12 Body Systems
By: Stephen E. Davis III
1. Circulatory system/Cardiovascular
2. system Digestive system
3. Endocrine system
4. Immune system
5. Lymphatic system
6. Integumentary system
7. Muscular system
8. Nervous system
9. Reproductive system
10.Respiratory system
11.Skeletal system
12.Urinary system
Urinary system
• The urinary system removes a type of waste called urea
from your blood. Urea is produced when foods containing
protein, such as meat, poultry, and certain vegetables, are
broken down in the body. Urea is carried in the
bloodstream to the kidneys.
• The kidneys are bean-shaped organs about the size of your
fists. They are near the middle of the back, just below the
rib cage. The kidneys remove urea from the blood through
tiny filtering units called nephrons. Each nephron consists
of a ball formed of small blood capillaries, called a
glomerulus, and a small tube called a renal tubule. Urea,
together with water and other waste substances, forms the
urine as it passes through the nephrons and down the renal
tubules of the kidney.
Skeletal system
• What is the Skeletal System? Your Skeletal system is all
of the bones in the body and the tissues such as
tendons, ligaments and cartilage that connect them.
Your teeth are also considered part of your skeletal
system but they are not counted as bones. Your teeth
are made of enamel and dentin. Enamel is the
strongest substance in your body.
• How does the Skeletal System help us? Support
The main job of the skeleton is to provide support for
our body. Without your skeleton your body would
collapse into a heap. Your skeleton is strong but light.
Without bones you'd be just a puddle of skin and guts
on the floor.
Skeletal system
• Protection
Your skeleton also helps protect your internal organs
and fragile body tissues. The brain, eyes, heart, lungs
and spinal cord are all protected by your skeleton. Your
cranium (skull) protects your brain and eyes, the ribs
protect your heart and lungs and your vertebrae (spine,
backbones) protect your spinal cord.
• Movement
Bones provide the structure for muscles to attach so
that our bodies are able to move. Tendons are tough
inelastic bands that hold attach muscle to bone.
Respiratory system
• The primary function of the respiratory system
is to supply the blood with oxygen in order for
the blood to deliver oxygen to all parts of the
body. The respiratory system does this
through breathing. When we breathe, we
inhale oxygen and exhale carbon dioxide. This
exchange of gases is the respiratory system's
means of getting oxygen to the blood.
Respiratory system
• Respiration is achieved through the mouth, nose,
trachea, lungs, and diaphragm. Oxygen enters the
respiratory system through the mouth and the nose.
The oxygen then passes through the larynx (where
speech sounds are produced) and the trachea which is
a tube that enters the chest cavity. In the chest cavity,
the trachea splits into two smaller tubes called the
bronchi. Each bronchus then divides again forming the
bronchial tubes. The bronchial tubes lead directly into
the lungs where they divide into many smaller tubes
which connect to tiny sacs called alveoli.
Respiratory system
• The average adult's lungs contain about 600
million of these spongy, air-filled sacs that are
surrounded by capillaries. The inhaled oxygen
passes into the alveoli and then diffuses
through the capillaries into the arterial blood.
Meanwhile, the waste-rich blood from the
veins releases its carbon dioxide into the
alveoli. The carbon dioxide follows the same
path out of the lungs when you exhale.
Respiratory system
• The diaphragm's job is to help pump the
carbon dioxide out of the lungs and pull the
oxygen into the lungs. The diaphragm is a
sheet of muscles that lies across the bottom of
the chest cavity. As the diaphragm contracts
and relaxes, breathing takes place. When the
diaphragm contracts, oxygen is pulled into the
lungs. When the diaphragm relaxes, carbon
dioxide is pumped out of the lungs.
Reproductive system
• Sexual reproduction is the process of producing
offspring for the survival of the species, and passing on
hereditary traits from one generation to the next. The
male and female reproductive systems contribute to
the events leading to fertilization. Then, the female
organs assume responsibility for the developing
human, birth, and nursing. The male and female
gonads (testes and ovaries) produce sex cells (ova and
sperm) and the hormones necessary for the proper
development, maintenance, and functioning of the
organs of reproduction and other organs and tissues.
Immune system
• The immune system is the body's defense against
infectious organisms and other invaders. Through a
series of steps called the immune response, the
immune system attacks organisms and substances that
invade body systems and cause disease.
• The immune system is made up of a network of cells,
tissues, and organs that work together to protect the
body. The cells involved are white blood cells, or
leukocytes, which come in two basic types that
combine to seek out and destroy disease-causing
organisms or substances.
Immune system
• Leukocytes are produced or stored in many locations in
the body, including the thymus, spleen, and bone
marrow. For this reason, they're called the lymphoid
organs. There are also clumps of lymphoid tissue
throughout the body, primarily as lymph nodes, that
house the leukocytes.
• The leukocytes circulate through the body between the
organs and nodes via lymphatic vessels and blood
vessels. In this way, the immune system works in a
coordinated manner to monitor the body for germs or
substances that might cause problems
Immune system
• The two basic types of leukocytes are:
• phagocytes, cells that chew up invading organisms
• lymphocytes, cells that allow the body to remember and
recognize previous invaders and help the body destroy
them
• A number of different cells are considered phagocytes. The
most common type is the neutrophil, which primarily fights
bacteria. If doctors are worried about a bacterial infection,
they might order a blood test to see if a patient has an
increased number of neutrophils triggered by the infection.
Other types of phagocytes have their own jobs to make
sure that the body responds appropriately to a specific type
of invader.
Immune system
• The two kinds of lymphocytes are B lymphocytes
and T lymphocytes. Lymphocytes start out in the
bone marrow and either stay there and mature
into B cells, or they leave for the thymus gland,
where they mature into T cells. B lymphocytes
and T lymphocytes have separate functions: B
lymphocytes are like the body's military
intelligence system, seeking out their targets and
sending defenses to lock onto them. T cells are
like the soldiers, destroying the invaders that the
intelligence system has identified
Lymphatic system
• The lymphatic system consists of organs, ducts, and
nodes. It transports a watery clear fluid called lymph.
• This fluid distributes immune cells and other factors
throughout the body. It also interacts with the blood
circulatory system to drain fluid from cells and tissues.
• The lymphatic system contains immune cells called
lymphocytes, which protect the body against antigens
(viruses, bacteria, etc.) that invade the body. See more
on lymphocytes below. It is abnormal cells of this type
that cause lymphoma.
Lymphatic system
• Main functions of the lymphatic system
• "to collect and return interstitial fluid,
including plasma protein to the blood,
and thus help maintain fluid balance,
• to defend the body against disease by
producing lymphocytes,
• to absorb lipids from the intestine and
transport them to the blood."
Integumentary system
• The integumentary system, formed by the skin, hair,
nails, and associated glands, enwraps the body. It is the
most visible organ system and one of the most
complex. Diverse in both form and function—from
delicate eyelashes to the thick skin of the soles—the
integumentary system protects the body from the
outside world and its many harmful substances. It
utilizes the Sun's rays while at the same time shielding
the body from their damaging effects. In addition, the
system helps to regulate body temperature, serves as a
minor excretory organ, and makes the inner body
aware of its outer environment through sensory
receptors.
Muscular system
• The muscles we have in our body are divided into
three classes of muscles: cardiac, smooth, and
skeletal. Usually, when we think of muscular
system we often only remember the skeletal
muscles because they make up what is
recognized as the muscular system. The muscular
system, composed of over 600 muscles, come in
a variety of shapes and forms. Diffrences
between each muscle are recognized by location,
function, structure, and the way they are
contracted.
Muscular system
• CARDIAC MUSCLE: The cardiac muscles is the
muscle of the heart itself. The cardiac muscle is
the tissue that makes up the wall of the heart
called the mydocardium. Also like the skeletal
muscles, the cardiac muscle is striated and
contracts through the sliding filament method.
However it is different from other types of
muscles because it forms branching fibers. Unlike
the skeletal muscles, the cardiac muscle is
attached together instead of been attach to a
bone.
Muscular system
• SKELETAL MUSCLE: The skeletal muscle makes up
about 40 % of an adults body weight. It has
stripe-like markings, or striations. The skeletal
muscles is composed of long muscle fibers. Each
of these muscles fiber is a cell which contains
several nuclei. The nervous system controls the
contraction of the muscle. Many of the skeletal
muscle contractions are automatic. However we
still can control the action of the skeletal muscle.
And it is because of this reason that the skeletal
muscle is also called voluntary muscle.
Muscular system
• SMOOTH MUSCLE:
• Much of our internal organs is made up of
smooth muscles. They are found in the urinary
bladder, gallbladder, arteries, and veins. Also the
digestive tract is made up of smooth muscle as
well. The smooth muscles are controlled by the
nervous system and hormones. We cannot
consciously control the smooth muscle that is
why they are often called involuntary muscles.
Nervous system
• The neuron is the functional unit of the
nervous system. Humans have about 100
billion neurons in their brain alone! While
variable in size and shape, all neurons have
three parts. Dendrites receive information
from another cell and transmit the message to
the cell body. The cell body contains the
nucleus, mitochondria and other organelles
typical of eukaryotic cells. The axon conducts
messages away from the cell body.
Circulatory system/Cardiovascular
system
• The circulatory system is made up of the
vessels and the muscles that help and control
the flow of the blood around the body. This
process is called circulation. The main parts of
the system are the heart, arteries, capillaries
and veins
Circulatory system/Cardiovascular
system
• As blood begins to circulate, it leaves the
heart from the left ventricle and goes into the
aorta. The aorta is the largest artery in the
body. The blood leaving the aorta is full of
oxygen. This is important for the cells in the
brain and the body to do their work. The
oxygen rich blood travels throughout the body
in its system of arteries into the smallest
arterioles.
Circulatory system/Cardiovascular
system
• On its way back to the heart, the blood travels
through a system of veins. As it reaches the
lungs, the carbon dioxide (a waste product) is
removed from the blood and replace with
fresh oxygen that we have inhaled through the
lungs.
Digestive system
• The digestive system is divided into regions
that specialize in the process of digestion. The
tract is primarily composed of a layer of cells,
that secrete digestive juices and mucous as
well as absorb nutrients, surrounded by
muscle. It includes the mouth, pharynx,
esophagus, stomach, small intestine, and large
intestine.
Endocrine system
• The endocrine system is made up of glands
that produce and secrete hormones. These
hormones regulate the body's growth,
metabolism (the physical and chemical
processes of the body), and sexual
development and function. The hormones are
released into the bloodstream and may affect
one or several organs throughout the body.
• Hormones are chemical messengers created by
the body. They transfer information from one set
of cells to another to coordinate the functions of
different parts of the body.
The major glands of the endocrine system are the
hypothalamus, pituitary, thyroid, parathyroids,
adrenals, pineal body, and the reproductive
organs (ovaries and testes). The pancreas is also a
part of this system; it has a role in hormone
production as well as in digestion.
• The endocrine system is regulated by feedback in
much the same way that a thermostat regulates
the temperature in a room. For the hormones
that are regulated by the pituitary gland, a signal
is sent from the hypothalamus to the pituitary
gland in the form of a "releasing hormone,"
which stimulates the pituitary to secrete a
"stimulating hormone" into the circulation. The
stimulating hormone then signals the target
gland to secrete its hormone.
• As the level of this hormone rises in the
circulation, the hypothalamus and the
pituitary gland shut down secretion of the
releasing hormone and the stimulating
hormone, which in turn slows the secretion by
the target gland. This system results in stable
blood concentrations of the hormones that
are regulated by the pituitary gland.