1. Nervous System

2. Purpose of the Nervous System
1. Allows for communication between the brain, senses, nerves, and the environment (Uses Electrical impulses-Nerve Impulses)
2. Allows us to react to changes (Stimuli)
3. Protects us from harm

3. Parts of the Nervous System
Brain
Brain
Brain stem
Spinal cord
Neurons
(nerves)
Brain Stem
Spinal Cord
Neurons

4. Neuron Structure
Cell Body- Similar to any other body cells, contains organelles
Dendrites- Finger-like structures that take in messages from other neurons and environment
Axon- Arm-like structures that carry messages away from the cell body 

5. Synapse- the space between neurons that signals travel across
Axon Terminal –send signals from one neuron across a synapse to another neuron
Synapse- the space between neurons that signals travel across
Dendrites
Axon
Cell Body
Axon Terminal
Synapse

6. Types of Neurons
1. Sensory Neurons- nerve cells that “send signals about stimuli from senses TO the spinal cord and brain”
2. Motor Neurons- nerve cells that “send messages for movement to muscles FROM the spinal cord and brain”

7. Communication
Neurotransmitters- chemicals found in synapses that allow for electrical impulses to pass from one nerve to the next
Nerve Impulses- Electrical charges that travel through nerve cells carrying a message
Reaction Time- Amount of time from stimulus to response

8. Senses Touch – sensory receptors in the skin
Taste – chemoreceptors on your tongue detect chemicals in food
Smell – chemoreceptors in your nose detect odor
Hearing – auditory receptors detect sound waves
Sight – rods and cones in the eyes detect light

9. Brain Main Parts
Cerebrum- Main part of the brain found in the front; controls memory, thinking, learning, speech, senses
Cerebellum- Back part of the brain that controls voluntary muscle functions, coordination, and balance 
Medulla- “Brain Stem” that connects the brain to the spinal cord, found in bottom back section of the brain, controls involuntary muscle functions

10. Cerebrum
Cerebellum
Brain Stem
(Medulla)

11. Brain Function Develops through experiences and stimuli
Creates new connections between neurons to find the fastest pathway for response
Receives messages about the environment and decides on responses (Long and Short Term memory)