The document explains the nervous system, which controls all body activities through the brain, spinal cord, and nerves. It describes how the central nervous system and the outer nervous system interact, including the role of sense organs in processing environmental stimuli. The document also details the brain's structure and functions, as well as the five senses: sight, hearing, touch, smell, and taste.

3. A system that controls all of the
activities of the body.
The nervous system is made of:
The brain The spinal cord
The nerves The senses

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

5. Your reactions are automatic.
Automatic means that you do not
have to think about your reactions.
Example: If a bug flies by your eye,
you will blink.

6. An organ that controls your
emotions, your thoughts, and every
movement you make.

7. The Outer Nervous System is made of
the nerves and the sense organs.
Nerves Sense organs

8. Messages carried throughout the body
by nerves.

9. * The Central Nervous System controls
all of the body’s activities.
* The Central Nervous System is
made of two main organs.
1. The brain
2. The spinal cord

10. * 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.

11. * 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.

12. * The Brain has three main parts…
1. The Cerebrum
2. The Cerebellum
3. The Brain Stem

14. * The outer nervous system is made of
the nerves and the sense organs.
Ear
Eye
Skin
Nerves
Tongue

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

16. * The outer nervous system
controls the body’s activities
automatically.
* Small intestine, your breathing, and
your heartbeat.
controls

17. Sense organs
carry messages
about the
environment to
the central
nervous
system.

18. The eyes, ears, nose, tongue, and
skin are examples of sense organs.
The sense organs gather
information (light, sound, heat,
and pressure) from the
environment.

19. The environment is everything
outside the body.

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

21. The eye is made of the iris
and the pupil.
The eye gathers pictures and
sends them to the brain.

22. The colored part of the
eye is the iris.
The black part of the
eye is the pupil.
The pupil becomes
larger and smaller as
it controls the light
coming into the eye.
Iris
Pupil

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

24. 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.

25. 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.

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

27. 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 five kinds of taste buds are
sweet, sour, bitter, umami, and salty.