigen and a hapten?
Antigens are proteins, polysaccharides, glycoproteins, or glycolipids that can elicit an
immune response. A smaller molecule that cannot by itself stimulate an immune response
may combine with a larger molecule, which makes it detectable to the immune system.
The small molecule is called a hapten.
3. How do T cells and B cells originate?
The precursors to T cells originate in the red bone marrow, and travel through the blood
to mature in the thymus. B cells originate and mature in the red bone marrow.
4. How do T cells become activated?
T cell activation may occur when a macrophage phagocytizes a bacterium and digests
it within a phagolysosome formed by the fusion of the vesicle containing the bacterium
(phagosome) and a lysosome. T cells can become activated through cytokines, like
interleukin-1. Helper T cells are activated when its antigen receptor combines with a
displayed foreign antigen. Cytokines produced by helper T cells can activate another
type of T cell, the cytotoxic T cell.
5. What are some functions of cytokines?
Cytokines are polypeptides secreted by T cells and some macrophages that enhance
certain cellular responses to antigens. Interleukin-1 activates T cells. Interleukin-2 causes
T cells to proliferate. Colony-stimulating factors (CSFs) stimulate leukocyte production in
red bone marrow and activate macrophages, etc.
6. Name three types of T cells.
Three types of T cells are cytotoxic T cells, helper T cells, and memory T cells.
7. How do cytotoxic T cells destroy cells bearing foreign antigens?
Helper T cells activate the cytotoxic T cells and they proliferate. Cytotoxic T cells
recognize and combine with nonself antigens displayed on the surfaces of the foreign
antigens. Cytotoxic T cells then release perforin protein that cuts holes in the foreign
cell’s cell membrane, ultimately destroying it.
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8. How are B cells activated?
When a B cell encounters an antigen whose molecular shape fits the shape of the B
cell’s antigen receptors, it becomes activated.
9. How does the antibody response protect against diverse infections?
An individual’s B cells can produce more than 1 billion different antibodies, each reacting
against a specific antigen. The enormity and diversity of the antibody response defends
against many pathogens.
10.Which immunoglobulins are most abundant, and how do they differ from each
other?
There are five different immunoglobulins (Ig): IgG, IgA, IgM, IgE, and IgD. The most
abundant are IgG, IgA, and IgM. IgG is in plasma and tissue fluids and is effective
against bacteria, viruses, and toxins. It also activates complement. IgA is commonly
found in exocrine gland secretions (breast milk, tears, nasal fluid, gastric juice, bile, urine,
etc.). IgM is in plasma and can also activate complement. IgM is the first Ig produced in
response to an infection. IgE is on the surfaces of basophils and mast cells and is
associated with the allergic response. IgD is found on the surface of B cells and helps
activate them.
11. In what general ways do antibodies function?
In general, antibodies react to antigens in three ways: direct attack, activation of
complement, or stimulate local changes (inflammation) that help prevent the spread of
pathogens or cells bearing foreign antigens.
12. How is complement activated?
When certain IgG or IgM antibodies combine with antigens (forming antigen-antibody
complexes), they expose reactive sites on antibody molecules, which triggers a series of
reactions leading to activation of complement.
13. What are the effects of complement activation?
Activation of complement produces a variety of effects including making the antigenantibody complexes more susceptible to phagocytosis (opsonization), attracting
macrophages and neutrophils to the region (chemotaxis), rupturing membranes of foreign
cells (lysis), agglutinating antigen-bearing cells, and altering the structure of viruses to
make them harmless.
14. Distinguish between a primary and a secondary immune response.
Activation of B cells or T cells after they first encounter the antigens for which they are
specialized to react constitutes a primary immune response. During such a response,
plasma cells release antibodies (IgM, followed by IgG) into the lymph. Following a
primary immune response, some of the B cells produced remain dormant as memory cells.
If the same antigen is encountered again, these memory cells produce IgG. The memory
B cells and the memory T cells constitute a secondary immune response.
15. Distinguish between active and passive immunity.
Active immunity results when a person produces an immune response to an antigen; it is
long-lasting. Passive immunity occurs when a person receives antibodies produced by
another individual. Passive immunity is short-term.
16. How are allergic reactions and immune reactions similar yet different?
An allergic reaction is an exaggerated immune response to a nonharmful antigen. In all
allergic reactions, the individual is presensitized to a particular antigen. Immune reactions
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and allergic reactions both involve activated Ig. Some allergic reactions can affect almost
anyone (just like how a virus, bacterium, fungus, or protozoan can affect almost anyone),
but others happen only to people with an inherited tendency toward and exaggerated
immune response.
17. How does a tissue rejection reaction involve an immune response?
The recipient of a tissue donation may recognize the donor’s tissue cell surfaces as
foreign and attempt to destroy the transplanted tissue. Tissue rejection resembles the
cellular immune response against a foreign antigen. The greater the antigenic difference
between the cell surface molecules (MHC antigens) of the recipient tissues and the
donor tissues, the more rapid and severe the rejection reaction.
18. How is autoimmunity an abnormal functioning of the immune response?
If the immune system becomes unable to distinguish a particular self antigen from a
nonself antigen, it can produce antibodies and cytotoxic T cells that attack and damage
the body’s own tissues and organs.
Use the Practices 14.7
Analyzing Data Explain how a vaccine is able to initiate an immune response,
thereby providing protection against a specific pathogen (use Figure 14.17 to
help formulate your explanation).
The immune system, specifically the primary immune response, works to eliminate the
pathogen and their levels rapidly increase following an encounter with the agent,
whether a pathogen or a vaccine. For several weeks or even years, the immune system
will provide some protection against reinfection of the same pathogen. Upon reinfection
of the pathogen, the immune system produces a secondary immune response in which
higher levels of antibodies are present in the blood stream. This is often why some
vaccines require at least two doses to be effective.
Figure Questions
Figure 14.17, page 533: Which immune response produces antibodies to a specific
antigen more rapidly, primary or secondary?
secondary immune response
Assess
Career Corner: Public Health Nurse
Consider This: Public health nurses are often called upon to educate
communities on public health risks, such as mosquito-borne illnesses. Imagine
you are a public health nurse giving a presentation to your community on
lowering their risk of contracting mosquito-borne diseases. Use your book
and internet resources to identify three strategies to share with your
audience.
There are several ways to protect against mosquito-borne illnesses. Examples
include wearing long –sleeved shirts and pants, applying bug sprays, and avoiding
areas with large mosquito populations (like heavily wooded areas or areas with
stagnant water).
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iseases, Diagnosis and Treatment: Immunity Breakdown:
D
HIV/AIDS
1.Explain the function of helper T cells in the body and how HIV interrupts this
function.
T cells recognize foreign antigens and stimulate B cells to produce antibodies. HIV adheres
to two receptors on the host cell surface, called CD4 and CCR5, and then infects the cell.
The virus undergoes replication inside the cell and then burst from the cell, killing it.
2. Why is it challenging to develop a vaccine against HIV?
Because of the great variability of HIV and the difficulty of testing the vaccine. A live vaccine
is too dangerous; and a killed vaccine does not generate a sufficient immune response.
Genetic Engineering: Persisting Fetal Cells and Autoimmunity
1. Describe the symptoms and potential cause of scleroderma.
Fatigue, swollen joints, stiff fingers, and hardening of the blood vessels and lung tissue. It
may be causes by fetal cells that persist in within a woman’s body after giving birth.
2. Explain the causes of autoimmune responses.
There are multiple potential causes of an autoimmune response. One reason might be
that viruses disguise themselves using proteins from a host cell. When the immune
system learns to attack the virus with this protein, it may also attack host cells that
display the protein. Another possibility is that T cells do not learn to distinguish self and
nonself cells. Thirdly, nonself antigens may resemble self antigens.
Case Study Connection
page 513: Peanut allergies are due to peanut glycoproteins. Would you expect
to find these molecules in lacteals?
No, lacteals specialize in fat absorption.
page 523: Peanut allergies trigger inflammation. How does this help us understand
the patient’s symptom of a swollen, flushed face?
Answers will vary somewhat, but students should identify that inflammation produces
localized responses of swelling and increased bloodflow.
page 526: Do you think an antigen-presenting cell was involved in this reaction?
Accept all student answers that demonstrate solid reasoning.
page 531: We know that an allergic reaction, like the one described in the case
study, involves antibodies that trigger inflammation. Before this inflammatory
reaction there was an initial exposure. What types of cells were involved in that
initial exposure?
mast cells and basophils
page 531: To test if our patient is indeed having an allergic reaction, we can test
her blood for antibodies. What kind of antibody are we likely to find?
IgE
page 535: Our patient began to notice swelling about five minutes after eating
the cookies. What type of hypersensitivity reaction was she likely having?
Type I
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. The lymphatic system is most closely associated with which
other organ system?
a. reproductive system
b. cardiovascular system
c. skeletal system
d. respiratory system
2. What connects lymph nodes to lymphatic trunks?
a. lymphatic capillaries
b. systemic capillaries
c. lymphatic vessels
d. collecting ducts
3. From where does tissue fluid originate?
a. tissues
b. small intestines
c. open wounds
d. blood plasma
4. If you’re feeling sick, why might a doctor feel your neck?
a. to see if your lymph nodes are swollen
b. to check your tonsils
c. to check your blood pressure
d. all of the above
5. Species resistance
a. is reliant on herd immunity.
b. is only found in Homo sapiens.
c. occurs because a species doesn’t have the right
environment for a pathogen.
d. is the reason why dogs can get mumps.
6. Which is not an innate defense?
a. mechanical barrier
b. antigen
c. chemical barrier
d. Natural Killer cell
7. What is an example of a second line of defense?
a. the lining in your nose
b. your external pH
c. your blood’s pH
d. cellular immune response
8. Which antibody is incorrectly matched with their function?
a. IgM - associated with allergic reactions
b. IgG - effective against bacteria, viruses, and toxins in
plasma and tissue fluids
c. IgA - found in exocrine secretions, including breast milk
d. IgD - important in B cell activation, and is on the surfaces
of most B cells
9. Which practical classification of immunity is correctly
matched with its example?
a. artificially acquired active immunity – vaccination
b. naturally acquired active immunity – injection of gamma
globulins
c. naturally acquired passive immunity – exposure to live
pathogens
d. artificially acquired passive immunity – a breast-fed newborn
Short Answer
1. Describe the functions of the lymphatic system.
The lymphatic system helps maintain plasma volume by
returning excess fluid to the blood stream. It also responsible
for giving us immunity to foreign invaders.
2. Explain the role of the spleen.
The spleen serves as a storehouse for lymphocytes and as a
filter for the blood.
3. What is complement?
The complement system is a group of plasma proteins. Part of
the immune system, it enhances, or “complements,” the action
of antibodies and phagocytes. Activation of the complement
system also stimulates the inflammation process.
4. Explain the role of a fever in the immune response.
A fever is a rise in body temperature. Increased body
temperature makes white blood cells become more active
makes the spleen and liver hold on to iron that is needed for
bacterial and fungal growth. Therefore, it is harder for
pathogens to grow.
5. What are Natural Killer (NK) cells?
Natural Killer (NK) cells are lymphocytes that help with
adaptive (specific) defense mechanisms. They are instrumental
in defending against viruses and cancer cells.
6. Describe species resistance.
Species resistance means that some species such as humans,
dogs, or cats will be resistant to certain infectious diseases
while others won’t be. This is based on receptors and body
temperature and chemistry. For example, humans contract
measles, mumps, and gonorrhea but dogs and cats do not.
7. Distinguish between B cells and T cells.
B cells and T cells are both lymphocytes, they help provide
immunity. Most of the lymphocytes in blood are T cells. T cells
often interact directly with the antigens or the pathogen
carrying the antigen. B cells respond to pathogens by producing
antibodies.
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8. What are the five major types of immunoglobulins?
IgG, IgA, IgM, IgD, and IgE
9. Distinguish between Immunoglobulin D (IgD) and
Immunoglobulin E (IgE).
IgD is found on the surface of most B cells. It helps activate B
cells. IgE is found on basophils and is associated with allergic
reactions.
10. What is autoimmunity?
Autoimmunity is when the immune system, mostly antibodies,
mistakenly recognize its own tissues as being foreign. An example
is the attack on the tissues in joints in rheumatoid arthritis.
11. What is an allergy?
An allergy, also known as type I hypersensitivity, is an
exaggerated immune response to an ordinarily non-harmful
antigen. This includes activation of IgE and basophils.
12. What is the relation between cardiovascular and lymphatic
capillaries?
All cardiovascular capillary networks have associated
lymphatic capillaries lying next to them. This enables the
lymphatic capillaries to pick the excess interstitial fluid that
leaves the cardiovascular capillaries.
13. Describe the structure of a lymph node.
Lymph nodes are usually small oval shaped structures. They
have afferent vessels bring lymph into them on one side. The
efferent vessels through which lymph exits are on the other
side of the node. Blood vessels enter on the efferent side. The
inner part of the node is called the medulla. The outer spaces
are called sinuses.
14. What is found in lymph?
Lymph is a fluid that is very similar in composition to plasma.
With the major exception that the large plasma proteins are
not found in lymph.
15. Distinguish between the right lymphatic duct and the
thoracic duct.
They are both lymphatic vessels that deliver fluid directly to
the cardiovascular system. The right lymphatic duct returns
fluid into the right subclavian vein. The thoracic duct returns
fluid to the left subclavian vein. From here the lymph flows into
the superior vena cava and then to the right atrium.
Critical Thinking and Clinical Applications
1. CLINICAL Connection An infant gets a dose of oral polio
vaccine. It is a weakened preparation of the virus. What type
of immunity will the infant develop?
The infant will develop active immunity by producing
antibodies to the antigens on the polio virus.
2. You and your friend encounter a rattlesnake in the woods.
Your friend was full of bravado and decided to try to catch it.
Unfortunately, she was not fast enough and got bitten and
injected with the snake’s venom. The emergency room
physician gave her the antivenin CroFab containing antibodies
to the snakes venom. Was this active or passive immunity?
Does your friend now have immunity to rattlesnake bites?
This is an example of passive immunity. The antibodies were
not made in her body, they were preformed and injected. Your
friend will produce their own antibodies which will have a
longer lasting effect. They will not, however, last forever, so
your friend is not immune to rattlesnake bites.
3. A one-year-old baby developed several bacterial infections in
the course of only a few months. Antibiotics were successfully
used to treat them. When she was infected with common viral
infection she recovered easily. Explain this.
The bacterial infections involve extracellular antigens. Resistance
is accomplished through antibody-mediated immunity, which
appears to not be functioning properly. Resistance to the viral
infections is accomplished through cell-mediated immunity,
which appears to be functioning properly.
4. WRITING Connection Explain: why does vaccination
provide long-lasting protection against a disease, while
gamma globulin (IgG) provides only short-term protection?
Vaccination (vaccines) contains antigens that stimulate the body
to produce antibodies for protection against a particular
pathogen in the future. Thus, it provides active immunity. Gamma
globulin contains antibodies not produced by the lymphocytes of
the individual receiving the injection. Thus, no immunological
memory is established as in the case of active immunity.
Lab Data Analysis: Monitoring Cancer with the Sentinel Node
1. How does the SLN Negative line differ from the SLN Positive
line?
The SLN Negative line has a much slower decline over time,
with a 90% survival rate after 120 months. The SLN Positive
line, however, has a much more rapid drop, with only a 40%
survival rate after 120 months.
2. What do these data suggest about the ability of a positive
sentinel node biopsy to predict disease progression?
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The data in this graph are strongly suggestive that a positive
sentinel node biopsy predicts a worsening disease progression.
3. What would this graph look like if the y-axis showed mortality
rate rather than survival rate?
Close to the opposite of the current graph. SLN Negative
would show low mortality, and SLN positive would show high
mortality.
UNIT
Absorption and
Excretion
Chapter
5
Pacing (class periods)
15 Digestive System and Nutrition
14
16 Respiratory System
11
17 Urinary System
10
18 Water, Electrolyte, and Acid-Base Balance
5
Unit 5 Resources
Unit Project Engineer a Healthier World – Engineering in Anatomy and Physiology
nit Project: Engineer a Healthier World—
U
Engineering in Anatomy and Physiology
Project 5: I Can’t Believe It’s Not a Liver
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Replacing the Liver” (p. 569), and use this to start
their investigation into building replacement organs.
A teacher guide for this project can be found online.
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CHAPTER
15
Digestive System and
Nutrition
Section
15.1 Introduction
Pacing
(class periods)
—
Learning Objectives
1. Describe the general functions of the digestive
system.
2. Name the major organs of the digestive
system.
15.2 General
Characteristics of
the Alimentary
Canal
2
15.3 Mouth
1
1. Describe the structure of the wall of the
alimentary canal.
2. Explain how the contents of the alimentary
canal are mixed and moved
1. Describe the functions of the structures
associated with the mouth.
2. Describe how different types of teeth are
adapted for different functions, and list the
parts of a tooth.
15.4 Salivary Glands
1
1. Locate the salivary glands and describe their
secretions.
2. Identify the function of salivary amylase.
3. Describe how saliva secretion is controlled.
15.5 Pharynx and
Esophagus
1
1. Locate the pharynx and esophagus, and
describe their general functions.
2. Describe the mechanism of swallowing.
15.6 Stomach
2
1. Locate the stomach and explain its functions.
2. Describe the secretions of the stomach.
3. Describe how stomach secretion is regulated.
15.7 Pancreas
2
1. Locate the pancreas and describe its
secretions.
2. Identify the function of each enzyme secreted
by the pancreas.
3. Describe how pancreatic secretions are
regulated.
15.8 Liver and
Gallbladder
1
1. Locate the liver and describe its structure.
2. Explain the various liver functions.
3. Locate the gallbladder and describe the
release of bile.
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15.9 Small Intestine
1
1. Locate the small intestine and describe its
structure.
2. Identify the function of each enzyme secreted
by the small intestine.
3. Describe how small intestinal secretions are
regulated.
4. Explain how the products of digestion are
absorbed in the small intestine.
15.10 Large Intestine
1
1. Locate the large intestine and describe its
structure.
2. Identify the functions of the large intestine.
3. Describe the mechanism of defecation.
15.11 Nutrition and
Nutrients
2
1. List the major dietary sources of carbohydrates,
lipids, and proteins.
2. Describe how cells use carbohydrates, lipids,
and proteins.
3. Identify the functions of each fat-soluble and
water-soluble vitamin.
4. Identify the functions of each major mineral
and trace element.
5. Describe an adequate diet.
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (10)
Chapter Resources
Extended Summary Review
Chapter 15 Test Bank
Chapter 15 Interactive Question Bank
Vocabulary Flashcards
APR Module 12: Digestive System
Laboratory Exercise 31: Digestive Organs
Laboratory Exercise 32: Action of a Digestive Enzyme
A Suggested Approach
The overall structure and function of the digestive system is the focus of this
chapter. This chapter can lead to uncomfortable discussions, and provides an
opportunity to consider what ground rules need to be in place when discussing
potentially embarrassing topics. Remind students being able to help people feel
comfortable in a skill they need to develop.
The length of the digestive track can be demonstrated by using a piece of string or
yarn. The sections of the digestive tract can be marked using a piece of tape.
Additionally, peristalsis can be modeled using a stocking open on both ends and a
tennis ball. By squeezing just above the tennis ball, you can demonstrate how long it
takes for a food bolus to move through the digestive tract.
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In addition to the digestive tract, students are introduced to the organs of digestion.
The endocrine functions of the pancreas were discussed in Chapter 11, but this
provides an opportunity to revisit type 2 diabetes, and how the foods consumed
affect blood sugar and insulin levels.
Students access their prior knowledge of biochemistry (covered in Chapter 2) to
study nutrition. They can apply it to how the body uses different types of nutrients,
and therefore deepen their understanding of the physical requirements needed for
survival. Students can apply their knowledge of nutrition to interpreting nutrition
labels on food, and decide if knowing the nutrition of a food choice would lead to
making different choices about what is consumed.
This chapter is expected to take 14 class periods including Lab 31, and Lab 32.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy used
to teach students how to construct explanations and craft scientific arguments.
A scientific claim answers a question or offers a solution to a problem. Give
students time to reflect and brainstorm, then have each student take a clear
stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is information
that supports or contradicts a claim. This information can come from a variety of
sources, such as research, experimentation, or data interpretation. It is important
to have multiple pieces of evidence to support a claim. Encourage students to
return to their claims and add evidence at multiple points in the chapter.
Students are generally fascinated with the current research on the microbiome.
This article really nicely summarizes a lot of information about the field:
https://www.nytimes.com/2013/05/19/magazine/say-hello-to-the-100-trillionbacteria-that-make-up-your-microbiome.html
Introduction to the Theme
Theme: Energy and Matter The digestive system has a job of breaking down
food into small enough particles that it can then be absorbed and use create energy
in the form of ATP.
Theme Activity: The Digestion Obstacle Course
For this activity, students will make the classroom into a physical obstacle course
that will illustrate the process of digestion.
First, create a physical list with the students: what are the major parts of the
digestion system? You can refer to the Chapter sections 15.3-15.10 as a list of the
major parts.
Next, allow students to move desks, chairs, books, etc around to make up each
“obstacle” or part. You may also want to bring in different things like boxes, masking
tape, yarn, etc. to aid in the design of each obstacle. Encourage the students to
think about what each part does. For example, for the mouth, there are teeth – so
perhaps you can flip a chair upside down and the chair legs would represent teeth.
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After the course is complete, you can make this a timed event if you like: the students
can become food particles and go through the obstacle course. You may need to go
to a larger space for this activity.
However, if space is limiting, you can just focus on the design of the obstacle course
and build this activity by having students to design a course on paper.
Section 15.1: Introduction
Learn
Classroom Activities
Section 15.1 sets the groundwork for activities in sections 15.2 and beyond.
Additional Discussion Questions
Provide students with an unlabeled diagram of the human body and ask them to
label the major organs of the digestive system.
The diagram should include the salivary glands, tongue, mouth, pharynx, teeth, esophagus,
liver, stomach, pancreas, gall bladder, small intestine, large intestine, rectum, and anus.
By using an anatomical model, ask students to trace the flow of bile.
Responses should include a discussion with emphasis on the liver, gall bladder, and all
associated ducts. Comment on the adverse effects of a blockage in this flow.
Provide students with a variety of microscopic slides of several different organs
found in the digestive system. Ask them to draw what they see and comment on
these observations.
Observations should include a discussion comparing cell shape, size, distribution, and function.
Distinguish between the cephalic phase and the gastric phase of digestion.
Responses should include a discussion of the cephalic phase, in which the stomach secretes
two digestive juices, hydrochloric acid and pepsin, that help break down food. The gastric
phase of digestion stimulates the release of another secretion, gastrin, which initiates the
secretion of gastric juices.
Practice
Practice Questions
1. What are the general functions of the digestive system?
Digestion is the mechanical and chemical breakdown of foods and the absorption of the
resulting nutrients by cells. The organs of the digestive system carry out these functions.
2. Which organs constitute the digestive system?
The digestive system consists of the alimentary canal and its components the mouth,
pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus. Accessory
organs of the digestive system are the salivary glands, liver, gallbladder, and pancreas.
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Use the Practices 15.1
Communicating Information Create a graphic organizer to review the four
major types of molecules your body requires and how these molecules are
metabolized (return to Chapters 2 and 4 to refresh your memory).
Answers will vary. Accept those organizers that differentiate correctly between lipids,
proteins, nucleotides, and carbohydrates.
Section 15.2: General Characteristics
of the Alimentary Canal
Learn
Classroom Activities
Visual Literacy: Clay Mold
Discuss the general structure of and movement within the alimentary canal with
students. Put students into pairs and provide each pair of students with four
different colors of portioned clay. Each pair must use their clay to complete each
of the tasks below. After each task is complete, they will raise their hand and find
another pair with their hands raised. They will switch and check each other’s work
for completion and accuracy. After they provide feedback to the other pair, they
return to their own station and continue with the next task.
Task 1: Use three colors of clay to create a model of the large intestine, small
intestine, and tongue to duodenum.
Task 2: Use all four colors of clay to create a model of the wall of the alimentary
canal. Each color of clay should represent one of the four layers. The thickness of
the clay layers and the order should represent the alimentary canal wall accurately.
Task 3: Create a drawing of your group’s model of the alimentary canal and label
each layer and the main function of each layer.
Differentiated Instruction
Instead of clay, students could model Task 1 with a rope or string. For Task 2,
students could use different foods such as bread or slices of ham to represent
and create the different layers. Students could raise their hands and have the
teacher check their work instead of switching with another team of students.
Rather than providing clay, you could allow students to bring in their own
items to make the models of the alimentary canal and wall. They could share
with the group what supplies they used and why they best represent each part.
Additional Discussion Questions
Ask students to develop a table that summarizes the composition and function of
each of the four major layers of the alimentary canal wall.
The table should contain information regarding the mucous membrane, submucosa, muscular
layer, and serosa.
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Discuss cancer of the esophagus.
Cancer of the esophagus is most commonly a squamous cell carcinoma. It appears to be more
common in men and is difficult to treat. This form of cancer affects the middle to distal sections
of the esophagus. Prognosis is poor, the patient typically succumbs to esophageal cancer
within three years.
Discuss how peristalsis would not change if someone was standing on their head or
in outer space.
Peristalsis is a gravity independent process.
Practice
Practice Questions
1. Describe the wall of the alimentary canal.
The wall of the alimentary consists of four distinct layers: mucosa, submucosa,
muscularis, and serosa. The mucosa is the surface epithelium, connective tissue and
smooth muscle of the innermost layer. Glands in the mucosa secrete mucus and
digestive enzymes. The submucosa contains considerable loose connective tissue,
glands, blood vessels, lymphatic vessels, and nerves. The muscularis layer is two layers
of smooth muscle, an inner circular layer and an outer longitudinal layer. The muscularis
layer provides for movement of materials through the alimentary canal. The outermost
layer is the serosa. Cells of the serosa secrete mucus to lubricate the outer surface of
the alimentary canal, allowing for the organs of the abdominal cavity to slide easily over
one another.
2. Name the two basic types of movements in the alimentary canal.
There are two basic movements in alimentary canal: mixing movements and propelling
movements.
Use the Practices 15.2
Using Mathematics Calculate the speed at which a piece of food travels
through each of the three portions of the alimentary canal. Use Figure 15.2 for
the lengths of each portion and assume food clears the esophagus and
stomach in 4 hours, the small intestine in another 5 hours, and the large
intestine 24 hours after that.
See Figure 15.2 as a sample.
Esophagus to stomach is 0.5m: 0.5m/ 4hr = 0.5m/240m = 0.5m/14400s = 0.0003m/s
Stomach to small intestine is 6m (approx.): 6 m/5 hr = 6m/18000s = 0.0003 m/s
Large intestine is 1.5 m: 1.5m/24hr = 1.5m/86400s = 0.00002 m/s
Figure Questions
Figure 15.2, p. 548: What is the distance from the tongue to the duodenum in English
units (inches)?
19.7 inches (based on the measurements in the figure)
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Section 15.3: Mouth
Learn
Classroom Activities
EL Strategy: Activate Prior Knowledge
Advanced/ Advanced High After students complete the chart, have them
work in small groups to compare answers and add each other’s information to
their own charts.
Have students use the information on the KWL chart to give a short oral
presentation about the passage.
Subject (The Mouth)
K- What I Already Know
From experience
From previewing
Eating
Functions and parts of the mouth
Ingesting nutrition
Breathing
W – What I Want to Learn
How does the mouth begin the digestive process?
What is the importance of the tongue and teeth?
What are some issues of the mouth?
L-What I Learned
The parts of the tooth
The tongue is attached to the hyoid bone and the tonsils
The mouth is used to start the digestive process by taking in food and breaking it down.
What I Want to Know More About
Are there ways to better protect the teeth
and mouth?
How I Will Learn More
Talk to my dentist
Read articles
Ask an expert
Visual Literacy: Dental Drawing
Provide students a small mirror, or have them use the front-facing camera on
their smartphones. Provide students with Figure 15.8 without the labels. Each
student will use the mirror and highlight the teeth on the diagram that they have
in their own mouth. Discuss with students that many people are missing
individual teeth, or have had some removed. Each student’s teeth will be
different. After students have completed identifying their own teeth, they
should label the figure with the types of teeth in each area. After everyone has
completed their figure, discuss the following questions as a class: Why is it
important to brush our teeth? What are some preventative treatments or methods
to protect your teeth besides brushing them daily?
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Differentiated Instruction
Instead of students examining their own teeth, have students work in small
groups to brainstorm and write out ways protect their own teeth and good
habits in caring for your teeth. Invite a local dentist to come speak to the class
about mouth, gum, teeth care and possibly provide students with health
samples such as toothbrushes or toothpastes. The dentists could discuss
different places to get dental care in the area and provide information to
students and their guardians.
Additional Discussion Questions
Provide students with an unlabeled diagram of a human tooth and ask them to label it.
The diagram should include the crown, root, enamel, pulp, nerves, blood vessels, and
periodontal ligament.
Practice
Practice Questions
1. How does the tongue function as part of the digestive system?
The tongue mixes food particles with saliva during chewing and moves food toward the
pharynx during swallowing. The tongue also helps position food for chewing. Rough
projections called papillae on the tongue surface provide friction, which helps move food.
2. Where are the tonsils located?
The tonsils are on the posterior wall of the pharynx, above the border of the soft palate.
3. How do primary teeth differ from secondary teeth?
The primary teeth usually erupt through the gums at regular intervals between the ages
of six months and two to four years, with 10 in each jaw, totaling 20. After their roots are
resorbed, the secondary teeth push the primary teeth out of their sockets. The secondary
teeth usually begin to erupt at six years of age and may not be complete until age 25.
Secondary teeth total to 32, 16 in each jaw.
4. Describe the structure of a tooth.
Each tooth contains two main parts: the crown and the root. The crown projects above
the gum and the root is anchored in the jaw. The crown and root meet at the neck of the
tooth. The crown is covered in enamel. Beneath the enamel is dentin, which surrounds
the tooth’s central pulp cavity. The pulp cavity contains blood vessels and nerves that
reach the pulp cavity via root canals. The root is enclosed by cementum and cementum
is surrounded by the periodontal ligament, which helps attach the tooth to the jaw.
5. Explain how a tooth is attached to the bone of the jaw.
Teeth are connected to the jaw by the periodontal ligament, made of collagen fibers that
pass between the cementum and bone.
Use the Practices 15.3
Using Models Develop a model that demonstrates how the shapes of the
teeth aid in mechanical digestion.
Answers will vary. Accept all models that demonstrate good reasoning.
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Section 15.4: Salivary Glands
Learn
Classroom Activities
Writing Connection: Salivary Glands
Discuss the major salivary glands and their locations with students. Have them feel in
their own jaw line right above their neck for the different glands. Provide students
the a print out of Figure 15.10, with the names of the glands removed. Have students
label the glands and include what each gland secretes and what type of specialized
cells they contain.
Differentiated Instruction
Instead of students labeling the diagram, students could make a table of
information for each of the glands. They could also find images on the internet
of the different glands and add them to the table.
Additional Discussion Questions
Distinguish among the types, numbers, and locations of deciduous and permanent
teeth.
Use an anatomical model to demonstrate these comparisons of incisors, cuspids, bicuspids,
and molars.
Practice
Practice Questions
1. What is the function of saliva?
Salivary glands secrete saliva, which moistens food particles, helps bind them, and
begins the chemical digestion of carbohydrates. Saliva is also a solvent, dissolving foods
so that they can be tasted, as well helping to cleanse the mouth and teeth.
2. What stimulates salivary glands to secrete saliva?
When a person sees, smells, tastes, or even thinks about appealing food,
parasympathetic impulses elicit the secretion of saliva.
3. Where are the major salivary glands located?
There are three major salivary glands: the parotid, submandibular, and sublingual. The
parotid glands are located anterior and somewhat inferior to each ear, between the skin
of the cheek and the masseter muscle. The submandibular glands are located on the
floor of the mouth and on the inside surface of the lower jaw. The sublingual glands are
in the floor of the mouth inferior to the tongue.
Use the Practices 15.4
Conducting Investigations Design an experiment that can test the function of
saliva in breaking down starch molecules.
Answers will vary. Example: Using indicators for starch (iodine) and simple sugars
(Benedict’s test) a sample of starch can be tested, both before mixed with saliva and
after mixed with saliva. In addition, saliva without any starch should be tested as a
control.
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Section 15.5: Pharynx and Esophagus
Learn
Classroom Activities
Writing Connection: Scripting a Video
Put students in small groups. Students will create a slow-motion video that explains
chewing and swallowing. Students should write a script describing the processes of
chewing and swallowing, then shoot their video. Once the video is shot, students
can use a program to add narration. Students will turn in their written narration to
the teacher as well as share their video in a blog or wiki space with the class.
Differentiated Instruction
If computer resources and video equipment are limiting, this activity can be
done soley as a writing activity. Have students write the script for the
narration, and perhaps take turns reading their scripts to the other groups.
Use any omissions or differences between scripts as an opportunity to
revisit topics.
Additional Discussion Questions
Ask students to create a set of index cards, each of which summarizes one major
step in the process of swallowing. Shuffle the cards and have students rearrange
them in the correct sequence.
The index cards should include the following key steps: soft palate raises, hyoid bone and
larynx are elevated, oral cavity sealed from pharynx, pharynx pulled upward toward the food,
esophagus opens, peristalsis forces food into the esophagus.
What causes thrush?
Thrush is also known as oral candidiasis, which is caused by Candida albicans. It is a fungal
infection that has clinical significance, particularly in AIDS patients.
Practice
Practice Questions
1. Describe the regions of the pharynx.
The pharynx has three parts: the nasopharynx, the oropharynx, and the laryngopharynx.
The nasopharynx communicates with the nasal cavity and provides a passageway for air
when breathing. The oropharynx is posterior to the soft palate and inferior to the
nasopharynx. It is a passageway for food moving downward from the mouth and for air
moving to and from the nasal cavity. The laryngopharynx is posterior to the larynx and
inferior to the oropharynx and is a passageway to the esophagus.
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2. List the major events of the swallowing.
The swallowing reflex includes the following: the soft palate rises, preventing food from
entering the nasal cavity. The hyoid bone and larynx are elevated, and the epiglottis
closes off the top of the larynx so that food is less likely to enter the trachea. The tongue
is pressed against the soft palate, sealing off the oral cavity from the nasopharynx. The
longitudinal muscles in the pharyngeal wall contract, pulling the pharynx upward toward
the food. Muscles in the laryngopharynx relax, opening the esophagus. Peristaltic waves
force food into the esophagus.
3. What is the function of the esophagus?
The esophagus is a food passageway from the pharynx to the stomach.
Use the Practices 15.5
Constructing Explanations Explain why if one were to swallow while upsidedown the food still moves towards one’s stomach.
The esophagus is a long collapsible tube which “contracts” only in one direction pushing
food along towards the stomach using peristalsis. Peristalsis is a coordinated wave of
muscle contraction and relaxation that moves in one direction.
Section 15.6: Stomach
Learn
Classroom Activities
Writing Connection: Gastric Specialist Interview
Divide the class in half. Half the students will be playing the role of a gastric specialist,
and the other half will be medical students studying the stomach. The gastric
specialist group will work together in small groups to review the following topics:
•
•
•
•
•
•
Parts and linings of the stomach
Gastric secretions
Gastric glands
Hiatal hernia and ulcers
Regulation of gastric secretions
The process of vomiting
Meanwhile, the students playing the medical students should come up with questions
related to the above topics. Once the students have finished doing their research
and preparation, they will pair off with a student from the other group to conduct
the interview. Students should discuss their answers to each question and note if
there were any discrepancies and ask the teacher.
Differentiated Instruction
Instead of students conducting the interviews with another student, have all
students in class create a list of interview questions with a partner over the
same categories. They will also practice answering their list of interview
questions. Students will then find an adult or another significant person in their
life to participate in the interview with them. Since they are the expert, they
person they choose will ask the questions. The student can then answer the
questions and teach the person they chose all about the stomach.
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Practice
Practice Questions
1. What are the secretions of the chief cells and parietal cells?
Chief cells secrete the digestive enzyme pepsinogen, which is later converted to pepsin in
the presence of stomach acid. Parietal cells secrete hydrochloric acid and intrinsic factor.
Chief cells and parietal cells both contribute to the secretions comprising gastric juice.
2. Which is the most important digestive enzyme in gastric juice?
Pepsin, produced from inactive pepsinogen, by the chief cells is the most important
digestive enzyme in gastric juice.
3. Why doesn’t the stomach digest itself?
Gastric glands called mucous neck cells release alkaline secretions that coat the
stomach’s inner surface and neutralize the stomach acid.
4. What controls gastric juice secretion?
When a person tastes, smells, or even sees appetizing food, or when food enters the
stomach, parasympathetic impulses on the vagus nerves (CN X) stimulate the release
of acetylcholine. Acetylcholine stimulates gastric glands to secrete gastric juice.
Parasympathetic impulses also stimulate stomach cells to release gastrin, which further
increases the activity of the gastric glands to secrete gastric juice. As food moves into
the small intestine, the stomach acid triggers sympathetic impulses that inhibit gastric
juice secretion.
5. What is the function of cholecystokinin?
Cholecystokinin is released from the small intestine in response to the presence of
proteins and fats inside the small intestine. Cholecystokinin decreases gastric motility
and also signals the gallbladder to contract and release bile into the small intestine to
aid in digestion.
6. Which substances can the stomach absorb?
The stomach can absorb small amounts of water, certain salts and lipid-soluble drugs,
and alcohol.
7. How is chyme produced?
Chyme is a semifluid paste of food particles and gastric juice that is produced from the
mixing movements of the stomach walls.
8. What factors influence how quickly chyme leaves the stomach?
The rate at which the stomach empties depends on the fluidity of the chyme and type of
food present. Liquids usually pass through rapidly, while solids remain until they are
well-mixed with gastric juice. Foods high in protein move through the stomach quickly,
while foods high in fat remain in the stomach longer. Carbohydrates pass through the
stomach more quickly than both proteins and fats.
9. What is the result of the vomiting center's montor response?
The results include deep breathing, raising the soft palate (thereby closing the nasal
cavity) closing the glottis, relaxing the lower esophageal sphincter, onctracting the
diaphragm, and contracting the abdominal wall muscles.
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Use the Practices 15.6
Arguing from Evidence Present evidence to support the idea that the stomach
is involved in either mechanical digestion, chemical digestion, or both.
Answers will vary. Students should point out that the stomach is involved in chemical
digestion through gastric secretions, but also mechanical digestion through mixing of chyme.
Section 15.7: Pancreas
Learn
Classroom Activities
Writing Connection: Pancreatic Juice
This is an individual activity where students will make their own set of study cards
about the enzymes in pancreatic juice. The teacher will provide students with
notecards to create their study cards. Encourage students to put any information on
the cards that will help them to remember the name of an enzyme and its function.
Students should include the following enzymes: pancreatic amylase, pancreatic lipase,
nucleases, trypsin, chymotrypsin, carboxypeptidase.
Differentiated Instruction
Instead of focusing on the types of enzymes, students could create a short
narrative story to share how, why, and when the pancreas releases the
pancreatic juice. Students should create a flow chart of events that occur to
pair with their short narrative.
Practice
Practice Questions
1. List the enzymes in pancreatic juice.
Trypsin, chymotrypsin, and carboxypeptidase are enzymes in pancreatic juice that digest
proteins.
2. What are the functions of the enzymes in pancreatic juice?
The enzymes in pancreatic juice aid in the digestion of proteins.
3. What regulates secretion of pancreatic juice?
The nervous and endocrine systems regulate release of pancreatic juice. Parasympathetic
impulses stimulate the pancreas to release pancreatic juice, as well as the presence of
acidic chyme, proteins, and fats in the small intestine.
Use the Practices 15.7
Asking Questions The pancreas has both endocrine and exocrine functions.
Propose a question to investigate the benefits of having one organ that fulfills
both functions.
Answers will vary. Example: The pancreas serves as two glands in one: an exocrine gland
to aid in digestion and a hormone producing endocrine gland. What would be one
advantage of having both types in one organ? What would be a disadvantage of having
both types in one organ?
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Section 15.8: Liver and Gallbladder
Learn
Classroom Activities
EL Strategy: Sequencing
Beginning To enhance and confirm students’ understanding, provide images
that represent the functions of the liver. Give the students terms from section 15.8
and use word walls to post the word next to the matching image. Have
students copy the word into their interactive notebook and draw their own
image to represent the function.
Writing Connection: Functions of the Liver
Put students in pairs, and provide each pair with the general and specific functions
of the liver from table 15.3 on separate, equal-sized strips of paper. Each student will
draw three pieces from the pile. Students will play the game “Go-fish” only using the
functions of the liver. They must find the match of between the general function and
the specific functions. For example, if student 1 is holding “Detoxification” they will
ask student 2 if they have the matching specific function (“Removes toxins from the
blood”). If student 2 does have the match, student 1 gets their card and now has a
match. If student 2 doesn’t have the card, student 1 draws from the pile and their
turn is over. The game continues until all matches have been made correctly.
Differentiated Instruction
Instead of playing this as a review game, students can take turns quizzing each
other on the general and specific functions of the liver. One student can hold a
print out of table 15.3 and read prompts to their partner. The partner will have
to name the general or specific function that partners with the prompt. Switch
roles and repeat the process.
Additional Discussion Questions
Discuss some of the risk factors that predispose a person to gallstones.
Some factors include history of diabetes, liver disease, inflammation of the pancreas, obesity,
diets high in fat and cholesterol, pregnancy, and certain medications.
What is cardiac cirrhosis?
Cardiac cirrhosis is a condition that results from right-sided heart failure that may initiate
congestion in the veins of the liver.
Practice
Practice Questions
1. Locate the liver.
The liver is in the right upper quadrant of the abdominal cavity, just inferior to the
diaphragm. It is partially surrounded by the ribs, and extends from the level of the fifth
intercostal space to the lower margin of the ribs.
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2. Describe a hepatic lobule.
The functional unit of the liver is the hepatic lobule. A lobule consists of many hepatic
cells radiating outward from a central vein. Blood-filled channels called sinusoids separate
platelike groups of these cells from each other. Blood from the digestive tract is carried in
the hepatic portal vein and brings newly absorbed nutrients into the sinusoids to nourish
the hepatic cells. In the inner linings of the sinusoids are Kupffer cells that remove
bacteria or other foreign particles from the blood entering the sinusoids. The lobules also
have many fine bile canaliculi, which carry bile to bile ductules. Bile ductules converge to
form the hepatic ducts, which in turn, merge and form the common hepatic duct.
3. Review liver functions.
Liver cells respond to insulin by polymerizing glucose to glycogen. Liver cells respond to
glucagon by breaking down glycogen into glucose or converting lipids into glucose. The
liver oxidizes fatty acids to produce lipoproteins, phospholipids, and cholesterol. The liver
converts excess carbohydrates into fat. The liver helps form urea, synthesizes blood
clotting proteins, stores glycogen, iron, and vitamins A, D, and B12. The liver helps to
remove alcohol and drugs from the bloodstream. The liver produces bile to aid digestion.
4. Explain how bile forms.
Bile is continuously secreted from hepatic cells and is composed of bile salts, bile
pigments, cholesterol, and electrolytes. The bile pigments are formed from the
breakdown of RBCs.
5. Describe the function of the gallbladder.
The gallbladder stores bile between meals, reabsorbs water to concentrate bile, and
contracts to release bile into the small intestine to aid digestion.
6. How is secretion of bile regulated?
Cholecystokinin, secreted by the intestine in response to the presence of proteins and
fats, stimulates the gallbladder to contract and release bile into the small intestine via
the hepatopancreatic sphincter. When there is no protein or fat in the small intestine, the
hepatopancreatic sphincter remains closed.
7. How do bile salts function in digestion?
Bile salts break fat globules into smaller droplets and make them more soluble in water
in a process call emulsification. Bile salts also enhance absorption of fatty acids,
cholesterol, and the fat-soluble vitamins A, D, E, and K.
Use the Practices 15.8
Analyzing Data The liver functions in the metabolism. Damage and breakdown
of the liver can lead to serious consequences. What signs of liver failure might
be present in a patient’s blood?
Answers will vary. Students should note the build-up of unmetabolized carbohydrates,
proteins, or lipids in the blood would indicate liver failure.
Figure Questions
Figure 15.19, page 569: Which other organ, besides the gallbladder, responds to
cholecystokinin stimulation, and what is the response of that organ to cholecystokinin
stimulation?
The pancreas is stimulated to secrete digestive enzymes.
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Section 15.9: Small Intestine
Learn
Classroom Activities
Writing Connection: Gallery Walk
Put students into small groups. Each group will walk around the room to the
different gallery stations. Each gallery station will contain a major concept about the
small intestine. Each group will be responsible for adding one piece of information
onto the board about the related concept. Once students have completed the
rotation, allow students to roam through the gallery and view the completed boards
and take their own notes.
Station 1: parts of the small intestine
Station 2: secretions of the small intestine
Station 3: digestive enzymes of the small intestine
Station 4: absorption in the small intestine
Station 5: movements of the small intestine
Differentiated Instruction
Instead of a gallery walk, this can be completed as a yearbook signing. The
teacher would provide each student with a packet of five papers with each
paper having one of the five station headings on it. Put students into groups of
five. The teacher will say go and everyone will pass around their small intestine
book on the first page. Each student must write something about that gallery
concept on each of the students’ books. Be sure that students know not to
repeat what someone else already wrote. They need to add new information.
Once the first page is complete and everyone has signed each one, repeat the
process with the other pages. At the end of the activity, each student will have
their own study book with lots of information about each station concept.
Practice
Practice Questions
1. Describe the parts of the small intestine.
The small intestine consists of three parts: the duodenum, the jejunum, and the ileum. The
duodenum lies posterior to the parietal peritoneum and is the most fixed portion of the
small intestine. It follows a C-shaped path passing anterior to the right kidney and upper
three lumbar vertebrae. The remainder of the small intestine (jejunum and ileum) is mobile
and lies free in the peritoneal cavity. The jejunum and ileum are not easily distinguished,
but the jejunum usually has a greater diameter and thicker wall than the ileum, and is
more vascular. The jejunum and ileum are suspended from the posterior abdominal wall
via a double-layered peritoneal membrane known as a mesentery.
2. What is the function of an intestinal villus?
Intestinal villi project into the lumen of the alimentary canal and greatly increase the
surface area of the intestinal lining, aiding in absorption of digestive products.
3. What is the function of the intestinal glands?
Intestinal glands secrete mucus and watery fluid to bring the digestive products to the
intestinal villi for absorption and digestion. The glands do not help in digestion themselves.
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4. List the intestinal digestive enzymes.
peptidase, sucrase, maltase, lactase, enterokinase, and intestinal lipase
5.Which substances resulting from digestion of carbohydrate, protein, and fat
molecules does the small intestine absorb?
Digestion of carbohydrates results in the absorption of monosaccharides. Digestion of
proteins results in the absorption of amino acids. Digestion of fat results in the
absorption of fatty acids and glycerol.
6. Describe how fatty acids are absorbed and transported.
Some fatty acids are small enough to be absorbed directly without being changed into
triglycerides. Most fatty acids diffuse into the epithelial cells of the intestinal villi, where
the endoplasmic reticuli uses them to resynthesize triglycerides. They are then encased
in protein becoming a chylomicrons. Chylomicrons leave the epithelial cells via lymphatic
vessels, making their way into the blood. Chylomicrons transport dietary triglycerides to
muscle and adipose tissue.
7. Describe the movements of the small intestine.
The major mixing movement of the small intestine is segmentation, in which periodic,
small, ringlike contractions cut chyme into segments and move it back and forth. Weak
peristaltic waves propel chyme short distances through the small intestine. If the small
intestine wall becomes overdistended or irritated, a strong peristaltic rush may pass
along the organ’s entire length, resulting in diarrhea.
8. What is a peristaltic rush?
A peristaltic rush occurs as a result of overdistension or irritation of the intestinal wall,
resulting in peristalsis that passes along the entire length of the small intestine. This
movement sweeps the contents of the small intestine into the large intestine so quickly
that nutrients and water, which would normally be absorbed, are not, resulting in diarrhea.
Use the Practices 15.9
Using Models Create a model that illustrates the relationship between the
structure of the small intestine and its function.
Answers will vary. See Figure 15.21 and Figure 15.24
Section 15.10: Large Intestine
Learn
Classroom Activities
Visual Literacy: Parts of the Large Intestine
This is an individual activity. The teacher will provide students with Figure 15.27
without the labels. Students will label each structure in the diagram as well as
describe its importance in function of the large intestine.
Differentiated Instruction
Instead of focusing on the structure and functions of the large intestine,
students research a disease that affects the large intestine, such as
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inflammatory bowel disease, colorectal cancer, hemorrhoids, or appendicitis.
Students should research how these infections or diseases occur, what part of
the large intestine they affect, and any current treatments or preventative
measures. Students can present their findings to the class.
Demonstration: DIY Digestive System
Bring in household items and have the students create a digestive system as you
discuss the different parts. Here is a list of ideas for inspiration:
Mouth
Fake teeth or coffee grinder
Pharynx
Paper towel roll
Esophagus
Finger trap/finger puzzle
Liver
A large sponge
Gallbladder
A plastic lime juice container
Pancreas
A plastic lemon juice container
Stomach
A whoopee cushion
Large intestine
A scarf
Small intestine
Yarn
Rectum
Turkey baster top
Anus
A hair elastic or rubber band
Practice
Practice Questions
1. What is the general function of the large intestine?
The large intestine absorbs water and electrolytes from chyme remaining in the
alimentary canal, as well as forms and stores feces.
2. Describe the parts of the large intestine.
The cecum, at the beginning of the large intestine, is a dilated, pouchlike structure
that hangs slightly below the ileocecal opening. The colon is divided into four parts:
ascending, transverse, descending, and sigmoid. The ascending colon begins at the
cecum and continues upward against the posterior abdominal wall to a point just
inferior to the liver. There, it turns sharply left and becomes the transverse colon. The
transverse colon is the longest and most movable part of the large intestine. It is
suspended by a fold of peritoneum and sags in the middle below the stomach. The
transverse colon turns downward and becomes the descending colon as it
approaches the spleen. The descending colon travels inferiorly to the brim of the
pelvis, where it makes an S-shaped curve called the sigmoid colon. The sigmoid colon
then becomes the rectum, which lies next to the sacrum. The rectum becomes the
anal canal about 5 cm below the tip of the coccyx. The anal canal is the last 2.5-4 cm
of the large intestine and is folded into six-to-eight longitudinal anal columns.
3.How does the structure of the large intestine differ from that of the small
intestine?
Mucus is the large intestine’s only significant secretion, while the small intestine secretes
digestive enzymes as well as mucus. The large intestine is colonized by bacteria normally,
whereas the presence of bacteria in the small intestine is pathological.
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4. Which substances does the large intestine absorb?
The large intestine absorbs water and electrolytes as well as the vitamins synthesized by
colonic bacteria (K, B12, thiamine (B1), riboflavin (B2)).
5.How does peristalsis in the large intestine differ from peristalsis in the small
intestine?
Peristaltic waves of the large intestine happen only two or three times per day and are
slower than the waves of the small intestine. These waves produce mass movements in
which a large section of the intestinal wall constricts vigorously, forcing the intestinal
contents toward the rectum.
6. List the major events of defecation.
As the rectum fills, its wall distends, triggering the defecation reflex. The internal anal
sphincter relaxes, the glottis closes, the diaphragm lowers, and the abdominal muscles
contract. This increases internal abdominal pressure and squeeze the rectum. The
external anal sphincter is signaled to relax, and feces are forced to the outside.
7. Describe the composition of feces.
Feces include materials not digested or absorbed, plus water, electrolytes, mucus, shed
intestinal cells, and bacteria. Feces are about 75% water and their color derives from bile
pigments altered by bacterial action.
Use the Practices 15.10
Constructing Explanations A great diversity and abundance of microorganisms
live in the human large intestine and normally perform a variety of functions.
Explain how microorganisms, under abnormal conditions, contribute to diarrhea
or constipation.
The main role of the large intestine is to absorb water that is left in the chyme and
produce feces. When a pathogen is located in the digestive tract, the body works to get
rid of it in a hurry.
Figure Questions
Figure 15.30, page 580: Note the many goblet cells in the mucosa of the large intestine.
Why are there so many more of these cells in the large intestinal wall than in the small
intestinal wall?
The major secretion from these cells in the large intestinal wall is mucus to protect against the
abrasiveness of material flowing through the tube. The large intestine needs more lubrication
because its contents are less liquid than those of the small intestine.
Section 15.11: Nutrition and Nutrients
Learn
Classroom Activities
Writing Connection: Food Tasting
In this activity, students will get to make or bring in any food of their choice. The
teacher should be cognizant of any food allergies. The food should represent
something special such as a favorite food to eat, something that represents the
student’s culture, or a food that has significance in an event in time. Students will
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pick a nutrient that is abundant in their food. They will create a short presentation
about their chosen nutrient and how the body uses it. The teacher may choose to
assign nutrients to the students depending on their food so that there is a variety of
nutrients being represented. After all students have presented, the class can have a
short picnic and try the different foods.
Differentiated Instruction
Instead of bringing different foods into the class for students to eat, students
can research the history of their favorite food as well as include the nutrient
portion of this activity. By researching the history of their favorite food, they
will learn about the cultural origins of their favorite food. This should be
included in the presentation with the nutrient information. Hold a class
discussion at the end of the presentations.
Group Activity: Digestion – The Board Game
After you have discussed the digestive system, ask students to brainstorm what the
digestive system would look like if it were a board game. Would the game be
unidirectional? Would you get points for creating ATP? Put some ideas on the
board, and then break students into groups to create their own board game that
explains the digestive process. You can then have students exchange their games
and see if others are able to play it successfully.
Additional Discussion Questions
Have students keep a log on the food intake for a three-day period. Record the
amounts of carbohydrates, lipids, and proteins ingested.
Apply the students’ results to the MyPlate guild lines and recommended requirements.
Prepare a set of index cards, each of which features a fat-soluble or water-soluble
vitamin on one side, and the characteristics, functions, sources, conditions associated
with excesses, and conditions associated with deficiencies on the reverse side.
The students will have a set of thirteen index cards when finished that they may use for future
reference.
Ask students to create a chart that compares the major and trace minerals found in
the human body, based on distribution, function, sources, and RDA for adults.
The chart should include information on calcium, phosphorus, potassium, sulfur, sodium,
chlorine, magnesium, iron, manganese, copper, iodine, cobalt, zinc, fluorine, selenium, and
chromium, at a minimum.
Ask students to collect labels from a variety of food products they frequently use at
home. Discuss and analyze the contents revealed from label information.
Discuss the labels in terms of calories, fat content, sugar content, and determine the nutritious
value of each product.
Compare the chemical structures and characteristics of a selection of vitamins and
minerals.
Vitamins are carbon-containing compounds that tend to be larger, more complex molecules.
Minerals are inorganic compounds that tend to be physiologically active in the ionized state.
Illustrations that compare structures would be beneficial, as would ball-and-stick models.
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In what ways may a student reduce his/her intake of sodium?
Responses may include gradually reducing salt intake, carefully reading food labels, reducing
snacks, adding reduced quantities of sodium when cooking, carefully ordering food in a restaurant,
limiting the use of processed cheese, and eliminating the salt shaker at the dinner table.
Analyze the health claims that advertisers claim about their food products.
Students may collect information from radio and television advertising, magazines, or newspapers.
Assess whether these claims are supported by the Food and Drug Administration.
Practice
Practice Questions
1. Identify and distinguish between macronutrients and micronutrients.
Carbohydrates, lipids, and proteins are macronutrients because they are required in
large amounts. They provide energy as well as other specific functions. Vitamins and
minerals are micronutrients and are required in much smaller amounts. They do not
directly provide energy but make possible biochemical reactions that extract energy
from macronutrient molecules.
2. How is food energy measured?
Macronutrients provided potential energy that can be expressed in calories, which are
units of heat. A calorie is the amount of heat required to raise the temperature of a gram
of water by one degree Celsius. The calorie used to measure food energy is 1,000 times
greater, a kilocalorie, but nutritional studies commonly refer to it as calorie.
3. List several common sources of carbohydrates.
Carbohydrates are ingested in a variety of forms: starch from grains and vegetables;
glycogen from meats; disaccharides from milk sugar, cane sugar, beet sugar, and molasses;
monosaccharides from honey and fruits.
4. Explain the importance of cellulose in the diet.
Humans cannot digest cellulose, so the portion of it that is not broken down by the
bacteria in the large intestine provides bulk against which the muscular wall of the
digestive system can push, easing the movement of intestinal contents.
5. Explain why the requirement for glucose has priority over protein synthesis.
Cells of the nervous system require a continuous supply of glucose for survival. Even a
temporary decrease in the glucose supply may seriously impair nervous system function.
6. Why do daily requirements for carbohydrates vary from person to person?
Carbohydrates provide the primary fuel source for cellular processes, so the need for
carbohydrates varies with individual energy expenditure; physically active individuals
require more fuel than those who are sedentary.
7. Which fatty acids are essential nutrients?
Linoleic and linolenic acids are both essential fatty acids and must be obtained from the diet.
8. What is the liver’s role in the use of lipids?
The liver regulates circulating lipids by using free fatty acids to synthesize triglycerides,
phospholipids, and lipoproteins that may then be released into the bloodstream. The liver
controls the total amount of cholesterol in the body by synthesizing cholesterol and releasing
it into the blood, or by removing cholesterol from the blood and excreting it into the bile.
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9. What are the functions of cholesterol?
Cholesterol provides structural material for cell and organelle membranes and it
furnishes starting material for the synthesis of certain sex hormones and adrenal cortex
hormones. Cholesterol is also a component of bile.
10. Which foods are rich sources of proteins?
Foods rich in protein include meats, seafood, poultry, cheese, nuts, milk, eggs, and
cereals.
11. Why are some amino acids called essential?
Amino acids that the body cannot synthesize and must be obtained from the diet are
called essential.
12. Distinguish between complete and incomplete proteins.
Complete proteins have adequate amounts of all the essential amino acids, while
incomplete proteins lack one or more of the essential amino acids.
13. List some proteins synthesized in the body.
The body synthesizes clotting factors, keratin for skin and hair, elastin and collagen of
connective tissue, plasma proteins that regulate water balance, muscle components
actin and myosin, certain hormones, antibodies, etc.
14. How does dietary protein provide energy?
When dietary proteins are digested, the resulting amino acids are absorbed and transported
by the blood to cells which use the amino acids to synthesize proteins. Proteins may also
supply energy after digestion breaks them down into amino acids. The amino acids are
transported to the liver, where they undergo deamination to form urea.
15. What are vitamins?
Vitamins are organic compounds required in small amounts for normal metabolism that
cells cannot synthesize in adequate amounts.
16. How are vitamins classified?
Vitamins are classified on the basis of solubility. Some are soluble in fats (A, D, E, and K)
and others are soluble in water (B & C vitamins; B12 is only partially water-soluble).
17. How do bile salts affect the absorption of fat-soluble vitamins?
Bile salts in the intestine promote absorption of fat-soluble vitamins.
18. List the fat-soluble and water-soluble vitamins.
The fat-soluble vitamins are A, D, E, and K. The water-soluble vitamins are the B and
C vitamins. Vitamin B12 is partially water-soluble.
19. What are minerals?
Minerals are inorganic elements essential in human metabolism obtained from the diet.
20. What are the major functions of minerals?
Minerals are incorporated into organic molecules, inorganic compounds, or are free ions.
Minerals are parts of the structural materials of all body cells. They also constitute
portions of enzyme molecules, contribute to the osmotic pressure of body fluids, and play
vital roles in impulse conduction in neurons, muscle fiber contraction, blood coagulation,
and maintenance of the pH of body fluids.
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21. Distinguish between a major mineral and a trace element.
Major minerals account for nearly 75% by weight of the mineral elements in the body.
Trace elements are found in minute amounts, making up <0.005% of adult body weight.
22. Name the major minerals and trace elements.
The major minerals are: calcium, phosphorus, potassium, sulfur, sodium, chlorine, and
magnesium. The trace elements are: manganese, copper, iodine, cobalt, zinc, fluorine,
selenium, and chromium.
23. What is an adequate diet?
An adequate diet provides sufficient energy (calories), essential fatty acids, essential
amino acids, vitamins, and minerals to support optimal growth and to maintain and
repair body tissues. Individual requirements for nutrients vary greatly with age, sex,
growth rate, physical activity, and level of stress, as well as with genetic and
environmental factors.
24. Which factors influence individual nutrient requirements?
Individual nutrient requirements vary greatly with age, sex, growth rate, physical activity,
and level of stress, as well as with genetic and environmental factors.
25. What causes malnutrition?
Malnutrition results from a lack of essential nutrients or an inability to utilize them.
Deficiency may stem from lack of availability or the poor quality of food. On the other hand,
malnutrition may result from overeating or from taking too many vitamin supplements.
Use the Practices 15.11
Using Mathematics Calculate your BMI (use Figure 15.34).
Answers will vary by student.
Assess
Career Corner: Registered Dietician
Consider This: Imagine you are the RD in the above scenario. The patient is
worried about type 2 diabetes. He has adjusted his diet to eat fewer sweets
and fruit, and most of his dinners include pasta. Using your book and the
internet, what feedback would you give him regarding his new diet?
It is important congratulate the patient for changing his eating habits, which is a difficult
undertaking. Unfortunately for the patient, eating pasta dishes frequently has the same
end-result as sweet-eating. Pastas (and anything made from grains) are carbohydrates,
or complexes of sugar that are broken down to simpler sugars (glucose, fructose,
maltose, etc.) through digestion. The sugar from a pasta dish and the sugar from a cake
are no different, as far as the body is concerned: the cake is already simple sugar and
the pasta will become simple sugar. For these reasons, people who are diabetics or who
are at-risk of becoming diabetic should limit their carbohydrate intake.
Healthy Lifestyle Choices: Dental Caries
1. How are bacteria involved in tooth decay?
The bacteria feed on the sugar left behind by sticky sweet foods. The bacteria
metabolize the carbohydrates and produce acid as a by-product. This acid degrades the
enamel and can cause damage further below if intervention is not pursued.
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2. Besides acid-producing bacteria, what other factors can degrade tooth enamel?
Enamel is not replaced by the body, so abrasive action or injury and age reduce enamel.
Diseases, Diagnosis, and Treatment: Hiatal Hernia and Ulcers
1. Describe the proposed causes of gastric ulcers.
Contrary to decades of believe that they were caused by stress, researchers now know
that ulcers are caused by the bacterium Helicobacter pylori.
2. Why is it important for gastric juices to be acidic?
Pepsin, the most important enzyme in gastric juice, is most active in an acidic environment.
ealthy Lifestyle Choices: Appendicitis, Hemorrhoids,
H
and Colorectal Cancer
1. Why does appendicitis require surgery?
because the appendix can rupture and cause infection in the abdominal cavity
2. Does the appendix have a digestive function? Is it part of another organ system?
The appendix does not have a digestive function. It does, however, contain lymphatic
tissue and is part of the lymphatic system and immune response.
Healthy Lifestyle Choices: Eating Extremes: Overeating and
Undereating
1.Both anorexia and bulimia involve disordered eating. What features define
each disease?
Anorexia nervosa is self-imposed starvation, where the sufferer drastically reduces their
caloric intake. In bulimia, the sufferer cycles through binge-purge states, where they
consume a large amount of calories and then purge them through vomiting.
2. What is the body mass index (BMI)? How is it calculated?
The body mass index is one metric to determining if people are over, under, or at a healthy
weight. To calculate BMI, a person’s weight in kilograms is divided by their height in meters.
Case Study Connection
page 546: The bacteria of the microbiome aid in digestion. What type of
digestion do they perform: mechanical or chemical?
chemical
page 550: In the patient with severe diarrhea, is peristalsis occurring faster or
slower than someone without diarrhea symptoms?
Faster, hence the rapid and unusual production of feces.
page 553: Do you think there is an oral microbiome? Why or why not?
Accept all answers that show good reasoning.
page 563: The gastrointestinal tract is open to the outside at the mouth and
anus. The pancreas is a digestive organ but it is not part of the digestive tract.
Do you think the pancreas has a microbiome? Why or why not?
Students should note that the pancreas has no access to the outside and thus no way to
develop a microbial colony. Accept variations on this answer which show good reasoning.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which is not part of the alimentary canal?
a. gallbladder
b. bladder
c. liver
d. pancreas
2. The teeth that are best adapted for grasping and tearing
food are the
a. incisors.
b. canines.
c. premolars.
d. molars.
3. What does salivary amylase break down?
a. saliva
b. proteins
c. fats
d. carbohydrates
4. How would removing 95% of the stomach (subtotal
gastrectomy) affect digestion and absorption?
a. Protein wouldn’t break down as well.
b. The person would have to take vitamin B12 supplements.
c. Fats wouldn’t break down as well.
d. The amount of food the person would able to consume
would be limited.
5. Chronic alcohol abuse does the most damage to which
organ?
a. liver
b. large intestine
c. pancreas
d. small intestine
6. Which is part of the small intestine?
a. duodenum
b. rectum
c. colon
d. cecum
7. Which muscle, organ, or action is correctly matched to its
type of control?
a. first stage of swallowing – involuntary control
b. esophagus – voluntary control
c. stomach emptying – voluntary control
d. internal anal sphincter muscle – involuntary control
8. Which vitamin is incorrectly matched with its function?
a. Vitamin B6 – protein and amino acid synthesis
b. Vitamin C – collagen production
c. Vitamin A – calcium absorption
d. Vitamin E – cell membrane stability
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9. Which mineral is correctly matched with its function?
a. potassium – impulse conduction in neurons
b. sulfur – helps break down ATP to ADP
c. copper – structure of bones and teeth
d. iodine – part of hemoglobin
Short Answer
1. Define digestion.
Digestion is the mechanical and chemical break down of food
into usable nutrients. The usable nutrients are what can be
absorbed into the bloodstream.
2. Distinguish the alimentary canal from the accessory organs.
The digestive “system” is comprised of the digestive tract
(alimentary canal) and accessory organs. The alimentary canal
is where the food stays. It includes: mouth, pharynx,
esophagus, stomach, small intestines, and large intestines. The
accessory organs produce enzymes and other chemicals that
aid in digestion and include: salivary glands, pancreas, liver,
and gall bladder.
3. What is the function of saliva?
Saliva contains mostly water for keeping the mouth moist. It
also contains enzymes that serve to kill bacteria and the
enzyme amylase to begin the chemical break down of starch.
4. Describe the structure of a tooth.
The part of a tooth above the gum line that is seen is the
crown, with an outer layer of enamel and an inner layer of
dentin. The root is below the gum line where the dentin
continues. In the middle of the dentin is the pulp cavity and
root canal where blood vessels and nerves are found. A tooth
is held in place in the jaw by the periodontal ligament.
5. What are the four layers in the alimentary canal?
The inner most layer is the mucosa and is made epithelium
and an underlying connective tissue. Beneath that is the
submucosa made of loose connective tissue, and glands and
contains blood vessels and lymphatic vessels. Beneath that
is the muscularis, layer of smooth muscle that generates the
forces of peristalsis and segmentation. The outer most layer
is the serosa, is comprised of epithelial and connective
tissue.
6. Distinguish between parietal cells and chief cells.
They are both found in gastric glands. Parietal cells are
instrumental in forming hydrochloric acid (HCl). Chief cells
produce the inactive enzyme pepsin. The HCl converts
pepsinogen into the active enzyme pepsin.
7. How and where is hydrochloric acid produced?
The parietal cells secrete H ions and Cl ions not the
stomach. There they unite to from HCl.
+
-
8. Distinguish between peristalsis and segmentation.
Peristalsis is the smooth muscle contraction in the digestive
tract that propels the contents forward. Segmentation is the
smooth muscle contraction that mixes and churns the food
with the digestive juices.
9. Describe the “double” supply of blood that the liver receives.
The liver needs a constant supply of oxygen just as any organ.
It receives this through the hepatic artery. It also receives
blood through the hepatic portal vein, which brings newly
absorbed nutrients from the digestive tract to be filtered and
detoxified.
10. What are the functions of the liver?
The liver has various functions: production bile for the
digestion of fats, storage of glycogen, detoxification and
filtering of blood, production of plasma proteins, and lipid
metabolism.
11. Distinguish between gastrin and secretin.
Gastrin stimulates gastric glands to secrete their products.
Secretin stimulates the pancreas to secrete juice with a high
bicarbonate concentration.
12. Distinguish between pancreatic lipase and bile.
Pancreatic lipase breaks triglycerides into individual fatty
acids. Bile breaks fat globules into smaller droplets. This is
called emulsification. It increases surface area for the action
of lipase.
13. What are chylomicrons?
Chylomicrons are reassembled triglycerides surrounded in
protein coat. They are absorbed in the lymphatic system.
14. Describe the structure and function of the large intestine.
The large intestine is called “large” because it has bigger
diameter than the small intestine. But at only 1.5 meters long, it
is much shorter. The first part of the large intestine, the cecum,
is where the small intestine ends. The appendix is a small
narrow tube extending from the cecum. The rest of the large
intestine is referred ads the colon. It has four parts: ascending
colon, transverse colon, descending colon, and the sigmoid
colon. The large intestine function to form feces for elimination
and it also is involved in water reabsorption.
15. What is meant by essential and non-essential amino acids?
Essential amino acids are those that you need in your diet.
Your body cannot produce them. Non-essential amino acids
are those that your body can produce so you do not need
them in your diet.
Critical Thinking and Clinical Applications
1. It is common to have a bowel movement shortly after a meal,
especially after breakfast. Explain why this is.
After a meal, the gastrocolic reflex is initiated in the small
intestine which triggers mass movements in the large intestine.
Peristalsis in the large intestine occurs usually two to three
times daily.
2. CLINICAL Connection If you were diagnosed with
acid-reflux, a medication that slowed the production of acid
could be prescribed. What digestive process might be
adversely affected by this? Why?
The digestion of proteins might be affected because it is
dependent HCl to convert pepsinogen into pepsin.
3. Some fad diets are heavy in meats and fats, but low in
carbohydrates to facilitate weight loss. What might be some
of drawbacks from such a diet?
Increasing cholesterol and fats in your diet can have long term
adverse effects such as cardiovascular diseases.
4. WRITING Connection Examine the label information on
the packages of a variety of breakfast cereals. Which types
of cereals provide the best sources of carbohydrates, lipids,
proteins, vitamins, and minerals? Which major nutrients are
lacking in these cereals?
answers will vary
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Lab Data Analysis: The Formation of Gallstones
1. What is the likelihood of a 60-year-old patient of normal
weight developing a gallstone?
~10%. This can be seen by following the green trend line along
the x-axis to age 60, and then following that point to the
percent likelihood along the y-axis.
2. Are overweight or underweight individuals at greater risk for
gallstone development?
Overweight. The overweight group, represented by the blue
line, has a higher percent chance of developing gallstones
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in every age group when compared to the underweight
group (red line).
3. Why might researchers limit their study to vegetarians?
A likely explanation is to remove an additional variable from
the study. Namely, the consumption of meat and whether or
not it increases the risk for gallstone development. In this way,
the researchers can be more confident in the conclusions they
draw about the effects of age and BMI on gallstone disease.
CHAPTER
16
Respiratory System
Section
Pacing
(class periods)
16.1 Introduction
—
16.2 Organs and
Structures of the
Respiratory System
2
16.3 Mechanics of
Breathing
2
16.4 Control of Breathing
16.5 Alveolar Gas
Exchanges
16.6 Gas Transport
Learning Objectives
1. Identify the general functions of the
respiratory system.
1. Locate the organs and associated structures
of the respiratory system.
2. Describe the functions of each organ of the
respiratory system.
1. Explain the mechanisms of inspiration and
expiration.
2. Define each of the respiratory volumes and
capacities.
1. Locate the respiratory areas in the brainstem
and explain how they control breathing.
3
2. Discuss how various factors affect the
respiratory areas.
1. Describe the structure and function of the
respiratory membrane.
2
2. Explain how air and blood exchange gases.
1. List the ways blood transports oxygen and
carbon dioxide.
2
Focus Activity Workbook
Focus Activities: Labeling (9)
Focus Activities: Vocabulary (5)
Chapter Resources
Extended Summary Review
Chapter 16 Test Bank
Chapter 16 Interactive Question Bank
Vocabulary Flashcards
APR Module 11: Respiratory System
Laboratory Exercise 29: Breathing and Respiratory Volume
Laboratory Exercise 30: Control of Breathing
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A Suggested Approach
Students can begin to learn about the physiology of the respiratory system by
experimenting with their breathing using party favors. Prior to class, obtain one
party blow horn for each student. Instruct students to create as much noise as
possible using the party favors. Then have the students perform some sort of simple
exercise for approximately five minutes to elevate their heart rate and breathing
rate. Instruct students to blow again in their party favors. Guide a discussion on
what changes they experienced during this activity.
To study the mechanism of breathing, students can build a simple model of a lung
demonstrating how the contraction of the diaphragm brings air into and out of the
lungs. If students have already had a chemistry course, they may be familiar with the
Boyle’s gas law which helps explain the functionality of our lungs. If students have
not had chemistry, they are still familiar with the concept of diffusion (covered in
Chapter 3). Diffusion and pressure are also used to explain gas exchange.
To demonstrate the control of breathing, students can participate in activities to
demonstrate breath control. For example, ask students to hold their breath for a
short time. Or ask students who are in choir or drama to describe how they use
the diaphragm to control their voice and to demonstrate their ability. Or ask all
students to sit quietly and take deep breaths. Guide a discussion in how they are
able to alter their breathing pattern, and the physiology of the factors that affect
breathing. Additionally, respiratory distress can be caused by an infection,
respiratory disorders, or trauma and can inhibit normal breathing patterns.
Students can simulate the constriction of their airways by breathing through
straws of different diameters.
This chapter is expected to take 11 class periods including Lab 29 and Lab 30.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy used
to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is information
that supports or contradicts a claim. This information can come from a variety of
sources, such as research, experimentation, or data interpretation. It is important
to have multiple pieces of evidence to support a claim. Encourage students to
return to their claims and add evidence at multiple points in the chapter.
This article provides some of the earliest and most widely-accepted evidence
that vaping can be harmful to your health. https://www.sciencedaily.com/releases/
2017/09/170910232512.htm
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Introduction to the Theme
Theme: Cause and Effect The human body is composed of trillion of cells that
need oxygen in order to function. Humans breathing in oxygen and releasing
carbon dioxide will effect each cell by ensuring it functions at optimum level.
Theme Activity: What Affects Breathing?
This activity has students determine what factors affect breathing.
For this activity, you may use the chart below or have students come up with a list of
factors.
Factor
Effect
Fear
Moderate exercise
Asthma
Prolonged breath-holding
Cystic fibrosis
Emphysema
Heavy exercise
Sleep or relaxing
Section 16.1: Introduction
Learn
Classroom Activities
Section 16.1 sets the groundwork for activities in sections 16.2 and beyond.
Additional Discussion Questions
Apply concepts learned in this chapter objective to discuss the effects of smoking
on the respiratory system.
The effects of smoking may include disappearance of cilia, accumulation of mucus, initiation of
chronic bronchitis, fatigue, cough, wheezing, development of emphysema, cancer, etc.
Discuss a variety of issues regarding cigarette smoking. Divide the class into two
factions, each supporting opposite views.
Some issues for discussion include governmental legislation that prohibits smoking in public
facilities, lowering the legal age for purchasing cigarettes, or the initiation of sin taxes.
Practice
Practice Questions
1. What is respiration?
The process of gas exchange between the atmosphere and cells is called respiration.
2. In what stage of respiration is oxygen used and carbon dioxide produced?
cellular respiration
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Use the Practices 16.1
Asking Questions Review the Chapter Contents outline on page 600.
Develop a question for each section of the chapter.
Answers will vary. Accept those questions that relate to the chapter contents outline.
Section 16.2: Organs of the
Respiratory System
Learn
Classroom Activities
EL Strategy: Oral Language Development
Intermediate Using figures 16.1 and 16.2 for vocabulary, partners make and use
flashcards to check each other’s pronunciation and understanding of vocabulary.
Writing Connection: Structure and Function
Discuss structures of the upper tract and lower respiratory tracts with students.
Allow students to choose any of the following structures. Students should create
an invention that does the same function as the structure in the respiratory
system. The teacher should provide household and school supplies to students for
this activity. Students should present their invention and how it works. They
should describe how the structure of their invention allows for the similar function
as the respiratory structure. Table 16.1 might help guide students.
Upper respiratory structures include: nose, nasal cavity, paranasal sinuses, pharynx,
and larynx.
Lower respiratory structures include: trachea, bronchial tree, and lungs
Differentiated Instruction
Students may find it difficult to brainstorm and invention that has a similar
structure and function to their respiratory structure. The teacher could allow
students to build a model of a particular respiratory structure and present how
the structure informs the function.
Demonstration: Lung Model
Start by breaking students into small groups. Each group will receive straws, two
balloons, a plastic water bottle with the bottom removed, a rubber glove, tape, and
modeling clay.
Students will build a lung using these materials. The balloons will represent the
lungs and the glove the diaphragm.
Detailed instructions on how to create and use this model can be found through the
Science Teacher’s Association of Ontario.
You may find it helpful to build a model prior to class to show to the students as an
example.
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Additional Discussion Questions
Provide students with an unlabeled diagram of the larynx and ask students to
correctly label it.
The diagram should include the identification of the epiglottic cartilage, hyoid bone, thyroid
cartilage, cricoid cartilage, trachea, corniculate cartilage, and arytenoid cartilage.
Discuss common diseases associated with the lungs.
Students may prepare a short report on asthma, pneumonia, COPD, bronchiogenic carcinoma,
hay fever, the common cold, etc.
Practice
Practice Questions
1. Which organs constitute the respiratory system?
The respiratory system can be divided into upper and lower portions. The upper
respiratory system includes the nose, nasal cavity, paranasal sinuses, pharynx, and larynx.
The lower respiratory system includes the trachea, bronchial tree, and lungs.
2. What are the functions of the mucous membrane that lines the nasal cavity?
The mucous membrane has pseudostratified ciliated epithelium that is rich in mucussecreting goblet cells. The mucus that is secreted entraps dust and other small particles
entering the nasal cavity. The mucus also helps to moisten the air entering the nasal
cavity as water evaporates off of the mucous membrane.
3. Where are the paranasal sinuses?
The paranasal sinuses are air-filled spaces within the frontal, ethmoid, sphenoid, and
maxillary bones of the skull that open into the nasal cavity.
4. What are the functions of the paranasal sinuses?
The paranasal sinuses reduce the weight of the skull and influence the quality of the voice.
5. Describe the structure of the larynx.
The larynx is composed of a framework of muscles and cartilages bound by elastic tissue.
Inside the larynx, two pairs of horizontal vocal folds, composed of muscle tissue and
connective tissue with a covering of mucous membrane, extend inward from the lateral
walls. The upper folds are called false vocal cords because they do not produce sound.
The lower folds have muscle fibers and strong but elastic connective tissue and are the
true vocal cords. The true vocal cords and the opening between them form the glottis.
Air enters the larynx through a flaplike structure called the epiglottis.
6. How do the vocal cords produce sound?
Air forced through the glottis causes the true vocal cords to vibrate, which produces
sound. Contracting or relaxing muscles alter the tension on the vocal cords and control
the pitch. The intensity of the sound reflects the force of air passing through vocal folds.
7. What is the function of the glottis? The epiglottis?
The glottis is a triangular slit made of the true vocal cords and the opening between them.
Air is forced through the glottis to vibrate the vocal cords and produce speech. The
epiglottis is a flaplike structure that allows air to enter the larynx and covers the opening
to the larynx during swallowing to prevent foods and liquids from entering the airways.
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8. What is the function of the cartilaginous rings in the tracheal wall?
The cartilaginous rings prevent the trachea from collapsing and blocking the airway.
The open posterior ends of the rings allow the nearby esophagus to expand as food
moves through it to the stomach.
9. Describe the bronchial tree.
The bronchial tree consists of branched airways leading from the trachea to the microscopic
air sacs in the lungs. Its branches begin with the right and left main bronchi, which arise from
the trachea. A short distance from its origin, each main bronchus divides into lobar bronchi,
which then branch into segmental bronchi, and then to smaller tubes called bronchioles,
categorized as terminal bronchioles and then respiratory bronchioles. Respiratory
bronchioles then branch into alveolar ducts, and the alveolar ducts become alveolar sacs.
Alveolar sacs lead to smaller air sacs called alveoli, where gas exchange occurs.
10. Predict the direction of diffusion of gases between alveoli and alveolar capillaries.
Oxygen diffuses from the alveoli into the blood in nearby capillaries, and carbon dioxide
diffuses from the blood into the alveoli.
11. Where are the lungs located?
The lungs are organs in the thoracic cavity, right and left lungs being separated by the
mediastinum medially and enclosed by the thoracic cage and diaphragm.
12. What is the function of serous fluid in the pleural cavity?
Serous fluid in the pleural cavity lubricates the pleural surfaces, reducing friction as they
move against one another during breathing and helps to hold them together.
13. What types of structures make up a lung?
A lung includes air passages, alveoli, blood vessels, connective tissues, lymphatic vessels,
and nerves.
Use the Practices 16.2
Using Models Create a model to illustrate the movement of air through the
upper and lower respiratory tracts. Be sure to identify the organs and
structures of both tracts.
Answers will vary. Sample: The respiratory tract could be like a town’s streets. A larger
highway, like the trachea, branches into a large street, the bronchi, which then branches
into smaller streets, the bronchioles, and ultimately leads to many houses, the alveoli.
Figure Questions
Figure 16.8, page 610: Why is the pulmonary artery colored blue in this figure?
The pulmonary artery carries oxygen-poor blood.
Section 16.3: Breathing Mechanism
Learn
Classroom Activities
Writing Connection: Storyboarding Breathing
Students can work individually on this activity. The teacher should provide students with
a poster-sized paper evenly split into six blocks, creating a storyboard. Each student
will pick a type of air movement (respiratory or not). In each block of the storyboard,
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the student should draw or write the step by step process for their chosen air
movement. Each storyboard box should also have two bars representing inspiratory
air movement and expiratory air movement. The student will color code the bars
representing the amount of air currently being moved and in which direction. The
complete storyboard cycle will show the action the student picked plus the amount
of air movement in or out at each step. Not all storyboards will use all six boxes.
Differentiated Instruction
Instead of students analyzing the amount of air moving in and out during an
action, students can focus on how the muscles and body works to create the
movement of air. Students could work in pairs and one student create the
storyboard and the other student can describe what muscles are moving to
make the action happen.
Additional Discussion Questions
What causes laryngitis?
Laryngitis is caused by inflammation and swelling of the mucous membrane of the larynx. It
may be caused by a variety of reasons, including infection or inhalation of irritants. Patients
lose their voice because the vocal cords are prohibited from freely vibrating.
Distinguish between ventilation and perfusion.
Ventilation is the amount of air found in the alveoli, whereas, perfusion equates to the amount
of blood in the capillaries of the lungs. A ratio of these two values is used to determine gas
exchange efficiency.
Distinguish between a Type I and Type II epithelial cell.
Type I and Type II epithelial cells comprise the alveoli, or air sacs of the lungs. Type I cells are
involved in the actual exchange of gases, composing the walls of the alveoli. Type II cells produce
surfactant, which aids in smooth inspiration and expiration.
Discuss various factors that influence the amount of carbon dioxide rich air leaving
the lungs.
Responses should include a discussion of the lungs’ propensity for expansion in terms of
capacity and volume, as well as resistance to these changes.
Practice
Practice Questions
1. Describe the events in inspiration.
Impulses conducted on the phrenic nerves stimulate skeletal muscle fibers in the
diaphragm below the lungs to contract. The diaphragm moves downward, the thoracic
cavity enlarges, and the pressure in the alveoli falls below atmospheric pressure. In
response, atmospheric pressure forces air through the airways into the alveoli.
2. How does expansion of the chest wall expand the lungs during inspiration?
When the external intercostal muscles move the thoracic wall upward and outward, and
the diaphragm moves downward, the parietal pleura moves also and the visceral pleura
follows it. These movements help expand the lung in all directions.
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3. Which forces cause normal expiration?
The forces for resting expiration come from the elastic recoil of tissues and from surface
tension.
4. What is tidal volume?
The tidal volume is the volume of air that moves, in then out, during a single respiratory
cycle, normally about 500 mL of air.
5. Distinguish between inspiratory and expiratory reserve volumes.
During forced maximal inspiration, air in addition to the resting tidal volume enters the
lungs. This extra volume is the inspiratory reserve volume, normally about 3 L of air.
During forced maximal expiration, the lungs can expel up to about 1.1 L of air beyond the
resting tidal volume. This volume is called the expiratory reserve volume.
6. How is vital capacity determined?
Combining the inspiratory reserve volume with the tidal volume and the expiratory
reserve volume gives the vital capacity, normally about 4.6 L of air. This is the maximum
volume of air a person can exhale after taking the deepest breath possible.
7. How is total lung capacity calculated?
The vital capacity plus the residual volume equals the total lung capacity, normally
about 5.8 L of air. Total lung capacity varies with age, sex, and body size.
Use the Practices 16.3
Using Mathematics Your friend tracks her vital capacity over a 60-day athletic
training program. On day 1 of the program, her vital capacity was 4800 mL. On
day 60, her vital capacity is 5260 mL. By what percent did your friend’s vital
capacity increase during the training?
5260ml-4800ml = 460ml (difference between day 1 and day 60)
460/4800 = 0.095 = 9.5%
Figure Questions
Figure 16.15, page 616: During inspiration, which direction would the line move in this
figure?
upward—refer to the vertical axis on the left side of the figure
Section 16.4: Control of Breathing
Learn
Classroom Activities
EL Strategy: Practice Linguistic Patterns
Beginning or Intermediate Have students work in small groups. This strategy
allows every student to have an opportunity to speak several times. Give a
prompt (Describe the location of the respiratory areas and name the major
components) and then pass a stick or other object to the student. The student
speaks, everyone listens, and then passes the object to the next person. The
next student speaks, everyone listens then the student passes the object on
until everyone has had one or two turns
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Writing Connection: The Limiting Blood Gas
Discuss with students the gases that control our breathing. Students may express
that running out of oxygen is a main concern, but remind them that carbon
dioxide is a major trigger for the respiratory response. Place students in pairs, and
have them find three ways to reduce respiration rate. Students should describe
how each process occurs. Finally, provide students with the negative feedback
loop from Figure 16.17 that allows a person to continue breathing when ventilation
is decreased. The teacher should remove some of the labels and have students fill
the missing information.
Differentiated Instruction
Instead of having students generate scenarios for decreased ventilation,
provide students with a few role-play options and challenge them to determine
what manner of decreased ventilation occurred.
Example: A swimmer was swimming underwater and randomly passed out.
Thank goodness his coach was monitoring him and was able to pull him out of
the pool. The swimmer said he hasn’t done much different except practicing
holding his breathe longer. What most likely happened to the swimmer that
caused the decrease in ventilation and why?
Additional Discussion Questions
Discuss the sympathetic and parasympathetic effects on the respiratory system.
Stress or emotional excitability stimulates a sympathetic response. Bronchial dilation may
result in rapid, deep breathing. Constriction of the bronchioles is initiated by a
parasympathetic response, as when the body is resting.
Ask students to create a diagram that illustrates how the medullary rhythmicity and
pneumotaxic areas of the respiratory center control breathing.
The diagram should include information regarding the role of nerve impulses, the involvement
of the ventral and dorsal respiratory groups, diaphragm and inspiratory muscles, and a comparison
of forceful versus normal breathing.
Discuss various stages in the development of lung cancer.
Lung cancer usually begins in the epithelial lining of a bronchus. In the early stages of lung
cancer, the basal cells repeatedly undergo mitosis. Eventually, these basal cells displace
columnar and goblet cells. Excess mucus is secreted and cilia become less efficient. Finally, the
basal cells invade the deeper connective tissue.
Compare the reactions involved with oxygen transportation and carbon dioxide
transportation.
Oxygen combines with iron atoms of hemoglobin molecules to form oxyhemoglobin.
Carbon dioxide is transported in three major ways. A small percentage is transported by
being dissolved in plasma. A larger percentage combines with hemoglobin molecules.
The largest percentage reacts with water and is eventually transported in the form of
bicarbonate ion.
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Practice
Practice Questions
1. Where are the respiratory areas?
Groups of neurons in the brainstem form the respiratory areas, which control both
inspiration and expiration. The respiratory centers of the medulla oblongata and the
pons are most important.
2. Describe how the respiratory areas maintain a normal breathing pattern.
The basic rhythm of breathing arises from the ventral respiratory group in the medulla
oblongata, which stimulates the inspiratory muscles. The dorsal respiratory group, also in
the medulla oblongata, processes sensory information regarding the respiratory system
and plays a role in certain cardiopulmonary reflexes that affect respiratory rhythm and
depth, as well as stimulating the inspiratory muscles and diaphragm. Neurons in the pons
form the pontine respiratory group and contribute to the rhythm of breathing by limiting
inspiration, thus affecting both respiratory rate and depth.
3. Explain how the breathing pattern may change.
Breathing patterns may be altered by varying stimuli that influence the rate at which the
ventral and dorsal respiratory centers of the medulla oblongata send impulses to the
inspiratory muscles and diaphragm.
4. Which factors affect breathing?
Factors that affect breathing include body fluid chemistry, lung tissue stretch, emotional
state, and physical activity.
5.What is the relationship of chemoreceptors, carbon dioxide, pH, and
ventillation rate?
Chemosensitive areas in the ventral medulla oblongata sense changes in the carbon
dioxide content of CSF, which reflects the levels of CO2 in the blood. If the levels rise, the
central chemoreceptors signal the respiratory areas to increase breathing rate and
volume. The signals stop when the CO2 in the blood returns to normal levels. Peripheral
chemoreceptors in the aortic arch and carotid bodies sense changes in the levels of
oxygen in the blood and send impulses to the medulla to increase breathing when levels
are low; however, this response is much less sensitive than the central chemoreceptor
response to elevated CO2. Thus, the levels of CO2 in the blood have a much greater
effect on breathing than the levels of O2.
6. Describe the inflation reflex.
The inflation reflex helps regulate the depth of breathing and occurs when stretched
lung tissues stimulate stretch receptors in the visceral pleura, bronchioles, and alveoli.
The sensory impulses of this reflex travel via the vagus nerve (CN X) to the brainstem
respiratory areas and shorten the duration of inspiratory movements, preventing
overinflation of the lungs during forceful breathing.
7. How does hyperventilation decrease the respiratory rate?
Hyperventilation lowers the blood carbon dioxide level below normal. As a result, it takes
longer for carbon dioxide levels to rise to the level that stimulates the respiratory areas
and respiratory rate declines.
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Use the Practices 16.4
Constructing Explanations Describe the relationship between carbon dioxide
levels in the blood and breathing rate.
Carbon dioxide stimulates the breathing rate as well as the depth. If the levels of carbon
dioxide rise in the blood, respiratory areas are stimulated that increase the rate and
depth of breathing.
Section 16.5: Alveolar Gas Exchanges
Learn
Classroom Activities
Group Discussion: Concentration Gradients
Complete the following activity with the whole class. Ask students what happens to
a carbonated drink when it sits out into the open air. Students should respond that the
drink becomes flat. Ask them what “going flat” means. Students should arrive at the
idea that CO2 is leaving the drink and entering the air. Draw a diagram with students
to show the concentration of CO2 in the drink and in the air before the drink is
open, then how it changes once the drink is allowed contact with the air. Ask
students to describe these changes. Have students use this example to create their
own visual showing gas exchange in the alveolus (rather than in a drink). Students
should label the particles and identify where the higher concentration gradient is
for O2 and CO2.
Differentiated Instruction
Instead of students creating their own diagram, the teacher could print out and
have students label the gas exchange and partial pressures on Figure 16.20.
Demonstration: Gas Exchange
Before students arrive to class, take some masking tape strips and create a line on
the floor. Obtain a bag and fill it with foam balls. Paint or label some of the balls as
O2 and others as CO2. Then, place the O2 balls along one side of the line and the
CO2 balls on the other.
The idea behind this activity is to illustrate gas exchange of oxygen (O2) and carbon
dioxide (CO2) molecules between the alveolus air and capillary.
Have your students walk along the line with the bag of foam balls. Ask them to move
the O2 and CO2 molecules from the side of higher concentrations to the lower
concentrations. After they have established an “equilibrium” of molecules, you can
ask the students to determine which direction CO2 and O2 diffuses.
You may choose to expand this activity by obtaining a small tub and labelling it
hemoglobin. Ask students how many O2 molecules can fit or “bind” to this tub and
where it will go next.
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Practice
Practice Questions
1. Describe the structure of the respiratory membrane.
The wall of an alveolus is primarily simple squamous epithelium, along with surfactantproducing cells. In close association with an alveolus is a dense capillary network, also
made of simple squamous epithelium. The fused basement membranes of these epithelial
layers join the alveolar and capillary walls. Two thicknesses of epithelial cells and layer of
fused basement membrane separate the air in an alveolus from the blood in a capillary.
2. What is the partial pressure of a gas?
In a mixture of gases such as air, each gas accounts for a portion of the total pressure
the mixture produces. The amount of pressure each gas contributes is called the partial
pressure of that gas and is proportional to its concentration.
3. Which force moves oxygen and carbon dioxide across the respiratory membrane?
Oxygen and carbon dioxide are moved across the respiratory membrane by diffusion.
Since both oxygen and carbon dioxide are dissolved (oxygen in the air and carbon
dioxide in the blood), they move across the respiratory membrane in accordance with
their partial pressures, moving from areas of high partial pressure to areas of low partial
pressure. For oxygen, that is from the air into the blood and for carbon dioxide that is
from the blood into the alveoli.
Use the Practices 16.5
Arguing from Evidence Explain how fluid accumulation in the lungs may
reduce gas exchange in the lungs.
Fluid in the lungs reduces the available surface area for gas exchange.
Section 16.6: Gas Transport
Learn
Classroom Activities
Writing Connection: Mixed-Up Columns
Students will play this game in pairs. The teacher should provide students with a few
blank notecards and one large sheet of paper with three columns on it. The three
columns should be labeled “Gas”, “Reaction Involved”, and “Substance Transported”
just as in Table 16.3. Students will create a notecard with each entry in each row on
Table 16.3. Once student have made all their notecards, they will play the game
below with the cards.
Example Game: Students place all the notecards face down in a pile. The first
student draws a card. The student must place the card under the correct column
header of the large sheet of paper. For example, if the student draws “oxyhemoglobin”
that would go under the “Substance Transported” column. The student then must
identify what gas and reaction is involved when oxyhemoglobin is transported. The
card is removed, and the next student draws from the pile repeating the game.
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Differentiated Instruction
A different more challenging version of the game is for one student to place
one card in each column on the sheet from the game above. The other student
must then evaluate if those cards are in the correct column or not and if they
are the correct gas-reaction-substance transported combination. This game
requires students to not just know basic knowledge but to be able to analyze
and evaluate information.
Practice
Practice Questions
1. How is oxygen transported from the lungs to cells?
Almost all (98%) of the oxygen that blood transports is bound to hemoglobin. The
remaining 1–2% of oxygen inhaled in the air is dissolved in the plasma, but this oxygen is
not able to be used by cells since it is not bound to hemoglobin.
2. What stimulates blood to release oxygen to tissues?
Oxygen is released from the hemoglobin in RBCs due to the increased partial pressure
of oxygen in the RBCs (PO2 = 95 mm Hg) compared to the partial pressure of oxygen in
the tissues (PO2 = 40 mm Hg). Other factors that influence the release of oxygen to
tissues include levels of CO2, acidity, and temperature.
3.Describe three forms in which blood can transport carbon dioxide cells to the
lungs.
Blood transports carbon dioxide to the lungs as carbon dioxide dissolved in plasma, by
its binding to hemoglobin, or as bicarbonate ions.
4. How can hemoglobin carry oxygen and carbon dioxide at the same time?
Oxygen binds to the iron atoms (the heme portion) in hemoglobin and carbon dioxide
binds to the amino groups in hemoglobin (the globin chains). Oxygen and carbon dioxide
do not compete for binding sites, and both can be transported at the same time.
5. How is carbon dioxide released from blood into the lungs?
Carbon dioxide binds with hemoglobin to form carbaminohemoglobin. Carbaminohemoglobin
decomposes at the low PCO2 near alveoli, releasing its carbon dioxide, which leaves the
RBC, crosses the respiratory membrane and enters the alveoli by diffusion.
Use the Practices 16.6
Communicating Information Create an infographic depicting how oxygen
and carbon dioxide are transported into and out of cells.
Answers will vary. See figures 16.1 and 16.2 for examples.
Assess
Career Corner: Respiratory Therapist
Consider This: Imagine you are applying for a job as a respiratory therapist at
a local nursing home. Write a cover letter, highlighting your qualifications,
training, and why you’re interested in this particular job.
Answers will vary. Accept those that show students understand the qualifications and
training needed to be a respiratory therapist.
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Genetic Engineering: Cystic Fibrosis
1. Why are individuals with cystic fibrosis more susceptible to lung infections?
The thick mucus houses bacteria that can cause opportunistic infections.
2. Why are individuals with cystic fibrosis at risk for malnutrition?
Mucus can clog the pancreas, preventing the secretion of digestive enzymes, leading to
reduced absorption of nutrients in the small intestine.
iseases, Diagnosis, and Treatment: Emphysema and
D
Lung Cancer
1.Would you expect someone with emphysema to have a greater or lesser vital
capacity than someone without the disease? Why?
Emphysema and all other obstructive diseases are ultimately diseases where the
lungs have problems getting air out. This trapped air causes the vital capacity to be
reduced.
2.Differentiate between primary pulmonary cancers and secondary lung
cancers.
Some cancerous growths in the lungs result secondarily from cancer cells that have
spread (metastasized) from other parts of the body, such as the breasts, intestines, liver,
or kidneys. Cancers that begin in the lungs are called primary pulmonary cancers. These
may arise from epithelia, connective tissue, or blood cells.
Healthy Lifestyle Choices: Exercise and Breathing
1.Describe the receptors and reflexes that result in increased breathing rates
during exercise.
Sensory structures called proprioceptors that are associated with muscles and joints
cause much of the increased breathing rate during vigorous exercise. Muscular
movements stimulate proprioceptors, triggering a joint reflex that sends impulses to the
respiratory center, increasing breathing rate.
2.Advertisements for exercise programs often instruct people to consult a
doctor before beginning an exercise program. Why might this be good
advice?
Exercise puts a strain on the heart and lungs. The heart must work harder to pump
more blood to the tissues and the lungs must be able to adequately oxygenate the
increased blood volume that it receives. In people who have certain heart diseases,
like very severe aortic stenosis or severely damaged hearts from infarction, the
increased work caused by exercise is too much for the heart to handle. In the same
way, if a person has severe lung disease, the lungs may not be able to adequately
oxygenate the blood. For these reasons, a physician consultation before beginning an
exercise regimen is recommended.
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Case Study Connection
page 608: If nasal mucosa is pseudostratified ciliated columnar epithelium and
alveolar mucosa is simple squamous epithelium, which would you think would be
more vulnerable to the ultrafine particles delivered by an e-cigarette?
Simple squamous epithelium is thinner and thus will be more easily penetrated by
particulates.
page 610: Do you anticipate any direct effects from the e-cigarette on the
pleura? Why or why not? What about indirect effects over time?
Student answers will vary, accept those that demonstrate sound reasoning.
page 612: What muscles are involved in inhaling from an e-cigarette? What
muscles are involved in an exhale? If someone coughs in response to inhaling
from an e-cigarette, are different muscles involved?
Muscles involved in inhalation include the external intercostal muscles, pectoralis minors,
and sternocleidomastoids. Exhalation involves the relaxation of the external intercostal
muscles. Coughing requires the internal intercostal muscles, and can also use the external
and internal obliques, transversus abdominis, and rectus abdominis.
page 622: Nicotine is a small, slightly nonpolar molecule. Nickel is a metal found
as an ultra-fine particle in e-cigarette vapor. Now that you understand the anatomy
of the respiratory membrane, can you predict if either of these components will
cross the membrane and enter the bloodstream? What information did you use to
make this prediction?
Student answers will vary but should discuss size and charge. Accept those answers that
demonstrate sound reasoning.
Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which one of the following is the beginning of the lower
respiratory tract?
a. trachea
b. nasal cavity
c. pharynx
d. larynx
2. Which structure is incorrectly matched with their
description?
a. true vocal cords – vibrate to make sound
b. epiglottis – covers the larynx opening
c. larynx – contains the vocal cords
d. visceral pleura – help close the airway during swallowing
3. What force makes it difficult for alveoli to inflate?
a. surfactants
b. surface tension
c. atmospheric pressure
d. expiration
4.
is the volume of air that leaves the lungs during a
normal, resting expiration.
a. Resting tidal volume
b. Expiratory reserve volume
c. Residual volume
d. Inspiratory reserve volume
5. Chemosensitive areas in the medulla oblongata are most
sensitive to levels of
a. nitrogen.
b. oxygen.
c. carbon dioxide.
d. sodium.
6. Hyperventilation is which of the following?
a. any decrease in breathing
b. a decrease in breathing that brings in oxygen too slowly
c. an increase in breathing that removes CO2 too quickly
d. any increase in breathing
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7. Which of the following factors does not increase the release
of oxygen from hemoglobin?
a. an increase in blood temperature
b. an increase in blood acidity
c. an increase in blood nitrogen levels
d. an increase in blood CO2 levels
8. Which of the following is not one of the ways blood
transports carbon dioxide?
a. dissolved in plasma
b. bonded to hemoglobin
c. as bicarbonate ions
d. as platelets
Short Answer
1. Define respiration.
Respiration refers to how an organism makes energy.
2. Distinguish between internal and external respiration.
External respiration includes ventilation, or breathing. This
allows for an exchange of gases between the capillaries in the
lungs and the air. Internal respiration is the transport of these
gases in the blood for exchange between all body cells.
3. Explain the functions of the respiratory system.
The respiratory system serves to exchange gases, aid in the
sense of smell, produces vocal sounds, and regulate blood pH.
4. Starting at the nose, list the structures that air passes
through until it reaches the point of gas exchange.
The flow of air: mouth and nose, pharynx, larynx, trachea,
bronchioles, and finally alveoli where gas exchange occurs.
5. Describe the pressure changes that allow air to move into
and out of the lungs.
For inspiration the diaphragm contracts and causes an
expansion of the lungs and a drop in pressure. The
atmospheric pressure is then slightly higher than the pressure
in the lungs, therefore air moves passively into the lungs. For
expiration the diaphragm relaxes and the lung size decreases,
but the pressure rises above that of the atmosphere. Air then
passively moves out.
6. Define tidal volume, IRV, ERV, and vital capacity.
The larynx is attached to the hyoid bone and lies beneath it. It
is composed mostly of cartilage. The anterior part is made of
the thyroid cartilage (Adams apple) and cricoid cartilage. The
thyroid and cricoid cartilages reach around on the posterior
side where there is also the cartilaginous flap of the epiglottis.
7. What do residual volume and surfactant have in common?
Tidal volume is the amount of air that moves into and back out
of the lungs during a normal resting breath. IRV is the amount
of air you can breathe in above and beyond tidal volume. ERV
is the amount of air you can exhale above and beyond tidal
volume. Vital capacity is the amount of air you breath in and
then back out in one huge breath. Vital capacity is calculated
by adding ERV, IRV, and tidal volume.
8. Describe the respiratory center in the medulla.
Residual volume and surfactant both help to avoid lungs
collapsing. The residual volume ensures that there is always a
volume of air in the lungs. Surfactant ensures that the alveoli
do not collapse.
9. What is the difference between the way oxygen and carbon
dioxide are carried in the blood?
Oxygen is mostly carried on the iron in hemoglobin on the red
blood cells. A very small amount is also in the plasms. Carbon
dioxide is primarily carried as the bicarbonate ion in the
plasma. A small amount is bound to hemoglobin and an even
smaller amount is floating freely in the plasma.
10. Write out the bicarbonate/carbonic acid buffering reaction.
CO2 + H2O ↔ H2CO3 ↔ H+ + HCO311. In the reaction from question 10, in which direction will it be
pushed if pH of the blood becomes a bit too low?
A low pH means it is too acidic with too many free H+ ions.
Therefore, it will be pushed to the left to increase pH by
combining free H+ ions with HCO3-.
12. When ventilation decreases, describe the negative feedback
mechanism that increases ventilation.
When ventilation decrease CO2 levels increase. This causes a
drop in plasma pH. Chemoreceptors in the aortic and carotid
bodies detect this and send sensory input to the respiratory
center in the medulla. At the same time the increased levels of
CO2 in the CSF is detected by the chemoreceptors in the medulla
which also send input the respiratory center in the medulla.
13. What are the non-respiratory air movements?
Non-respiratory movements include coughing, sneezing,
laughing, yawning, and hiccupping.
Critical Thinking and Clinical Applications
1. If you hyperventilate before swimming you can increase the
time underwater. However, you might pass out underwater
and possibly drown. Explain why this is.
Hyperventilating causes a decrease in CO2 levels. Lower CO2
levels result in an increased pH (alkalosis). This is turn causes
vasoconstriction of cerebral arteries and decreased blood flow
to the brain, which can result in fainting.
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2. CLINICAL Connection A runner is taking part in a study to
monitor blood pH. Samples are taken at even intervals while
she runs on a treadmill. Her blood pH increased for a brief
time. Explain the processes that are occurring.
At the start, her breathing rate will increase faster than the
levels of CO2 increases. This will cause a slight elevation in pH.
Eventually CO2 production will catch up and restore pH to
normal.
3. Emphysema is a disease that destroys alveoli in the lungs,
greatly reducing the surface area of the respiratory membrane.
Patients with emphysema are given oxygen therapy, but often
still have the urge to take a deep breaths. Why?
Emphysema causes a decrease in the surface are in the alveoli.
This will have an adverse effect on both O2 and CO2 diffusion.
Therefore, even with oxygen therapy, the build-up of CO2 and
reduced O2 in the blood will stimulate the respiratory center in
the medulla.
4. WRITING Connection It is below 0°F outside, but the
dedicated runner bundles up and hits the road anyway.
“You’re crazy,” shouts a neighbor. “Your lungs will freeze.”
Explain why this well-meaning neighbor is wrong.
One function of the nasal cavity is to warm inspired air. The
mucous membranes of the nasal cavity contain an extensive
network of blood vessels that function to warm the inspired air.
Lab Data Analysis: Smoking in the 20th Century
1. What trends are illustrated among the three cohorts?
The 1959–1965 cohort stays at a relatively stable mortality rate
across age groups. In contrast, the 1982–1988 cohort has slowly
increasing mortality among older populations. The 2000–2010
cohort has an even steeper mortality increase as the
population ages.
2. Why do you think the mortality rates increase with age for
the 1982–1988 and 2000–2010 cohorts?
3. Propose a hypothesis for the increase in female smoker
mortality over the last half-century.
Answers will vary. Example: With increasing awareness of the
negative health effects of smoke, tobacco manufacturers have
altered cigarettes to continue effectively marketing their
product. Among these changes, cigarettes are now more easily
inhaled (due to lowered pH) and are packaged in more porous
material, allowing for the chemicals in cigarettes to more
easily pass into the bloodstream.
The longer an individual smokes, the longer their respiratory
tract is exposed to carcinogens found in cigarettes. Thus, with
increased age comes increased risk of cancer development
and subsequent mortality.
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CHAPTER
17
Urinary System
Section
Pacing
(class periods)
17.1 Introduction
—
17.2 Kidneys
3
Learning Objectives
1. List the general functions of the organs of the
urinary system.
1. Describe the locations and structure of the
kidneys.
2. Provide the functions of the kidneys.
3. Trace the pathway of blood through the major
vessels in a kidney.
17.3 Urine Formation
4. Describe a nephron, and explain the functions
of its major parts.
1. Explain how glomerular filtrate is produced, and
describe its composition.
4
2. Explain the factors that affect the rate of
glomerular filtration and how this rate is
regulated.
3. Discuss the role of tubular reabsorption in urine
formation.
17.4 Urine Elimination
4. Define tubular secretion, and explain its role in
urine formation.
1. Describe the structure of the ureters, urinary
bladder, and urethra.
3
2. Explain the process and control of micturition.
Focus Activity Workbook
Focus Activities: Labeling (7)
Focus Activities: Vocabulary (3)
Chapter Resources
Extended Summary Review
Chapter 17 Test Bank
Chapter 17 Interactive Question Bank
Vocabulary Flashcards
APR Module 13: Urinary System
Laboratory Exercise 33: Urinary Organs
Laboratory Exercise 34: Urinalysis
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A Suggested Approach
The urinary system provides another opportunity for students to understand
homeostasis within the human body as the primary function of the kidney is to
maintain homeostasis by regulating the composition and volume of extracellular
fluid.
Although the dissection of a kidney does not explain the physiology of the nephron,
it does provide a visual.
Students can model the basic processes and structure involved in urine formation
by building a nephron model. If necessary, you may need to review the concepts of
osmosis and diffusion (covered in Chapter 2) to assist students in the construction
of their model. In building the model, students demonstrate the processes of
filtration, reabsorption and secretion.
The urinary system also provides another opportunity to understand how diagnostic
tests can give information about a person’s health condition. As the kidney’s primary
function is to remove waste material, minerals, fluids, and other substances from the
blood for elimination in the urine, the urine can contain hundreds of different waste
products. Many factors) affect what is in urine. Students can conduct a lab analyzing
artificial urine samples.
This chapter is expected to take 10 class periods including Lab 33.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy used
to teach students how to construct explanations and craft scientific arguments.
A scientific claim answers a question or offers a solution to a problem. Give
students time to reflect and brainstorm, then have each student take a clear
stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can
come from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support a
claim. Encourage students to return to their claims and add evidence at multiple
points in the chapter.
This is a great opportunity for students to make connections among different
chapters of the material. Here we can explore the functioning of the urinary
system and its intimate ties to the cardiovascular system. Shiga toxin binds to
endothelial cells and causes destruction of capillaries, leading to bruising and
blood loss. When it damages the glomerular capillaries, blood filtration is
compromised, as in HUS. When it damages intestinal capillaries, dysentery can
result. Here is an open-source review article that may help students: Paton,
James C., and Adrienne W. Paton. 1998. Pathogenesis and diagnosis of
Shiga Toxin-Producing Escherichia coli Infections. Clinical Microbiology
Reviews 11 (1): 450–479.
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Introduction to the Theme
Theme: Energy and Matter The human body needs energy in order to function.
This energy (ATP) is produced with water and electrolytes. This matter is balanced
with the help of the kidneys and urinary system.
Theme Activity: Hydration Journal
Students will do this activity over one week. For this activity, students will keep
a journal. They will monitor what beverages they drink and the color of their
urine. At the end of the week, they should then review their results. Is there a
correlation between urine color and how much they drink? Type of drink?
Quantity of beverage?
Section 17.1: Introduction
Learn
Classroom Activities
Visual Literacy: Food Poisoning or Stomach Bug Venn Diagram
and Frequency Table
For this activity, you will have students create two-way frequency tables. Begin by
discussing the difference between what causes food poisoning versus diseases
that cause nausea and diarrhea, such as Norovirus. Review the dangers that
Escherichia coli 0157:H7 can have on the urinary system.
Next, take a poll to determine the number of students who:
Have experienced food poisoning
Have experienced a disease (such as norovirus)
Have experienced neither food poisoning nor norovirus
Using this data, have students create a Venn diagram and two-way frequency table.
Remind students that there is one more category (have experienced BOTH).
Students can than determine the relative frequency of food poisoning. Have
students come up with a list of factors where this number may be higher.
Additional Discussion Questions
Provide students with unlabeled diagrams of a human kidney and a nephron. Ask
them to label each structure and comment on the function of each.
The diagram of the kidney should include information regarding the medulla, renal artery, renal
pyramid, renal calyx, renal vein, renal pelvis, ureter, and cortex. The nephron should include the
glomerulus, Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted
tubule, and collecting tubule.
Discuss diagnostic tests performed during a routine urinalysis.
Responses should include a discussion of appearance, color, specific gravity, pH, protein,
glucose, ketones, bile, and hemoglobin. Microscopic examination may include screening
for white or red blood cells, epithelial cells, casts, crystals, bacteria, yeast, mucin, and
parasites.
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Practice
Practice Questions
1. Describe the general functions of the organs of the urinary system.
The urinary system consists of a pair of kidneys, which remove substances from the
blood, form urine, and help regulate certain metabolic processes; a pair of tubular
ureters, which transport urine from the kidneys; a saclike urinary bladder, which stores
urine; and a tubular urethra, which conveys urine to the outside of the body.
Use the Practices 17.1
Using Mathematics The average plasma volume is about 3 liters. Every day
about 180 liters of fluid is filtered from the plasma by the kidneys. Plasma is
approximately 55% blood. How many times per day is the body’s blood filtered?
0.55 × 3L = 1.65 L
180 L/1.65 L = 109 times
Section 17.2: Kidneys
Learn
Classroom Activities
EL Strategy: Comprehension Skills
Advanced First, ask questions about lesson content to elicit short answers.
Then have students write a question to ask the class: What does “retroperitoneally
positioned” mean? What is the function of the kidneys?
Group Activity: Game Show
This is a whole class activity that reviews key concepts of the kidneys. Put students
into three groups. Assign each group one of the three topics below:
• Kidney location and structure
• Kidney function
• Nephrons
Each group member will come up with a written/verbal response question related
to their category. The question will be worth five points. Once all groups have their
questions ready, the game can start. Pick two teams to face off against each other
to start; the third group will read their questions.
The first member of the questioning group steps up to the front. The two teams
competing will send one team member to the front (Note: ensure each team
member of the competing teams gets to compete at the front at least one time).
The question reader will read the first written/verbal response question. The first
team member to ring the buzzer or raise their hand gets the first chance to answer.
They will provide their answer. The questioning team will then rate/grade their
response on a scale of 1-5. The score the individual earns counts towards their team
score. The process repeats until all students in the questioning group have read
their question. Switch groups around so that each group gets to ask their questions
as well as compete.
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Differentiated Instruction
Instead of playing the game, the teacher could just have students create their
written responses for the above categories and then rotate through with a
partner practicing answer them. Students should keep score of their points
and practicing grading each other’s responses. Students may be creative on
how they answer by either writing the response, verbally describing it, or
drawing or sketching the information.
Additional Discussion Questions
Provide students with microscopic slides of the renal cortex and ask them to draw
and identify what they observe.
Students should be able to identify the renal tubules, glomerular capsule, and glomerulus.
What are the effects of angiotensin II as it applies to this chapter objective?
Angiotensin II may result in vasoconstriction, increased aldosterone secretion, increased ADH
secretion and increased thirst. Its overall affect is to conserve sodium and water.
Ask students to develop a flowchart depicting the pathway of blood through the
kidney and nephron, beginning with the renal artery and ending with the renal vein.
The flowchart should include the renal artery, interlobar artery, arciform artery, interlobular
artery, afferent arteriole, glomerular capillary, efferent arteriole, vasa recta and peritubular
capillary, interlobular vein, arciform vein, interlobar vein, and renal vein.
Discuss urinary tract infections. Ask students to devise a list of important topics that
they feel should be emphasized to any patient with a suspected UTI.
Topics may include signs and symptoms, risk factors, diagnostic tests, prevention, prognosis,
treatment methodologies, dietary suggestions, etc.
Discuss ways in which fluid reabsorption from the renal tubule is enhanced.
Fluid reabsorption may be enhanced because the wall of the peritubular capillary is more
permeable than that of other capillaries and peritubular capillary blood is under low pressure.
Discuss acute glomerulonephritis.
The glomeruli become very permeable which may lead to hematuria, albuminuria, and casts.
Oliguria may occur. The patient often experiences chills and fever, weakness, and edema.
The cause of the acute form is commonly a previous streptococcal infection. The prognosis is
generally good.
Practice
Practice Questions
1. Explain the general functions of the kidney.
The primary function of the kidneys is to help maintain homeostasis by regulating the
composition (including pH) and the volume of the extracellular fluid. The kidneys also
secrete erythropoietin to control RBC production, activate vitamin D, and maintain blood
pressure and volume by secreting renin.
2.Trace the renal blood supply, beginning at the abdominal aorta and ending at
the inferior vena cava.
The renal arteries are branches of the abdominal aorta. A renal artery enters a kidney
through the hilum and gives off several branches, called interlobar arteries. The interlobar
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arteries branch into arcuate arteries, which in turn give rise to cortical radiate arteries
(interlobular arteries). The final branches of the cortical radiate arteries are the afferent
arterioles, which lead to the nephrons.
3. Name the parts of a nephron.
The parts of the nephron are: the renal corpuscle (made of the glomerulus and surrounded
by a glomerular capsule) and the renal tubule (divided into proximal convoluted, descending
limb, ascending limb, and distal portions).
4. Identify the two ty pes of nephrons and their associated blood vessels.
The afferent arteriole forms a cluster of capillaries that form the glomerulus. Glomerular
capillaries carry blood to efferent arterioles, which then branch into peritubular capillaries.
After flowing through the peritubular capillary network, blood enters the venous system
of the kidney.
5. Which structures form the juxtaglomerular apparatus?
Epithelial cells of the ascending limb form a structure called the macula densa and in the wall
of the afferent arteriole near the glomerulus are smooth muscle cells called juxtaglomerular
cells. The macula densa and juxtaglomerular cells form the juxtaglomerular apparatus.
Use the Practices 17.2
Arguing from Evidence The Centers for Disease Control and Prevention
released a report indicating that high blood pressure is the second leading
cause of kidney failure in the United States. Recall what you have learned
about the cardiovascular system and outline a connection between high blood
pressure and kidney failure.
High blood pressure causes arteries to harden, weaken and narrow. The kidneys are
supplied with many arteries, and a large volume of blood flow through them. The damaged
arteries do not provide adequate blood flow, and affect the filtration of the kidneys.
Additionally, kidneys produce a hormone to control blood pressure. As the kidneys become
more damage, they lose the ability to regulate blood pressure adding to the damage.
Figure Questions
Figure 17.5, page 642: Which arteriole has a larger diameter, and what is the functional
significance?
The afferent arteriole has a larger diameter to ensure adequate blood flow into the glomerulus.
Section 17.3: Urine Formation
Learn
Classroom Activities
EL Strategy: Using Visual and Contextual Support
Intermediate Before reading, have students take a close look at the visual
support (Figure 17.15). They should use the image to make predictions about the
process of sodium and water reabsorption. Have them use the image as they
work in pairs to form questions about the selection. After reading, have partners
compare their original predictions to the questions. Have them discuss how their
ideas changed or stayed the same. Move around the room to monitor progress.
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Writing Connection: Chart Presentation
Assign students into small groups. Provide each group with the Figure 17.14 with the
words removed. See example below. Students will discuss which labels go where for
the figure by using the words printed out and cut apart so they are moveable. Once
students feel their figure is properly labelled, they should take turns describing one
molecule or process that contributes to one of the three processes that make urine
formation occur.
• Glomerular filtration
• Tubular reabsorption
• Tubular secretion
Example of student response: In the process of glomerular filtration there are tiny
cells called podocytes that cover the glomerular capillaries making them impermeable
to larger substances such as proteins and red blood cells
Differentiated Instruction
Student may want to take turn in a specific order describing the order of how
the three processes work instead of picking randomly. A flow chart or work
order of steps may be created while students work to keep track of what they
have already described and keep the steps in order of urine formation. Provide
students resources and possibly limit the number of molecules to keep the
flow chart simple.
Demonstration Activity: Cycle of Matter
You will need a kidney model and colored post-it notes for this activity. Begin by
having students create a list of what types of matter passes through the kidneys.
Then, have them transfer items of the list onto post-it notes. This may include things
such as: sodium ions, water, protein, glucose, etc. Have students start with their
stack of post-in note matter at the top of the kidney. What passes through to the
other side? What gets absorbed here? Have students show the cycling of matter
through the kidney in order to help with energy production.
Additional Discussion Questions
What is the role of ADH in regulating urine concentration and volume?
ADH initiates several effects. The concentration of water in blood decreases, osmotic pressure
increases, ADH is carried to the kidneys where it causes the distal convoluted tubules and
collecting ducts to increase water reabsorption. Urine becomes more concentrated and its
volume decreases.
Apply knowledge gained in this chapter objective to discuss three ways in which the
kidneys help to collect and eliminate waste products.
The kidneys assist in waste removal through tubular reabsorption, tubular secretion, and
glomerular filtration.
What factors influence the glomerular filtration rate?
Glomerular filtration rate is influenced by filtration pressure, blood vessel pressure, and
capillary wall permeability.
Discuss the signs and symptoms of gout.
Deposits of uric acid crystals localize in joints, producing inflammation and pain. Joints of the
hands and feet are most often involved.
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Ask students to comment on the relationship between concentration gradient and
the length of loop of Henle.
The discussion should emphasize that the concentration gradient would increase with an increase
in the length of the loop.
Discuss cases in which glucose may be observed in the urine.
Responses should include a discussion of dietary intake, pregnancy, and diabetes.
Practice
Practice Questions
1. Which processes form urine?
Urine is the product of glomerular filtration, tubular reabsorption, and tubular secretion.
2. Which forces affect net filtration pressure?
The main force that moves substances by filtration through the glomerular capillary wall
is the hydrostatic pressure of the blood inside. In contrast, the colloid osmotic pressure of
plasma in the glomerulus opposes filtration. Net filtration pressure is a result of the
hydrostatic and colloid osmotic pressures.
3. Which factors influence the rate of glomerular filtration?
Glomerular filtration rate is influenced by hydrostatic pressure (both in the glomerular
capsule and glomerulus), glomerular plasma osmotic pressure, and changing diameters
of the afferent and efferent arterioles.
4. What is the function of the macula densa?
The macula densa senses decreased numbers of chloride, potassium, and sodium ions
reaching the end of the ascending limb of the nephron and signals the juxtaglomerular
cells to release renin, modulating the glomerular filtration rate.
5. How does renin help regulate filtration rate when blood pressure drops?
Renin converts angiotensinogen to angiotensin I, which in turn is converted by
angiotensin-converting enzyme (ACE) to angiotensin II. Angiotensin II has a number of
effects (constricting efferent arteriole, stimulating aldosterone secretion) that help to
maintain sodium balance, water balance, and blood pressure, which in turn regulates the
glomerular filtration rate.
6. Which chemicals are normally present in the glomerular filtrate but not in urine?
Glucose is present in glomerular filtrate but normally absent in urine. Similarly, the amount
of sodium in the urine is typically much less than the amount of sodium in the glomerular
filtrate.
7. Which mechanisms reabsorb solutes from the glomerular filtrate?
Active transport, osmosis, and passive transport mechanisms are all utilized to reabsorb
certain solutes from the glomerular filtrate along the length of the renal tubule.
8. Describe the role of passive transport in urine formation.
Active transport reabsorbs sodium and as the sodium is reabsorbed into the peritubular
capillaries, chloride ions follow. Chloride ions follow the sodium because chloride is
negatively charged and sodium is positively charged; the negative ions are attracted to
the positive ions. This attraction that moves chloride ions is a form of passive transport.
With an increase in the amount of sodium and chloride ions in the peritubular capillaries,
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the osmotic pressure of the peritubular capillaries increases and water is reabsorbed
from the renal tubule and into the peritubular capillaries. The fluid that is left in the renal
tubule at the end of this process is urine, and is isotonic with the plasma.
9. Define tubular secretion.
Tubular secretion is the reverse of tubular reabsorption. In tubular secretion, certain
substances move from the plasma of blood in the peritubular capillaries into the tubular
fluid.
10. Which substances are actively secreted?
Organic compounds like histamine, as well as certain drugs, hydrogen ions, ammonia,
and potassium ions are actively secreted.
11. How does sodium reabsorption affect potassium secretion?
Active reabsorption of sodium ions from the tubular fluid results in a negative electrical
charge within the tubule. Because positively charged potassium ions are attracted to
negatively charged regions, they move passively through the tubular epithelium and
enter the tubular fluid.
12. What stimulates the adrenal glands to secrete aldosterone?
Angiotensin II stimulates the adrenal gland to secrete aldosterone, wich in turn
stimulates tubular reabsorption of sodium.
13. How does the hypothalamus regulate urine concentration and volume?
Neurons in the hypothalamus produce ADH, which the posterior pituitary releases in
response to a decreasing water concentration in blood or a decrease in blood volume.
When ADH reaches the kidney, it increases the water permeability of the distal
convoluted tubule and collecting duct, and water is reabsorbed from these segments.
This regulates urine concentration and volume.
14. What produces urea and uric acid?
Urea is a by-product of amino acid metabolism and enters the renal tubule by filtration.
About 80% of it is reabsorbed and the remainder is excreted in the urine. Uric acid is the
product of the breakdown of organic bases and nucleic acids. A small of amount of uric
acid secreted into the renal tubule and excreted in the urine, while most is reabsorbed.
15. List the normal constituents of urine.
Urine is about 95% water, contains urea and uric acid, and has trace amounts of amino
acids and electrolytes. Urine’s composition varies greatly with variations in diet and
physical activity.
16. Which factors affect urine volume?
Urine volume depends largely on fluid intake and whether that intake is sufficient to
replace the fluid lost through sweating and exhaling. The environmental temperature,
body temperature, and humidity of the air can influence urine volume. A person’s
emotional condition can affect urine volume; anxiety can increase urine volume and
stress can reduce it.
Use the Practices 17.3
Using Models Create a model depicting the three stages of urine formation.
See Figure 17.7 for an example; student answers will vary.
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Figure Questions
Figure 17.11, page 647: Vasoconstriction of which arteriole in part (a) of this figure would
decrease glomerular filtration?
afferent arteriole
Figure 17.13, page 650: Would renin inhibitor medication be given to a patient who
has low blood pressure (hypotension) or high blood pressure (hypertension)?
high blood pressure (hypertension)
Figure 17.14, page 651: Which of the three processes (glomerular filtration, tubular
reabsorption, tubular secretion), if increased for a substance, would reduce urinary
excretion of that substance?
tubular reabsorption
Section 17.4: Urine Elimination
Learn
Classroom Activities
Writing Connection: Problems with Urine Elimination
Discuss with the class different types of urine issues in males and females. Below is a
list to work from. This is an individual activity, but students could collaborate in small
groups to develop their own answers after the group discussion. Each student
should pick 2–3 issues from the list that can occur during urine elimination. Have
students explain the normal process that should occur, what goes wrong to create
the issue, and explain if and how the issue can be solved with medical intervention.
•
•
•
•
•
Prostatitis effects on urine flow
Ureteritus (urinary tract infection)
Automatic bladder
Kidney stones
Incontinence
Differentiated Instruction
Students could pick only one of the issues described above and research how
often the issue occurs in different races, cultures, or subgroups of people
(example: incontinence in post-natal women). Provide students reflection
questions to guide their research such as: is the issue is something that is
inherited or more common in a certain ethnicity? What ways do people work
to prevent the issue from occurring? Are there any general prevention tips for
the researched urine elimination problem?
Additional Discussion Questions
What is shock-wave lithotripsy?
Lithotripsy is a non-invasive treatment for the pulverization of kidney stones. The patient is
placed in a stainless-steel tank filled with water. Underwater shock waves are generated and
focused on the exact location of the stone. If successful, the smaller fragments can then be
passed out of the body via normal urine flow.
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Ask students to discuss each of the eight major events in the process of micturition.
Responses should include a discussion of distension of the urinary bladder, stimulation of the
micturition center, stimulation of the detrusor muscle, contraction of the urethral sphincter,
generation of an impulse from the pons and hypothalamus, contraction of the detrusor muscle,
muscle relaxation, and reflex center fatigue.
Discuss the effects of diabetes mellitus on renal plasma threshold.
The limited transport capacity is overloaded due to an excess number of glucose molecules.
More glucose molecules remain in the filtrate, having driven the renal plasma threshold to a
critical level. The excess glucose molecules spill over into the urine and are excreted.
Discuss possible causes of incontinence.
Possible causes of incontinence include loss of external sphincter control, undeveloped
control of the external sphincter, stress, emotional upset, pregnancy, stroke, deep sleep, or
spinal cord injury.
Practice
Practice Questions
1. Describe the structure of a ureter.
The ureter has three layers: inner, middle, and outer. The inner layer (mucous coat) is
continuous with the linings of the renal tubules and urinary bladder. The middle layer
(muscular coat) consists largely of smooth muscle, and the outer layer (fibrous coat) is
connective tissue.
2. How is urine moved from the renal pelvis to the urinary bladder?
Peristaltic movements of the muscular walls of the ureters originating in the renal pelvis
propel the urine along the length of the ureter. When a peristaltic wave reaches the
bladder, a jet of urine spurts through a fold of mucous membrane that surrounds the
opening to the bladder and urine enters.
3.What prevents urine from backing up from the urinary bladder into the
ureters?
The angle at which the ureters enter the bladder causes the bladder wall to act as a
valve, allowing urine to enter the bladder but preventing it from flowing backwards into
the ureters as the bladder fills.
4. Describe the trigone of the urinary bladder.
The internal floor of the bladder includes a triangular area called the trigone, which has
an opening at each of its three angles. Posteriorly, at the base of the trigone, the
openings are those of the ureters. Anteriorly and inferiorly, at the apex of the trigone, a
short, funnel-shaped extension called the neck of the bladder contains the opening to
the urethra.
5. Describe the structure of the bladder wall.
The bladder wall has four layers: inner (mucous coat), submucous coat, muscular coat,
and serous coat. The mucous coat includes layers of transitional epithelial cells and its
thickness changes as the bladder expands and contracts. The submucous coat consists
of connective tissues and has many elastic fibers. The muscular coat is made of bundles
of smooth muscle that form the detrusor muscle. The serous coat is made of parietal
peritoneum and is only on the bladder’s upper surface. Elsewhere, the serous coat is
made of connective tissue.
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6. What are the kind of nerve fiber that innervate the detrusor muscle?
The detrusor muscle is innervated with parasympathetic nerve fibers that function in the
micturition reflex.
7. Describe the structure of the urethra.
The urethral wall is lined with mucous membrane and has a thick layer of smooth muscle
tissue, whose cells are directed longitudinally. The urethral wall also has abundant
mucous glands which secrete mucus into the urethral canal. The male urethra extends
from the urinary bladder to the tip of the penis. The female urethra is shorter and has its
external urethral orifice anterior to the vaginal opening and posterior to the clitoris.
8. Describe micturition.
Micturition involves reflex contraction of the detrusor muscle and reflex relaxation of the
internal urethral sphincter. It also requires voluntary relaxation of the external urethral
sphincter. Spinal reflexes keep the internal and external urethral sphincters contracted
as the bladder fills, and keep the detrusor muscle relaxed, so the bladder can expand.
Continued filling of the bladder stimulates stretch receptors in the bladder wall,
triggering the micturition reflex. As a result of this reflex, parasympathetic impulses
stimulate contraction of the detrusor muscle and relaxation of the internal sphincter.
Conscious effort may keep the external urethral sphincter closed, preventing urination.
9. How is it possible to consciously inhibit the micturition reflex?
The external urethral sphincter is composed of skeletal muscle and can be consciously
controlled. The external urethral sphincter must relax to permit flow of urine into the
urethra and outside the body.
Use the Practices 17.4
Constructing Explanations Inflammation of the urinary bladder (called cystitis)
is more common in women than men. Propose an explanation for this discrepancy
based on your knowledge of the anatomy of the urinary system.
Answers will vary. Some students might identify the difference in external anatomy
around the urethra as a potential explanation.
Figure Questions
Figure 17.18, page 659: How would prostatitis (inflammation of the prostate gland)
affect urine flow in a male?
reduce urine flow
Assess
Career Corner: Dialysis Technician
Consider This: Imagine you are on the curriculum development committee at
your local community college. The college is interested in creating a new dialysis
technician training program. Develop a list of courses for this program, that
includes notes on why each course is important for training new dialysis
technicians.
Answers will vary. Accept those that show students understand the qualifications and
training needed to be a dialysis technician.
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Diseases, Diagnosis, and Treatment: Kidney Stones
1.Describe how the presence of a kidney stone in the ureter can result in a
reduced glomerular filtration rate.
An untreated stone may cause pressure in the ureter to rise. As a result, pressure may
back up into renal tubules and raise the hydrostatic pressure in glomerular capsules. Any
increase in capsular pressure opposes glomerular filtration, and the GFR may decrease
significantly.
2.Why might a physician want to retain a patient’s kidney stone after it has been
passed?
It is very helpful for a physician to analyze the composition of the stones, because certain
drugs may prevent recurrence.
Case Study Connection
page 644: One of the symptoms of HUS is blood in the urine. Where did that
blood come from?
the glomerulus
page 646: As HUS progresses, blood pressure steadily rises. As HUS progresses
do you anticipate a rise in urine volume? A decrease? What about the amount
of blood in the urine, increase or decrease?
An increase in blood pressure will increase glomerular filtration rates. As GFR increases,
urine production can increase.
page 650: One of the symptoms of HUS is an increase in blood pressure. What
will happen to the levels of each of these hormones in the blood as blood
pressure rises?
As blood pressure increases, renin and angiotensin II production can increase.
page 652: One symptom of HUS is blood in the urine. Why are the blood cells
not reabsorbed?
they are too large
page 659: In HUS, blood often appears in the urine. Do you think this blood
could have come from the ureters? Why or why not?
Accept all student answers which demonstrate good reasoning.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which part of the kidney produces urine?
a. renal sinus
b. renal cortex
c. ureter
d. nephrons
2. Which one of the following is abundant in blood plasma, but
only in small amounts in glomerular filtrate?
a. sodium ions
b. water
c. glucose
d. protein
3. How would you describe the rate of glomerular filtration?
a. relatively constant
b. goes through natural cycles throughout the day
c. increases when the body must conserve fluid
d. all of the above
4. The major action of ADH in the kidneys is to
a. increase water absorption by the proximal convoluted
tubule.
b. increase glomerular filtration rate.
c. increase water reabsorption by the collecting duct.
d. increase potassium excretion.
5. After water, what are the two most abundant substances in
urine?
a. sodium and chloride
b. urea and uric acid
c. urea and chloride
d. uric acid and sodium
Short Answer
1. List the organs of the urinary system.
The organs of the urinary system include: kidneys, ureters,
bladder, and urethra.
2. What are the functions of the urinary system?
The urinary system functions to maintain water and electrolyte
balance and eliminate waste by forming urine. It also helps to
maintain pH, regulate blood pressure, and form red blood
cells.
3. Describe the gross anatomy of a kidney.
A kidney is convex on its later side, but concave on its medial
surface. On the medial side a depression leads to a hollow
chamber called renal sinus. The hilium is the entrance into the
renal sinus, where blood vessels, the ureters, and nerves pass.
The outer layer is called the cortex, and the inner layer is
called the medulla, which is divided into renal pyramids and
columns.
4. Describe the functional unit of a kidney.
The functional unit of the kidney is the nephron consisting of a
renal corpuscle and renal tubule. The nephron is where
filtration occurs.
5. Describe the structure and function of the glomerulus.
The glomerulus is a cluster of blood vessels. An afferent
arteriole enters the glomerulus, and an efferent arteriole exits
it. While in the glomerular capsule the blood vessels begin the
process of filtration. What leaves the blood and enters the
renal tubule is called the primary filtrate.
6. Which organ stores urine?
a. bladder
b. kidneys
c. urethra
d. rectum
6. Explain the difference between filtrate and urine.
7. Which of the following involves skeletal muscle?
a. contraction of the internal urethral sphincter
b. contraction of the external urethral sphincter
c. ureteral peristalsis
d. detrusor muscle contraction
7. Diuresis means “flow of urine from the kidney.” Is this
consistent with what ADH does?
8. Which kidney structure is probably damaged if protein in the
urine?
a. glomerulus
b. proximal convoluted tubule
c. collecting duct
d. ureter
The filtrate is what initially leaves the blood and enters the
renal tubules. Its composition changes as it makes its way
through the convoluted tubules. What finally enters the
collecting ducts is eliminated as urine.
Yes. ADH (antidiuretic hormone) prevents water loss. This
prevents “flow of urine from the kidney.”
8. Describe or diagram the blood flow into and out of the
kidney.
The path of blood into the kidneys: renal arteries, interlobular
arteries, arcuate arteries, cortical radiate arteries, afferent
arterioles into glomerulus, and then efferent arterioles out of
the glomerulus. Venous blood return from the nephrons
through a series of correspond generally to the arteriole
pathway. The renal vein then joins the inferior vena cava.
CHAPTER 17
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337
9. How is sodium reabsorbed in the proximal segment of the
renal tube?
Sodium is reabsorbed in the proximal segment of the renal
tubule by way of active transport.
10. Where is angiotensinogen formed?
Angiotensinogen is produced in the liver.
11. What causes a release of renin? What is its immediate effect?
Renin is released in response to a drop in blood pressure and
sympathetic stimulation. Renin converts angiotensinogen into
angiotensin I.
12. What is the ultimate effect of angiotensin II?
Angiotensin II causes a rise in blood through vasoconstriction,
increased ADH and aldosterone secretion, and stimulating thirst.
13. What effect does atrial natriuretic peptide have on
glomerular filtration rate?
ANP increases glomerular filtration rate.
14. What is urea? What is its role in urine formation?
Urea is a by-product of amino acid breakdown. It enters the
renal tubule by filtration. About 80% of it is reabsorbed. The
remainder is excreted and aids in urine formation as water will
follow it.
15. Explain the urination reflex.
Urination is known as micturition. Continued filling of the
bladder stimulates stretch receptors, triggering the micturition
reflex. It involves reflex contraction of the detrusor muscle and
reflex relaxation of the internal urethral sphincter. It also
requires voluntary relaxation of the external urethral sphincter.
Critical Thinking and Clinical Applications
1. One of your classmates told you that for lunch they had a
huge bag of salty corn chips with nothing to drink. How will
this affect urine concentration and production? Explain.
The sodium in the salty chips will cause a retention of water.
This will reduce urine formation. And the urine that is produced
will be more concentrated (less water).
2. CLINICAL Connection Explain why urinalysis is a routine
part of a physical exam.
Normal urine will contain certain levels of ions, glucose, and
proteins. If these levels are too high or low, they can indicate
conditions such kidney disease and diabetes.
3. WRITING Connection Imagine you are adrift at sea. Why
will you dehydrate more quickly if you drink seawater instead
of fresh water to quench your thirst?
This situation is quite complex and there are two ways in
which dehydration could occur due to drinking seawater.
First, ingesting seawater will introduce a large quantity of
hypertonic solution into the gut. Water will move from the
tissues of the gut into the lumen of the gut due to osmosis.
This water may not be reabsorbed in the intestine due to the
hypertonicity of the fluid in the gut. Thus, water will be lost
from body tissues and dehydration will result. Second, if large
amounts of the salt from the seawater is absorbed from the
lumen of the gut into the bloodstream, the solute concentration
of the blood may increase. Dehydration is a state in which the
body fluids become hypertonic, as is the case when ingesting
seawater instead of freshwater.
4. Why are people following high-protein diets advised to drink
large volumes of water?
Proteins are difficult for the kidneys to deal with. Protein
building blocks, called amino acids, can be filtered through the
glomerulus into the urine. This process is very difficult for the
transport molecules in the tubules of the kidney, but this
process is assisted if the individual is well hydrated.
5. If blood pressure drops in a patient in shock as a result of a
severe injury, how would you expect urine volume to change?
Why?
The volume of urine would decrease. Narrowed renal arteries
would decrease blood flow to the glomeruli, which would
result in decreased glomerular filtration rate, glomerular
filtrate, and urine.
Lab Data Analysis: Diabetic Nephropathy
1. How do eGFR and proteinuria differ before and after the
administration of spironolactone?
eGFR declines prior to the start of spironolactone, and then
shows a gradual improvement of function over the next
36 months after starting treatment. Likewise, proteinuria
continues to increase prior to administration of spironolactone,
with a precipitous drop thereafter.
2. Summarize the impact of spironolactone on eGFR and
proteinuria. How does the drug affect kidney function?
Low eGFR and high proteinuria are signs of progressive
kidney damage. The graph shows reversal of damage in
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both trend lines after beginning spironolactone at time
t=0 months.
3. By what percent does the eGFR increase between t=0 and
t=36 months?
Answers will vary slightly depending on how students read the
graph t0 measurement is approximately 48 ml/min/1.73m2, and
t36 is approximately 55 ml/min/1.73m2. 55-48 = 7; 7/48 = 14.5%.
CHAPTER
18
Water, Electrolyte, and
Acid-Base Balance
Section
Pacing
(class periods)
18.1 Introduction
18.2 Distribution of Body
Fluids
18.3 Water Balance
18.4 Electrolyte Balance
18.5 Acid-Base Balance
—
1
1
1
1
Learning Objectives
1. Explain water and electrolyte balance.
1. Describe how body fluids are distributed in
compartments.
1. List the routes by which water enters and
leaves the body.
2. Explain how water intake and output are
regulated.
1. List the routes by which electrolytes enter
and leave the body.
2. Explain how electrolyte intake and output
are regulated.
1. List the major sources of hydrogen ions in
the body.
2. Distinguish between strong and weak acids
and bases.
18.6 Acid-Base Imbalances
1
3. Explain how chemical buffer systems, the
respiratory center, and the kidneys keep
the pH of body fluids relatively constant.
1. Describe the causes and consequences of
an increase or a decrease in body fluid pH.
Focus Activity Workbook
Focus Activities: Labeling (8)
Focus Activities: Vocabulary (5)
Chapter Resources
Extended Summary Review
Chapter 18 Test Bank
Chapter 18 Interactive Question Bank
Vocabulary Flashcards
APR Module 13: Urinary System
CHAPTER 18
|
Water, Electrolyte, and Acid-Base Balance
339
A Suggested Approach
As the concepts of Chapter 18 require a broad understanding of homeostasis, the
concepts in this chapter could be covered by case studies. The National Center for
Case Study Teaching in Science has a number of case studies on acid – base
balance, and electrolyte balance.
Additionally, the concepts could be incorporated into the chapter on blood or the
urinary system.
This chapter is expected to take five class periods.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy used
to teach students how to construct explanations and craft scientific arguments.
A scientific claim answers a question or offers a solution to a problem. Give
students time to reflect and brainstorm, then have each student take a clear
stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is
information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support a
claim. Encourage students to return to their claims and add evidence at multiple
points in the chapter.
Use the following information to lead a discussion with students about whether
female recruits may be more susceptible to heat intolerance and heat stroke.
Average height for a woman in the US is 5 feet, 4 inches and her average weight
is 170 pounds. Average height for a man in the US is 5 feet, 9 inches and his
average weight is 197 pounds. If the female average is 52% water by weight, how
many pounds of water is in the average female body? If the male average is 63%
water by weight, how many pounds of water is in the average male body? The
average weight of military equipment for a US soldier is 60 pounds. Compare
the amount of weight as a proportion of body weight for a male versus a female
soldier. Do these calculations provide additional evidence or allow you to
reconsider your claim?
Introduction to the Theme
Theme: Stability and Change Blood composition must remain stable in order to
maintain homeostasis of the body. Changes in any three (water, electrolyte, or
acid-base balance will result in permanent long-lasting changes.
Theme Activity: Acid-Base Balance
This activity will require a beaker of water, pH strips or a pH probe, and household
liquids – such as vinegar, lemon juice, soda pop, diluted bleach, diluted sodium
bicarbonate solution. You can do this activity as a demonstration in front of the class
or have students can do this activity with the proper safety gear.
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You will start with a beaker of water and take the pH. After you write this down, add
a dropper of substance, and retake the pH. This activity will show how small things
can upset the stability of a system. Have students record the changes of the pH as
they add different chemicals to the water.
Section 18.1: Introduction
Learn
Classroom Activities
Section 18.1 sets the groundwork for activities in sections 18.2 and beyond.
Additional Discussion Questions
What are the major sources and outputs of water and electrolytes?
The major sources of water are provided by drinking beverages (water, coffee, etc). Also,
ingesting water as part of solid food and forming water through cellular respiration are major
sources. The major output of water is through urination. The major sources of electrolytes are
derived from the diet. The major outputs of electrolytes include perspiration, digestive system
secretions, and urination.
Discuss various factors that contribute to water and electrolyte imbalances.
Responses should include a discussion of reduced input, vomiting, excessive perspiration,
excessive urination, hyperventilation, inflammation, decreased absorption, renal disease, burns,
dehydration, and diarrhea.
Practice
Practice Questions
1. How are water and electrolyte balance interdependent?
Water balance and electrolyte balance are interdependent because electrolytes
are dissolved in the water of body fluids. Consequently, anything that alters the
concentrations of the electrolytes will alter the concentration of the water, either by
adding solutes to it or by removing solutes from it. Likewise, anything that changes the
concentration of water will change concentrations of the electrolytes by concentrating
or diluting them.
Use the Practices 18.1
Conducting Investigations Water and electrolyte concentrations in the
body are interdependent. Hypothesize what happens to the electrolyte
concentration of the extracellular fluid when the volume of water in the body
increases.
As the concentration of water increases, the amount of dissolved electrolytes
decreases.
CHAPTER 18
|
Water, Electrolyte, and Acid-Base Balance
341
Section 18.2: Distribution of
Body Fluids
Learn
Classroom Activities
EL Strategy: Word Origins
Beginning or Intermediate Using the section on fluid compartments, students
should look at the words “intracellular,” “extracellular,” and “transcellular.”
Have the students think of words that share the root word intra, extra and
trans from previous chapters, or prior knowledge. Ask: How will this help us to
remember the differences between each fluid compartment? For additional
support, have students find the Aid to Understanding Words table to find the
cognates, or words that have come from a common ancestor, which can help
them understand new vocabulary.
Math Connection: Graph Making Activity
Students can work in pairs. Have students discuss the different concentrations of
ions in the intracellular matrix as well as the extracellular matrix. Provide students
with the data table representing information from a recent mock cellular test
showing ion concentrations. Students will use the information in the graph to create
their own bar graph. They should compare their data to Figure 18.2 showing what
the levels are supposed to be. Once students analyze both graphs, they should
write a conclusion about the issue in ion concentrations in their mock cell and what
that specific ion level will trigger to occur in the cell. Students should include
homeostasis in their answer.
Mock Data Set 1 Teacher Note: (low Na+ concentration in the extracellular fluid)
Intracellular Fluid Ion
Concentration (m Eq/L)
Extracellular Fluid Ion
Concentration (m Eq/L)
Na+
30
50
K
140
6
3
7
55
4
4
103
HCO3
10
28
PO4
-3
75
5
SO4
-2
2
1
+
Ca
+2
Mg
+2
Cl
-
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Mock Data Set 2 Teacher Note: (high K+ concentration in the extracellular fluid)
Intracellular Fluid Ion
Concentration (m Eq/L)
Extracellular Fluid Ion
Concentration (m Eq/L)
Na+
10
140
K+
130
120
3
7
55
4
4
103
HCO
10
28
-3
4
PO
75
5
-2
4
SO
2
1
Ca
+2
Mg
+2
Cl
3
Differentiated Instruction
Instead of students having to create a graph and compare it to Figure 18.2,
provide students with the already made graph of the mock data. They could
then just analyze the two graphs and highlight the differences between ion
concentration from what is normal and what is in the mock graph. Students
would still need to reflect on what these ion concentration differences could
mean for the cell and how the cell might respond through homeostasis.
Visual Literacy: Body Fluids
The human body is full of different types of fluids: what makes up these fluids, and
where do these fluids reside?
For this activity, students will explore the different types and concentrations of ions
between extracellular fluids and intracellular fluids.
Using the data from the bar chart in Figure 18.2, students will create an illustration
of the different ions and their concentrations. Provide students with a drawing of a
cell for this activity and colored pencils.
Remind students that different concentrations between the extra and intracellular
fluids are an important piece to their visual.
Example: The ratio of Na+ extracellular: intracellular is 14:1. Students draw 14 Na+
ions on one side of the cell but only 1 on the inside.
Additional Discussion Questions
What are the effects of diabetes insipidus on water and electrolyte balances?
Diabetes insipidus may result in polyuria, urine dilution, severe dehydration, and electrolyte
imbalances. This condition usually stems from a decreased secretion of ADH. ADH normally
signals the kidneys to reabsorb more water, which decreases water loss through urination.
What is the effect on red blood cell structure by administering a hypertonic
solution? Hypotonic?
Administration of a hypertonic solution results in an osmotic outflow from cells causing cell
shrinkage. Cell swelling caused by an osmotic inflow to cells would be expected from the
administration of a hypotonic solution.
CHAPTER 18
|
Water, Electrolyte, and Acid-Base Balance
343
Practice
Practice Questions
1. Describe the normal distribution of water in the body.
The body of an average adult female is about 52% water and that of an average adult male
is 63% water by weight. Water in the adult human body (about 40L) with its dissolved
electrolytes is distributed into two major compartments: an intracellular fluid compartment
and an extracellular fluid compartment. The intracellular fluid is the fluid inside cells, about
63% by volume of total body water. The extracellular fluid is the fluid outside of cells, in tissue
spaces, blood vessels, and lymphatic vessels, about 37% by volume of total body water.
2.Which electrolytes are in higher concentrations in extracellular fluids?
In intracellular fluid?
Extracellular fluids include high concentrations of sodium, chloride, calcium and
bicarbonate, with lesser concentrations of potassium, magnesium, phosphate, and
sulfate ions. Blood plasma portion of extracellular fluid has considerably more protein
than either the interstitial fluid or lymphatic fluid portions. Intracellular fluid has high
concentrations of potassium, phosphate, and magnesium ions. It includes a greater
concentration of sulfate ions and lesser concentrations of sodium, chloride, calcium,
and bicarbonate ions than extracellular fluid. Intracellular fluid also has a greater
concentration of protein than plasma.
3. How does the protein concentration vary among body fluids?
Intracellular fluid has a greater concentration of protein than plasma. The blood plasma
portion of extracellular fluid has more protein than the interstitial fluid or lymph.
4.Which factors control the movement of water and electrolytes from one fluid
compartment to another?
Two major factors contribute to the movement of fluid from one compartment to another:
hydrostatic pressure and osmotic pressure. Fluid leaves the plasma and enters the
interstitial spaces because of the outward force of hydrostatic pressure (blood pressure).
Fluid returns to the plasma from the interstitial spaces because of the inward force of
plasma proteins, the colloid osmotic pressure.
5.How does the sodium ion concentration in body fluids affect the net movement
of water between the compartments?
The total solute concentration in extracellular and intracellular fluids is normally equal. A
decrease in extracellular sodium ion concentration causes a net movement of water from
the extracellular compartment into the intracellular compartment by osmosis. The cells
swell. Conversely, if the extracellular sodium ion concentration increases, cells shrink as
they lose water by osmosis.
Use the Practices 18.2
Using Models Develop a model to illustrate the movement of water into or out
of the intracellular fluid during dehydration and during excessive water intake.
Answers will vary. Use Fig. 18.3 as a starting point.
Figure Questions
Figure 18.2, page 672: According to the graph, which positively charged intracellular
fluid ion is in the highest concentration?
potassium ion
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Section 18.3: Water Balance
Learn
Classroom Activities
Writing Connection: Edema Flow Chart
This activity can be completed in small groups or pairs of students. Provide students
with 15 blank rectangles printed on paper. Students will color code five rectangles
into each group to make three sets of five rectangles. Next students should identify
three factors resulting in edema. Each set of rectangles will represent one of the
three factors. Students will use the set of five rectangles to write down the steps
that occur causing edema for each of the three factors they identified. They need to
make sure they have the steps in the correct order. Once students complete this
the first time, they should mix up the steps and try to reorder them again in the
correct way. Repeat until all students feel confident in explaining the steps that
occur in a body, specifically with fluid and plasma protein concentrations.
Differentiated Instruction
Athletes were once recommended to drink lots of water during an athletic event.
However, drinking all of this water could lead to the possibility of hyponatremia.
Have students research what events occurred to trigger scientists to believe this
could happen. Students should identify any events that occurred as well as the
process of hyponatremia that happened at this event. The opposite of water
intoxication is dehydration. Ask students to explain why these processes are
opposite and what specifically occurs within the body with fluid exchanges.
Demonstration Activity: Water In, Water Out
As students will know by now, water plays an important role in maintaining our
bodily systems. This activity helps students visualize where we get our water from
and where it goes.
Break students into small groups. Provide each group with three 250 mL beakers of
water and a 100 mL graduated cylinder or plastic syringe. Two beakers will be filled
to 100 mL. The middle beaker will be empty. One beaker represents water entering
the body, one represents water exiting the body, and the empty beaker represents
the body.
You will use Figure 18.4 for this activity. Begin by partially “filling” the body. As you
go through the sources of the intake of water, students will put in the corresponding
amount of water into the “body.”
Additional Discussion Questions
What might be the effects of decreased plasma volume, even when the plasma
remains isotonic?
Possible effects may include shock, reduced perspiration, oliguria, increased hematocrit, and
reduced skin firmness.
Ask students to discuss cases in which the result is a decrease in extracellular fluid
volume.
Extracellular fluid volume might be decreased by chronic diarrhea or an aerobic exercise
workout. Increases might be the result of the infusion of a hypertonic I.V. solution.
CHAPTER 18
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Water, Electrolyte, and Acid-Base Balance
345
Practice
Practice Questions
1. What is water balance?
Water balance is the relationship between water intake and water output, and exists
when intake equals output.
2. Where is the thirst center?
As the body loses water, the osmotic pressure of extracellular fluids increases. This
stimulates osmoreceptors in the hypothalamus and the hypothalamus causes the person
to feel thirsty and seek water.
3. What stimulates fluid intake? What inhibits it?
As the body loses water, the osmotic pressure of extracellular fluids increases. This
stimulates osmoreceptors in the hypothalamus and the hypothalamus causes the person
to feel thirsty and seek water. The act of drinking and the resulting distension of the
stomach wall trigger impulses that inhibit the thirst mechanism.
4. By what routes does the body lose water?
Water is lost by a variety of routes: in the urine, feces, sweat (sensible perspiration),
evaporation from the skin (insensible perspiration), and from the lungs during breathing.
5. What is the primary regulator of water loss?
The primary regulator of water loss is urine production. The renal distal convoluted
tubules and collecting ducts are the effectors of the mechanism that regulates urine
volume. ADH increases the permeability of the distal convoluted tubule and collecting
duct to water, thereby increasing water reabsorption and reducing urine production. In
the absence of ADH, less water is reabsorbed and more urine is produced.
Use the Practices 18.3
Using Mathematics You record your water intake and outputs over the course
of a day. You took in 1400 mL of water in beverages, 700 mL in food, and
250 mL in metabolic water. You lost 1800 mL through urine, 450 mL through
your skin, 325 mL through respiration, and 250 mL through feces. Calculate the
total volume gained and the total volume lost. Is there a net loss or gain?
Total intake: 1400 + 700 + 250 = 1350mL
Total output: 1800 + 450 + 325 + 250 = 2825mL
There is a net loss
Section 18.4: Electrolyte Balance
Learn
Classroom Activities
Writing Connection: Let’s Go Shopping
Students will need access to the internet. Discuss with students why electrolyte
balance is important. In small groups students should make a small poster to hang
up on the importance of staying hydrated with not just water, but with electrolytes
also. Next students, in their small groups, will research drinks that provide electrolytes
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by shopping online. Students will click on the item in the online store and view its
description to find what types of ions and electrolytes are in the drink. Students
should make a list of drinks that they find that have the most electrolytes for the
best price. Student groups may present their findings to the class.
Differentiated Instruction
Instead of students researching online, ask students to bring in the label off
of one of their favorite drinks to class. Students in small groups can help
each other analyze their labels and evaluate if their drink is a good way to
hydrate or not.
Additional Discussion Questions
Ask students to discuss common causes of potassium imbalances.
Responses should include a discussion of dietary insufficiency or excess, diabetes, vomiting,
chronic diarrhea, renal disease, abnormal levels of aldosterone, or trauma.
Discuss the roles of calcitonin and parathormone in maintaining blood ion
concentration balance.
Calcitonin causes calcium to be deposited in bones for future release to blood. When blood
levels of calcium become too low, parathormone signals the release of calcium from bone back
into the bloodstream.
Practice
Practice Questions
1. Which electrolytes are most important to cellular functions?
The electrolytes of greatest importance to cellular functions dissociate to release
sodium, potassium, calcium, magnesium, chloride, sulfate, phosphate, bicarbonate, and
hydrogen ions.
2. Which mechanisms ordinarily regulate electrolyte intake?
A person obtains sufficient electrolytes by responding to hunger and thirst.
3. By what routes does the body lose electrolytes?
The body loses electrolytes by perspiring, as well as by production of urine and feces.
4. How does aldosterone regulate the sodium and potassium ion concentrations?
Aldosterone increases sodium ion reabsorption in the distal convoluted tubule and
collecting ducts. Aldosterone is secreted in response to rising potassium levels and
enhances tubular secretion of potassium ions.
5. How is calcium regulated?
When calcium ion concentrations drop below normal, the parathyroid glands are
stimulated to secrete PTH. PTH works on the bones, digestive system, and kidneys to
restore calcium levels to normal.
6. What mechanism regulates the concentrations of most negatively charged ions?
Generally, the regulatory mechanisms that control positively charged ions secondarily
control the concentrations of negatively charged ions, because the negatively charged
ions are attracted to the positively charged ions and follow them. Some negatively
charged ions are regulated by active transport mechanisms, but this plays less of a role.
CHAPTER 18
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Water, Electrolyte, and Acid-Base Balance
347
Use the Practices 18.4
Constructing Explanations Marathon runners may suffer from dehydration.
Symptoms include signs of central nervous system dysfunction such as
confusion, disorientation, and lethargy, and in severe cases, seizure or even
death. Construct an explanation for these symptoms based on the movement
of electrolytes and their role in the nervous system.
During dehydration, water is loss out of the extracellular fluid resulting in the osmolarity
of the extracellular fluid being higher than that of the intracellular fluid. In order to
balance the electrolytes, water will be drawn out of cells, including neurons, to balance
the concentration. The loss of water will cause neuron to shrink, resulting in non-specific
symptoms of the nervous system.
Section 18.5: Acid-Base Balance
Learn
Classroom Activities
Writing Connection: Acid-Base Challenge
Students will complete this review activity in pairs. The teacher will prepare a set of
game cards (the size of a deck of cards) for each pair of students with the following
information:
•
•
•
•
•
•
•
•
•
•
Bicarbonate system ×2
Phosphate system ×2
Protein system ×2
Respiratory mechanism ×2
Renal mechanism ×2
H+ (make multiple cards of H+)
CO2 (make multiple cards of CO2)
H2CO3 (make multiple cards of H2CO3)
H2CO4- (make multiple cards of H2CO4-)
HPO4-2 (make multiple cards of HPO4-2)
Students will separate the cards evenly so that each one has an equal amount of
each card. The center of the desk represents the human body in general. The first
student will go and either put an influx of one type of ion in the center (body). The
second student will have to choose a buffer system or secondary response and the
correct compound to correct the influx of that type of ion. For each round, students
should write on a group paper what the round involved and why that buffer system
worked or not. Students can refer to Table 18.1 and Figure 18.8 for guidance on how
the body responds in these situations.
Differentiated Instruction
The Acid-Base card game is very challenging because students have to
analyze the situation and then apply a fix just as the body would with the
buffer systems. Instead of students playing the game, the teacher could
provide students with pre-made scenarios of changes in ion levels (acids or
bases) and then students can work together to create a response or action.
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Additional Discussion Questions
Under what conditions would the administration of sodium bicarbonate be indicated?
Ammonium chloride?
An emphasis should be placed on the concepts of acidosis and alkalosis.
Compare the dissociation of a strong acid and a weak acid.
An excellent analysis may be made by comparing the dissociation of hydrochloric acid with the
dissociation of carbonic acid.
Discuss the effects of a high protein diet on hydrogen ion concentration in the body.
A high protein diet would result in increased formation of sulfuric acid and phosphoric acid,
both of which are sources of hydrogen ions. The hydrogen ion concentration would ultimately
increase in body fluids and in the urine.
Give examples of various factors that may contribute to metabolic acidosis.
Metabolic acidosis may be the result of renal disease, chronic vomiting, chronic diarrhea, diabetes
mellitus, etc.
Practice
Practice Questions
1. Distinguish between an acid and a base.
Electrolytes that release hydrogen ions are called acids, and electrolytes that release
ions that combine with hydrogen ions are called bases.
2. What are the major sources of hydrogen ions in the body?
Most hydrogen ions in body fluids are by-products of metabolic processes. The major
metabolic sources are: aerobic respiration of glucose, anaerobic respiration of glucose,
incomplete oxidation of fatty acids, oxidation of amino acids containing sulfur, and
hydrolysis of phosphoproteins and nucleic acids.
3. What is the difference between a strong acid or base and a weak acid or base?
Acids that ionize more completely are strong acids, and those that ionize less completely
are weak acids. Strong bases dissociate or release more hydroxide ions or its equivalent
than do weak bases.
4. How does a chemical buffer system help regulate the pH of body fluids?
The chemical components of a buffer system can combine with strong acids to convert
them to weak acids. Likewise, these buffers can combine with strong bases to convert
them to weak bases. Such relations help minimize pH changes in body fluids.
5. List the major chemical buffer systems of the body.
The major chemical buffer systems of the body are: the bicarbonate buffer system, the
phosphate buffer system, and the protein buffer system.
6. How does the respiratory system help regulate acid-base balance?
The respiratory center in the brainstem helps regulate the H+ ion concentrations in the
body fluids by controlling the rate and depth of breathing. If body cells increase their
production of CO2, carbonic acid production increases. As carbonic acid dissociates, the
concentration of hydrogen ions increases, and the pH drops. Increasing CO2 in the CNS
stimulates the respiratory center to increase the rate and depth of breathing, so that the
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lungs excrete more CO2, which in turn decreases the H+ ion concentration, and the pH
returns to normal. Conversely, if body cells are less active and CO2 and H+ ion
concentrations remain low, breathing rate and depth stay at resting levels.
7. How do the kidneys respond to excess hydrogen ions?
Nephrons help regulate hydrogen ion concentration of body fluids by excreting hydrogen
ions in the urine.
8. How do the reaction rates of chemical and physiological buffer systems differ?
Physiological buffer systems function more slowly and constitute a second line of defense
against shifts in pH. Chemical buffers can convert strong acids or bases into weak acids
or bases almost immediately. Chemical buffer systems are considered a first line of
defense against shifts in pH.
Use the Practices 18.5
Asking Questions Several buffering mechanisms maintain pH homeostasis in
the human body. Use the information in Table 18.1 to develop a question about
the interactions between the intracellular and extracellular buffer systems.
Answers will vary by student:
Which buffer systems are present in intercellular fluids, extracellular fluids or both?
Which buffer system is most important in extracellular fluids?
Figure Questions
Figure 18.8, page 682: How does respiratory excretion of CO2 buffer the pH of body
fluids?
Because of the bicarbonate buffer reaction (CO2 + H2O ↔ H2CO3 ↔ HCO3‾ + H+), when
pH is lower than 7.35, exhaling more CO2 lowers the hydrogen ion concentration in the
plasma (as the reaction proceeds to the left), reestablishing the normal internal environment
pH range of 7.35–7.45
Section 18.6: Acid-Base Imbalances
Learn
Classroom Activities
EL Strategy: Context Clues
Beginning Help students identify context-clue words in the text they could
use to determine important concepts to understand acid-base imbalance. Have
students circle the words. Say the vocabulary words and context – clue words
aloud. Have students repeat them. Then have students copy the clue word into
the appropriate spaces of a three – column chart.
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Writing Connection: Acidosis/Alkalosis T-Chart
Students should make a T-Chart comparing the following categories of acidosis and
alkalosis.
Three-column chart
Words
Context Clues
Meanings
Acidosis
Accumulation of acids
Loss of bases pH below 7.35
Condition in which too much acid
accumulates in the body
Alkalosis
Excessive loss of hydrogen or
gain of bases. pH above 7.45
Condition caused by decreased carbon
dioxide or increased bicarbonate
• Types of each
• Causes
• Symptoms
Differentiated Instruction
Students will have to research and provide the information in the T-chart for
acidosis and alkalosis. Instead, students may want the visual flow of each type
of factor causing these conditions. Students could create a flow chart like in
Figure 18.13 instead of organizing information into the T-Chart. Students
should highlight the same information: Types of each, causes, and symptoms.
Additional Discussion Questions
Compare and contrast the clinical signs and symptoms associated with pH imbalances.
Students may be required to research this topic via the library, book stores, or Internet.
Practice
Practice Questions
1.What is the difference between a respiratory acid-base disturbance and a
metabolic acid-base disturbance?
Factors that increase carbon dioxide levels, which increases the concentration of carbonic
acid, cause respiratory acidosis. Metabolic acidosis is due to an abnormal accumulation of
any other acids in the body fluids or to loss of bases, including bicarbonate ions. Respiratory
alkalosis results from excessive loss of carbon dioxide and consequent loss of carbonic
acid. Metabolic alkalosis is due to excessive loss of hydrogen ions or gain of bases.
2. How do the symptoms of acidosis compare with those of alkalosis?
The symptoms of acidosis include drowsiness, disorientation, stupor, and cyanosis. The
symptoms of alkalosis include light-headedness, agitation, dizziness, and tingling
sensations. In severe cases, impulses may be triggered spontaneously on motor neurons,
and muscles may respond with tetanic contractions.
Use the Practices 18.6
Communicating Information High altitude climbers may experience
respiratory alkalosis. Explain why this occurs, as well as how the body
compensates for the alkalosis.
High altitudes with the lack of oxygen, result in hyperventilation and respiratory alkalosis.
As the person spends increasing time at high altitude, they are able to compensate by
increasing ventilation, and maintain adequate levels of oxygen.
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Assess
Career Corner: Medical Laboratory Technician
Consider This: Most medical laboratory technicians are generalists, but some
may specialize. Use your book and internet resources to describe what types
of tests might be conducted by specialists in the following fields: hematology,
parasitology, cytogenetics.
Answers will vary. Accept those that show students conducted appropriate research.
Diseases, Diagnosis, and Treatment: Water Balance Disorders
1. Define dehydration, water intoxication, and edema.
Dehydration is when water output exceeds water intake. Water intoxication is when
excessive water is taken in, and edema is an abnormal accumulation of fluids in the
interstitial spaces.
2.Describe what happens on a cellular level when a dehydrated person drinks
only water, rather than water and appropriate electrolytes.
If only water is replaced, the extracellular fluid will become more dilute than normal,
causing cells to swell.
Case Study Connection
page 671: Is this information about body water differences instructive as to how
long women versus men can endure high temperatures? Why or why not?
Student answers will vary, but they should note the higher percentage of water found in
men versus women.
page 676: How might heat intolerance change if the troops were in areas with
low water availability? Is thirst likely to vary before and after a meal?
Students should identify that adults receive an average of 60% of their water intake from
drinking water or other beverages. Thirst should be reduced after a meal since
approximately 30% of water intake comes from eating.
page 676: What do you expect will happen to urine volume in a person suffering
from heat intolerance?
urine volume would decrease
page 678: The sodium concentration in sweat is around 40mM and sodium is the
predominant positively charged ion. If the sodium concentration increased
significantly, what do you think would happen to the sweat concentration of
chloride, the predominant negatively charged ion?
Accept all student answers that demonstrate solid reasoning.
page 678: Heat intolerance risk increases with exercise. During exercise, as
all forms of metabolism increase, what will happen to the acidity of sweat?
Use Figure 18.6 in your answer.
Students should identify that all the metabolic processes shown in Figure 18.6 produce acidic
products. These would increase the acidity (lower the pH) of sweat.
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. Which of the following statements about water and
electrolyte balance is true?
a. Water intake affects electrolyte balance, but electrolyte
intake does not affect water balance.
b. Electrolyte intake affects water balance, but water intake
does not affect water balance.
c. Water intake affects electrolyte balance and electrolyte
intake affects water balance.
d. none of the above
2. Water and electrolytes enclosed by cell membranes
constitute the
a. transcellular fluid.
b. intracellular fluid.
c. extracellular fluid.
d. lymph.
3. Which of the following is not a way for the human body to
obtain water?
a. drinking
b. food
c. perspiration
d. metabolism
Short Answer
1. Describe how Na+ levels are regulated in body fluids.
The hormone aldosterone helps to regulate Na+ and other ion
concentrations. Aldosterone causes Na+ to reabsorbed by the
kidneys.
2. Explain how buffers respond to changes in pH.
Buffers can combine with acids and bases when pH changes.
Usually buffers are able to maintain pH by accepting or donating
excess H+ ions.
3. What are the causes of acidosis?
Respiratory acidosis can be caused by decreased breathing
rate and depth, obstruction of air passageway, and diseases
that decrease gas exchange such as pneumonia or emphysema.
Metabolic acidosis can be caused by kidney disease, prolonged
vomiting or diarrhea, and diabetes.
4. What are the various fluid compartments in the body?
The fluid compartments are: intracellular fluid, extracellular
fluid (plasma, lymph, and interstitial fluid). Transcellular fluid is
found in places where there are cavities: CSF, eyes, joints,
membranes.
4. Electrolytes in body fluids of importance to cellular functions
include:
a. sodium
b. potassium
c. calcium
d. all of the above
5. How do electrolytes affect water balance?
5. Which process results in the greatest loss of electrolytes?
a. urination
b. defecation
c. perspiration
d. dehydration
6. What are the causes of alkalosis?
6. Which of the following is a strong acid?
a. carbonic acid
b. hydrochloric acid
c. A and B
d. Neither A nor B
7. What is an example of a second line of defense against shifts
in pH?
a. bicarbonate buffer system
b. protein buffer system
c. respiratory mechanisms
d. white blood cells
8. A student hyperventilates and is disoriented just before an
exam. What is this student likely to be experiencing?
a. acidosis
b. alkalosis
c. emphysema
d. none of the above
Water moves in response to the dissolved electrolytes. For
example, a decrease in extracellular sodium ion concentration
causes a net movement of water from the extracellular
compartment into the intracellular compartment by osmosis.
Respiratory alkalosis: hyperventilation, due to fever, anxiety,
high altitude, and poisoning. Metabolic alkalosis: gastric
drainage and certain diuretics.
7. Which ions are in high concentration in the intracellular fluid?
Potassium, magnesium, PO4-, and SO4-.
8. Which ions are in high concentration in the extracellular fluid?
Sodium, calcium, chlorine, HCO3-.
9. What controls the volume of water gained each day in your
body?
Water in beverages, water in moist food, and metabolic water.
10. Write the reaction of the protein buffering system.
NH2 + H+ ↔ NH3+ and COOH ↔ COO + H+
11. Where is the phosphate buffering system most important?
It is most important in the control of hydrogen ion concentrations
in the tubular fluid of the nephrons and in urine.
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12. Describe how K+ levels are regulated in body fluids.
14. What is hydrostatic pressure?
Aldosterone regulates K ions in body fluids. A rise in K ions
stimulates the adrenal cortex to secrete aldosterone.
Aldosterone enhances tubular secretion of K+ ions at the same
time it causes tubular reabsorption of Na+ ions.
+
+
13. What is osmotic pressure?
Osmotic pressure is what accounts for the osmosis of water
based upon electrolyte concentration.
Hydrostatic pressure (blood pressure) is the net outward force
of fluid from the capillaries.
15. What is edema?
An edema is an abnormal build-up of extracellular fluid in the
interstitial spaces.
Critical Thinking and Clinical Applications
1. A college sophomore went to the campus health center
complaining of severe diarrhea. A culture revealed that she
had an E. coli infection. Chronic diarrhea will contain high
concentrations of HCO3- How will this affect her blood pH
and respiration rate?
This will cause an increase in H+ concentration, resulting in a
low plasma pH. It will increase breathing rate because the
respiratory center in the medulla is stimulated by a drop in pH.
2. WRITING Connection Mannitol is a sugar that is filtered
but not reabsorbed by the kidneys. Explain what effect
drinking a mannitol solution would have on the volume of
urine produced.
Since mannitol is not reabsorbed there would be an increase
in tubular osmolarity. This means that water will follow
mannitol and be eliminated. This will result in an increase
volume of urine.
3. Your lab partner insists that all water will conduct an
electrical current. You decide to design an experiment to
test this hypothesis. You prepare three solutions: one with
deionized water (no solutes, only water molecules), one with
10% glucose in the water, and one with 10% NaCl in the
water. Which, if any, of these will conduct a current? Explain
your answer.
The solution with 10% NaCl is the only one that will conduct a
current. It’s the electrolytes that are responsible for conducting
the current. Deionized water contains no electrolytes, and
glucose does not dissociate into ions in water.
4. CLINICAL Connection After eating an undercooked
hamburger, a 25-year-old male developed diarrhea due to
infection with a strain of Escherichia coli that produces a
shigatoxin. How would this affect his blood pH, urine pH, and
respiratory rate?
In severe cases of diarrhea, large amounts of bicarbonate and
potassium are lost from the GI tract. This will cause blood pH
to decrease. If blood pH decreases, then urine pH will also be
decreased. The respiratory system will attempt to raise blood
pH by increasing the rate of respiration to decrease blood
carbon dioxide concentration.
Lab Data Analysis: Mechanical Ventilation
1. How does the acid/base status of both groups compare?
The average blood pH of the nonventilated group (pH = 7.16)
is higher than that of the ventilated group (pH = 7.12). Thus,
the ventilated group has more acidic blood.
2. If normal blood pH is in the range 7.32–7.42, is the mechanically
ventilated group in respiratory acidosis or alkalosis?
The average blood pH for the ventilated group is 7.12. Thus,
they are in respiratory acidosis. Remember: a pH less than 7 is
acidic, greater than 7 is alkalotic (basic).
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3. How would you adjust respiration of the rat pups in the
ventilated group if you wanted to normalize the pH of their
blood?
As described in the chapter, carbon dioxide is retained in the
blood as an acid. The more carbon dioxide we breathe off, the
more basic our blood becomes. Thus, since the ventilated
group is in respiratory acidosis, we would increase their
respiratory rate to eliminate carbon dioxide and shift the pH
back to the normal range.
UNIT
The Human Life
Cycle
Chapter
6
Pacing (class periods)
19 Reproductive Systems
5
20 Pregnancy, Growth, Development, and Genetics
5
Unit 6 Resources
Unit Project Engineer a Healthier World – Engineering in Anatomy and Physiology
nit Project: Engineer a Healthier World—
U
Engineering in Anatomy and Physiology
Project 6: Brave New Babies
This project introduces students to the engineering design loop and the integration
of engineering processes into the study of A&P and the healthcare field. Students
will first read the boxed feature “Fetal Chromosome Checks” (p. 760), and use this
to start their investigation into building replacement organs.
A teacher guide for this project can be found online.
UNIT 6
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355
CHAPTER
19
Reproductive Systems
Section
Pacing
(class periods)
19.1 Introduction
—
19.2 Organs of the Male
Reproductive System
1/2
19.3 Spermatogenesis
19.4 Hormonal Control of
Male Reproductive
Functions
1/2
1/2
19.5 Organs of the
Female Reproductive
System
19.6 Oogenesis and the
Ovarian Cycle
1/2
19.7 Mammary Glands
19.8 Birth Control
19.9 Sexually Transmitted
Infections
Learning Objectives
1. State the general functions of the male and
female reproductive systems.
1. Describe the structure and function(s) of
each part of the male reproductive system.
2. Describe semen production and exit from
the body.
1. Outline the process of spermatogenesis.
1. Explain how hormones control the activities
of the male reproductive organs and the
development of male secondary sex
characteristics.
1. Describe the structure and function(s) of
each part of the female reproductive system.
1/2
1. Describe the process of oogenesis.
2. Explain how hormones control the activities
of the female reproductive organs and the
development of female secondary sex
characteristics.
3. Describe the major events during a female
reproductive cycle.
1. Review the structure of the mammary glands.
1. Describe several methods of birth control,
including the relative effectiveness of each
method.
1. List the general symptoms of sexually
transmitted infections.
1/2
1
1
Focus Activity Workbook
Focus Activities: Labeling (9)
Focus Activities: Vocabulary (8)
Chapter Resources
Extended Summary Review
Chapter 19 Test Bank
Chapter 19 Interactive Question Bank
Vocabulary Flashcards
APR Module 14: Reproductive Systems
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A Suggested Approach
Because school districts vary in their approach to the study of the reproductive
system, it is the instructor’s responsibility to determine whether adjustments need
to be made in accordance to the district’s standards. Most students have been
exposed to the material in either their health course or biology course.
As with previous chapters, this chapter provides an opportunity to consider
what ground rules need to be in place when discussing potentially embarrassing
topics. Remind students of the ground rules developed. One way to cover both
the ground rules and their prior knowledge of the reproductive system is to
generate a discussion of reproductive anatomy without using any euphemisms
or slang.
As with other chapters, students can demonstrate their understanding to the feedback
cycles involved in female reproductive cycle by creating visual representations either
digitally or on paper.
Contraception can be an important topic to cover with high school students. One
approach is to have students conduct a role-playing exercise in which students
portray a person in need of contraception, and an advisor. The advisors ask
questions and listen to their “clients” in order to provide the best resources and
options for them.
This chapter is expected to take five class periods.
Case Study
After reading the case study, students should access their online Claim, Evidence,
Reasoning (CER) chart and make their claim. CER is a strategy used to teach
students how to construct explanations and craft scientific arguments. A
scientific claim answers a question or offers a solution to a problem. Give
students time to reflect and brainstorm, then have each student take a clear
stand and write a claim.
As students read the chapter and complete classroom and laboratory
activities, they will collect evidence related to their claim. Scientific evidence
is information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support a
claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
Different birth control methods work in different ways. Discussing the options
can lead to further understanding about the anatomy and physiology of the
reproduction system. The National Institutes of Health website has a
comprehensive website covering contraception.
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Reproductive Systems
357
Introduction to the Theme
Theme: Systems and Model Systems The reproductive system, by producing
offspring, will provide continuity of all species and the systems that run them.
Theme Activity: Discussion Groups - Systems Involved in Reproduction
Many different systems play a role in reproduction. For this activity, have students
get into groups and provide and answer to the following question: how do other
systems and processes relate to sex or affect reproduction? You may want to
jump-start their discussion by asking a question to the class such as “What role does
the skeletal system play in reproduction?” and having students offer answers.
Remind students of the different systems of the human body. See page 605 to help
facilitate these discussion groups
Section 19.1: Introduction
Learn
Classroom Activities
Section 19.1 sets the groundwork for activities in sections 19.2 and beyond.
Practice
Practice Questions
1. What are the male and the female sex cells called?
Male sex cells are sperm and female sex cells are oocytes.
Use the Practices 19.1
Asking Questions Develop a question about the importance of the
reproductive systems to the survival of humans as a species.
Answers will vary. Examples: what would happen to your family tree if you could no
longer reproduce? What would happen to the human race?
Section 19.2: Organs of the Male
Reproductive System
Learn
Classroom Activities
Writing Connection: Organs and their Functions
Prepare a station in the classroom that is labelled with one of the male reproductive
organs (Table 19.1) as well as Figure 19.1 or 19.2 for a visual aid depending on the
organ. Pair students together. Each pair of students will have a worksheet with a
blank table. They will rotate around and write the name of the organ on one of the
lines as well as what the function of the organ is. They will also write down any
question they have about that organ. At the end of the rotation, review student
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questions and choose appropriate questions that will benefit the class through
discussion. Pose the questions to the class and lead a short discussion to ensure
everyone understand the concept in question.
Example table:
Organ Name
Function of Organ
Question about Organ?
Differentiated Instruction
Instead of rotating around the room in pairs, students may prefer to complete
this activity individually. Instead of students asking questions about the organ
structure and function, ask students to research further into major medical
issues related to the male reproductive system such as prostate cancer and
make infertility.
Additional Discussion Questions
Ask students to create a chart that summarizes the organs and functions of the male
reproductive system.
The chart should include information regarding the testis, epididymis, vas deferens, seminal
vesicle, prostate gland, bulbourethral gland, scrotum, and penis.
Give the students a diagram of the male reproductive organs in a sagittal view and
have them trace the path of semen.
Answers will vary.
Discuss various treatments for an enlarged prostate gland.
Responses should include a discussion of surgical removal, radiation, drugs, microwaves,
balloons, liquid nitrogen, and stents.
Practice
Practice Questions
1. Describe the structure of a testis.
The testes are ovoid structures within the cavity of the saclike scrotum. A tough, white,
fibrous capsule encloses each testis. Along the capsule’s posterior border, the connective
tissue thickens and extends into the testis, forming thin septa that divide the testis into
about 250 lobules. A lobule contains one to four highly coiled, convoluted seminiferous
tubules. These tubules unite posteriorly to form a network of channels that join the
epididymis. The epididymis is coiled on the outer surface of the testis and continues to
become the ductus deferens.
2. Where in the testes are the sperm cells produced?
Spermatogenic cells line the seminiferous tubules of the testes.
3. Which cells produce male sex hormones?
Interstitial cells (cells of Leydig) lie in the spaces between the seminiferous tubules and
produce male sex hormones.
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4. Describe the structure of the epididymis.
The epididymis is a network of tightly coiled tubes, each connected to ducts within a
testis. It emerges from the top of the testis, descends along the posterior surface of the
testis, and then courses upward to become the ductus deferens.
5. Trace the path of the ductus deferens.
Each ductus deferens passes upward along the medial side of a testis and through a
passage in the lower abdominal wall (inguinal canal), enters the pelvic cavity, and ends
behind the urinary bladder. Just outside the prostate gland, the ductus deferens unites
with the duct of a seminal vesicle to form an ejaculatory duct, which passes through the
prostate and empties into the urethra.
6. What is the function of a seminal vesicle?
The glandular tissue lining the inner wall of a seminal vesicle secretes a slightly alkaline
fluid, which helps to regulate the pH of the tubular contents as sperm travels to the
outside. Additionally, seminal vesicle fluid neutralizes the acidic secretions of the vagina,
helping to sustain sperm cells that enter the female reproductive tract. Seminal vesicles
also secrete fructose for the sperm cell to use as an energy source, and prostaglandins
which cause the muscles of the female reproductive tract to contract and move the
sperm towards the oocyte.
7. Where is the prostate gland located?
The prostate gland surrounds the proximal part of the urethra, just inferior to the urinary
bladder.
8. What is the function of the bulbourethral glands?
Bulbourethral glands (Cowper’s glands) secrete a mucuslike fluid in response to sexual
stimulation. This fluid lubricates the glans penis in preparation for sexual intercourse.
9. What are the components of semen?
Semen is composed of sperm cells and secretions from the seminal vesicles, prostate,
and bulbourethral glands. Semen contains prostaglandins and nutrients and has a
slightly alkaline pH.
10. Describe the structure of the penis.
The penis is a cylindrical organ that conveys urine and semen through the urethra to the
outside. The body or shaft of the penis has three columns of erectile tissue: a pair of
dorsally-located corpora cavernosa and a single, ventral corpus spongiosum. A tough
capsule of dense connective tissue surrounds each column. Skin, a thin layer of
subcutaneous tissue, and a layer of connective tissue enclose the penis. The corpus
spongiosum enlarges at its distal end to form the cone-shaped glans penis. The glans
covers the ends of the corpora cavernosa and bears the external urethral orifice. The
skin of the glans is very thin and contains sensory receptors for sexual stimulation. A
loose fold of skin called the prepuce (foreskin) originates posterior to the glans and
extends anteriorly to cover it as a sheath.
11. What is circumcision?
Circumcision is a surgical procedure that removes the prepuce (foreskin).
12. What controls blood flow into penile erectile tissues?
During sexual stimulation, parasympathetic impulses from the sacral spine release nitric
oxide, which dilates the arteries leading into the penis, increasing blood flow into erectile
tissues. At the same time, the increasing pressure of arterial blood entering the vascular
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spaces of erectile tissue compresses the veins of the penis, reducing the flow of blood
away from the organ. Consequently, blood accumulates in the erectile tissues and the
penis swells and elongates, producing an erection.
13. Distinguish among orgasm, emission, and ejaculation.
The culmination of sexual stimulation is orgasm, a pleasurable feeling of physiological and
psychological release. Emission is the movement of sperm cells from the testes and secretions
from the prostate gland and seminal vesicles into the urethra, where they mix to form semen.
Emission is the result of sympathetic impulses from the spine. As the urethra fills with semen,
sensory impulses are sent to the sacral spine and in response, motor impulses are conducted
from the spine to certain skeletal muscles at the base of the penile erectile columns,
rhythmically contracting them. This increases the pressure in the erectile tissues and aids in
forcing the semen through the urethra to the outside, a process called ejaculation.
14. Review the events associated with emission and ejaculation.
Emission is a response to sympathetic impulses from the spinal cord, which stimulate
peristaltic contractions in smooth muscle in the walls of the testicular ducts,
epididymides, ductus deferentia, and ejaculatory ducts. During emission, sperm cells and
secretions from the prostate gland and seminal vesicles move into the urethra and mix to
form semen. As the urethra fills with semen, sensory impulses pass into the sacral spine.
In response, motor impulses are conducted from the spinal cord to certain skeletal
muscles at the base of the penile erectile columns, rhythmically contracting them. This
increases the pressure in the erectile tissues and aids in forcing the semen through the
urethra to the outside, a process called ejaculation. The sequence of events during
emission and ejaculation is coordinated so that the fluid from the bulbourethral glands is
expelled first. This is followed by the release of fluid from the prostate gland, the
passage of sperm cells, and finally the ejection of fluid from the seminal vesicles into the
urethra. Immediately after ejaculation, sympathetic impulses constrict the arteries that
supply the erectile tissue, reducing inflow of blood. Smooth muscle in the walls of the
vascular spaces partially contracts, and the veins of the penis carry excess blood out of
these spaces. The penis gradually returns to its flaccid state.
Use the Practices 19.2
Communicating Information Describe the path the male gamete follows from
formation to fertilization of the female gamete.
Sperm originate in the testes. They mature as they make their way through the epididymis.
The testes are constantly making sperm throughout a man’s life, but unused sperm are
reabsorbed. Mature sperm travel through the vas deferens and are ejaculated out of the
urethra.
Section 19.3: Spermatogenesis
Learn
Classroom Activities
Visual Literacy: Steps of Spermatogenesis
Put students into pairs and provide them a printout of the steps of spermatogenesis
(see figure 19.3). Students will cut out each circle stage and mix them up. Students
should take turns putting the circles in the correct order of flow that meiosis occurs
CHAPTER 19
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361
(I and II). Once students have practiced, have them write three questions to ask
another group. Question should be about how sperm are created and the internal
steps involved in the male reproductive organs that allows sperm to be ejaculated
for sexual reproduction. Group student pairs together so they can ask each other
their questions and discuss their responses.
Differentiated Instruction
Instead of students receiving a printed copy and reorganizing, students may
choose to artistically draw the steps of meiosis. Each student can draw their
own flow chart of meiosis and then have them to study. Groups should still
create and ask each other the review questions and possibly present their own
drawings to the small group.
Additional Discussion Questions
Explain how spermatogenesis begins with 46 chromosomes and ends with
23 chromosomes.
Responses should emphasize two successive meiotic divisions. The first meiotic division results
in secondary spermatocytes and the second meiotic division results in spermatids.
Ask students to develop a chart that compares the processes of spermatogenesis
and oogenesis.
Emphasis should be placed on the hormones involved, the time needed to complete the process,
structures involved, and the concepts of mitosis and meiosis.
Practice
Practice Questions
1. Explain the function of supporting cells in the seminiferous tubules.
The epithelium of the seminiferous tubules consists of sustentacular cells (Sertoli cells) and
spermatogenic cells. Sustentacular cells support, nourish, and regulate the spermatogenic
cells.
2. Review the events of spermatogenesis.
In the male embryo, the undifferentiated spermatogenic cells are called spermatogonia.
Each spermatogonium contains 46 chromosomes (23 pairs) in its nucleus. Beginning
during embryonic development, hormones stimulate spermatogonia to undergo mitosis.
Each cell division gives rise to two new cells, one of which (type A) maintains the supply
of undifferentiated cells, the other of which (type B) differentiates, becoming a primary
spermatocyte, and the process pauses until puberty. At puberty mitosis resumes and new
spermatogonia form. Testosterone increases and primary spermatocytes reproduce by
meiosis. Meiosis includes two successive divisions, called the first and second meiotic
divisions. The first meiotic division separates homologous chromosome pairs, resulting in
a haploid cell with 23 chromosomes called a secondary spermatocyte. The secondary
spermatocytes undergo the second meiotic division to produce spermatids. Spermatids
mature into sperm cells and the process of spermatogenesis is complete and will repeat
in this fashion throughout the life of the male.
3. Describe the structure of a sperm cell.
A mature sperm cell is a tadpole-shaped structure that consists of a flattened head,
cylindrical midpiece (body), and elongated tail. The head of the sperm contains the
nucleus and its chromosomes. A small protrusion of the head, called the acrosome,
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contains enzymes that aid the sperm cell in penetrating the layers surrounding the oocyte
during fertilization. The midpiece (body) of a sperm cell has a central, filamentous core
with many mitochondria that provide the sperm cell with energy necessary for propelling
its tail. The tail of a sperm cell consists of several microtubules.
Use the Practices 19.3
Using Models Create a graphic organizer to summarize the events of
spermatogenesis.
Answers will vary
Figure Questions
Figure 19.3, page 702: Why is it important that a sperm possess only 23 chromosomes?
It is important for the sperm and egg to each possess 23 chromosomes, so that upon fertilization
of the egg by the sperm, the developing zygote will have the full complement of 46 chromosomes
(no more, no less) found in human body cells.
Section 19.4: Electrolyte Balance
Learn
Classroom Activities
EL Strategy: Listening and Speaking
Advanced Tell students to listen without taking notes while you read aloud
the paragraphs for each topic. After you have finished, have students write
down what they remember from your reading. Have students work in small
groups to compare their notes. Then have each group write a summary of their
understanding. Once you have modeled the reading, students can take turns
reading the paragraphs to each other and repeating the steps (listen, note,
compare, summarize).
Visual Literacy: Hormone Regulation
Briefly discuss with students how the hypothalamus regulates testosterone output
through negative feedback. You may also want to discuss how other negative feedback
loops work in other areas of the body. After the class discussion, put students in pair
and have them label the three organs involved in this feedback loop (Figure 19.6) and
the results of testosterone stimulation also known as secondary sex characteristics.
Differentiated Instruction
Instead of labelling the organs, students could label the blue, red, and green
arrows. Remove the key from the image above and have them describe what
each color means and why. Students should also still identify the results of
testosterone stimulation also known as secondary sex characteristics.
Demonstration: The Many Twists of Meiosis
This activity will focus on reproduction at the cellular level.
Using black and red licorice, students will model the process of meiosis and
crossing over. In this way, students can easily visualize variation that meiosis
creates in a population.
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This activity may be done separately, in pairs, or in small groups. Provide students
with four pieces of licorice in two different colors (longer varieties, such as Red
Vine© work best) and a pair of scissors. Students will use these pieces of licorice to
represent chromosomes in a cell.
As you review the stages of meiosis, students will create a moving model using the
strips of licorice. Have students cut pieces of the licorice when synapsis occurs to
represent the exchange of genetic material during crossing over. Discuss what the
effects of this recombination represents.
Additional Discussion Questions
What would be the result of a failure of the testes to descend from the abdomen
into the scrotum?
Sterility would most likely result, since the temperature in the abdomen, when compared to the
temperature in the scrotum, is too warm for sperm to fully mature.
Discuss the clinical characteristics normally assessed during male fertility testing.
Responses should include a discussion of volume, sperm cell density, percent motility, sperm
cell density, average velocity, morphology, and the presence of white blood cells.
Practice
Practice Questions
1. Which hormone initiates the changes associated with male sexual maturity?
Testosterone is secreted by the testes, which begins during fetal development and continues
for several weeks following birth, but nearly ceases until puberty. At puberty, testosterone
secretion increases and is responsible for the changes associated with male sexual maturity.
2. Describe several male secondary sex characteristics
Male secondary sex characteristics include: increased growth of body hair, lowering the
pitch of the voice, enlargement of the larynx, thickening of the skin, increased muscular
growth, thickening and strengthening of the bones, etc.
3. List the functions of testosterone.
Testosterone stimulates enlargement of the testes and accessory organs of the
reproductive system, as well as development of male secondary sex characteristics.
Testosterone increases the rate of cellular metabolism and red blood cell production.
Testosterone stimulates sexual activity by affecting certain parts of the brain.
4. Explain how the secretion of male sex hormones is regulated.
Increasing blood testosterone concentration inhibits the hypothalamus, and hypothalamic
stimulation of the anterior pituitary gland by GnRH decreases. As the pituitary gland’s
secretion of LH falls in response, testosterone release from the interstitial cells decreases.
As the blood testosterone concentration drops, the hypothalamus becomes less inhibited,
and it once again stimulates the anterior pituitary gland to release LH. Increasing LH
secretion then causes interstitial cells to release more testosterone, and the blood
testosterone concentration increases.
Use the Practices 19.4
Using Models Diagram the negative feedback system that controls testosterone
levels in the male body.
See figure 19.6 as an example
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Section 19.5: Organs of the Female
Reproductive System
Learn
Classroom Activities
Writing Connection: Reproductive Organ T-Chart
This is an individual activity. Students will create a T-chart to compare internal
accessory reproductive organs and external accessory reproductive organs. Once
students sort each reproductive organ into the correct column, they should describe
the major function of each organ.
Differentiated Instruction
Students may work in groups and prefer to label Figure 19.7 as a visual of which
organs are located internally and which ones are external. Students should still
describe the function of each organ.
Additional Discussion Questions
Ask students to develop a flowchart that illustrates the process of oogenesis from a
single ovarian cell to a zygote.
The flowchart should include information regarding a primary oocyte, first meiotic division,
secondary oocyte, fertilization, second polar body, second meiotic division, and a zygote.
Discuss the importance of a Pap smear.
The discussion should emphasize the detection of cervical cancer.
Provide students with various microscopic slides of the uterine wall and ask them to
draw and identify what they observe.
Students should be able to identify the lumen, endometrium, myometrium, and perimetrium.
Provide students with an anatomical model and ask them to trace the movement of
an ovum through the female reproductive system.
Discussion should emphasize the process of ovulation, movement through the uterine tube, etc.
Comment on the hormones that are involved in the process if the ovum is/is not fertilized.
Practice
Practice Questions
1. What are the primary sex organs of the female?
The female primary sex organs are the two ovaries.
2. Describe the structure of an ovary.
The ovaries are ovoid structures that lie in shallow depressions in the lateral wall of the
pelvic cavity. Ovarian tissues are divided into two indistinct regions: an inner medulla
and an outer cortex. The ovarian medulla is mostly composed of loose connective tissue
and contains many blood vessels, lymphatic vessels, and nerve fibers. The ovarian cortex
consists of more compact tissue and has a granular appearance due to tiny masses of
cells called ovarian follicles. A layer of cuboidal epithelium covers the ovary’s free surface.
Just beneath this epithelium is a layer of dense connective tissue.
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3. Describe a primordial follicle and the cell it contains.
A primordial follicle is found in the outer region of the ovarian cortex. Each follicle
contains a single primary oocyte surrounded by epithelial follicular cells.
4. Approximately, how many primary oocytes are present at birth? At puberty?
Approximately one million are present at birth, and 300,000 at puberty.
5. How is a secondary oocyte moved along a uterine tube?
Simple columnar epithelial cells, some ciliated, line the uterine tube. The epithelium
secretes mucus, and the cilia beat toward the uterus. These actions help draw the
secondary oocyte and expelled follicular fluid into the infundibulum following ovulation.
Ciliary action and peristaltic contractions of the uterine tube’s smooth muscle layer aid
transport of the oocyte down the uterine tube.
6. Describe the structure of the uterus.
The uterus is a hollow, muscular organ located medially in the anterior part of the pelvic
cavity, superior to the vagina, and usually bends forward over the urinary bladder. The
upper two-thirds or body of the uterus has a dome-shaped top called the fundus. The
uterine tubes connect at the upper lateral edges of the uterus. The lower third of the uterus
is called the cervix and extends downward into the upper part of the vagina. The uterine
wall is thick and has three layers: endometrium, myometrium, and perimetrium. The inner
endometrium is covered with columnar epithelim and contains abundant tubular glands.
The middle myometrium consists of bundles of smooth muscle cells. The outer perimetrium
consists of a serosal layer, which covers the body of the uterus and part of the cervix.
7. Describe the structure of the vagina.
The vagina is a muscular tube extending from the uterus to the outside of the body. It is
posterior to the urinary bladder and urethra, anterior to the rectum, and attached to these
structures by connective tissues. A thin membrane of connective tissue and stratified
squamous epithelium called the hymen partially covers the vaginal orifice. The vaginal
wall has three layers: mucosal, muscular, and fibrous. The inner mucosal is stratified
squamous epithelium and lacks mucous glands. The middle muscular consists of smooth
muscle in an outer circular layer and inner longitudinal layer. The outer fibrous consists of
dense connective tissue interlaced with elastic fibers.
8. What is the male counterpart of the labia majora? Of the clitoris?
The labia majora correspond to the scrotum of the male. The clitoris corresponds to the
penis in males.
9. Which structures are within the vestibule?
The vestibule contains the vagina, the urethra, the clitoris, and a pair of vestibular glands.
10.What events result from parasympathetic stimulation of the female reproductive
organs?
Erectile tissues in the clitoris and around the vaginal entrance respond to sexual
stimulation. Following such stimulation, parasympathetic impulses from the sacral spine
cause the release of nitric oxide, which dilates the arteries associated with the erectile
tissues. As a result, blood inflow increases, erectile tissues swell, and the vagina expands
and elongates. If sexual stimulation is sufficiently intense, parasympathetic impulses
stimulate the vestibular glands to secrete mucus into the vestibule, moistening and
lubricating the tissues surrounding the vestibule and lower end of the vagina, facilitating
insertion of the penis.
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11. What changes occur in the vagina just prior to and during orgasm?
Just prior to orgasm, the tissues of the outer third of the vagina engorge with blood and
swell. Orgasm initiates a series of reflexes involving the sacral and lumbar spine. In
response to these reflexes, the muscles of the perineum and the walls of the uterus and
uterine tubes contract rhythmically. These contractions help transport sperm cells
through the female reproductive tract toward the upper ends of the uterine tubes.
Use the Practices 19.5
Constructing Explanations During spermatogenesis, the cytoplasm from the
primary spermatocyte is distributed evenly between sperm cells. During
oogenesis, the cytoplasm is distributed unequally. Explain why unequal
distribution of cytoplasm in oogenesis is advantageous.
Unlike sperm, the egg cell must contain the cytoplasm and organelles required to
carry the zygote thought the first few cell divisions. This is why the egg is the largest
cell in the human body, and the sperm is the smallest. The advantage of the oocyte
dividing unequally, allows for the maximum amount of cytoplasm and organelles to be
in one cell.
Section 19.6: Hormonal Control of
Female Reproductive Functions
Learn
Classroom Activities
EL Strategy: Information in Pictures
Intermediate Instruct a small group of students to write a paragraph
describing what is happening in Figure 19.10 (Oogenesis). Their paragraphs
should describe all parts of the cycle in their own words. Ask for volunteers to
read their paragraphs. Have students ask for clarification as needed.
Writing Connection: Group Jigsaw
Put students into groups of four. Each member of the group is assigned a job to
find more information about. The four jobs of each group are: oogenesis,
menstrual cycle, female infertility, menopause. Each group member should gather
enough information, pictures, tables needed to teach their group about their
assignment. After each group has assigned each member a job, the teacher will
have all of the members assigned similar categories conduct research together.
For example, everyone from each group that is assigned oogenesis will meet
together and find information together. The same with the other assignments.
Provide students access to the textbook, internet, and books to complete their
research. Once all members have their research complete, they will return to their
original group to take turns presenting what they learned. Each group will
combine their information into one presentation. The teacher may have students
present them or just turn them in.
Differentiated Instruction
Students are completing the jigsaw activity with the four categories above, but
to limit time, have each group of four students work in pairs and only research
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two categories: oogenesis and the menstrual cycle. Each pair can then share
what they learned with the other pair. Each group should make a copy of their
information so that each member will get information on both assignments.
Additional Discussion Questions
Compare the secondary sex characteristics of the male and female.
Discuss the major similarities and differences, in terms of growth of body hair, larynx, integument,
muscular changes, skeletal changes, etc.
Ask students to create a poster that illustrates and compares the major events of
the ovarian cycle and menstrual cycle.
The poster should address the follicular and luteal phases of the ovarian cycle, and menstruation,
proliferative phase, and secretory phase of the menstrual cycle in terms of major events, timing,
endometrial thickness, and hormonal concentrations.
Discuss concerns related to this chapter objective for young, female athletes who
train vigorously.
Irregular menstrual flow and decreased estrogen levels, which may lead to osteoporosis, are
concerns for serious, competitive, female athletes in training.
Ask students to create a set of index cards, each of which contains a key phrase
representing a major step in the process of menstruation. Based on the key phrase,
ask students to describe, in more detail, that particular step.
Suggestions for key phrases include FSH secretion, follicle maturation, estrogen secretion,
LH stimulates ovulation, corpus luteum cells appear, corpus luteum degenerates, uterine
lining vessels constrict, uterine lining sloughs off, secretion of FSH and LH, and menstrual
cycle repeats.
Practice
Practice Questions
1. Describe changes that occur in a follicle and its oocyte during maturation.
During early follicle maturation, the primary oocyte within the follicle enlarges, and
surrounding follicular cells proliferate by mitosis. These follicular cells organize into
layers, and eventually a cavity (antrum) appears in the cellular mass. The structure is now
called an antral follicle. A clear follicular fluid fills the antrum. The antral follicle enlarges
and bulges outward on the ovary surface. The primary oocyte within the mature antral
follicle is surrounded by a layer of glycoprotein called the zona pellucida, with layers of
follicular cells called the corona radiate. Processes from these follicular cells extend
through the zona pellucida and supply nutrients to the primary oocyte. One dominant
follicle develops fully and the remaining follicles degenerate.
2. What causes ovulation?
Release of LH from the anterior pituitary gland plays a role in triggering ovulation.
3. What happens to an oocyte following ovulation?
After ovulation, the secondary oocyte and one or two layers of follicular cells surrounding
it are normally propelled to the opening of a nearby uterine tube. If the secondary oocyte
is not fertilized within hours, it degenerates.
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4. What stimulates sexual maturation in a female?
The hypothalamus begins to secrete increasing amounts of GnRH, which, in turn,
stimulates the anterior pituitary to release FSH and LH. These hormones play primary
roles in controlling female sex cell maturation and in producing female sex hormones.
5. What is the function of estrogens?
Estrogens stimulate enlargement of reproductive organs, including the vagina, uterus,
uterine tubes, ovaries, and external reproductive structures. Estrogens also develop and
maintain the female secondary sex characteristics.
6. What is the function of androgen in a female?
Androgens produce increased hair growth in the pubic and axillary regions in females at
puberty.
7. Trace the events of the menstrual cycle.
The anterior pituitary secretes FSH and LH. FSH stimulates maturation of a dominant
follicle. Follicular cells produce and secrete estrogens, which thickens the endometrium.
The anterior pituitary releases a surge of LH, which leads to ovulation. Follicular cells
become corpus luteum cells, which secrete estrogen (stimulating the uterine wall) and
progesterone (stimulating the endometrium to become more glandular and vascular).
Estrogen and progesterone inhibit the secretion of FSH and LH. If secondary oocyte is
not fertilized, corpus luteum degenerates and no longer secretes estrogen and
progesterone. As the concentrations of estrogens and progesterone decline, blood
vessels in the endometrium constrict. The uterine lining disintegrates and sloughs off,
producing menstrual flow. Anterior pituitary is no longer inhibited and again secretes
FSH and LH, repeating the cycle.
8. What causes menstrual flow?
When the corpus luteum ceases to function, concentrations of estrogens and progesterone
rapidly decline, and in response, blood vessels in the endometrium constrict. This reduces the
supply of oxygen and nutrients to the thickened endometrium and these lining tissues soon
disintegrate and slough off. At the same time, blood leaves damaged capillaries, creating a
flow of blood and cellular debris that passes through the vagina as menstrual flow.
9. What are some changes that may occur at menopause?
Reduced concentrations of estrogens and lack of progesterone can cause the breasts,
vagina, uterus, and uterine tubes to shrink and the pubic and axillary hair may thin.
Use the Practices 19.6
Using Mathematics Hormonal birth control often contains synthetic forms of
progesterone and estrogen. The pills are taken daily for the entirety of the
menstrual cycle, because the hormones are metabolized by the kidneys within
24 hours. Create a graph depicting blood concentrations of estrogen and
progesterone, throughout the menstrual cycle, in an individual taking oral
birth control.
Students should create a graph showing that estrogen and progesterone levels reach a
peak and then decline over every 24 hour period.
Figure Questions
Figure 19.11, page 714: Which structure is formed by the follicular cells attached to and
surrounding the secondary oocyte?
corona radiata
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Section 19.7: Mammary Glands
Learn
Classroom Activities
Writing Connection: Mammary Glands in Males and Females
Discuss with students a brief overview of how mammary glands are structured
and differences between males and females. Present students with the following
case study:
Case Study: A female in her early twenties had been monitoring her mammary gland
development. One breast was not changing as she went through puberty while the
other seemed to develop normally. She went to the doctor to better understand what
could be going on.
Ask students to explain how the structure of a breasts in females develops through
puberty and to predict one reason why the one breast is not developing. Students
should use structural evidence in their response.
Differentiated Instruction
Instead of using the case study, ask students to discuss in group the different
and similar structural characteristics of the breast and mammary glands in males
and females. Student groups may take notes of their discussion. Encourage
each student to contribute one time to the conversation and to reply one time
to of their classmates.
Additional Discussion Questions
Discuss the best preventive measures against breast cancer.
Responses should include a discussion of baseline and yearly mammograms.
Discuss the similarities and differences in the development of the male/female breast.
Some similarities do exist. Emphasize the role of ovarian hormones, the enlargement of the
alveolar glands and ducts, and the formation of fat deposits.
Practice
Practice Questions
1. Describe the structure of a mammary gland.
Mammary glands are accessory organs of the female reproductive system specialized
to secrete milk following pregnancy and located in the breasts. A mammary gland is
composed of fifteen to twenty lobes. Each lobe contains glands (alveolar glands)
drained by alveolar ducts, which drain into a lactiferous duct. Lactiferous ducts lead to
the nipple and open to the outside. Adipose and dense connective tissues separate
the lobes.
2. How does ovarian hormone secretion change the mammary glands?
Ovarian hormones stimulate development of the mammary glands, enlarging the alveolar
glands and ducts, and depositing fat around and within the breasts.
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Use the Practices 19.7
Arguing from Evidence Males and females have mammary glands. Explain
why only females develop mammary glands capable of producing milk.
During puberty, ovarian hormones stimulate gland development. Males, lacking ovaries,
do not develop glands.
Section 19.8: Birth Control
Learn
Classroom Activities
Presentation Activity: Contraception Types
Briefly discuss with students that contraceptives are forms of birth control or ways
to avoid fertilization of an egg cell following sexual intercourse. There are many
degrees and effectiveness differences between each type. Assign each group one
form of contraceptive to research and present to the class about. They should
include what the contraceptive is, how it works or prevents fertilization, if there are
any risks associated with it.
•
•
•
•
•
•
•
Coitus interruptus
Rhythm method
Mechanical barriers
Chemical barriers
Hormone contraceptives
Intrauterine devices
Sterilization
Differentiated Instruction
Instead of students presenting to the class, each group can make an awareness
poster to hang in the classroom. Have students take a gallery walk to learn
more about each type of contraceptive and any potential dangers or risks. The
teacher could invite an obstetrician into the classroom to discuss the process
of fertilization and how technology has helped develop the different
contraceptives in use today.
Writing Connection: Reproductive Health Pamphlet
Depending on your school district’s approach to teaching about the reproductive
system, pick a topic that is appropriate for your guidelines. Students will then create
a pamphlet on this topic, as one would find in a doctor’s office.
Have students include up-to-date statistics on the topic. If the pamphlet is on a
disease, suggest they include information on prevention or treatment. If the
pamphlet is on a naturally occurring cycle, suggest students include relevant charts
or diagrams
Examples of topics: sexually transmitted infections, types of contraception,
changes to the body during puberty, stages of the menstrual cycle, or cancers in
the reproductive system
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Additional Discussion Questions
Compare a variety of birth control methods.
Ask students to report on the cost, safety, effectiveness, and practicality of each method.
Divide the class into two groups. One group supports birth control, the other does
not. Allow students an opportunity to debate the issues.
Responses will emphasize the moral, legal, ethical, and economical ramifications of both factions.
Practice
Practice Questions
1.What factors make the rhythm method less reliable than some other methods
of contraception?
The rhythm method requires abstinence from sexual intercourse two days before and one
day after ovulation, which is often difficult to ascertain. The rhythm method also requires
adherence to a particular pattern of behavior and restricts spontaneity in sexual activity.
2. Describe two methods of contraception that use mechanical barriers.
The male condom is a thin latex or natural membrane sheath placed over the erect penis
before intercourse to prevent semen from entering the vagina upon ejaculation. A female
condom resembles a small plastic bag and is inserted into the vagina prior to intercourse,
blocking sperm cells from reaching the cervix.
3. How do combined hormone contraceptives prevent pregnancy?
Combined hormone contraceptives deliver estrogen and progestin to prevent pregnancy.
These drugs disrupt the normal pattern of FSH and LH secretion, preventing follicle
maturation and the LH surge that leads to ovulation. They also thicken cervical mucus to
prevent the sperm from joining an oocyte.
Use the Practices 19.8
Communicating Information A variety of contraceptive methods provide
birth control. Create a table identifying four types of contraception, how they
work, and their success rates (if used correctly).
Answers will vary by student.
Contraceptive Method
and Example
Chemical barrier
Example: spermicide
Combined Hormone
Example: Birth Control Pill
Intrauterine Devices
Example: IUD
Sterilization
Example: tubal ligation
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How it Works
Success Rate
(if used correctly)
Creates unfavorable
environment for sperm
High failure rate
Deliver estrogen/progestin
to disrupt normal hormone
patterns
Nearly 100%
Interferes with fertilization and Nearly 100% (up to 5 years)
implantation (may contain
hormones)
Uterine tubes are cut and
ligated to block sperm from
reaching egg
The Human Life Cycle
Most reliable form
Figure Questions
Figure 19.15, page 723: Which of these methods of birth control uses hormones to
prevent pregnancy?
Section 19.9: Sexually Transmitted
Infections
Learn
Classroom Activities
Writing Connection: STI Diagnosis
Provide students Table 19.4 which describes some of the diseases associated with
sexually transmitted infections. Put students in pairs and provide them with a few
case studies, examples below. Student will read the case study and use Table 19.4 to
predict the most likely diagnosis. Ask students to use evidence from the case study
and the table to defend their diagnosis.
Case Study 1: A patient reported to the doctor that they are having a fever as well
as sore spots in their genital region. (Answer: genital herpes)
Case Study 2: A patient reported to the doctor that they had a long time ago a rash
that appeared near their mouth, since then they haven’t reported any issues, but
now years later they are having liver failure, heart failure, and other nervous system
issues. (Answer: syphilis)
Case Study 3: A male patient reported to the doctor that they have painful urination
but no other symptoms. The doctor tested for a urinary tract infection, but the
results were negative. (Answer: gonorrhea)
Case Study 4: A patient reported to the doctor that they get sick very quickly and
over the past few years it seems to happen even faster. They feel weak and get
fevers with infections all the time. (Answer: AIDS)
Case Study 5: A patient reported to the doctor that they are having mucous discharge
from the vagina and it hurts during urination as well as intercourse. (Answer: chlamydia)
Case Study 6: A patient reported to the doctor that they have small bumps that look
like a wart in their genital area. (Answer: genital warts)
Differentiated Instruction
Instead of student reviewing the case studies, each student could choose to
research a type of sexually transmitted infection. They could research which
types of cultures and areas in the United States and World have outbreaks and
if there are any preventative measures during intercourse that could prevent
the spread of the infection.
Additional Discussion Questions
Show a videotape that illustrates the devastating effects of STDs.
A videotape will make an impression on students and will incite some very interesting
discussions. Emphasize the physiological, emotional, and psychological effects of STDs on
patients and families.
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Discuss various combinations of STD symptoms that should be brought to the
attention of a physician.
Responses should include a discussion of painful urination, abdominal pain, fever, swollen glands,
discharge, inflammation, painful intercourse, sores, rash, or itchy, runny eyes.
Practice
Practice Questions
1.Why is the term sexually transmitted infection replacing the term sexually
transmitted disease?
The term sexually transmitted infection is replacing the term sexually transmitted disease
because a person can be infected with a pathogen and transmit the pathogen to others
but not develop the symptoms of the disease.
2.What are some common symptoms of diseases associated with sexually
transmitted infections?
Common symptoms of diseases associated with sexually transmitted infections include:
burning sensation during urination, pain in the lower abdomen, fever or swollen glands in the
neck, discharge from the vagina or penis, pain, itching, or inflammation in the genital or anal
area, pain during intercourse, sores, blisters, bumps, or a rash anywhere on the body, etc.
Use the Practices 19.9
Conducting Investigations For any one of the sexually transmitted infections
listed in Table 19.4, plan an investigation to identify the pathogen that causes
the infection.
Answers will vary. Accept answers that show an understanding of experimental design.
Assess
Career Corner: Nurse-Midwife
Consider This: Imagine you are conducting an informational interview with a
certified nurse-midwife. Prepare a list of questions to ask during the interview.
Answers will vary. Accept those that show students conducted appropriate research.
Diseases, Diagnosis, and Treatment: Prostate Cancer
1. What is the role of the prostate in the male reproductive system?
The prostate gland secretes a fluid which contains nutrients for the sperm and an
enzyme that helps to liquify semen.
2. How do health care professionals screen for prostate cancer?
Health care professionals conduct rectal exams to feel for an enlarged prostate gland
and conduct blood tests.
Diseases, Diagnosis, and Treatment: Male Infertility
1. What organs in the male reproductive system are involved in male infertility?
mainly the testes
2. What are some causes of male infertility?
undescended testes, misshapen sperm cells, low sperm counts, and others
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Healthy Lifestyle Choices: Disruption of Menstrual Cycle
1. What is the difference between oligomenorrhea and amenorrhea?
Oligomenorrhea is low menstrual flow while amenorrhea is the complete stoppage of
menstrual flow.
2. Why would extremely low body fat affect the menstrual cycle?
Adipose tissue (fat) secretes leptin, which is associated with lowered secretions of GRH,
which in turn lowers blood estrogen.
Diseases, Diagnosis, and Treatment: Female Infertility
1. Define endometriosis.
Endometriosis is when pieces of the uterine lining move through the uterine tubes during
menstruation and attach in other areas of the abdominal cavity.
2. How are ultrasounds used in diagnosing infertility?
Ultrasounds can identify the presence and appearance of reproductive organs and
structures.
Case Study Connection
page 698: Trace the path of the donated sperm.
Sperm are formed in the testes, and then travel through the epididymis which becomes the
ductus deferens. The ductus deferens is a muscular tube which passes alongside the testis
and through the abdominal wall. The ductus deferens merges with the seminal vesicle to
form the ejaculatory duct, which empties into the urethra. The urethra travels through the
penis and is the pathway for ejaculation.
page 700: In some cases, sperm for donation are harvested directly from the
testes, rather than through semen collection. Would the material collected be
different in these two procedures? If so, how?
Students should identify that sperm collected directly from the testes would be in a sample
containing just sperm cells and interstitial cells. A sample in semen collection would contain
other cell types and enzymes.
page 709: Using this diagram, compare and contrast the path of sperm to the
egg versus the path of the needle in egg retrieval. Why do you think they take
different paths?
Students should identify that sperm travels into the uterine tube to unite with the egg, while
a collection needle would enter the ovary directly.
page 715: The first hormone Sherrie injects causes several ovarian follicles to
mature. Which reproductive hormone was this? The second hormone Sherrie
injects bring the eggs close to being released. What hormone is this one?
follicle maturation: FSH; ovulation: LH
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Chapter Assessment
Chapter Review Questions
Multiple Choice
1. General functions of the male and female reproductive
systems include:
a. producing sex cells
b. transporting sex cells to sites of fertilization
c. secreting hormones
d. all of the above
2. Which is not a secondary organ of the male reproductive
system?
a. prostate gland
b. penis
c. testes
d. scrotum
3. What is the function of the prostate gland?
a. secrets fluid that lubricates the end of the penis
b. secretes citrate to nourish semen
c. secretes an alkaline fluid to regulate semen pH
d. produces sperm cells
4. What is a second polar body?
a. a secondary oocyte
b. an ovum
c. a cell that allows for oocyte production
d. a cell with 46 chromosomes
Short Answer
1. List the structures of the male reproductive system.
The testes, epididymis, penis, urethra, seminal vesicle, prostate
gland, and bulbourethral gland.
2. What is the function of the seminal fluid? Which glands
contribute to it?
Seminal fluid, or semen, contains contributions from the testes,
seminal vesicles, prostate gland, and bulbourethral glands.
Sperm cells, prostaglandins, and nutrients are found in semen.
3. Describe the structure of testicle.
The testicles are oval shaped organs found in the scrotum.
Internally they are divided into lobules that contain
seminiferous tubules that converge into the epididymis.
4. Where are sperm cells produced?
Sperm cells are produced in the seminiferous tubules of the testes.
5. Distinguish between a primary spermatocyte and a
spermatid.
A primary spermatocyte is formed from spermatogonia by way
of mitosis. It is diploid. A primary spermatocyte then goes
through meiosis to become a secondary spermatocyte, which
is haploid. Secondary spermatocytes go through another
meiotic division to become spermatids. They then mature into
sperm cells.
5. What occurs during menstrual flow?
a. the uterine lining disintegrates and sloughs off
b. ovulation takes place
c. the corpus luteum forms
d. FSH and LH are highest
6. Why are the testes not found in the abdominal cavity?
6. Do male humans have mammary glands?
a. no
b. yes, but only after puberty
c. yes, but only before puberty
d. yes, but they are nonfunctional
7. Describe the role if testosterone in puberty and adulthood.
7. Which birth control method is incorrectly matched with its
description?
a. rhythm method – penis removed from vagina before
ejaculation
b. condom – keeps sperm from entering cervix
c. spermicide – kills sperm
d. vasectomy – sperm cells never reach penis
8. Painful urination is most likely a symptom of
a. AIDS
b. gonorrhea
c. syphilis
d. herpes
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UNIT 6
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The Human Life Cycle
Testes are found outside of the abdominal cavity to ensure
that they maintain the correct temperature for sperm cell
production.
During puberty testosterone stimulates development of the
testes and accessory organs of the reproductive system. It also
stimulates development of male secondary sex characteristics:
increased growth of body hair, enlargement of the larynx for a
deeper voice tone, thickening of the skin, and increased
muscle and bone growth. Testosterone levels slowly decline
through adulthood.
8. List the internal structures of the female reproductive
system.
The internal female reproductive organs are: ovaries, uterine
tubes, uterus, cervix, and vagina.
9. What is the corpus luteum?
The corpus luteum is a temporary glandular structure formed
by the remnants of the follicle after ovulation. It secretes
progesterone and estrogens.
10. Where does fertilization take place?
Fertilization usually takes place in the uterine tube.
11. List the external female reproductive structures.
The external female reproductive organs are: labia major,
labia minor, clitoris, and the vestibule.
12. Describe the stages of the ovarian (menstrual) cycle.
Following menstruation is the follicular phase where the
mature follicle develops under the influence of FSH. Ovulation
occurs at about day 14 where the follicle is released. If
pregnancy does not occur the corpus luteum will degenerate
during the luteal phase. The next phase is menstruation.
14. Distinguish between mechanical and chemical barriers of
contraception.
Mechanical barriers actually block the sperm cells from
entering the female reproductive tract during intercourse.
Chemical barriers have spermicidal properties either killing
sperm cells or creating an unfavorable environment for the in
the vagina.
15. Distinguish between genital warts and gonorrhea.
Genital warts are found on the genitals and are removed with
chemicals or surgery. Gonorrhea is caused by a bacterium and
can be treated with antibiotics.
13. Why is the rhythm method of birth control unreliable?
It is very hard to know exactly when ovulation will occur and how
long the oocyte will stay viable in the female reproductive tract.
Critical Thinking and Clinical Applications
1. CLINICAL Connection If an adult male had his testes
removed, what would happen to levels of FSH, LH, and
testosterone in his blood?
Testosterone would be absent. LH and FHS levels would
increase.
2. WRITING Connection Birth control pills for women
contain estrogen and progesterone. Explain how these
hormones can prevent pregnancy, when they are also
naturally produced by the body.
They inhibit FSH and LH secretion, preventing follicle
maturation and the LH surge that leads to ovulation.
3. Some men are unable to become fathers because their
spermatids do not mature into sperm. Injection of their
spermatids into their partners’ secondary oocytes sometimes
results in conception. Men have fathered healthy babies this
way. Why would this procedure work with spermatids, but
not with primary spermatocytes?
Primary spermatocytes divide to form secondary
spermatocytes, and then can mature into sperm, but this
process of spermatogenesis only occurs properly in the testis.
Spermatids only need maturation time to become sperm,
which can happen outside the testis.
Lab Data Analysis: Exercise and Estrogen
1. How does the total estradiol exposure compare between
women who did no exercise and those who exercised for
150 minutes or more per week?
The women exercising 150 minutes per week or more
(represented graphically as the dashed line) have lower
estradiol exposure at every point of the menstrual cycle, from
day 0-28 (shown along the x-axis).
2. Explain the pattern of rising and falling estradiol levels
shown in both groups.
The rising and falling estradiol levels represent hormonal
changes during the menstrual cycle.
CHAPTER 19
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377
CHAPTER
20
Pregnancy, Growth,
Development, and
Genetics
Section
Pacing
(class periods)
Learning Objectives
—
1. Distinguish between growth and development.
20.1 Introduction
2. Distinguish between prenatal and postnatal.
20.2 Fertilization
1
1. Describe fertilization.
20.3 Pregnancy and the
Prenatal Period
1
1. List and provide details of the major events of
cleavage.
2. Describe implantation.
3. Describe the extraembryonic membranes, as
well as the formation and function of the
placenta.
4. List the structures produced by each of the
primary germ layers.
5. Describe the major events of the fetal stage
of development.
6. Trace the path of blood through the fetal
cardiovascular system.
7. Discuss the hormonal and other changes in
the maternal body during pregnancy.
8. Explain the role of hormones in the birth
process and milk production.
20.4 Aging: The Human
Life Span
1
1. Describe the major cardiovascular and other
physiological adjustments in the newborn.
2. Describe the stages of postnatal development.
20.5 Genetics
2
1. Distinguish among the modes of inheritance.
2. Describe the extensions of Mendelian
inheritance.
Focus Activity Workbook
Focus Activities: Labeling (10)
Focus Activities: Vocabulary (4)
Chapter Resources
Extended Summary Review
Chapter 20 Test Bank
Chapter 20 Interactive Question Bank
Vocabulary Flashcards
APR Module 14: Reproductive Systems
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UNIT 6
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The Human Life Cycle
A Suggested Approach
As with the prior chapter, it up to the teacher to determine whether adjustments
need to be made in accordance to the district’s standards.
Students could use the ELISA testing method to perform a fake pregnancy test.
Additionally, the students could provide advice to sample couples on the development
of their fetus.
As most students have been introduced to genetics in their biology course, they
could develop a presentation that describes how chromosomes are passed along
through sexual reproduction. Additionally, students could perform a karyotype on
sample couples and provide genetic advice based on results.
This chapter is expected to take five class periods.
Case Study
After reading the case study, students should access their online Claim,
Evidence, Reasoning (CER) chart and make their claim. CER is a strategy
used to teach students how to construct explanations and craft scientific
arguments. A scientific claim answers a question or offers a solution to a
problem. Give students time to reflect and brainstorm, then have each
student take a clear stand and write a claim.
As students read the chapter and complete classroom and laboratory activities,
they will collect evidence related to their claim. Scientific evidence is
information that supports or contradicts a claim. This information can come
from a variety of sources, such as research, experimentation, or data
interpretation. It is important to have multiple pieces of evidence to support
a claim. Encourage students to return to their claims and add evidence at
multiple points in the chapter.
There are a number of topics relevant to the case study that make for good
class discussions. Patent foramen ovale is a relatively common birth defect
occurring in the heart. Ask your students what they would predict the
symptoms and side effects of this defect could be. For more information,
access the American Heart Association website.
Introduction to the Theme
Theme: Patterns The growth and development of a species is a series of pattered
events that are dictated by each individual’s genetic make-up.
Theme Activity: Early Human Prenatal Development Flip Book
Students will explore the stages of early human embryonic development by creating
a flip book.
Provide students with a stack of small pieces of paper and a binder clip or a stack of
post-it notes. Using these materials, students will create a small, illustrated animated
guide to the stages of early embryonic development.
Begin by having the students draw the early stages of development in their
book. Remind them, that cells get larger as they grow, so they should start their
drawings small.
CHAPTER 20
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379
To understand the timing of zygote, cleavage, morula, blastocyst formation, and
gastrula, instruct the students to write the time-period on each one of their pages
as well.
When students are done with their drawings, they can then “animate” their books by
flipping through the stack of their papers.
You can choose to extend this activity to include the first few weeks of fetal
development as well.
Section 20.1: Introduction
Learn
Classroom Activities
Section 20.1 sets the groundwork for activities in sections 20.2 and beyond.
Additional Discussion Questions
Ask students to address why it is important that they study the prenatal stages of
development.
Responses should emphasize the importance of understanding the anatomy and physiology of
normal embryonic development, and how abnormal development may occur.
How is the approximate time of conception calculated?
The approximate time of conception is calculated by adding 14 days to the date of the onset of
the last menstrual period. Also, this date can be estimated using ultrasound and measuring the
crown-to-rump length.
Practice
Practice Questions
1. Distinguish between growth and development.
Growth is an increase in size, while development, which includes growth is the continuous
process by which an individual changes from one life phase to another.
2. When is the beginning and ending of the postnatal period?
The postnatal period begins at birth and ends with death.
Use the Practice 20.1
Communicating Information All living organisms share key characteristics,
including reproduction, development, and growth. Explain how these
characteristics distinguish a living thing from a non-living thing.
Answers wi