11 MAJOR ORGAN
SYSTEMS IN THE HUMAN
BODY
1) Circulatory System
Major Structures:
Heart, Blood vessels,
Blood, lymph nodes and
vessels, lymph
Functions:
Transports nutrients,
wastes, hormones, and
gases
The Closed Circulatory System
Humans
have a closed circulatory
system, typical of all vertebrates, in which
blood is confined to vessels and is
distinct from the interstitial fluid.
The
heart pumps blood into large vessels
that branch into smaller ones leading into the
organs.
Materials
are exchanged by diffusion
between the blood and the interstitial fluid
bathing the cells.
The
Blood
Carry
hemoglobin
and oxygen. Do
not have a nucleus
and live only about
120 days.
Can
not repair
themselves.
2) Digestive System
Major Structures:
Mouth, Throat, Esophagus,
Stomach, Liver, Pancreas,
Small intestine, Large
intestine
Functions:
Extracts and absorbs
nutrients from food;
removes wastes; maintains
water and chemical
balances
3) Endocrine System
Major Structures:
Hypothalamus, pituitary, pancreas
Functions:
Regulates body temperature, metabolism,
development, and reproduction; maintains
homeostasis; regulates other organ systems
4) Excretory System
Major Structures:
Kidneys, urinary
bladder, ureters,
urethra, skin, lungs
Functions:
Removes wastes
from blood; regulates
concentration of body
fluids
– filter out excess water
and urea
 Kidneys
– filter out carbon dioxide, CO2,
from the blood.
 Skin – excretes water, as sweat, which
contains some trace chemical wastes,
including urea.
 Lungs
I. The Kidneys
 Every
drop of blood in
your body is filtered by
your kidneys more than
300 times per day!
 Kidneys eliminate urea,
minerals and excess
water.
 Kidneys regulate the
amount of water we need
to maintain in our bodies.
5) Immune System
Major Structures:
White blood cells, lymph nodes and vessels, skin
Functions:
Defends against pathogens and disease
* More
about this
tomorrow!!
6) Integumentary System
Major Structures:
Skin, nails, hair
Functions:
Protects against injury, infection, and fluid
loss; helps regulate body temperature
7) Muscular System
Major Structures:
Skeletal, smooth, and
cardiac muscle
tissues
Functions:
Moves limb and trunk;
moves substances
through body;
provides structure and
support
8) Nervous System
Major Structures:
Brain, spinal cord, nerves,
sense organs
Functions:
Regulates behavior,
maintains homeostasis;
regulates other organ
systems; controls sensory
and motor functions
9) Reproductive System
Major Structures:
Testes, penis (males),
ovaries, uterus, breasts
(females)
Functions:
Produces gametes and
offspring
10) Respiratory System
Major Structures:
Lungs, nose, mouth, trachea
Functions:
Moves air into and out of the lungs;
controls gas exchange between blood and
lungs
11) Skeletal System
Major Structures:
Bones and joints
Functions:
Protects and supports the
body and organs;
interactions with skeletal
muscles; produces red
blood cells, white blood
cells, and platelets