Q: During an action potential, which sequence of events occurs at the axon membrane?

Na\textsuperscript{+} influx, K\textsuperscript{+} efflux, repolarization

Question 1

Which of the following best describes the role of Schwann cells in the peripheral nervous system (PNS)?

Accepted Answer

They insulate axons by forming myelin sheaths, which speeds up signal transduction.

Question 2

A patient is diagnosed with multiple sclerosis, a demyelinating disease. Which of the following is the most likely effect on neural signaling?

Accepted Answer

Signal conduction will slow down due to increased current leak and loss of myelin.

Question 3

Which of the following best explains why large-diameter axons conduct action potentials faster than small-diameter axons?

Accepted Answer

There is less cytoplasmic resistance and fewer ions in contact with the axon wall, reducing friction.

Question 4

During an action potential, which sequence of events occurs at the axon membrane?

Accepted Answer

Na	extsuperscript{+} influx, K	extsuperscript{+} efflux, repolarization

Question 5

A neuron receives several graded potentials at its dendrites. Which of the following best describes what happens if the combined graded potentials at the axon hillock reach threshold?

Accepted Answer

An action potential is generated and travels down the axon without losing strength.

Question 6

Which of the following is TRUE regarding the absolute refractory period of a neuron?

Accepted Answer

No stimulus, regardless of strength, can trigger another action potential.

Question 7

A patient is given a drug that blocks voltage-gated Na	extsuperscript{+} channels. What is the most likely effect on neuronal function?

Accepted Answer

Action potentials will be unable to initiate or propagate.

Question 8

Which of the following best describes the difference between spatial and temporal summation in neurons?

Accepted Answer

Spatial summation involves multiple graded potentials from different locations arriving simultaneously; temporal summation involves multiple graded potentials from the same location arriving in rapid succession.

Question 9

Which glial cell type is responsible for forming the myelin sheath in the central nervous system (CNS)?

Accepted Answer

Oligodendrocytes

Question 10

A neuron is exposed to hyperkalemia (elevated extracellular K	extsuperscript{+}). What is the most likely effect on the resting membrane potential (RMP) and neuronal excitability?

Accepted Answer

RMP becomes less negative, making the neuron more likely to fire.

Question 11

Which of the following is a correct pairing of neurotransmitter and its receptor type?

Accepted Answer

Acetylcholine — Cholinergic nicotinic receptor

Question 12

Which of the following best describes the process of fast axonal transport?

Accepted Answer

It moves substances quickly in both directions between the cell body and axon terminals.

Question 13

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

Accepted Answer

Providing substrates for ATP production and helping maintain extracellular fluid homeostasis

Question 14

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Myelin prevents current leak, allowing the action potential to jump from node to node (saltatory conduction).

Question 15

Which of the following scenarios best illustrates the concept of convergence in neural pathways?

Accepted Answer

Multiple presynaptic neurons synapse onto a single postsynaptic neuron.

Question 16

Which of the following is a characteristic of graded potentials?

Accepted Answer

They vary in strength, lose strength as they move, and occur at dendrites.

Question 17

Which of the following mechanisms does NOT terminate neurotransmitter action at a synapse?

Accepted Answer

Continuous opening of voltage-gated Na	extsuperscript{+} channels

Question 18

A neuron is exposed to a neurotoxin that blocks voltage-gated K	extsuperscript{+} channels. What is the most likely effect on the action potential?

Accepted Answer

Repolarization will be delayed, prolonging the action potential.

Question 19

Which of the following best describes the role of the axon hillock in a neuron?

Accepted Answer

It is the integrating center where action potentials are initiated if threshold is reached.

Neurons: Cellular and Network Properties (Chapter 8) - Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards