What if…..? - Suffolk County Community College

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WELCOME TO A&P I
Vladimir Jurukovski PhD
Associate Professor
Suffolk County Community College
Smithtown Science Building T-218
(631) 451-4362
jurukov@sunysuffolk.edu
http://www2.sunysuffolk.edu/jurukov
WHAT IF…..?
INTRODUCTION
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Anatomy and physiology (A&P) is about human
structure and function—the biology of the human body
We want to know how our body works!
A&P is a foundation for advanced study in health care,
exercise physiology, pathophysiology, and other healthcare-related fields
Considers the historical development and a central
concept of physiology—homeostasis
1-4
THE SCOPE OF ANATOMY
AND PHYSIOLOGY
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Expected Learning Outcomes
 Define
anatomy and physiology and relate them
to each other.
 Describe several ways of studying human
anatomy.
 Define a few subdisciplines of human
physiology.
1-5
ANATOMY—THE STUDY OF FORM
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Examining structure of the
human body
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Cadaver dissection
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Figure 1.1
Inspection
Palpation
Auscultation
Percussion
Cutting and separation of
tissues to reveal their
relationships
Comparative anatomy

Study of more than one species
in order to examine structural
similarities and differences, and
analyze evolutionary trends
1-6
Cadaver
Dissection
ANATOMY—THE STUDY OF FORM
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Exploratory surgery
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Medical imaging
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Examination of cells with microscope
Ultrastructure
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Study of structure and function of cells
Histology (microscopic anatomy)
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Study of structures that can be seen with the naked eye
Cytology
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Viewing the inside of the body without surgery
Radiology—branch of medicine concerned with imaging
Gross anatomy

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Open body and take a look inside
View molecular detail under electron microscope
Histopathology
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Microscopic examination of tissues for signs of disease
1-8
Exploratory Surgery
Cytology
Histology
Medical Imaging
Gross Anatomy
PHYSIOLOGY—THE STUDY OF FUNCTION
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Subdisciplines
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Neurophysiology (physiology of nervous system)
Endocrinology (physiology of hormones)
Pathophysiology (mechanisms of disease)
Comparative physiology
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Limitations on human experimentation
Study of different species to learn about bodily function
Animal surgery
 Animal drug tests
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Basis for the development of new drugs and medical
procedures
1-10
LIVING IN A REVOLUTION
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Modern biomedical science

Technological enhancements
 Advances
in medical imaging have enhanced our
diagnostic ability and life-support strategies
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Genetic Revolution
 Human
genome is finished
 Gene therapy is being used to treat disease
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Early pioneers were important
Established scientific way of thinking
 Replaced superstition with natural laws
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1-11
HUMAN STRUCTURE
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Expected Learning Outcomes
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List the levels of human structure from the most complex to
the simplest.
Discuss the clinical significance of anatomical variation
among humans.
1-12
1-13
HIERARCHY OF COMPLEXITY
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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Organism is composed of organ
systems
Organism
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Organ Systems composed of
organs
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Organs composed of tissues
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Tissues composed of cells
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Cells composed of organelles
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Organelles composed of
molecules
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Organ system
Tissue
Organ
Cell
Macromolecule
Organelle
Molecules composed of atoms
Atom
Molecule
1-14
HIERARCHY OF COMPLEXITY
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Organism – a single, complete individual
Organ System – human body made of 11 organ systems
Organ – structure composed of two or more tissue types that work together to
carry out a particular function
Tissue – a mass of similar cells and cell products that form discrete region of
an organ and performs a specific function
Cells – the smallest units of an organism that carry out all the basic functions
of life
 Cytology – the study of cells and organelles
Organelles – microscopic structures in a cell that carry out its individual
functions
Molecules – make up organelles and other cellular components
 macromolecules – proteins, carbohydrates, fats, DNA
Atoms – the smallest particles with unique chemical identities
CHARACTERISTICS OF LIFE
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Organization
Cellular composition
Metabolism
 anabolism, catabolism and excretion
Responsiveness and movement
 Stimuli
Homeostasis
Development
 differentiation and growth
Reproduction
Evolution
 mutations
1-15
ANATOMICAL VARIATION
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No two humans are exactly alike
70% most common structure
 30% anatomically variant
 Variable number of organs
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 Missing
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muscles, extra vertebrae, renal arteries
Variation in organ locations (situs solitus, situs inversus,
dextrocardia, situs perversus)
Normal
Pelvic kidney
Normal
Horseshoe kidney
1-16
Variations in branches of the aorta
PHYSIOLOGICAL VARIATION
Sex, age, diet, weight, physical activity
 Typical physiological values
 reference man
22 years old, 154 lbs, light physical activity
consumes 2800 kcal/day
 reference woman
same as man except 128 lbs and 2000
kcal/day
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1-17
HOMEOSTASIS
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Homeostasis – the body’s ability to detect change, activate
mechanisms that oppose it, and thereby maintain relatively stable
internal conditions

Claude Bernard (1813-78)
 constant internal conditions regardless of external
conditions
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internal body temperature ranges from 97 to 99 degrees despite
variations in external temperature
Walter Cannon (1871-1945)
 coined the term ‘Homeostasis’
 state of the body fluctuates (dynamic equilibrium) within
limited range around a set point
 Negative feedback keeps variable close to the set point
Loss of homeostatic control causes illness or death
1-18
NEGATIVE FEEDBACK LOOP
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Body senses a change and activates mechanisms to reverse it—dynamic
equilibrium
Because feedback mechanisms alter the original changes that triggered
them (temperature, for example), they are called feedback loops
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Room temperature
fallsto66°F(19°C)
1
C10°
15°20°25°
6 Room cools down
F50°
60°70°80°
2
C10°
15°20°25°
Thermost atactivates
furnace
F50°
60°70°80°
Figure 1.9a
5 Thermostat shuts
off furnace
4 Room temperature
rises to 70°F (21°C)
3 Heat output
(a)
1-19
NEGATIVE FEEDBACK
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Room temperature (oF)
75
(b)

Furnace turned
off at 70 oF
70
Set point 68 oF
65
Furnace turned
on at 66 oF
60
Figure 1.9b
Time
Example: Room temperature does not stay at set point of
68°F—it only averages 68°F
1-20
NEGATIVE FEEDBACK
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Core body temperature
Sweating
37.5 oC
(99.5
oF)
Vasodilation
37.0 oC
(98.6
oF)
36.5 oC
(97.7
oF)
Set point
Vasoconstriction
Figure 1.10
Time
Shivering
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Example: Brain senses change in blood temperature
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
If too warm, vessels dilate (vasodilation) in the skin and sweating
begins (heat-losing mechanism)
If too cold, vessels in the skin constrict (vasoconstriction)
and shivering begins (heat-gaining mechanism)
1-21
HOMEOSTATIS AND NEGATIVE FEEDBACK
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Sitting up in bed causes a drop in blood pressure in
the head and upper torso region (local imbalance in
homeostasis); detected by baroreceptors
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Baroreceptors (sensory nerve endings) in the arteries
near the heart alert the cardiac center in the
brainstem. They transmit to the cardiac center
Cardiac center sends nerve signals that increase the
heart rate and return the blood pressure to normal;
regulates heart rate
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Failure of this to feedback loop may produce dizziness
in the elderly
1-22
POSTURAL CHANGE IN BLOOD PRESSURE
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Person rises
from bed
Blood pressure rises
to normal; homeostasis
is restored
Cardiac center
accelerates heartbeat
Blood drains from
upper body, creating
homeostatic imbalance
Baroreceptors above
heart respond to drop
in blood pressure
Figure 1.11
Baroreceptors send signals
to cardiac center of brainstem
HOMEOSTASIS AND NEGATIVE FEEDBACK
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Receptor—senses change in the body (e.g.,
stretch receptors that monitor blood pressure)
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Integrating (control) center—control center that
processes the sensory information, “makes a
decision,” and directs the response (e.g.,
cardiac center of the brain)
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Effector—carries out the final corrective action
to restore homeostasis (e.g., cell or organ)
1-24
POSITIVE FEEDBACK AND RAPID CHANGE
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Self-amplifying cycle
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Leads to greater change in the same direction
Feedback loop is repeated—change produces more
change
Normal way of producing rapid changes
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Occurs with childbirth, blood clotting, protein
digestion, fever, and generation of nerve signals
1-25
POSITIVE FEEDBACK AND RAPID CHANGE
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During birth, the head of the fetus pushes
against the cervix and stimulates its nerve
endings
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Hormone oxytocin is secreted from the pituitary
gland
Oxytocin travels through the bloodstream to the
uterus stimulating it to contract
This action pushes the fetus downward toward
cervix, thus stimulating the cervix more, causing
the positive feedback loop to be repeated
1-26
POSITIVE FEEDBACK LOOPS
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
3 Brain stimulates
pituitary gland to
secrete oxytocin
4
Oxytocin stimulates uterine
contractions and pushes
fetus toward cervix
2 Nerve impulses
from cervix
transmitted
to brain
1 Head of fetus
pushes against cervix
1-27
POSITIVE FEEDBACK AND RAPID CHANGE
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Fever > 104°F
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Metabolic rate increases
Body produces heat even faster
Body temperature continues to rise
Further increasing metabolic rate
Cycle continues to reinforce itself
Becomes fatal at 113°F
1-28
REVIEW OF MAJOR THEMES
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Cell Theory
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Homeostasis
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The human body is a product of evolution
Hierarchy of Structure
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The purpose of most normal physiology is to maintain stable conditions
within the body
Evolution
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All structure and function result from the activity of cells
Human structure can be viewed as a series of levels of complexity
Unity of Form and Function
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Form and function complement each other; physiology cannot be
divorced from anatomy
1-29
MEDICAL IMAGING
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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Radiography (X-rays)
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(a) X-ray (radiograph)
William Roentgen’s
discovery in 1885
Penetrate tissues to
darken photographic
film beneath the body
Dense tissue appears
white
Over half of all medical
imaging
Until 1960s, it was the
only method widely
available
© U.H.B. Trust/Tony Stone Images/Getty Imagese
Figure 1.13a
1-30
MEDICAL IMAGING
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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Radiopaque substances
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Injected or swallowed
Fills hollow structures
 Blood
vessels
 Intestinal tract
Figure 1.13b
(b Cerebral angiogram
Custom Medical Stock Photos, Inc.
1-31
MEDICAL IMAGING
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Computed tomography
(CT scan)
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Formerly called a CAT scan
Low-intensity X-rays and
computer analysis
 Slice-type
image
 Increased sharpness of
image
Figure 1.13c
(c) Computed tomographic (CT) scan
© CNR/Phototake
1-32
MEDICAL IMAGING—NUCLEAR MEDICINE

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Positron emission tomography (PET)
scan
 Assesses metabolic state of tissue
 Distinguished tissues most active at
a given moment
 Mechanics—inject radioactively
labeled glucose
Positrons and electrons collide
 Gamma rays given off
 Detected by sensor
 Analyzed by computer
 Image color shows tissues using the
most glucose at that moment
 Damaged tissues appear dark
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(d) Positron emission tomographic
(PET) scan
Tony Stone Images/Getty Images
Figure 1.13d
1-33
MEDICAL IMAGING
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Magnetic resonance imaging
(MRI)
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Slice-type image
Superior quality to CT scan
Best for soft tissue
Mechanics
 Alignment and realignment
of hydrogen atoms with
magnetic field and radio
waves
 Varying levels of energy
given off used by computer
to produce an image
(e) Magnetic resonance image (MRI)
© Monte S. Buchsbaum, Mt. Sinai School of Medicine, New York, NY
Figure 1.13e
1-34
MEDICAL IMAGING
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Sonography
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Second oldest and
second most widely
used
Mechanics
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High-frequency sound
waves echo back
from internal organs
Avoids harmful X-rays
Obstetrics
 Image not very sharp
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Figure 1.14
1-35
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