Anatomy & Physiology 34A Lecture Outline
Chapter 1 – Human Body Orientation
I. Overview
A. Overview of Anatomy & Physiology
B. Levels of Structural Organization
C. Maintaining Life
D. Homeostasis & Feedback
II. Overview of Anatomy & Physiology
A. Anatomy (to cut up, or dissect) is the study of body
structures and their relationships.
1. Morphology is the science of form.
2. Physiology (study of nature) is the study of body
functions. Anatomy is intimately intertwined with
physiology – structure reflects function.
3. Anatomical terminology - learning the word roots inside
the text back cover quickly will help you immensely.
B. Topics of Anatomy
1. Gross Anatomy is the study of body structures that can be
observed with the naked eye. Dissection is used to study
gross anatomy
2. Regional Anatomy - study of structures in a particular
body region (e.g.: head or neck). Often used by med.
schools.
3. Systemic Anatomy - study of organs with related
functions (i.e.: within a body system). We will use this
approach.
4. Surface Anatomy deals with surface features that can be
observed beneath the skin or palpated (examined by touch)
5. Microscopic Anatomy is concerned with structures
smaller than 0.1 mm that can only be seen with a
microscope. Anatomical sciences that require
microscopes include:
a. Cytology - the study of cells
b. Histology - the study of tissues
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C. Topics of Physiology
1. Physiology concerns the functions of specific organs or
organ systems. Examples include:
a. Cardiovascular physiology examines the operation of
the heart and blood vessels
b. Neurophysiology attempts to explain how the nervous
system works
2. Physiology is initiated on a cellular level, and is based
upon physical and chemical interactions within and
among cells
D. Complementarity of Structure and Function
1. Functions are intimately related to anatomical structure
2. Example: the upper bronchial tubes are lined with a tissue
that has tiny, hair-like projections to sweep debris out of
the lungs.
III. Levels of Structural Organization
atoms  molecules  organelles  cells  tissues 
organs  organ systems  organism
A. Cellular Level
1. Minute particles called atoms bond together to form
molecules; Four classes of macromolecules form cells:
a. Carbohydrates (sugars)
b. Lipids (fats)
c. Proteins
d. Nucleic acids (DNA & RNA)
2. Molecules group together in specific ways to form
organelles, functional structures within cells
a. Each organelle carries out specific functions in the cell
b. The nucleus, mitochondrion, and ER are examples of
organelles
3. A cell is the basic structural and functional component of
life
a. Humans are composed of 60-100 trillion cells
b. Metabolism, growth, responsiveness, repair, and
replication are carried on at the cellular level
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4. Organelles and cytoplasm surrounded by a plasma
membrane compose a cell
a. The human body contains many distinct types of cells,
each specialized to perform specific functions (e.g.:
skin, bone, fat, blood, nerve & muscle cells)
b. The structure of each cell type is related to its function
B. Tissue level
1. Tissues are layers or groups of similar cells that perform a
common function. The body is composed of 4 major
kinds of tissues:
a. Epithelial - covers & lines body surfaces
b. Connective – binds tissues together, supports and
protects body organs
c. Muscular – provides movement
d. Nervous – allows rapid internal communication via
electrical nerve impulses
2. Histology is the microscopic study of tissues
C. Organ level
1. An organ is an combination of 2 or more tissue types that
performs a specific function
2. Examples include the heart, liver, pancreas, bones, skin,
etc.
3. Each organ has one or more primary tissues and several
secondary tissues
a. In the stomach, the inside epithelial lining is the
primary tissue because it is involved with secretion and
absorption
b. Secondary tissues of the stomach are the connective,
vascular, nervous, and muscle tissues
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D. System level
1. A body system consists of various organs that have
similar or related functions
2. The 11 major systems of the body and their functions
include:
a. Integumentary - external support and protection of the
body; vit. D synthesis; has sense receptors, sweat, & oil
glands
b. Skeletal - internal support and flexible framework for
body movement; blood cell production; stores minerals
c. Muscular - body movement; heat production
d. Nervous - control and regulation of all other systems of
the body; activates muscles & glands
e. Endocrine - secretion of hormones for chemical
regulation of growth, metabolism, reproduction, etc.
f. Cardiovascular - transports oxygen, nutrients,
hormones to body cells; removes metabolic wastes &
CO2 from cells
g. Lymphatic - body immunity; absorption of fats; returns
tissue fluid to the blood
h. Respiratory - supplies oxygen to blood; removes
carbon dioxide from blood
i. Digestive - breakdown and absorption of food
materials; undigested matter eliminated as feces
j. Urinary - eliminates nitrogenous wastes from the body;
regulates water, electrolyte, & acid-base balance
k. Reproductive
1) Female - production of female sex cells (ova);
receptacle for sperm from male; site for fertilization
of ovum; implantation, and development of embryo
and fetus; delivery of fetus
2) Male - production of male sex cells (sperm); transfer
of sperm to female reproductive system
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IV. Maintaining Life
A. Characteristics of life include the following:
1. Maintenance of boundaries between the external
surroundings and the internal environment. What
structures provide this?
2. Movement of our bodies, as well as materials such as
blood, food, urine, etc., within our bodies. What tissues are
involved?
3. Responsiveness – the ability to sense changes (stimuli) in
the environment and react to them. What system is most
involved?
4. Digestion – the breakdown of ingested food into simple
molecules, which are absorbed into the bloodstream. What
two systems are most involved?
5. Metabolism – all chemical reactions within our cells; 2
types:
a. Anabolism – building smaller molecules into larger
ones
b. Catabolism- breaking large molecules into smaller ones
6. Excretion of wastes from the body. What 3 systems are
most involved?
7. Reproduction at both the cellular and organismal levels
a. Organismal level - sperm unites with an egg
b. Cellular reproduction involves mitosis or meiosis
1) Mitosis results in two genetically identical daughter
cells, which are used in growth and repair
2) Meiosis occurs in the formation of gametes (sperm
and eggs)
8. Growth – an increase in the size of an organism, usually
by increasing the number of cells. What process allows
this?
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B. Survival Needs include oxygen, water, nutrients, normal
body temperature, and atmospheric pressure
1. Oxygen is needed for chemical reactions that produce
ATP energy from nutrients
2. Water (H2O) is obtained from food and drink, and lost via
breathing, sweating, and bodily excretions. Functions:
a. The most abundant inorganic substance in the body
b. Universal solvent – dissolves water-based substances
c. Allows metabolic/biochemical reactions
d. Transports substances within the body
3. Nutrients, acquired from foods, contain chemicals needed
for
a. Energy production (ATP molecules)
b. Organic building materials (e.g.: monosaccharides,
fatty acids, amino acids, nucleic acids) for cells and
growth
c. Vitamins & minerals for chemical reactions
4. Normal Body Temperature (37C) is maintained mainly
by muscle metabolism, and is essential for chemical
reactions.
a. Low body temperature slows metabolic reactions
b. High body temperature can denature enzymes
5. Atmospheric pressure is the force that air exerts on our
body surface; needed for breathing and gas exchange in
the lungs.
V. Homeostasis & Feedback Mechanisms
A. Homeostasis is the maintenance of a relatively stable
internal environment
1. Physiology is a group of mechanisms for maintaining
homeostasis, or dynamic equilibrium
2. Dynamic equilibrium describes the way in which body
conditions fluctuate within a narrow range, then return to a set
point
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B. Negative Feedback and Stability
1. Negative feedback – the body senses a change and activates
mechanisms in the opposite direction to reverse the change
2. Common example: a thermostat is activated when the
temperature drops below the set temp., the heater turns on
and brings the temp. up, the thermostat turns off
3. Body temperature example:
a. Body temperature increase triggers skin blood vessels to
vasodilate (widen) and sweating, which cools the
circulating blood, which cools the body down to normal
temp.
b. Body temperature decrease triggers skin blood vessels to
vasoconstrict and shivering, which warms the circulating
blood, bringing body temperature up
4. Homeostatic control mechanisms include 3 components:
a. Receptor – structure that senses a change in the body and
sends info. to the
b. Control center – area that processes the incoming info.
and formulates an appropriate response and sends it to an
c. Effector – structure that carries out the response and
restores homeostasis
C. Positive Feedback and Rapid Change
1. Positive feedback– physiological change that leads to
greater change in the same direction
2. Example: during childbirth a hormone release from the
brain stimulates increasing labor contractions until the baby
is born
D. Homeostatic Imbalance
1. Disease (dis-ease) occurs when bodily homeostasis is
disturbed
2. Negative feedback mechanisms can be overwhelmed by
disease causing organisms and with advanced age