Anatomy and Physiology Notes
Unit 1: Anatomical Orientation
Chapter 1: Intro to A & P
Section 1.1: A&P directly affect your life
Anatomy is considered the oldest medical science. It serves as the foundation for understanding all other basic
life sciences, and for making common sense decisions about your own life. This course will devote considerable
time to explaining how the body responds to normal and abnormal conditions and maintains homeostasis, a
relatively constant internal environment.
Section 1.2: Good study strategies are crucial for success
Tips for success in this course:
 Attend all lectures, labs, and study sessions
 Read your lecture and lab assignments before going to class
 Devote a block of time each day to your A&P course
 Set up a study schedule and stick to it
 Do not procrastinate
 Approach the information in different ways
 Develop the skill of memorization, and practice it regularly
 As soon as you experience difficulty with the course, seek assistance
CLE3251.1.1:
Objectives:
Distinguish between anatomy and physiology
Illustrate the interconnections between anatomy and physiology using a concept map.
Section 1.3: Anatomy is structure and Physiology is function
1. Anatomy: (Greek: “a cutting open”) the study of internal and external structures of the body and the
physical relationships among body parts.
2. Physiology: (Greek) the study of how living organisms perform their vital functions
3. Medical terminology: a special language that involves the use of four types of word parts to construct
terms related to the body in health and disease; usually derived from Greek or Latin
a. Word roots: basic, meaningful parts of a term that cannot be broken down into another term
with another definition
b. Prefixes: word elements that are attached to the beginning of words to modify their meaning
but cannot stand alone
c. Suffixes: word elements or letters added to the end of a word or word part to form another
term
d. Combining forms: independent words or word roots that occur in combination with words,
prefixes, suffixes, or other combining forms to build a new term
4. Eponym: a commemorative name for a structure or clinical condition that was originally named for a
real or mythical person; usually named after the person who discovered it or the most famous victim
5. International Anatomical Terminology (Terminologia Anatomica, or TA): serves as the international
standard for anatomical vocabulary
CLE3251.1.2:
Objectives:
Investigate the interrelationship between the structures and functions of the body systems.
Sequence the levels of structural organization from the molecular level through the
organismic level.
Classify organ systems of the body as either: Protection, support and movement; regulation
and integration; transport; absorption and excretion.
Identify the major organs and describe the functions of each body system
Section 1.4: Anatomy and Physiology are closely integrated
1. All specific functions are performed by specific structures. Anatomy explains key structural relationships,
how each structure is attached to one another. Physiology explains functional relationships between the
structures, how each structure works in relation to another to complete specific processes.
2. Two degrees of anatomical detail:
a. Gross anatomy (AKA Macroscopic anatomy): involves the examination of relatively large
structures and features usually visible with the unaided eye.
i. Surface anatomy: the study of general form and superficial markings
ii. Regional anatomy: anatomical organization of specific areas of the body (i.e. head,
neck, abdomen)
iii. Systemic anatomy: the study of the structure of organ systems
iv. Developmental anatomy: describes the changes in form that occur between conception
and physical maturity
v. Clinical anatomy: includes a number of subspecialties that are important in clinical
practice (i.e. pathological anatomy, radiographic anatomy, surgical anatomy)
b. Microscopic anatomy: deals with structures that cannot be seen without magnification, and
thus the boundaries are established by the limits of the equipment used.
i. Cytology: the analysis of the internal structure of individual cells, which are the simplest
units of life
ii. Histology: the examination of tissues, which are groups of specialized cells and cell
products that work together to perform specific functions.
3. Four divisions of study within physiology:
a. Cell physiology: the study of the functions of cells at the chemical and molecular levels
b. Organ physiology: the study of functions of specific organs
c. Systemic physiology: the study of the functions of specific organ systems
d. Pathological physiology: the study of the effects of diseases on organ or system functions
Section 1.5: Levels of organization progress from molecules to a complete organism
1. Interdependent levels of organization
a. Chemical / Molecular level: Atoms, the smallest stable units of matter, can combine to form
molecules with complex shapes, which will determine the function of the molecules.
b. Cellular level: Molecules interact to form various types of organelles, each with specific
functions.
c. Tissue level: A tissue is a group of cells working together to perform one or more specific
functions.
d. Organ level: Organs consist of two or more tissues working in combination to perform several
functions.
e. Organ system level: Organs interact in organ systems
f. Organism level: The highest level of organization. All organ systems of the body must work
together to maintain the life and health of the organism.
2. The body can be divided into 11 organ systems, but all work together and the boundaries between them
are not absolute. Figure 1-2 introduces these systems, their major organs, and functions.
a. Integumentary system
g. Lymphoid system
b. Skeletal system
h. Respiratory system
c. Muscular system
i. Digestive system
d. Nervous system
j. Urinary system
e. Endocrine system
k. Reproductive system (Male)
f. Cardiovascular system
l. Reproductive system (Female)
CLE3251.1.5:
Objectives:
Describe the body mechanisms that maintain homeostasis.
Provide examples of bodily mechanisms that serve to maintain homeostasis.
Explain how the body regulates temperature, blood carbon dioxide levels, and blood glucose
levels.
Section 1.6: Homeostasis is the tendency toward internal balance
1. Homeostasis: the existence of a stable environment; maintaining this is vital to an organism’s survival;
failure to maintain homeostasis soon leads to illness or even death
2. Homeostatic regulation: the adjustment of physiological systems to preserve homeostasis; involves two
mechanisms:
a. Autoregulation (AKA intrinsic regulation): occurs when a cell, tissue, organ, or system adjusts
its activities automatically in response to some environmental change.
b. Extrinsic regulation: results from the activities of the nervous system or endocrine system, two
organ systems that control or adjust the activities of many other systems simultaneously
3. The function of homeostatic regulation is to always keep the characteristics of the internal environment
within certain limits. A homeostatic regulatory mechanism consists of three parts:
a. Receptor: a sensor that is sensitive to a particular environmental change, or stimulus
b. Control center: (aka integration center) receives and processes the information supplied by the
receptor and sends out commands
c. Effector: a cell or organ that responds to the commands of the control center and whose activity
either opposes or enhances the stimulus
Section 1.7: Negative feedback opposes variations from normal, whereas positive feedback exaggerates them
1. Negative feedback: A corrective mechanism that opposes or negates a variation from normal limits;
provide long-term control over the body’s internal conditions (maintain homeostasis) by counteracting
the effects of a stimulus.
a. Thermoregulation: the control of body temperature; where the relationship between heat loss
(occurs at body surface) and heat production (occurs in all active tissues) is altered.
i. Figure 1-4: Negative feedback in the control of body temperature
ii. A control center in the brain (the hypothalamus) functions as a thermostat with a set
point of 37° C. If body temperature exceeds 37.2°C, heat loss is increased through
enhanced blood flow to the skin and increased sweating.
iii. The thermoregulatory center keeps body temperature oscillating within an acceptable
range, usually between 36.7° and 37.2°C.
iv. “Normal is relative”… depending on genetic factors, age, gender, general health,
environmental conditions, activity levels. 95% of people fall within “normal” range, but
there is always the 5% whose “abnormality” is “normal”…
2. Positive feedback: A mechanism that increases a deviation from normal limits after an initial stimulus,
rather than opposing it; amplifies or reinforces the effects of a stimulus; typically found when a
potentially dangerous or stressful process must be completed quickly before homeostasis can be
restored.
a. Useful because it is used in processes that must move quickly to completion
i. Blood clotting: positive feedback accelerates the clotting process until a blood clot forms
and stops the bleeding.
1. Immediate danger from a severe cut is loss of blood, which can lower blood
pressure and reduce the efficiency of the heart. The body’s response to blood
loss is diagrammed in Figure 1-5.
b. Harmful in situations when a stable condition must be maintained, because it tends to increase
any departure from the desired condition.
i. Positive feedback in Regulation of body temperature: would cause a slight fever to spiral
out of control, with fatal results. This is why most physiological systems are regulated by
negative feedback, which opposes any departure from the norm.
3. When homeostasis fails, organ systems function less efficiently or even malfunction. The result is the
state that we call disease. If the situation is not corrected, then death can result.
a. Disease: an impairment of the normal state of a living organism’s body or one of its parts that
interrupts or modifies the performance of the vital functions, is typically manifested by
distinguishing signs and symptoms, and is a response to environmental factors (as malnutrition,
industrial hazards, or climate), to specific infective agents (as worms, bacteria, or viruses), to
inherent defects of the organism (as genetic anomalies), or to combinations of these factors
4. Table 1-1: Identifies the roles of various organ systems in regulating several important physiological
characteristics that are subject to homeostatic control. Note that in each case such regulation involves
several organ systems.
5. State of Equilibrium: exists when opposing processes or forces are in balance. The body always tries to
maintain equilibrium because the failure to do so leads to disease and/or death. Each physiological
system functions to maintain a state of equilibrium that keeps vital conditions within normal limits. Any
adjustments made by one physiological system have direct and indirect effects on a variety of other
systems.
a. When the body continuously adapts, utilizing homeostatic systems, it is said to be in a state of
dynamic equilibrium.
CLE3251.1.4:
Objectives:
Use correct anatomical terminology when discussing body structures, sections, and regions.
Apply correct terminology to reference anatomical orientation.
Section 1.8: Anatomical terms describe body regions, anatomical positions and directions, and body sections
1. Superficial anatomy: involves locating structures on or near the body surface
a. Palpable structures: anatomical landmarks
i. Anatomical position: an individual is standing, with the hands at the sides, palms facing
forward, and feet together
1. Anterior view: anatomical position as seen from the front
2. Posterior view: anatomical position as seen from the back
3. Supine: anatomical position, lying down, face up
4. Prone: anatomical position, lying down, face down
b. Anatomical regions: specific areas used for reference purposes (lines dividing the regions
resemble a tic-tac-toe game)
i. Table 1-2: Identifies regions of the human body; See also Figure 1-6
ii. Abdominopelvic quadrants: (Figure 1-7a)formed by a pair of imaginary perpendicular
lines that intersect at the umbilicus (navel); provides useful references for the
description of aches, pains, and injuries, which can help physicians locate and determine
the possible cause; right upper quadrant (RUQ), right lower quadrant (RLQ), left upper
quadrant (LUQ), left lower quadrant(LLQ)
iii. Abdominopelvic regions: (Figure 1-7b) nine precise and specific descriptions that help
more closely identify the location and orientation of internal organs; epigastric,
umbilical, hypogastric (pubic), right hypochondriac, left hypochondriac, right lumbar,
left lumbar, right inguinal, left inguinal
iv. Figure 1-7c: shows the relationship between the Abdominopelvic quadrants and regions
and the locations of the internal organs
c. Anatomical directions (Figure 1-8 and Table 1-3):
i. Left and right: always refers to the left and right side of the subject, NOT of the observer
ii. Ventral: belly side; same as anterior
iii. Dorsal: behind; same as posterior
iv. Cranial / cephalic: head
v. Superior: above; at a higher level (toward the head in humans)
vi. Caudal: tail (coccyx in humans)
vii. Inferior: below; at a lower level
viii. Medial: toward the middle; toward the body’s longitudinal axis; toward the midsagittal
plane
ix. Lateral: away from the middle; away from the body’s longitudinal axis; away from the
midsagittal plane
x. Proximal: toward an attached base
xi. Distal: away from an attached base
xii. Superficial: at, near, or relatively close to the body surface
xiii. Deep: farther from the body surface
2. Sectional Anatomy: sectioning off a 3-D object to see internal organization
a. Sectional planes (Figure 1-9 and Table 1-4): plane: an axis; section: a single view or slice along a
plane; three planes are necessary for describing any 3-D object
i. Transverse plane (AKA horizontal): lies at right angles to the long axis of the body,
dividing it into superior and inferior portions
1. Transverse section: a cross section of the transverse plane
ii. Frontal plane: (AKA coronal plane) extends from side to side, dividing the body into
anterior and posterior portions
1. Coronal: usually refers to sections passing through the skull
iii. Sagittal plane: extends from the front to back, dividing the body into left and right
portions
1. Midsagittal section (AKA median section): A cut the passes along the midline
and divides the body into left and right halves
2. Parasagittal section: a cut that runs parallel to the midsagittal line, but
separates the body into unequal left and right portions
CLE3251.1.3:
Objectives:
Investigate the body cavities, the subdivisions of each cavity, and the organs within each area.
Identify and label the body cavities including the subdivisions and organs of each
Section 1.9: Body Cavities protect internal organs and allow them to change shape.
1. Two functions of body cavities:
a. Protect delicate organs from accidental shocks, and cushion them from the thumps and bumps
that occur when we walk, jump, or run
b. Permit significant changes in the size and shape of internal organs (expand and contract without
distorting surrounding tissues or disrupting the activities of nearby organs)
2. Viscera: Organs in the ventral body cavity
a. Visceral: pertaining to the viscera or their outer coverings
b. Serous membrane: a delicate layer that lines the walls of these internal cavities and covers
surfaces of the enclosed viscera
i. Visceral layer: the portion of a serous membrane that covers a visceral organ
ii. Parietal layer: the opposing layer that lines the inner surface of the body wall or
chamber
3. Ventral body cavity (AKA coelom): appears early in embryonic development and contains most vital
organs. As these organs develop, their relative positions change, which causes a subdivision in the
ventral body cavity divided by the diaphragm: a flat sheet of respiratory muscle that separates the
thoracic cavity from the Abdominopelvic cavity
a. Thoracic cavity: superior position, surrounded by chest wall and diaphragm
i. Right pleural cavity: surrounds right lung
ii. Mediastinum: contains the trachea, esophagus, and major vessels
1. Pericardial cavity: surrounds the heart; allows the heart to expand and contract
during beats
a. Pericardium: the serous membrane surrounding the heart
b. Parietal pericardium: the opposing layer that lines the pericardial cavity
c. These linings prevents friction between the heart and adjacent
structures in the thoracic cavity
iii. Left pleural cavity: surrounds left lung
iv. Pleura: the serous membrane lining a pleural cavity
1. Visceral pleura: covers the outer surfaces of a lung
2. Parietal pleura: covers the mediastinal surface and the inner body wall
b. Abdominopelvic cavity: extends from the diaphragm to the pelvis
i. Peritoneal cavity: a chamber lined by a serous membrane known as the peritoneum,
and the parietal peritoneum, which lines the inner surface of the body wall
1. Allows the organs of the digestive system to slide across one another without
damage to themselves or the walls of the cavity. (Makes the gurgling sound
produced when the contraction of a digestive organ produces a movement of
liquid or gas)
ii. Abdominal cavity: superior portion that extends from the bottom of the diaphragm to
the level of the superior margins of the pelvis.
1. Contains the liver, stomach, spleen, small intestine, and most of the large
intestine (Figure 1-7c)
2. Retroperitoneal: organs that lie behind the peritoneal lining, near the muscular
wall of the abdominal cavity
a. Kidneys and pancreas
iii. Pelvic cavity: Inferior portion; contains the distal portion of the large intestine, urinary
bladder, and reproductive organs
CH 1, Page 10-11, Figure 1-2: Create a table identifying the organ systems, the major organs of each system, and
the functions of the organ system
Organ System
Integumentary
Skeletal
Muscular
Nervous
Endocrine
Cardiovascular
Major Organs
Skin
Hair
Sweat glands
Nails
Bones
Cartilages
Associated ligaments
Bone marrow
Skeletal muscles
Cardiac muscles
Smooth muscles
Associated tendons
Brain
Spinal Cord
Peripheral nerves
Sense organs
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Pituitary gland
Thyroid gland
Pancreas
Suprarenal glands
Gonads (testes/ovaries)
Endocrine tissues in
other systems
Heart
Blood
Blood vessels
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Lymphoid
Respiratory
Continued next page…
Spleen
Thymus
Lymphatic vessels
Lymph nodes
Tonsils
Nasal cavities
Sinuses
Larynx
Trachea
Bronchi
Lungs
Alveoli
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Functions
Protects against environmental hazards
Helps regulate body temp
Provides sensory information
Provides support and protection for other
tissues
Stores calcium and other minerals
Forms blood cells
Provides movement
Provides protection and support for other
tissues
Generates heat that maintains body temp
Directs immediate responses to stimuli
Coordinates or moderates activities of other
organ systems
Provides and interprets sensory info about
external conditions
Directs long-term changes in the activities of
other organ systems
Adjusts metabolic activity and energy use by
the body
Controls many structural and functional
changes during development
Distributes blood cells, water, and dissolved
materials, including waste products, oxygen,
and carbon dioxide
Distributes heat and assists in control of body
temp
Defends against infection and disease
Returns tissue fluids to the bloodstream
Delivers air to alveoli (site in lungs where gas
exchange occurs)
Provides oxygen to bloodstream
Removes carbon dioxide from bloodstream
Produces sounds for communication
Digestive
Urinary
Reproductive (Male)
Reproductive (Female)
Teeth
Tongue
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Liver
Gallbladder
Pancreas
Kidneys
Ureters
Urinary bladder
Urethra
Testes
Epididymides
Ductus deferens
Seminal vesicles
Prostate gland
Penis
Scrotum
Ovaries
Uterine tubes
Uterus
Vagina
Labia
Clitoris
Mammary glands
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Processes and digests food
Absorbs and conserves water
Absorbs nutrients (ions, water, and the
breakdown products of dietary sugars,
proteins, and fats)
Stores energy reserves
Excretes waste products from the blood
Controls water balance by regulating volume of
urine produced
Stores urine prior to voluntary elimination
Regulates blood ion concentrations and pH
Produces male sex cells (sperm), suspending
fluids, and hormones
Sexual intercourse
Produces female sex cells (oocytes) and
hormones
Supports developing embryo from
contraception to delivery
Provides milk to nourish newborn infant
Sexual intercourse