CH. 12 Reading Quiz A&P 223

The afferent division of the PNS __________. a) controls skeletal muscle. b) carries motor commands. c) carries sensory information. d) controls smooth muscle.

c) carries sensory information.

If a nerve cell receives many IPSPs in different locations at the same time, __________. a) the nerve cell will approach. b) the membrane potential will depolarize. c) it will show spatial summation.

c) it will show spatial summation.

Most CNS neurons fall into which structural category? a) unipolar. b) anaxonic. c) multipolar. d) bipolar.

c) multipolar.

Which of these neurotransmitters is released at CNS adrenergic synapses? a) GABA. b) serotonin. c) norepinephrine. d) adrenaline.

c) norepinephrine.

The most abundant intracellular cation is __________, while the most abundant extracellular anion is __________. a) sodium, chloride. b) sodium, protein anions. c) potassium, chloride. d) potassium, protein anions.

c) potassium, chloride.

The neurotransmitter GABA blocks presynaptic voltage-gated calcium channels. Consequently, GABA produces __________. a) presynaptic facilitation. b) IPSPs. c) presynaptic inhibition. d) EPSPs.

c) presynaptic inhibition.

Which of these types of neuroglia are abundant in peripheral ganglia? a) astrocytes. b) oligodendrocytes. c) satellite cells. d) microglia.

c) satellite cells.

The simplest level of information processing takes place at the __________. a) dendrites. b) axon hillock. c) axon terminals. d) soma.

b) axon hillock.

If EPSPs summate to a sustained value above threshold, then the initial segment will __________. a) generate larger than normal action potentials. b) generate a string of action potentials. c) hyperpolarize. d) be inhibited.

b) generate a string of action potentials.

Which type of ion channel is always open? a) leak. b) mechanically-gated. c) chemically-gated. d) voltage-gated.

a) leak.

Which of these neurotransmitters does NOT bind to a plasma membrane receptor? a) nitric oxide. b) norepinephrine. c) GABA. d) serotonin.

a) nitric oxide.

Neuroglia perform all of these functions EXCEPT __________. a) release neurotransmitters. b) regulate extracellular fluid composition. c) secrete CSF. d) provide supportive framework.

a) releases neurotransmitters.

Which division of the PNS would contain sensory nerve fibers from special sensory receptors? a) afferent. b) sympathetic. c) efferent. d) parasympathetic.

a) afferent.

When a person has a stroke, blood leaks into the brain tissue. Which type of neuroglia cells would make structural repairs to the damage? a) astrocytes. b) oligodendrocytes. c) satellite cells. d) ependymal cells.

a) astrocytes.

Which ion triggers synaptic vesicles to discharge neurotransmitter into the synaptic cleft? a) calcium. b) sodium. c) potassium. d) magnesium.

a) calcium.

When you take a pain reliever, which of the following best describes, in general terms, how this affects the threshold of neurons? a) taking a pain reliever does not affect the threshold of neurons. b) taking a pain reliever increases the threshold. c) taking a pain reliever decreases the threshold. d) taking a pain reliever affects the all-or-none principle or neurons. So, neurons reaching threshold send an action potential at 50%.

b) taking a pain reliever increases the threshold.

What most directly causes the exocytosis of Ach in synaptic vesicles? a) arrival of an action potential at the presynaptic terminal. b) active transport of calcium ions out of the axon terminal. c) arrival of calcium ions in the axon terminal. d) depolarization of the membrane at the axon terminal.

c) arrival of calcium ions in the axon terminal.

During propagation of the action potential, __________. a) after threshold is reached, voltage-gated sodium channels open rapidly. b) local currents depolarize a spot adjacent to the active zone. c) the axon hillock depolarizes the initial segment. d) all of the listed responses are correct.

d) all of the listed responses are correct.

Resynthesis of ACh occurs in the __________. a) cell body. b) synapse. c) axon. d) axon terminal.

d) axon terminal.

Typical CNS neurons are amitotic due to the absence of what structure? a) axons. b) dendrites. c) ribosomes. d) centrioles.

d) centrioles.

In order to communicate with multiple cells at the same time, an axon may branch along its length, producing side branches called __________. a) initial segment. b) axon terminal. c) telodendria. d) collaterals.

d) collaterals.

Which of these substances is NOT considered a neuromodulator? a) endorphins. b) enkephalins. c) opioids. d) substance P.

d) substance P.

What happens just after an axon is depolarized to threshold? a) chemically-gated sodium channels open. b) some potassium channels open. c) all potassium channels open. d) voltage-gated sodium channels open.

d) voltage-gated sodium channels open.

The neurotransmitter glutamate opens channels that are permeable to sodium ions. What effect does glutamate produce on a postsynaptic neuron? a) both IPSPs and EPSPs. b) IPSPs. c) neither IPSPs nor EPSPs. d) EPSPs.

e) EPSPs.