chapter 11 quiz

The effect of acetylcholine can be stimulating or inhibiting. Which of the following gives the best explanation for why this is so?

• Acetylcholine has many different forms.

• Postsynaptic cells have a dynamic and changing metabolism and respond differently at different times.

• Different postsynaptic cells will have different receptors.

• Acetylcholine has a "dose effect." Larger doses are stimulating while small doses inhibit.

Saltatory conduction is made possible by ________.

• diphasic impulses

• the myelin sheath

• large nerve fibers

• erratic transmission of nerve impulses

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system.

• True

• False

When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the postsynaptic cell?

• Chemically gated sodium channels will open.

• Chemically gated sodium channels will be closed.

• Chemically gated chloride channels will open.

• Chemically gated potassium channels will open.

Strong stimuli cause the frequency of action potentials generated to increase.

• True

• false

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier.

• True

• False

The term central nervous system refers to the ________.

• spinal nerves

• sensory (afferent) nerves

• somatic nerves

• brain and spinal cord

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?

• ligand-gated channel

• leakage channel

• mechanically-gated channel

• voltage-gated channel

Which of the following is NOT a characteristic of neurons?

• They are mitotic.

• They have an exceptionally high metabolic rate.

• They have extreme longevity.

• They conduct impulses.

Distinguish the characteristic that does NOT describe Nissl bodies within a neuron:

• Consist of rough endoplasmic reticulum

• Associated with ribosomes

• Found primarily within the axon

• 
  Involved in protein synthesis