1. “If I Only Had a Brain”
H-15 Answers to homework

2. Jobs of the Nervous System:
Receiving Information
You are aware of what is happening around you
Responding to Information
Your body often reacts to an action
Maintaining Homeostasis
Your nervous system tells your body how to respond when it receives information

3. The Neuron
Neuron: the cells that carry information through your nervous system
Nerve Impulse: the message that a neuron carries

4. Structure of a Neuron
Dendrite: an extension of a cell body at carries impulses toward a cell body
Axon: carries impulses away from a cell body
Nerve: a bundle of nerve fibers

5. Structure of a Neuron 1. Dendrites 3. Cell Body 2. Nucleus 4. Axon
5. Axon Tips

6. Kinds of Neurons
Sensory Neuron: picks up stimuli from the internal or external environment on converts each stimulus into a nerve impulse
Interneuron: a neuron that carries nerve impulses from one neuron to another
Motor Neuron: sends an impulse to a muscle – the muscle contracts in response

7. Path of a Nerve Impulse Sensory Neuron (1&2)
Nerve receptors pick up stimuli, the receptors then trigger nerve impulses in sensory neurons

8. Path of a Nerve Impulse Interneuron (3 & 4)
Nerve impulse is passed to the brain. Your brain decides what you need to do

9. Path of a Nerve Impulse Motor Neuron (5 & 6)
Impulses pass along motor neurons to muscles. The muscles carry out the response.

10. How a Nerve Impulse Travels
120 meters per second
Assume distance is one meter
total distance = 2 meters
120 m = 2 m solve using
1 sec x ratios
0.017 seconds
 meter 

11. Central Nervous System
Two parts of the CNS:
Brain and Spinal Cord
What does the CNS do?
It is the control center of the body

12. Peripheral Nervous System
What is the PNS and what does it do?
It is a network of nerves that branch out from the central nervous system and connect it to the rest of the body
What is the Somatic Nervous System?
This controls voluntary actions like writing
What is the Autonomic Nervous System?
This controls involuntary actions like breathing

13. What is a reflex?
An automatic response that occurs very rapidly and without conscious control