Anatomy & Physiology
• Anatomy – studies the structure of body
parts and their relationship to one another
• Physiology – function of the body’s
structural machinery or how all the body
parts work and carry out their lifesustaining activities
Topics in Anatomy
• Gross anatomy - study of large body structures
visible to the naked eye
– EX: heart, kidneys, etc
• Regional anatomy – all the structures in one
particular region of body
• Systemic – the gross anatomy is studied system
by system
• Surface anatomy – the study of internal body
structures as they relate to the overlying skin
surface
Topics in Anatomy – cont’d
• Microscopic anatomy – structures too
small to be seen with the naked eye
– Cytology – study of the cells of the body
– Histology – study of the body tissue
• Developmental anatomy – traces
structural changes that occur in the body
throughout the life span
Levels of structural organization
• 1. Chemical level – atoms combine to
form molecules like water, sugar, and
proteins
• 2. Cells – All cells have some common
functions, but only certain cell types form
certain tissue
Levels of structural organization
• 3. Tissue level – groups of cells that have
a common function
– 4 basic types
•
•
•
•
Epithelium
Muscle
Connective
Nervous
Levels of structural organization
• 4. Organ – composed of at least 2 tissue
types
– Extremely complex functions become
possible
Levels of structural organization
• 5. Organ system – organs that work
closely with one another to accomplish a
common purpose
– 11 organ systems
Levels of structural organization
• 6. Organism level – sum of all structural
levels working together to promote life
Necessary Life Functions
• Maintaining boundaries – every living
organism must have a boundary different
from the inside and the outside of the body
– The external boundaries protect the internal
body
• Movement or contractibility – occurs
when substances such as blood,
foodstuffs, and urine are propelled through
internal organs
Necessary Life Functions
• Responsiveness – aka irritability – ability
to sense changes to the environment and
then respond to them
• Digestion – process of breaking down
ingested foodstuffs to simple molecules
that can be absorbed into the blood
Necessary Life Functions
• Metabolism – includes all chemical
reactions that occur within body cells
– Catabolism – breaking substances down
– Anabolism – synthesizing more complex
cellular structures from simpler substances
• Excretion – process of removing waste
from the body
Necessary Life Functions
• Reproduction – responsible for producing
offspring
• Growth – increase in the size of a body
part or the organism
– Usually by increasing the number of cell
Survival needs
• 1. Nutrients – contain the chemical substances
used for energy and cell building
• 2. Oxygen – needed for the respiratory and
cardiovascular systems
• 3. Water – accounts for 60% to 80% of body
weight
– Provides the environment necessary for chemical
reactions and fluid base for body secretions and
excretions
Survival needs
• 4. Normal body temperature
– Too low – metabolic reactions become slower
and slower until they stop
– Too high – chemical reactions occur at such a
fast rate that body proteins lose their shape
and stop functioning
• 5. Atmospheric pressure – force that air
exerts on the surface of the body
Homeostasis
• The ability to maintain relatively stable
internal conditions even though the
outside world changes continuously
• Our body is dynamic - Very complex
• The state of equilibrium varies, but always
within relatively narrow limits
Homeostasis – 3 components
• 1. Receptor – some type of sensor that
monitors the environment and responds to
changes by sending information to the
control center
• 2. Control center – determines the set
point at which a variable is to be
maintained, analyzes the input and
determines the response
Homeostasis – 3 components
• 3. Effector – response of the feedback to
influence the stimulus, either causing it to
be depressed or stimulate it so it goes
faster
Negative Feedback mechanism
• The output of the system shuts off the
original stimulus or reduces its intensity
• Similar to the heating system in a house
• Withdrawal reflex – cut or burning
• Glucose levels
Positive Feedback Mechanism
• Results or response enhances or
exaggerates the original stimulus so that
the activity is accelerated
• Likely to race out of control so they are
rarely used to promote the moment to
moment well-being of the body
– EX: blood-clotting and labor contraction
– P. 13
Homeostatic Imbalance
• As we age, our body’s control systems
become less efficient and our internal
environment becomes less and less stable
• This increases our risk of for illness
Anatomical positions and
Directional Terms
• Anatomical position – body is erect with
feet only slightly apart and palms facing
forward with the thumbs pointing away
from the body
Anatomical positions and
Directional Terms
• Directional terms – explain exactly where
one body structure is in relation to another
– The terms are found on page 16
Regional Terms
• 2 divisions of the body
• Axial part – makes up the main axis of our
body and includes the head, neck, and
trunk
• Appendicular part – consists of the
appendages that are attached to the
body’s axis
Body cavities and membranes
• Dorsal cavity – protects the nervous
system organs
– Cranial cavity – skull
– Vertebral or spinal cavity which protects the
spinal cord
• Ventral cavity –
– Thoracic cavity – surrounded by the ribs and
muscles of the chest
– Abdominopelvic cavity – includes the
diaphragm and the abdominal and pelvic
cavities
Homeostatic Imbalance
• P. 19
• What organs are most damaged in a
vehicle accident?
Membranes in the Ventral cavity
• Serous membrane – thin, double-layered
membrane that covers the walls of the
ventral cavity and the outer surfaces of the
organs
– Serous fluid – fluid found in between the 2
layers of the serous membrane
• Parietal membrane – part of the
membrane lining the cavity walls
Other body cavities
• 1. Oral and digestive cavities – organs??
• 2. Nasal cavity – part of the respiratory system
• 3. Orbital cavities – house the eyes
• 4. Middle ear cavity
• 5. Synovial cavity – joint cavities that surround
freely movable joints like the knee and shoulder
Abdominopelvic Regions and
Quadrants