Question 1

Which of the following best describes the difference between the anatomical and functional divisions of the nervous system?

Accepted Answer

Anatomical divisions refer to the CNS and PNS, while functional divisions refer to sensory and motor pathways.

Question 2

Which structure is defined as a gap in the myelin sheath of a nerve, facilitating rapid conduction of action potentials?

Accepted Answer

Node of Ranvier

Question 3

A patient presents with impaired blood-brain barrier function. Which type of neuroglia is most likely affected?

Accepted Answer

Astrocytes

Question 4

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

Accepted Answer

They myelinate axons in the CNS, increasing the speed of action potential propagation.

Question 5

During the generation of a resting membrane potential, which equation is used to calculate the equilibrium potential for potassium ($K^+$)?

Accepted Answer

The Nernst equation: $E_{K^+} = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$

Question 6

Which process is primarily responsible for maintaining the resting membrane potential in neurons?

Accepted Answer

Active transport of ions by the sodium-potassium pump ($3 Na^+$ out, $2 K^+$ in)

Question 7

A neuron is exposed to a toxin that blocks voltage-gated sodium channels. What effect will this have on the action potential?

Accepted Answer

The neuron will be unable to depolarize, preventing action potential initiation.

Question 8

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

Accepted Answer

Saltatory conduction allows action potentials to jump between nodes of Ranvier.

Question 9

Which equation can be used to estimate the speed of action potential propagation in a myelinated axon?

Accepted Answer

$v \propto \sqrt{d}$, where $v$ is velocity and $d$ is axon diameter

Question 10

A neuron is at rest with a membrane potential of $-70$ mV. If the membrane suddenly becomes permeable only to sodium ions ($Na^+$), what will happen to the membrane potential?

Accepted Answer

It will depolarize toward the equilibrium potential of sodium ($E_{Na^+}$), which is positive.

Question 11

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

Accepted Answer

A period during which a second action potential cannot be initiated, regardless of stimulus strength.

Question 12

Which of the following is NOT a function of neuroglia?

Accepted Answer

Transmitting electrical impulses along axons

Question 13

Which term describes the process by which an action potential travels along a myelinated axon, jumping from one node of Ranvier to the next?

Accepted Answer

Saltatory propagation

Question 14

A neuron is classified as multipolar. Which of the following best describes its structure?

Accepted Answer

One axon and multiple dendrites

Question 15

Which of the following scenarios would most likely result in hyperpolarization of a neuron?

Accepted Answer

Opening of potassium ($K^+$) channels, allowing $K^+$ to exit the cell

Question 16

Which of the following best describes the threshold potential in a neuron?

Accepted Answer

The membrane potential at which voltage-gated sodium channels open, initiating an action potential

Question 17

Which of the following is a correct comparison between saltatory and continuous propagation of action potentials?

Accepted Answer

Saltatory propagation is faster and occurs in myelinated axons, while continuous propagation is slower and occurs in unmyelinated axons.

Question 18

Which of the following best explains the effect of increased axon diameter on the speed of action potential propagation?

Accepted Answer

Increasing axon diameter decreases internal resistance, allowing faster conduction.

Question 19

Which of the following is a function of microglia in the nervous system?

Accepted Answer

Phagocytosis of cellular debris and pathogens

Study Guide: Nervous System Structure and Function

Study Guide - Practice Questions

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