The document provides information about the nervous system and its main components. It discusses (1) how the nervous system controls all activities of the body, (2) the central nervous system which includes the brain and spinal cord as the control center, and (3) the outer nervous system which connects the central nervous system to the rest of the body using nerves and sense organs. The brain is divided into the cerebrum, cerebellum, and brain stem which each have specific functions. The spinal cord connects the brain to the rest of the nervous system and carries messages throughout the body.

1. Cells
• Simple organisms
such as bacteria, are
single cell.
• Plants and animals are
made up of many
cells.
• Each kind of cell has a
particular function.

2. Cells: Size & Shape
• Size and Shape depend upon its function.
• Red blood cells are small and disc shaped
to fit through the smallest blood vessel.
• Muscle cells are long and thin. When they
contract they produce movement.
• Nerve cells which carry signals to the brain
are very long.

3. Functions of Cells

4. Tissues, Organs, & Systems
• Cells that work together to perform a specific
function form a tissue.
• Just as cells that work together form a tissue,
tissues that work together form an organ.
• Organs that work together to perform a function
form a system. Example: circulatory system.
• Plant cells also form tissues, such as the bark of a
tree. And plant cells work together, forming
organs, such as roots and leaves.

5. The Circulatory System
Purpose/Function: Carries needed materials (Oxygen, Sugar) to
cells, and carries waste (Carbon Dioxide) away from cells.
Main Organs:
1. Heart - The muscle that pumps blood to and from cells.
2. Blood Vessels: The tubes that transport blood from the heart
throughout the body and back again.
a) Arteries - Carry oxygen-rich blood cells from the heart
throughout the body.
i. Capillaries - Are narrow arteries.
b) Veins - Carry oxygen-poor blood cells from the body
back into the lungs and heart.

6. The Circulatory System
Relationship with other systems:
Respiratory System: Blood cells are transported through the lungs
to gain oxygen and to get rid of carbon dioxide.
Skeletal System: Red blood cells are produced in bone marrow.
Immune System: Blood cells are responsible for delivering
disease fighting materials.
Interesting Facts:
• The body of an adult contains over 60,000 miles of blood
vessels!
• An adult's heart pumps nearly 4000 gallons of blood each
day!
• The average three-year-old has two pints of blood in their
body; the average adult at least five times more!
• A "heartbeat" is really the sound of the valves in the heart
closing as they push blood through its chambers.

7. The Respiratory System
• Purpose/Function: Exchanges Oxygen and
Carbon Dioxide Gases.
• Main Organs:
• Air enters the body through nasal passages is
filtered, then travels down the trachea
(Windpipe).
• The trachea branches into two tubes called
bronchi, which lead to the lungs containing tiny
tubes called bronchioles.
• At the end of the bronchioles (tiny tubes) are
alveoli, small air sacs.

8. The Respiratory System
• Relationship with other systems:
• Circulatory System: Oxygen & Carbon Dioxide
are transported through the blood in and out of
the lungs.
• Skeletal System: Respiratory organs are protected
by the rib cage.
• Interesting Facts:
• Lungs inflate (expand) when you inhale (breathe
in), and deflate (contract) when you exhale
(breathe out).

9. The Digestive System
• Purpose/Function: Break Down Food and Drink
for nutrients and sugars.
• Main Organs:
• Digestion begins in the MOUTH as you chew
food. Glands in your mouth produce saliva to
moisten food.
• The food passes through the ESOPHAGUS to the
STOMACH and moves to the SMALL
INTESTINE.
• Nutrients & Sugars diffuse through the VILLI,
tiny projections from the intestine, into the blood.

10. The Digestive System
Relationship with other systems:
• Circulatory System: Digestive system transports
the sugars into the blood stream to be carried to
cells.
• Muscular System: Digestive organs are a type of
muscle tissue.
Interesting Facts:
• The esophagus has muscles that constrict to force
food down into the stomach.
• Laundry Detergents use the same enzymes to
clean stains that the digestive system uses to
break down food.

11. The Excretory System
• Purpose/Function: Removes waste from the
body. Cell wastes include carbon dioxide and
ammonia.
• Main Organs: The kidneys, bladder, and urethra
make up part of the excretory system.
• The body also removes wastes through sweating.
Sweat is a salty liquid that evaporates from the
skin.

12. The Excretory System
• Relationship with other systems:
– Respiratory System: The lungs are responsible for
getting rid of the carbon dioxide waste product.
– Integumentary System: The skin allows the body to
sweat salty liquid waste through pores to be evaporated.
• Interesting Facts:
– The average person pees 3,000 times a year.
– Humans can live with only one kidney.

13. The Integumentary System
Main Organs:
• Skin (Epidermis & Dermis)
• Hair
Purpose/Function:
• Protects the body - from injury, infection, and water loss
• Maintaining Temperature
• Eliminating Waste - through sweating
• Produce Vitamins - (Such as Vitamin D)

14. The Integumentary System
Interesting Facts:
• Skin is the largest organ in the body.
• An average adult has 20 sq. ft. of skin.
• Every month you have a whole new layer of skin.
Relationship with other system(s):
• Nervous System: The skin is connected to the sense of
touch and offers a first alarm source.
• Muscular System: Skin Protects the muscles from harm.

15. The Muscular System
Main Organs:
• Skeletal / Voluntary Muscles: move bones and hold your
skeleton upright.
• Smooth Muscles: contract slowly and move substances
through the internal organs they surround.
• Cardiac Muscle: make up the walls of the heart.
Function is to pump blood.
Purpose/Function: To create movement
and strength of the body, and to create
movement of body organs.

16. The Muscular System
Interesting Facts:
• You have over 30 facial muscles which create looks like
surprise, happiness, sadness, and frowning.
• Eye muscles are the busiest muscles in the body. Scientists
estimate they may move more than 100,000 times a day!
• The strongest muscle in the body is the tongue.
Relationship with other systems:
• Skeletal - allows movement of joints.
• Circulatory - The heart is the cardiac
muscle.
• Digestive System - Smooth muscles help
the digestive organs to break down food.

17. The Immune System
Main Organs:
• White Blood Cells:
– T Cells (Identify Diseases).
– B Cells (Antibodies - Destroy diseases).
Purpose/Function:
• Protects the body from disease pathogens such as bacteria
and viruses.

18. The Immune System
Interesting Facts:
• A vaccination is a weakened form of a virus that is injected
into the body on purpose to trigger the T cells to be on the
lookout for the virus.
• An antibiotic is a chemical that kills bacteria in the body.
• T Cells are produced in the Thymus (Lymph nodes in the
chest).
• B Cells are produced in the Bone Marrow.
Relationship with other system(s):
• Integumentary - Skin is the first line of defense from
disease.
• Endocrine - The endocrine system is responsible for
producing body chemicals that help prevent diseases.

19. The Reproductive System
Purpose/Function: For the continuation of the species (Making
Babies)
Main Organs:
• Testes - (in males) Produce the male gamete (sperm) for sexual
reproduction, and also stimulate the production of male hormones
(ex: testosterone).
• Ovaries - (in females) Produce the female gamete (ovum/egg) for
sexual reproduction, and also produce female hormones (ex:
estrogen and progesterone).

20. The Reproductive System
Relationship with other systems:
Nervous System: All reproductive activities are stimulated by the nervous
system.
Endocrine System (Hormone). Some reproductive organs stimulate hormone
development in the Endocrine System.
Interesting Facts:
• About 500 million sperm cells mature daily in an average male.
• At puberty, a female has between 300,000 to 400,000 viable eggs that can
be fertilized.
• Upon fertilization between a sperm and egg, a chemical reaction occurs
causing the outer shell of the egg to become impenetrable.

21. The Nervous System
Main Organs:
• Brain (Includes Cerebrum, Cerebellum, and Brain Stem)
• Spinal Cord - contains the nerve highway for the body (found in
the vertebrae/backbone).
• Nerves & Neurons (Nerve Cells)
• Senses (Vision, Hearing (and balance), Smell, Taste, Touch)
Purpose/Function:
• Receives information internally and externally from
the sense organs, and directs the body to respond to the
information. (Stimulus & Response)
• Helps body to maintain homeostasis (ability to
maintain a constant stable internal condition).

22. The system that controls all of the
activities of the body. (1)
The nervous system is made up of the
following : (2)
The brain The spinal cord
The sensesThe nerves

23. The nervous system allows you to
react to a stimulus.
A stimulus is a change in the environment. (3)
Example: A hot stove
Or… tripping over a rock

24. * An automatic reaction that
happens without thinking about it.
* A reflex happens quickly in
less than a second.

25. Most of our reactions are automatic.
Automatic means that you do not
necessarily have to think about your
reactions.
Example: If a bug flies by your eye,
you will blink automatically.

26. The Nervous System controls
Homeostasis
The maintenance of a
constant environment in
the body
– Temperature
– Water levels
– Glucose (Sugar) concentration

27. Messages carried throughout the body
by nerves.

28. Basic Process of the Nervous System (4)
Sensory Input:
Monitors both
outside and inside
environments.
Processing: Collects
the information and
often combines
(integrates) it with
already stored
information.
Motor output: If
needed, it will signal
certain organs to
make an appropriate
response.

29. The Central Nervous System is made
of the brain and the spinal cord. (5)
The Central Nervous System is the
Control Center for the body. (6)

30. * The brain controls everything in the
body.
* The brain is made of more than 10
billion nerves!
* The brain is divided into three
parts and is protected by the skull.
(relationship with Skeletal System).

31. * The Brain has three main parts… (7)
1. The Cerebrum
2. The Cerebellum
3. The Brain Stem

32. * The Cerebrum is the largest part of
the brain.
1. The cerebrum controls your thinking.
2. The cerebrum controls your memory.
3. The cerebrum controls your speaking.
4. The cerebrum controls your movement and identifies
the information gathered by your sense organs.

33. * The cerebellum is below and to the
back of the cerebrum.
1. The cerebellum controls your balance.
2. The cerebellum controls your posture.

35. * The Brain Stem connects the brain to
the spinal cord.
* The nerves in the brain stem control
your heartbeat, breathing, and blood
pressure.

36. * The spinal cord sends messages to the
brain.
* The spinal cord is the part of the
nervous system that connects the brain
to the rest of the nervous system. (8)

38. * The vertebrae are the many
bones that protect the nerves in
the spinal cord. (Relationship with
the Skeletal System)

39. The Outer Nervous System is made of
the nerves and the sense organs. (9)
Nerves Sense organs

40. * The Outer Nervous System’s job
is to connect the Central Nervous
System to the rest of the body.
* The outer nervous system carries
messages between the central nervous
system and the rest of the body.

41. * The outer nervous system
controls the body’s activities
that you don’t necessarily think
about.
* The outer nervous system controls
activities in your small intestine, your
breathing, and your heartbeat. (10)
controls

43. Sense organs
carry messages
that concern
the
environment to
the central
nervous
system.

44. The eyes (Vision), ears (Hearing),
nose (Smell), tongue (Taste), and
skin (Touch) are examples of sense
organs.
The sense organs gather
information (light, sound, heat,
and pressure) from the
environment.
(11)

45. Vision is your ability to see.
Vision involves the eye and the brain.

46. When a sound is made, the air
around the sound vibrates.
Hearing starts when some of the
sound waves go into the ear.

47. The ear canal is the tube between the
outside of the ear and the ear drum.
The ear drum is in the middle ear. It
vibrates when sound waves hit it.
The pinna is the part of the ear
that you can see.

48. The ear works with the brain to
control your balance.
All of your movements are controlled
by balance and muscles.
The liquid in your inner ear is responsible
for your balance.
The liquid in your ear moves when we move.
The liquid movement sends information to the
brain to tell it how we are moving.

49. The sense of touch is located in the skin.
The nerves in the skin allow us
to feel texture, pressure,
heat, cold, and pain.
Texture is how something feels.

50. The nose controls your sense of smell.
The nose is able to smell 80
different kinds of smells.

51. Your sense of taste comes from the
taste buds in the tongue.
Taste buds are the parts on the tongue
that allow us to taste.
The four kinds of taste buds are
sweet, sour, bitter, and salty.

53. Tastes and smells work
together to make flavors.
Flavors are the tastes
of food and drinks.

54. The Nervous System
Interesting Facts:
• Only four percent of the brain's cells work while the
remaining cells are kept in reserve.
• There are more nerve cells in the human brain than
there are stars in the Milky Way.
• The total surface area of the human brain if stretched
out is about the size of a pillow case
Relationship with other systems:
• All other systems: The brain is responsible for
sending information signals to all other systems in
order for them to function.

55. Did You Know?…..
That you have a nerve along your whole
arm.
The “funny bone” is the only place on
the arm where the nerve is not
protected.
The “funny bone” is on the elbow.

56. Optical Illusion- Visually perceived
images that differ from reality.