Question 1

Which of the following best describes the role of oligodendrocytes in the central nervous system (CNS)?

Accepted Answer

They produce myelin sheaths around axons in the CNS, increasing the speed of action potential propagation.

Question 2

A patient presents with muscle weakness and loss of sensation in the limbs. Which division of the nervous system is most likely affected?

Accepted Answer

Peripheral nervous system (PNS)

Question 3

Which of the following equations correctly represents the resting membrane potential of a neuron?

Accepted Answer

$$V_{rest} \approx -70\ \mathrm{mV}$$

Question 4

During an action potential, which event occurs immediately after the threshold is reached?

Accepted Answer

Voltage-gated Na$$^+$$ channels open, allowing Na$$^+ to $$enter the cell.

Question 5

Which type of neuron is most commonly found in the CNS and is characterized by having many dendrites and one axon?

Accepted Answer

Multipolar neuron

Question 6

A local anesthetic blocks voltage-gated Na$$^+$$ channels. What is the most direct effect on neuronal signaling?

Accepted Answer

Action potentials cannot be generated, preventing nerve impulse transmission.

Question 7

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

Accepted Answer

Action potentials jump between nodes of Ranvier in a process called saltatory conduction.

Question 8

Which equation describes the relationship between axon diameter and conduction velocity?

Accepted Answer

$$v \propto d$$, where $$v is $$conduction velocity and $$d is $$axon diameter

Question 9

Which neurotransmitter is primarily associated with learning, memory, and stimulation of muscle function?

Accepted Answer

Acetylcholine

Question 10

A patient is unable to feel pain in their skin but can still sense muscle stretch. Which sensory division is most likely impaired?

Accepted Answer

Somatic sensory division

Question 11

Which of the following best describes the absolute refractory period of a neuron?

Accepted Answer

No additional stimulus, no matter how strong, can produce another action potential.

Question 12

Which glial cell type is responsible for circulating cerebrospinal fluid in the CNS?

Accepted Answer

Ependymal cells

Question 13

Which of the following events occurs at a chemical synapse to transmit a signal from one neuron to another?

Accepted Answer

Neurotransmitters are released from the presynaptic neuron and bind to receptors on the postsynaptic cell.

Question 14

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

Accepted Answer

Regulate the blood-brain barrier and maintain extracellular environment.

Question 15

Which of the following best describes the process of depolarization in a neuron?

Accepted Answer

Na$$^+$$ ions enter the cell, making the inside more positive.

Question 16

Which of the following neurotransmitters is primarily inhibitory in the CNS and can decrease the firing rate of neurons?

Accepted Answer

GABA

Question 17

A neuron receives multiple excitatory postsynaptic potentials (EPSPs) in rapid succession at the same synapse. What is this phenomenon called?

Accepted Answer

Temporal summation

Question 18

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

Accepted Answer

White matter contains myelinated axons, while gray matter contains unmyelinated axons and cell bodies.

Question 19

Which of the following equations represents the Nernst equation for calculating the equilibrium potential of an ion?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \left( \frac{[ion]_{out}}{[ion]_{in}} \right)$$

Chapter 11

Study Guide - Practice Questions