1. Nervous System

2. Important Vocabulary Neuron Central nervous system Dendrite
Peripheral nervous system
Axon
Cerebrum
Sensory neuron
Cerebellum
Interneuron
Brain stem
motor neuron
reflec
Synapse

3. EXPLORE ACTIVITY pg. 677
What did you find out about their heights? How were your eyes tricked?

4. Response to Stimuli
Any change inside or outside your body that brings a response is called a stimulus
Stimuli
Our bodies have internal control systems that maintain homeostasis
Breathing, heartbeat,digestion

5. Neurons Neuron: the working unit of the nervous system
A neuron is made up of a cell body and branches called dendrites
Dendrites receive messages and send them to the cell body
An axon carries messages away from the cell body
Messages carried by a neuron is called an impulse

6. Types of Neurons
Sensory: receive information and send impulses to the brain or spinal cord
Interneurons: relay impulses from the sensory to motor neurons. There are more of interneurons than any other type
Motor: conduct impulses from the brain or spinal cord to muscles or glands throughout your body.

8. Synapse
Since neurons don’t touch each other, how does an impulse move from one another?
Synapse: small space where an impulse moves from one neuron to another.
When impulse reaches the end of the axon, a nerve transmitting chemical is released by the axon
This chemical diffuses across the synapse and starts an impulse in the dendrite or cell body of the next neuron

9. CNS AND PNS

10. Central Nervous System
Made up of the
Brain
Spinal cord
All body activities are coordinated
If steps on your foot, your whole body reacts

11. The Brain Made up of 100 billion neurons Divided into 3 parts Cerebrum
Cerebellum
Stem
Cerebrum:
divided into two large sections called hemispheres
Impulses from the senses are interpretted,
Memory is stored
Voluntary muscle control center

12. The Brain Cerebellum Behind and under the cerebrum
Coordinates voluntary muscle movement
Maintains balance and muscle tone
Stem
Extends from the cerebrum and connects the brain to the spinal cord
Parts: midbrain, pons, medulla
Controls heartbeat, breathing, blood pressure

13. Peripheral Nervous System
Brain and spinal cord are connected to the rest of your body by the peripheral nervous system
Made up of 12 pairs of cranial nerves from your brain
31 pairs of spinal nerves from your spinal cord
These nerves link your CNS with all parts of your body
Spinal Nerves: made up of bundles of sensory and motor neurons
Somatic System and autonomic system

14. Somatic and Autonomic System
Somatic: consists of the cranial and spinal nerves that go from the CNS to your skeletal muscles
Connect the central nervous system to the organs, muscles, and skin
It is like a passageway from the environment to the central nervous system
processing sensory information that arrives via external stimuli including hearing, touch and sight
Autonomic: controls heartbeat rate, breathing, digestions and gland functions
When salivary glands release saliva

15. Reflex

16. Drugs and the Nervous System

17. Activity 25-1 p. 685