Q: Which equation correctly represents the exchange of sodium and potassium ions by the sodium/potassium pump in a resting neuron?

$$3\ \mathrm{Na}^+\ \text{out},\ 2\ \mathrm{K}^+\ \text{in}$$

Question 1

Which of the following best describes the difference between afferent and efferent divisions of the peripheral nervous system (PNS)?

Accepted Answer

Afferent division carries sensory information to the CNS, while efferent division carries motor commands from the CNS to effectors.

Question 2

Which of the following is NOT a function of neuroglia in the central nervous system (CNS)?

Accepted Answer

Transmitting action potentials between neurons

Question 3

A neuron lacks centrioles. What is the most significant consequence of this?

Accepted Answer

The neuron cannot divide by mitosis.

Question 4

Which of the following best describes the outcome of rabies infection in terms of axoplasmic transport?

Accepted Answer

Rabies virus uses retrograde transport to move toward the soma, leading to fatal CNS infection.

Question 5

Which neuron structure is primarily located in white matter, and why does white matter appear whitish?

Accepted Answer

Axons; because they are covered in myelin

Question 6

A disease causes demyelination of axons in the PNS. What is the most likely effect on action potential transmission?

Accepted Answer

Action potentials will propagate slower due to loss of saltatory conduction.

Question 7

Which equation correctly represents the exchange of sodium and potassium ions by the sodium/potassium pump in a resting neuron?

Accepted Answer

$$3\ \mathrm{Na}^+\ 	ext{out},\ 2\ \mathrm{K}^+\ 	ext{in}$$

Question 8

Which of the following best describes the resting membrane potential of a typical neuron?

Accepted Answer

$$-70\ 	ext{mV}$$

Question 9

Which of the following statements about leak channels is correct?

Accepted Answer

Leak channels are always open and allow passive movement of ions.

Question 10

During depolarization of a neuron, which ionic movement occurs and what initiates this process?

Accepted Answer

Sodium ions enter the cell, initiated by opening of sodium channels.

Question 11

Which of the following best describes the difference between graded potentials and action potentials?

Accepted Answer

Graded potentials vary in magnitude and decay with distance, while action potentials are all-or-nothing and propagate without decrement.

Question 12

What is the threshold value for initiating an action potential in a typical axon?

Accepted Answer

$$-55\ 	ext{mV}$$

Question 13

Which of the following factors would increase the speed of action potential propagation?

Accepted Answer

Increasing axon diameter and adding myelin

Question 14

Which type of nerve fiber propagates action potentials the fastest, and which is unmyelinated?

Accepted Answer

Type A fibers are fastest; Type C fibers are unmyelinated.

Question 15

At a chemical synapse, which ion enters the axon terminal to trigger the release of acetylcholine (ACh)?

Accepted Answer

$$\mathrm{Ca}^{2+}$$

Question 16

Which enzyme breaks down acetylcholine (ACh) into choline and acetate at the synaptic cleft?

Accepted Answer

Acetylcholinesterase

Question 17

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

Accepted Answer

Temporal summation occurs when one synapse is activated repeatedly over time; spatial summation occurs when multiple synapses are activated simultaneously.

Question 18

Which of the following is a function of Schwann cells in the PNS?

Accepted Answer

Producing myelin to insulate peripheral axons

Question 19

Which of the following best describes an excitatory postsynaptic potential (EPSP)?

Accepted Answer

A graded depolarization that increases the likelihood of an action potential

Chapter 12 Nervous Tissue Study Guide – Step-by-Step Anatomy & Physiology Guidance

Study Guide - Practice Questions

Study Guide - Flashcards