Question 1

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

Accepted Answer

Oligodendrocyte

Question 2

A patient recovering from COVID-19 experiences 'brain fog' and slowed cognitive processing. Which neuroglial cell is most likely involved in this process, and what is its effect?

Accepted Answer

Microglia; trigger inflammation and reduce oligodendrocyte precursors

Question 3

Which of the following best describes the function of ependymal cells in the CNS?

Accepted Answer

They circulate and monitor cerebrospinal fluid

Question 4

Which neuroglial cell type in the peripheral nervous system (PNS) is responsible for myelinating axons and aiding in axonal repair?

Accepted Answer

Neurolemmocyte (Schwann cell)

Question 5

What is the primary function of the myelin sheath?

Accepted Answer

To increase the speed of nerve impulse conduction

Question 6

Which of the following statements about myelination in the CNS and PNS is correct?

Accepted Answer

Oligodendrocytes myelinate multiple axons, while neurolemmocytes myelinate only one axon segment each

Question 7

Which process is described by the degeneration of the axon and myelin sheath distal to an injury, followed by phagocytosis of debris?

Accepted Answer

Wallerian degeneration

Question 8

Why do myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Myelin prevents ion leakage and allows saltatory conduction

Question 9

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

Accepted Answer

It is about $$-70\ \mathrm{mV}$$ due to potassium efflux through leak channels

Question 10

A neuron is exposed to a stimulus that opens ligand-gated sodium channels. What is the immediate effect on the membrane potential?

Accepted Answer

The membrane potential becomes less negative (depolarization)

Question 11

Which type of ion channel opens in response to a change in membrane potential?

Accepted Answer

Voltage-gated channel

Question 12

What is the role of the sodium-potassium pump in maintaining the resting membrane potential?

Accepted Answer

It moves two potassium ions in and three sodium ions out, maintaining ion gradients

Question 13

Which of the following is true about local (graded) potentials?

Accepted Answer

They are reversible and decremental

Question 14

During an action potential, which state describes the sodium channel when the inactivation gate is closed and the activation gate is open?

Accepted Answer

Inactivated state

Question 15

Which of the following best explains why regeneration of nervous tissue is limited in the CNS?

Accepted Answer

Astrocytes form scar tissue and growth factors are absent

Question 16

A patient has a loss of myelin in the CNS. Which of the following symptoms would most likely result?

Accepted Answer

Slower nerve impulse conduction

Question 17

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

Accepted Answer

Regulate the extracellular environment around neuron cell bodies

Question 18

Which of the following best describes the difference between white matter and gray matter in the CNS?

Accepted Answer

White matter consists of myelinated axons, while gray matter consists of unmyelinated areas

Question 19

Which sequence correctly describes the steps of axon regeneration in the PNS after injury?

Accepted Answer

Degeneration, growth processes form, regeneration tube forms, growth into tube, reconnection

Question 20

Which of the following best describes the effect of opening a ligand-gated chloride channel on the postsynaptic membrane?

Accepted Answer

Hyperpolarization

Neuroglia, Myelin Sheath, and Electrophysiology of Neurons: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards