Human Anatomy and Body Systems
Levels of Organization
The human body is organized in several levels,
from the simplest to the most complex.
Cells – the basic unit of life
Tissues – clusters of cells performing a similar
function
Organs – made of tissues that perform one
specific function
Organ Systems – groups of organs that
perform a specific purpose in the human body
Organism – the whole human
The 11 Human Body Systems
The purpose of the 11 organ systems is for the human body to maintain
homeostasis
The 11 human body
systems are:
1. digestive system
2. excretory system
6. endocrine system
7. skeletal system
8. muscular system
3. respiratory system
9. lymphatic (immune)
system
4. circulatory system
10.reproductive system
5. nervous system
11.integumentary
system
The Digestive System
Purpose: to convert food particles into simpler
macromolecules that can be absorbed into the
bloodstream and used by the body
Major Organs and their Functions:
Mouth – to chew and grind up food
-- saliva also begins the chemical breakdown
Esophagus – pipe connecting mouth to stomach
Stomach – secretes an extraordinarily strong acid (pH = 2) that
leads to breakdown of food
-- once the food is broken down in the stomach and
mixed with digestive juices, it is called chyme
Pancreas – produces the hormone insulin that regulates blood
sugar levels
-- also help neutralize stomach acid
Liver – produces bile, which breaks down fats in foods
Gallbladder – pouch-like organ that stores bile for future use
Small Intestine – after digestion is complete, the chyme
enters the small intestine where it is absorbed into the
bloodstream
-- the chyme is propelled along by folded surfaces
called villi, on the intestine
Large Intestine – removes water from the chyme and gets the
waste ready for excretion
Digestive System
• The digestive system is made up of the
alimentary canal and the other abdominal
organs that play a part in digestion, such as
the liver and pancreas.
• The digestive tract is the long tube of
organs — including the esophagus, the
stomach, and small and large intestines —
that runs from the mouth to the anus.
• An adult's digestive tract is about 30 feet
long.
• The function is to breakdown and absorb
nutrients that are necessary for growth and
maintenance.
Digestive System
• The digestive system breaks down food two ways:
– mechanical digestion- the chewing (in the
mouth) and churning (in the stomach) that can
be used by the body.
– chemical digestion- with the help of enzymes,
into substances that cells can absorb and use.
This occurs in the mouth, stomach and small
intestines.
Image of the Digestive System
POP QUIZ
21. The function of the digestive system is to:
a. break down and absorb nutrients
b.
c.
support soft tissues and protects organs
controls activities through electrical impulses
a.
b.
c.
heart, lungs, and veins
spleen, thymus, and lymph nodes
esophagus, stomach, and intestines
a.
b.
c.
mechanical and chemical
chemical and physical
physical and physiological
a.
b.
c.
small intestine, stomach, and mouth
bones, veins, and heart
spleen, heart, and lungs
22. The digestive tract contains the following organs:
23. The digestive system breaks down food in two ways:
24. Chemical digestion occurs in:
The Excretory System
Purpose: to rid the body of wastes, including excess water
and salts
Major Organs and Their Functions
Kidneys – the main organs of the excretory system
-- waste-laden blood enters the kidney and the kidney
filters out urea, excess water and other waste
products, which eventually travel out of the kidney as
urine
-- eventually they travel through the ureter to the
urinary bladder
Rectum – solid (food) waste travels out of the body through
the rectum
Skin – sweat glands remove excess water and salts from the
body
Lungs – expel the waste gas carbon dioxide
Image of the Excretory System
The Respiratory System
Purpose: to provide the body with a fresh supply of oxygen
for cellular respiration and remove the waste product carbon
dioxide
Major Organs and Their Functions
Nose – internal entry and exit point for air
Pharynx – serves as a passage way for both air and food at
the back of the throat
Larynx – your “voicebox”, as air passes over your vocal
chords, you speak
Trachea – the “windpipe”, or what connects your pharynx to
your lungs
-- a piece of skin, called the epiglottis, covers the
trachea when you swallow, preventing food from
entering
Bronchi – the two large passageways that lead from the
trachea to your lungs (one for each lung)
-- the bronchi are further subdivided into bronchioles
-- eventually, the further subdivisions lead to tiny air
sacs called alveoli
-- alveoli are in clusters, like grapes
-- capillaries surrounding each alveolus is where
the exchange of gases with the blood occurs
The diaphragm is the muscle that causes you to breath
-- hiccups are involuntary contractions of the
diaphragm
Respiratory System
• The function of the respiratory system is
breathing in oxygen from the air and
carbon dioxide is expelled from the body.
• The system that allows breathing (gas
exchange) includes the nose, pharynx,
trachea, and lungs.
• Respiratory system provides gas exchange
between blood and the environment.
Respiratory System
• Although it may seem easier to breathe
through the mouth, it is healthier to
breathe through the nose. The hairs and
mucus in the nose (part of the nasal
cavity) help filter and warm the air as it
comes in.
• LUNGS- gases are transferred between
lungs and blood from the circulatory
system.
• The diaphragm is a muscle beneath the
lungs that helps move air in and out of
the body.
Image of the Respiratory System
POP QUIZ
9.
10.
11.
12.
Function of the respiratory system is breathing in _________ from the
air and expelling _________________.
a.
b.
c.
oxygen, carbon dioxide
carbon dioxide, oxygen
oxygen, nutrients
a.
b.
c.
lungs, heart, and arteries
thymus, spleen, and bone marrow
nose, lungs, and pharynx
a.
b.
c.
gas
cavity
muscle
a.
b.
c.
waste removal
gas exchange
food exchange
The respiratory system includes the following organs and tissues:
The diaphragm is a
Respiratory system provides ________________.
The Circulatory System
Purpose: to deliver oxygenated blood to the various cells and
organ systems in your body so they can undergo cellular
respiration
Major Organs and Their Functions
Heart – the major muscle of the circulatory system
-- pumps blood through its four chambers (two
ventricles and two atria)
-- pumps deoxygenated blood into the lungs, where it
gets oxygenated, returned to the heart, and then
pumped out through the aorta to the rest of the body
-- valve regulate the flow of blood between the
chambers
Arteries – carry blood away from the heart and to the major
organs of the body
Veins – carry blood back to the heart away from the major
organs of the body
Capillaries – small blood vessels where gas exchange occurs
Blood – the cells that flow through the circulatory system
-- red blood cells contain hemoglobin, an iron-rich
protein that carries oxygen
-- white blood cells function in the immune system
-- platelets help in blood clotting
Spleen – helps to filter out toxins in the blood
Circulatory System
•
•
•
•
•
•
•
Arteries
Veins
The circulatory system is responsible for bringing
oxygen, nutrients, and hormones to cells.
It’s function is to remove wastes and regulate
body temperature.
The heart is central to the human circulatory
system; it pushes blood through the body’s
network of arteries and veins.
Blood is pumped from the heart to the lungs,
acquires oxygen and releases carbon dioxide.
The blood travels back to the heart and pumps
back to the rest of the body.
Blood passes the body cells, it transfers oxygen to
the cells, and picks up wastes.
It returns to the heart and the process is repeated.
Circulatory System
• Arteries are tubes that carry blood away from
the heart
• Veins are tubes that return blood to the heart
• Capillaries connect arteries and veins. They are
tiny tubes that exchange food, oxygen and
wastes between blood and body cells.
• Pulmonary circulation is the movement of
blood between the heart and lungs
• Coronary circulation is the movement of blood
from within the heart chambers to the heart
tissues themselves
• Systemic circulation is the movement of blood
between the heart and the rest of the body
• The circulatory system is pretty important, huh?
Image of the Circulatory System
Circulatory System
Circulatory Song
Verse 1:
Verse 2:
Pump, pump, pumps your blood.
The aortic valve’s, where the blood leaves
the heart, then it's channeled to the rest of
the body.
The right atrium’s where the process
begins, where the CO2 blood enters the
heart.
Through the tricuspid valve, to the right
ventricle, the pulmonary artery, and
lungs.
Once inside the lungs, it dumps its
carbon dioxide and picks up its oxygen
supply.
Then it’s back to the heart through the
pulmonary vein, through the atrium and
left ventricle.
Pump, pump, pumps your blood.
Pump, pump, pumps your blood.
The arteries, arterioles, and capillaries too
bring the oxygenated blood to the cells.
The tissues and the cells trade off waste
and CO2, which is carried through the
ventricles and the veins.
Through the larger vena cava to the atrium
and lungs, and we're back to where we
started in the heart.
Pump, pump, pumps your blood.
POP QUIZ
5.
The circulatory system is responsible for bringing
_____________________to the cells.
a.
b.
c.
6.
Arteries are tubes that
a.
b.
c.
7.
return blood to the heart
exchange food, oxygen and wastes between the blood and body cells
carry blood away from the heart
Pulmonary circulation is
a.
b.
c.
8.
gas, carbon dioxide, and the environment
oxygen, nutrients, and hormones
white blood cells, pathogens, and bone marrow
the movement of blood between the heart and the lungs
the movement of blood from within the heart chambers
the movement of blood between the heart and the rest of the body
Blood is pumped from the heart to the lungs and acquires
______________ and releases _________________________.
a.
b.
c.
carbon dioxide , oxygen
oxygen, carbon dioxide
oxygen, nutrients
The Nervous System
Purpose: to coordinate the body’s response to changes in its
internal and external environment
Major Organs and Their Functions
Brain – control center of the body, where all processes are
relayed through
-- consists of cerebrum (controls though and senses)
and cerebellum (controls motor functions)
Spinal Cord – sends instructions from the brain to the rest of
the body and vice versa
-- any organism with a major nerve cord is classified as
a chordate
Nerves – conduct impulses to muscle cells throughout the
body
Nervous System
• The brain, spinal cord, and network of
nerves (peripheral nervous system)
receive messages from inside and
outside the body and transmit
instructions about how to respond.
• The nervous system is the control
center of the body; it interprets the
senses and enables you to respond.
• Smell, taste, touch, sight, and sound
are controlled by this system.
Nervous System
• Things to know about the nervous system:
– A neuron (nerve cell) is the basic unit of
structure and function of the nervous
system.
– A response that is made automatically is
a reflex.
– Your spinal cord is made of bundles of
neurons that carry impulses from all parts
of the body to the brain and from the
brain to all parts of your body.
– The spinal cord is about as big around as
an adult thumb and 43 cm long.
Diagram of a Nerve Cell
POP QUIZ
17. The nervous system controls cells:
a. by releasing hormones
b.
c.
through electrical impulses
through muscular movement
a.
b.
c.
brain, spinal cord, and nerves
nerves, capillaries, and lungs
spinal cord, trachea, and esophagus
a.
b.
c.
works in pairs
is an automatic response
occurs in the blood system
a.
b.
c.
to push blood through the arteries and veins
breath in oxygen and breathe out carbon dioxide
to receive messages from inside an outside of the body and
transmits instructions about how to respond
18. The organs of the nervous system are:
19. A reflex:
20. The function of the nervous system is:
The Endocrine System
Purpose: to control growth, development, metabolism and
reproduction through the production and secretion of
hormones
Major Organs
-- hypothalamus
-- pituitary gland
-- thyroid
-- parathyroid
-- adrenal glands
-- pancreas
-- testes
-- ovaries
The Skeletal System
Purpose: to provide structure and support to the human
body
Bones are where new blood cells are generated (in the
marrow), and require the mineral calcium for strength
Major Bones of the Human Body
-- femur (thigh bone)
-- humerus (upper arm)
-- radius and ulna (lower arm)
-- cranium (skull)
-- sternum (breastbone)
-- clavicle (shoulder blade)
-- fibula and tibia (calf)
-- vertebrae (back)
-- scalpula (shoulder)
-- pelvic bone
-- coccyx (tail bone)
-- phalanges (fingers/toes)
Skeletal System
• The function of the skeletal system is to
give the body support and protect vital
organs.
• Without a skeletal system, the human
body would be limp and floppy.
• The skeletal system consists of bones,
ligaments, cartilage, and tendons.
• Your skull, a series of fused bones, acts
like a hard protective helmet for your
brain.
• The bones, or vertebrae, of your spinal
column surround your spinal cord; a
complex bundle of nerves.
Skeletal System
• The skeletal system provides attachment sites
for the organs.
– Imagine what could happen to your heart
and lungs without the protective armor of
your rib cage!
• How many bones do humans have?
When you were born you had over 300 bones.
• As you grew, some of these bones began to
fuse together.
– The result? An adult has only 206 bones!
Skeletal System
• Bones are living structures with 5 functions:
– protect internal organs
– support the body
– make blood cells
– store minerals
– allow for muscle attachment
• A point where two or more bones connect is called
a joint.
• There are two different types of joints in the body:
– Movable joints (like ball-and-socket, hinge,
gliding and pivot joints)
– Immovable joints (like the bones of the skull and
pelvis) which allow little or no movement
• You have over 230 moveable and semi-moveable
joints in your body.
POP QUIZ
1.
2.
3.
4.
Skeletal system supports
a. chemical reactions in the body
b.
c.
supports soft tissues and protects organs
carries oxygen-rich blood to cells
a.
b.
c.
support the body
provides protection from disease
digest food
a.
b.
c.
nose, pharynx, trachea, and lungs
lungs, heart, arteries, and veins
ligaments, cartilage, bones, and tendons
a.
b.
c.
provide gas exchange
support the body
protect vital organs
Bones
Skeletal system is made of
Which is NOT a role of the skeletal system?
The Muscular System
Purpose: works with the skeletal and nervous system to
produce movement, also helps to circulate blood through the
human body
-- muscle cells are fibrous
-- muscle contractions can be voluntary or involuntary
Major Muscles in the Human Body
-- biceps
-- triceps
-- glutes
-- hamstrings
-- deltoids
Muscular System
• There are 600 muscles in the body, both voluntary
and involuntary.
– Voluntary muscles are muscles that you can
move whenever you want to.
– Involuntary muscles contract and relax
automatically inside your body. We can not
control our involuntary muscles.
• Muscle contracts to move bones and body parts.
• Muscles look either striated or smooth:
– Striated muscle has stripes or striations in it.
– Smooth muscle does not have striations.
• The cardiac muscle is unique in the human
muscular system because it is made of smooth and
skeletal muscle, controls the heart and is
involuntary.
Muscular System
Function:
• Controls movement of internal organs such
as the stomach, intestine, heart, and
circulatory system.
• Controls contractions of the heart.
• Works with skeletal system to move the
body.
• Skeletal muscles work in pairs. When one
contracts, the other relaxes.
• They are attached to bone by bands of
tissue called tendons.
• Helps circulate blood and move food
through the digestive system.
POP QUIZ
13. What one organ is formed of cardiac muscle?
a. the spleen
b.
c.
the liver
the heart
a.
b.
c.
skeletal
smooth
striated
a.
b.
c.
internal organs
external organs
the dermis
a.
b.
c.
peripheral, neural, and cardiac
smooth, autonomic, and skeletal
skeletal, smooth, and cardiac
14. What muscle of the muscular system makes up the walls of the
stomach, intestines, and blood vessels?
15. The function of the muscular system controls movement of
16. What are the three types of muscles in the human body?
The Immune System
Purpose: to remove infectious diseases and other pathogens
from the human body
Major Organs and Their Functions
Skin – also called the integumentary system, the skin is the
body’s first line of defense
White Blood Cells – recognize disease agents (antigens) and
create antibodies to tag and remove these antigens
-- phagocytes are the white blood cell type that actually
eats and destroys these antigens
Lymph Nodes – help restore fluid lost by the blood and return
it to the circulatory system
Immune System
• Your immune system is like an army that
protects you from disease.
• Your skin is the first wall of protection
against disease causing agents called
pathogens.
• The second line of defense are fluids like
mucus found in your respiratory system and
tears from your eyes.
• If the pathogens do pass through these
defenses there is an army battalion of white
blood cells and their weapons that fight the
germs.
Immune System
• Bone Marrow
– is the soft tissue found in the hollow interior of
bones. It is the place where most new blood cells
are produced.
• Thymus
– is an organ located in the upper anterior portion of
the chest cavity. It is of central importance in the
maturation of T cells.
• Spleen
– is an organ of the upper abdomen, where it
functions in the destruction of old red blood cells
and holding a reservoir of blood.
• Lymph Nodes
– act as filters that collect and destroy bacteria and
viruses.
– When the body is fighting an infection,
lymphocytes multiply rapidly and produce a
characteristic swelling of the lymph nodes.
POP QUIZ
25. The immune system:
a.
b.
c.
provides attachment sites for the organs
protects you from disease
a complex bundle of nerves
b.
c.
circulatory
respiratory
a.
b.
c.
red blood cells
gas
germs
a.
b.
c.
arteries, veins, capillaries, and circulation
stomach, intestine, heart, and circulatory system
lymph nodes, bone marrow, thymus, and spleen
26. All of these systems of the body are part of your immune
system EXCEPT
a. skeletal
27. White blood cells fight:
28. Organs of the immune system are:
Reproductive System
• Purpose: to create sex cells for the purpose of
creating new organisms
• Major Organs and their functions:
Integumentary System
• Purpose: to protect the internal organs from the
outside world; to create a semi-permeable
barrier
• Major Organs and their functions:
• Skin
– Hair
– Nails
– Glands