The
Human Body
Levels of Organization in
Humans
Human Organ Systems

Skeletal System
Nervous

Muscular System
Reproductive

Circulatory System


Respiratory System
Integumentary

Digestive System
Excretory
System
System
Endocrine System
System
System
Lymphatic/Immune
System
Skeletal System

Structures: Bones, Cartilage, Ligaments,
tendons

Functions: Supports the body, protects
internal organs, allows movement,
stores mineral reserves, provides a site
for blood cell formation
• Makes up the general framework of the body.
• Composed of 206 named bones of various
shapes and sizes.
• Ligaments hold bones together.
• Cartilage can be found between many of the
bones. This smooth, slightly elastic
connective tissue works to cushion the ends
of the bones where they bump together at a
joint.
• Bones are alive and continue to grow until
about age 25.
• They are hard due to the high concentration
of certain minerals such as calcium and
phosphorus.
Human Joints

The joint is the place where two bones meet.

There are two types of joints:
 Immovable joints do not permit any movement of the bones.

The suture joints of the skull and the fused
bones of the sacrum and coccyx are examples
of this type of joint.

Movable joints allow the body to move
depending on the type of joint will determine
how the joint will move.
Movable Joints

Hinge joints
 found in knee and elbow
 permit back and forth motion in only one direction.

Ball-and-socket joints
 The hip and shoulder joints
 They permit nearly a full range of motion.

Pivot joint
 The joint at the base of the skull
 It allows movement of the head in a circular motion.

Gliding joints
 The joints of the wrist and ankle.
 The many small bones found in the wrist and ankle move
slightly over one another permitting movement to occur.
ASIMO = Advanced Steps In
Mobility
http://asimo.honda.com/default.aspx
Muscular System

Structures: Skeletal Muscle, smooth
muscle, cardiac muscle

Function: Works with skeletal system to
produce voluntary movement, helps to
circulate blood and move food through
the digestive system
http://trc.ucdavis.edu/biosci10v/bis10v/week10/08muscularsystem.htm
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homepage.smc.edu/.../anatomy1/1muscles.html
Circulatory System

Structures: heart, blood vessels, blood

Function: Brings oxygen, nutrients, and
hormones to cells, fights infections,
removes cell wastes, helps to regulate
body temperature
Blood Flow through the Heart
1. Oxygen-poor blood flows from the
body into the right atrium.
2. Blood flows through the right atrium
into the right ventricle.
3. The right ventricle pumps the blood to
the lungs, where the blood releases
waste gases and picks up oxygen.
4. The newly oxygen-rich blood (shown
in red) returns to the heart and enters
the left atrium.
5. Blood flows through the left atrium into
the left ventricle.
6. The left ventricle pumps the oxygenrich blood to all parts of the body.
www.pbs.org/wgbh/nova/eheart/human.html
Respiratory System

Structures: Nose, pharynx, larynx,
trachea, bronchi, bronchioles,
lungs

Function: Provides oxygen needed
for cellular respiration and
removes excess carbon dioxide
from the body
One of the main jobs of the cardiovascular
system is to deliver oxygen (O2) to the
body.
 As our bodies work, it uses up oxygen,
replacing it with carbon dioxide (CO2).


Air enters our lungs through pressure
changes.

Inhalation – Diaphragm and related
muscles contract, chest expands, air
gets pulled in

Exhalation – Muscles relax, elastic
cartilage pulls ribs in, chest contracts,
air is pushed out of lungs
Digestive System

Structures: Mouth, pharynx, esophagus,
stomach, small and large intestines,
rectum

Functions: Converts food into simpler
molecules that can be used by the cells
of the body, absorbs food, eliminates
wastes
Nervous System

Structures: Brain, spinal cord. Peripheral
nerves

Functions: Recognizes and coordinates
the body’s responses to changes in its
internal and external environments
Reproductive Systems

Structures:
 Males-Testes, epididymis, vas deferens, urethra,
and penis
 Females-Ovaries, Fallopian tubes uterus, vagina

Functions: Produces reproductive cells
 Males-sperm
 Females- eggs, also nurtures and protects
developing embryo
○ Stages development
 Sperm & egg unite during fertilization to create a
zygote- blastocyst – embryo- fetus- Infant
Endocrine System

Structures: Glands- Hypothalamus,
pituitary, pineal, thyroid, parathyroid,
adrenals, pancreas, ovaries (females),
testes (males)

Function: Controls growth,
development, and metabolism,
maintains homeostasis
Male
Female
1. Pineal gland,
2. Pituitary gland,
3. Thyroid gland,
4. Thymus,
5. Adrenal gland,
6. Pancreas,
7. Ovary, female only
8. Testis, male only
Integumentary System

Structures: Skin, hair, nails, sweat and
oil glands

Functions: Serves as a barrier to
regulate body temperatures, provides
protection against ultraviolet radiation
from the sun
Excretory System

Structures: Skin, Lungs, kidneys,
ureters, urinary, bladder, urethra

Functions: Eliminates waste products
from the body in ways that maintain
homeostasis
Lymphatic/immune System

Structures: White blood cells, thymus,
spleen lymph nodes, lymph vessels

Functions: Helps protect the body from
disease. Collects fluid lost from blood
vessels and returns the fluid to the
circulatory system
Lymphatic System
ʘ Part of the immune system,
which defends the body
against infection.
ʘ A network of small lymph
nodes connected by very
thin lymph vessels, which
branch into every part of the
body except the brain and
spinal cord.

The major nodes can be found in the neck,
armpits, chest, abdomen, pelvis and groin.
Other parts of the lymphatic system include
the spleen, thymus and bone marrow.

A clear fluid called lymph flows through the
lymph vessels.
 It contains white blood cells called lymphocytes,
special proteins called antibodies, and some waste
products.


The lymph fluid passes through the lymph
nodes, which filter out bacteria and other
harmful things