Question 1

Which of the following best describes the function of the sodium–potassium exchange pump in maintaining the resting membrane potential of a neuron?

Accepted Answer

It stabilizes the resting membrane potential at approximately $$-70\ 	ext{mV} by $$actively transporting $$3$$ sodium ions out and $$2$$ potassium ions in.

Question 2

A patient suffers damage to the Schwann cells in their peripheral nervous system. Which of the following consequences is most likely?

Accepted Answer

Loss of myelination in PNS axons, resulting in decreased speed of nerve impulse transmission.

Question 3

Which type of neuron is always located in the CNS and is responsible for distributing sensory inputs and coordinating motor outputs?

Accepted Answer

Interneuron

Question 4

During an action potential, which sequence of events occurs after the membrane depolarizes to threshold?

Accepted Answer

Activation of voltage-gated sodium channels and rapid depolarization, then inactivation of sodium channels and activation of potassium channels.

Question 5

A nerve impulse travels much faster in myelinated axons than in unmyelinated axons. Which mechanism explains this phenomenon?

Accepted Answer

Saltatory propagation, where the action potential leaps from node to node, skipping myelinated regions.

Question 6

Which of the following is TRUE regarding the effect of neurotransmitters on the postsynaptic membrane?

Accepted Answer

The effect depends on the properties of the receptor on the postsynaptic membrane.

Question 7

A neuron receives simultaneous excitatory inputs from multiple synapses. What is this process called, and what is its effect?

Accepted Answer

Spatial summation; increases the likelihood of action potential generation.

Question 8

Which glial cell type is responsible for myelinating axons in the CNS?

Accepted Answer

Oligodendrocyte

Question 9

If a neuron’s axon is damaged in the PNS, which process may allow functional repair?

Accepted Answer

Wallerian degeneration

Question 10

Which of the following best describes the all-or-none principle of action potential generation?

Accepted Answer

An action potential is generated only if the membrane potential reaches threshold; otherwise, no action potential occurs.

Question 11

A patient is experiencing synaptic fatigue due to exhaustion of acetylcholine (ACh) stores. What is the most likely effect on neural communication?

Accepted Answer

Reduced ability to transmit signals across cholinergic synapses.

Question 12

Which of the following is a function of microglia in the CNS?

Accepted Answer

Phagocytosis of pathogens and debris

Question 13

A neuron is exposed to GABA at an axoaxonic synapse, resulting in reduced neurotransmitter release. What is this process called?

Accepted Answer

Presynaptic inhibition

Question 14

Which equation best represents the electrochemical gradient across a neuron’s plasma membrane?

Accepted Answer

The sum of all chemical and electrical forces acting across the membrane: $$	ext{Electrochemical Gradient} = 	ext{Chemical Gradient} + 	ext{Electrical Gradient}$$

Question 15

Which of the following best describes the role of neuromodulators in neural communication?

Accepted Answer

They influence the postsynaptic cell’s response to neurotransmitters, altering either the rate of neurotransmitter release or the response.

Question 16

A neuron’s axon hillock receives both excitatory and inhibitory inputs. Which of the following determines whether an action potential will be generated?

Accepted Answer

The integration of EPSPs and IPSPs at the axon hillock, and whether the membrane potential exceeds threshold.

Question 17

Which of the following is a characteristic of Type A nerve fibers?

Accepted Answer

Large diameter, myelinated, rapid propagation speed.

Question 18

Which scenario best illustrates the function of the afferent division of the PNS?

Accepted Answer

Sensory information from a receptor in the skin being transmitted to the CNS.

Question 19

Which of the following statements about synaptic delay is correct?

Accepted Answer

Synaptic delay is caused by the time required for calcium ion influx and neurotransmitter release at chemical synapses.

Question 20

A neuron is exposed to a lipid-soluble gas neurotransmitter. How does this neurotransmitter affect the postsynaptic cell?

Accepted Answer

It has an indirect effect through intracellular enzymes.

Chapter 12: Nervous Tissue and Neural Signaling – Study Outline

Study Guide - Practice Questions

Study Guide - Flashcards