A ECL 365 SI

Worksheet 17: Nervous System

1. What are the two main subdivisions and their components?

2. In the diagram below, label the different parts of the neuron (axon, dendrites, myelin sheath, synapse, nodes of Ranvier). Which direction does the signal move?

3. What are the three different classes of neurons in the nervous system?

4. A difference in charge between the inside and outside of the neuron is referred to as ____________ ____________.

5. If the membrane potential reaches threshold, the response is binary. If this is true, how does the nervous system communicate different stimulus intensities?

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6. In the diagram below, label the different steps in an action potential. What is happening during each step?

7. What are two ways you can increase the speed of impulse conduction?

8. The synapses are the sites where signals are transmitted from one neuron to another. What are the two types of synapses?

9. What are the steps of signal transmission in a chemical synapse?

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10. What are some general trends we see in the development of the nervous system among invertebrates and vertebrates?

11. As body size of an animal increases, the brain size in proportion to body size ____________.

12. The motor neurons in the peripheral nervous system can be split into two different types of nerves. What are they?

13. In the autonomic nervous system, the _____________ is responsible in raising heart and respiration rate. The _____________ does the opposite.

14. ____________ ____________ are neurological feedback loops that are able to bypass the brain, causing nearly instant reactions.