Introduction to Anatomy
Unit 1
Anatomy and Physiology

Anatomy: study of the structure of body
parts
Physiology: study of the function of
body parts
Levels of Biological Organization

Atoms (least complex)
Molecules
Macromolecules
Organelles
Cells
Tissues
Organs
Organ Systems
Organism (most complex)
Homeostasis

Homeostasis is the maintenance of a
stable internal environment
Feedback mechanisms help maintain
homeostasis
Positive Feedback

Positive feedback mechanisms lead to
changes that move further away from
the normal state
Positive Feedback

Examples
When injury occurs,
clotting factors are
released that stimulate
the release of more
clotting factors. This
occurs until a blood
clot forms.
Positive Feedback

During childbirth,
contractions of the
uterus stimulate the
release of hormones
that cause
contractions to increase
in intensity.
Positive Feedback

When a nerve
impulse is conducted,
sodium channels in
the nerve cell open.
This opening
stimulates the
opening of more
sodium channels.
Negative Feedback

Negative feedback mechanisms restore
the body to its normal state
Negative Feedback

Examples
When body
temperature
decreases,
shivering occurs to
increase body
temperature back
to its normal level
Negative Feedback

When body
temperature
increases,
perspiration occurs
and cools the body
down
Organization of the Human Body

The human body is
divided into two
portions
The axial portion
consists of the head,
neck and trunk
The appendicular portion
consists of the upper
and lower limbs
Body Cavities

Cranial cavity:
contains the brain
Vertebral canal:
contains the spinal
cord
Body Cavities

The thoracic cavity is divided
into two compartments by the
mediastinum
These two compartments hold
the left and right lungs
The heart, esophagus, trachea
and thymus are all within the
mediastinum
All organs in the thoracic
cavity are called viscera
Body Cavities

The thoracic cavity
and abdominal cavity
are separated by the
diaphragm
The abdominal cavity
contains the stomach,
liver, spleen,
gallbladder, kidneys
and most of the small
and large intestines
Body Cavities

The pelvic cavity contains the end of
the large intestine, the urinary bladder
and reproductive organs
Membranes

Membranes line some of the body
cavities and some of the organs within
those cavities
Parietal membranes line the walls of the
cavities
Visceral membranes surround the
organs within that cavity
Pleural Membranes

Pleural membranes
are found within the
thoracic cavity
The parietal pleura
line the walls of the
thoracic cavity
The visceral pleura
surround the lungs
Pericardial Membranes

The pericardial
membranes are found
within the mediastinum
The parietal
pericardium lines the
walls of the cavity that
contains the heart
The visceral pericardium
surrounds the heart
Peritoneal Membranes

Peritoneal membranes
are found within the
abdominopelvic cavity
The parietal
peritoneum lines the
walls of the
abdominopelvic cavity
The visceral
peritoneum lines each
organ within this cavity
Organ Systems

The integumentary
system is made up of
skin, hair, nails, sweat
glands, and sebaceous
glands
The functions of this
system include
protection, temperature
regulation, and sensory
reception
Organ Systems

The skeletal system
consists of bones,
ligaments, and
cartilage
The muscular
system functions
include movement,
posture, and
generation of heat
Organ Systems

The nervous system
consists of the brain,
spinal cord, and nerve
cells
The endocrine system
includes all glands that
secrete hormones and
works with the
nervous system
Organ Systems

The cardiovascular
system includes the
heart, arteries,
veins, capillaries
and blood. Its main
function is transport
of nutrients and
waste products
Organ Systems

The lymphatic
system is composed
of lymph, lymphatic
vessels, the thymus,
and the spleen
The lymphatic
system is involved
in immune responses
Organ Systems

The digestive system
breaks down food into
molecules that can be
absorbed into the blood
The respiratory
system is responsible
to moving oxygen into
the body and carbon
dioxide out of the
body
Organ Systems

The urinary system
consists of the kidneys,
ureters, urinary
bladder, and urethra
The urinary system is
responsible for getting
rid of waste products
Organ Systems

The male and female
reproductive systems
are responsible for
producing sperm and
egg cells
The female
reproductive system is
also responsible for
development of
offspring in the uterus
Anatomical Position

Body is standing up
Face forward
Upper limbs are at the
sides
Palms facing forward
The terms left and right
refer to the right and left
sides of the person
standing in anatomical
position
Relative Positions

Superior: above
The head is
superior to the
neck.
Inferior: below
The feet are
inferior to the knee.
Relative Positions

Anterior (ventral):
toward the front
The eyes are anterior
to the brain.
Posterior (dorsal):
toward the back
The spinal cord is
posterior to the chest.
Relative Positions

Medial: toward the
midline
The nose is medial
to the eyes.
Lateral: away from
the midline
The ears are lateral
to the eyes.
Relative Positions

Proximal: closer to a
point of attachment to
the trunk
 The elbow is proximal
to the wrist.
Distal: further away
from a point of
attachment to the trunk
 The foot is distal to
the knee.
Relative Positions

Superficial: closer to
the surface
The skin is
superficial to the
bones.
Deep: further from the
surface
 The dermis is deep to
the epidermis.
Body Sections

To observe internal
structures of the
human body, the
body must be cut into
sections
Different cuts reveal
different structures
Body Sections

Sagittal cuts divide the body into right
and left portions
Body Sections

Transverse cuts divide the body into
superior and inferior portions
Body Sections

Coronal cuts divide the body into
anterior and posterior portions
Body Regions

The abdominopelvic
cavity is divided
into 9 main regions
Epigastric: upper
middle
Left and right
hypochondriac: on
either side of the
epigastric
Body Regions

Umbilical: middle
portion
Right and left
lumbar: on either
side of the
umbilical
Body Regions

Hypogastric: lower
middle
Left and right iliac:
on either side of the
hypogastric
Adjectives Used to Describe
Body Regions

Abdominal: region between the thorax
and pelvis
Acromial: point of the shoulder
Antebrachial: the forearm
Antecubital: the space in front of the
elbow
Adjectives Used to Describe
Body Regions

Axillary: the armpit
Brachial: the arm
Buccal: the cheek
Carpal: the wrist
Celiac: the abdomen
Cephalic: the head
Adjectives Used to Describe
Body Regions

Cervical: the neck
Costal: the ribs
Coxal: the hip
Crural: the leg
Cubital: the elbow
Digital: the finger or toe
Adjectives Used to Describe
Body Regions

Dorsal: the back
Femoral: the thigh
Frontal: the forehead
Genital: the reproductive organs
Gluteal: the buttocks
Inguinal: the groin
Adjectives Used to Describe
Body Regions

Lumbar: the region of lower back
between ribs and pelvis
Mammary: the breast
Mental: the chin
Nasal: the nose
Occipital: the lower posterior region of
the head
Adjectives Used to Describe
Body Regions

Oral: the mouth
Orbital: the eye cavity
Otic: the ear
Palmar: the palm of the hand
Patellar: the front of the knee
Pectoral: the chest
Adjectives Used to Describe
Body Regions

Pedal: the foot
Pelvic: the pelvis
Plantar: the sole of the foot
Popliteal: the area behind the knee
Sacral: the posterior region between the
hip bones
Adjectives Used to Describe
Body Regions

Sternal: the middle of the thorax,
anteriorly
Sural: the calf
Tarsal: the instep of the foot
Umbilical: the navel
Vertebral: the spinal column
Adjectives Used to Describe
Body Regions
