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Chapter 1
Introduction to Anatomy and
Physiology
What is Anatomy?
Anatomy is the branch
of science that deals
with the morphology
(structure) of body
parts.
It primarily deals with
the organization and
form of body
structures.
Anatomy will tell you that this is a spine, that it
is composed of osteocytes, and that it is located
in the dorsal (posterior) area of most animals.
What is Physiology?
Physiology is more
concerned with the
function of the body
part.
It wants to answer the
questions of what does
it do and how does it
do it.
Physiology would tell you that it acts as support and
protection for the spinal cord. That the vertebrae are
designed to allow for mobility while still protecting
the spinal cord.
Characteristics of Life
As you might imagine anatomy and
physiology deals with living organisms or at
least organisms that were at one point alive.
Before we can continue we need to know
what constitutes life.
What are some of the characteristics you
can think of?
Characteristic
Description
Movement
Self initiated change in position, motion of internal parts
Responsiveness
Ability to sense changes and react to them
Growth
Increase in size
Reproduction
Producing new individuals
Respiration
Obtaining O2, using it to release energy, and removal of waste
Digestion
Chemically changing food substances, and waste removal
Absorption
Passage of digested products through membranes and into body
fluids
Circulation
Movement of substances throughout the body
Assimilation
Chemically changing absorbed substances to new substances
Excretion
Removal of waste
Metabolic Process
All physical and chemical changes occurring in an organism
Homeostasis
Tendency of the body to maintain a stable, balanced internal
environment. Accomplished through self regulating
adjustments
Maintenance of Life
There are five basic requirements for
organisms to remain living.
Water, Food, Oxygen, Heat, and Pressure.
All of these are involved in processes in the
body and these processes must be regulated.
This is where homeostasis comes in.
Homeostasis
It is the condition of a stable internal
environment.
It uses a set point and receptors and
effectors to determine what actions to take.
It is a systems that when it detects an
imbalance corrects the imbalance, this is
known as a negative feed back loop.
Levels of organization
Going from smallest
to largest, you start
with an atom and end
with an organism.
To reach the next level
you need to group the
parts to gather.
Lots of atoms=molecule;
lots of molecules=
organelle; lots of
organelles= a cell; and so
on.
General organization of the body
It consists of two main
portions.
The axial portion in
blue which includes
the head, neck and
trunk.
The appendicular
portion in pink which
contains the arms and
legs.
There are several body cavities in the body.
These cavities are lined with membranes.
These cavities also house a variety of
organs and organ systems. This is known as
viscera or visceral organs.
Body Cavities
Cranial –holds the brain
Spinal—holds the spine
Thoracic—holds the heart, lungs,
esophagus, and trachea
Abdominal—holds the stomach, spleen
liver, gall bladder, small intestine
Pelvic—Holds part of the large intestine,
urinary bladder, reproductive organs
The thoracic and abdominal cavities are
separated by a muscle known as the
diaphragm.
Organs within the cavities are surrounded
by a double layer membrane to help cushion
the organs and hold them in place.
Membranes
Pleura—surrounds the lungs
Pericardium—surrounds the heart
Peritoneum—surrounds all the
organs
Organ Systems
There are nine organ systems in the human
body.
Integumentary—Body covering. This
includes skin, hair, nails, and sweat glands.
It’s purpose is to protect underlying tissues
and regulate body temperature.
Skeletal—Bones, ligaments, and cartilage.
I provides support, movement, protection,
and provides the blood cells
Muscular—muscles of the body, provides
movement, maintenance of posture, and
body heat.
Nervous—Brain, spinal cord, and nerves
throughout the body, its function is
communication throughout the body, mental
activities, and maintaining homeostasis.
Endocrine—Ductless glands such as
pituitary, adrenal, thyroid, parathyroid,
pancreas, ovaries, testes, thymus, and pineal
glands. Its purpose is secretion of
hormones, and communication between
body parts
Digestive—mouth, teeth, pharynx,
esophagus, stomach, small intestine, large
intestine, liver, gall bladder ect. Its purpose
is to breakdown food into simpler forms
that can be absorbed.
Circulatory—Heart, blood vessels, and
blood. It transports materials throughout
the body. *The lymphatic system is usually
included with the circulatory system since
they use the same path ways.*
Urinary—Kidneys, ureters, urinary bladder,
and urethra. It removes (“filters”) wastes
from the body and helps maintain the
body’s water and electrolyte balance.
Reproductive—Reproductive organs
(primarily the ovaries and testes). Its
purpose is to produce reproductive cells to
allow for reproduction.
Anatomical Terminology
The official anatomical position is :
Standing erect, face forward, arms at side,
palms facing forward.
All descriptions of placement are based on
this position and are relative positions,
meaning they are dependent on the
placement of other objects.
Superior—a body part is above another part
or closer to the head.
Ex: The thoracic cavity is superior the
abdominopelvic cavity.
Inferior—body part is below another body
part or towards the feet.
Ex: The neck is inferior to the head.
Anterior (ventral)—Towards the front
Ex: The eyes are anterior to the brain.
Posterior (dorsal)—Towards the back.
Ex: The pharynx is posterior to the oral
cavity
Medial—an imaginary line that divides the
body into equal right and left halves. A
body part is medial when it is closer to this
center line than another body part.
Ex: The nose is medial to the eyes.
Lateral—means towards the side with
respect to the imaginary line.
Ex: The ears are lateral to the eyes
Proximal—Describes a body part closer to a
point of attachment to the trunk than
another body part.
Ex: The elbow is proximal to the wrist.
Distal—describes a body part that is farther
away from the trunk.
Ex: The fingers are distal to the wrist
Superficial—situated near the surface.
Ex: The epidermis is the superficial layer of
skin.
Deep—describes parts that are more
internal compared to a superficial part.
Ex: The dermis is the deep layer of skin.
Body Regions
Sagittal—refers to a length wise plane that
divides the body into left and right portions.
Transverse (horizontal)—refers to a plane
that divides the body into superior and
inferior portions.
Frontal (coronal)—refers to a plane that
divides the body into anterior and posterior
positions.