Neuron Worksheet

1. You are looking at a neuron under a microscope. You find many structures coming off the cell body. Some of these are relatively thick and branch many times. One of the structures, however, is very thin and very long. This latter structure is most likely the neuron's __________ , which carries the __________.
a. dendrite; efferent signal
b. dendrite; afferent signal
c. axon; action potential
d. axon; receptors

2. If the myelin sheathing on neurons is absent or removed in a given individual, he or she will exhibit difficulties in speaking, vision, and balance because without myelin the
a. quantity of neurotransmitters released into synapses will be reduced.
b. quantity of neurotransmitters released into synapses will be increased.
speed of neural conduction along critical paths will be too fast.
d. speed of neural conduction along critical paths will be too slow.

3. A neuron cell body reaches threshold and depolarizes. The depolarization propagates down the length of the __________, is chemically transmitted across the __________, and directly affects the electrical potential in the __________ of the successive neuron.
a. axon; synapse; dendrites
b. dendrites; synapse; axon
c. myelin; synapse; dendrites
d. dendrites; receptor; axon

4. You are a reporter who is watching an action potential in progress. Which of the following statements should you broadcast to your listeners to best describe what you are witnessing? “Currently, I see
a. an electrical impulse shooting from an axon to a dendrite.”
b. mitochondria moving toward a synapse.”
c. positively charged ions rushing in as gates open one after another along the axon.”
d. many more negative ions inside than there were previously.”

5. Carlos was in a car accident and received a head injury that resulted in a decreased ability to produce speech. Carlos has more than likely damaged his __________ nervous system.
a. sympathetic
b. peripheral
c.
sensory

6. The main divisions of the peripheral nervous system are the __________ and the __________.
a. somatic; autonomic
b. sympathetic; parasympathetic
c. afferent; efferent
d. reticular; limbic

7. When a man grabbed Opal's purse, she ran after him, tackled him, and retrieved her purse. Then she realized that her heart was racing, her breathing was irregular, and she was trembling. Opal's __________ nervous system was responsible for this reaction.
a. sympathetic
b. central
c. parasympathetic
d. somatic

8. Latoria is horseback riding when she falls and hits her head. After the accident, she has difficulty performing finely coordinated movements. Latoria has most likely damaged her
a. medulla oblongata.
b. recticular formation.
c. cerebellum.
d. locus coeruleus.

9. Herman suffers a stroke that destroys the connections between the reticular formation and the rest of his brain. Herman will most likely
a. be in a permanent coma.
b. have increased activity in the locus coeruleus.
c. lose automatic control of his heart rate, breathing, and blood pressure.
d. lose all