1. The Nervous System

2. Functions of the Nervous System
Control center for all body activities
Responds and adapts to changes that occur both inside and outside the body
(Ex: pain, temperature, illness)

3. A system that controls all of the activities of the body.
Nervous System
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
Automatic means that you do not have to think about your reactions.
Example: If a bug flies by your eye,
you will blink.

6. Two Major Divisions of the Nervous System

7. Central Nervous System
The Central Nervous System is made of the brain and the spinal cord.
The Central Nervous System controls everything in the body.

8. Links the brain to the rest of the body
Nervous System
The Peripheral Nervous System is made of the nerves and the sense organs.
Links the brain to the rest of the body
Nerves
Sense organs

9. Messages carried throughout the body by nerves.
Nerve Impulse
Messages carried throughout the body by nerves.

10. Cells of the Nervous System
Neurons : microscopic nerve cells that make up the brain, spinal cord, and nerves
- 30,000 neurons can fit on a pinhead

11. Anatomy of a Neuron Each neuron contains: - Cell body with nucleus
- Dendrites : fibers that receive messages from other neurons
- Axons : fibers that send messages to other neurons

12. Neurons do NOT touch; there is a gap between them called a synapse
Messages are sent across the synapses by special chemicals called neurotransmitters

13. Communication Between Neurons
The use of neurotransmitters causes an electrical current
There is enough electrical current in the brain to power a flashlight

14. The Central Nervous System
* 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

15. The Spinal Cord
* 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.

16. The Brain
* 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.

17. The Four Parts of the Brain
1. The Cerebrum
2. The Cerebellum
The Brain Stem
The Diencephalon

18. * 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.

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

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

21. The Vertebrae
* The vertebrae are the many bones that protect the nerves in the spinal cord.

22. The Diencephalon
relays sensory information (from your 5 senses) between brain regions.
It controls many autonomic functions of the peripheral nervous system.

23. The Peripheral
Nervous System

24. Peripheral Nervous System
carries messages between the central nervous system and the rest of the body.
connects the Central Nervous System to the rest of the body.
Controls sensory and mobile action.

25. Peripherals Nervous System
The peripheral nervous system is made of the nerves and the sense organs.
Nerves
Eye
Ear
Tongue
Skin

26. Automatic Nervous System
The peripheral nervous system controls:
the body’s activities that you don’t think about.
activities in your small intestine, your breathing, and your heartbeat.