31.1 The Neuron

Understand Key Concepts

1. The basic units of structure and function in the nervous system are

   1. neurons.

   2. axons.

   3. dendrites.

   4. neurotransmitters.

2. In the diagram below, the letter A is pointing to the

   1. myelin sheath.

   2. axon.

   3. dendrite.

   4. cell body.

      

3. The place where a neuron transfers an impulse to another cell is the

   1. synapse.

   2. dendrite.

   3. myelin sheath.

   4. receptor.

4. Name the three types of neurons and describe their function in the nervous system.

5. Describe the movement of sodium and potassium ions during the resting potential.

6. Why can an action potential be described as an all-or-none event?

Think Critically

7. Infer Suppose a portion of an axon is cut so that it is no longer connected to its cell body. What effect would that have on the transmission of impulses?

8. Use Analogies How are a neuron and an electrical extension cord similar? How are they different?

31.2 The Central Nervous System

Understand Key Concepts

9. The central nervous system consists of the

   1. sense organs.

   2. reflexes.

   3. brain and spinal cord.

   4. sensory and motor neurons.

10. Voluntary, or conscious, activities of the body are controlled primarily by the

    1. medulla oblongata.

    2. cerebrum.

    3. cerebellum.

    4. brain stem.

11. Methamphetamines are a type of drug that affects the brain by

    1. causing the release of excess dopamine.

    2. blocking the production of dopamine.

    3. increasing the number of dopamine receptors.

    4. increasing the number of synapses in the brain.

12. Describe the structure and function of the cerebrum.

13. Describe the relationship between the brain stem and the spinal cord.

14. How does nicotine influence dopamine receptors in the brain?

Think Critically

15. Infer A stroke occurs when blood flow to part of the brain stops due to a clot or broken blood vessel. What conclusion might you make about the location of damage in a person who has difficulty speaking and cannot move many of his muscles on the right side of his body?

16. Compare and Contrast In what ways are the effects of methamphetamine and cocaine on the brain similar? How are they different?

31.3 The Peripheral Nervous System

Understand Key Concepts

17. The sympathetic nervous system and the parasympathetic nervous system are specific divisions of the

    1. peripheral nervous system.

    2. central nervous system.

    3. somatic nervous system.

    4. autonomic nervous system.

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