Nervous Systems

Chapter 48

1. Give a brief description of nervous systems found in animals from different phyla.

2. What are the functions of the CNS and PNS?

3. Describe a reflex arc.

4. Describe and account for the difference in the speed of transmission of a nerve impulse in a myelinated axon vs. an unmyelinated axon.

5. How does a neuron maintain a potential difference across the cell membrane?

6. Compare and contrast ligand-gated channels and voltage-gated channels.

7. With reference to the gated ion channels, outline the events associated with the action potential, from resting potential to the restoration of resting potential

8. How is the action potential propagated along a neuron?

9. What is meant by “threshold potential?”

10. What is the refractory period and why is it important?

11. Although the action potential is an all-or-none event, you are able to distinguish a wide range of stimuli. How is this possible?

12. Describe the two different types of sumation.

13. How is an action potential transmitted from one neuron to the next?

14. How can the same neurotransmitter have an excitatory effect on some postsynaptic neurons and an inhibitory effect on others?