Question 1

Which of the following best describes the primary function of glial cells in the vertebrate nervous system?

Accepted Answer

They support, protect, and insulate neurons, and can modulate synaptic activity.

Question 2

A patient is diagnosed with multiple sclerosis. Which glial cell type is most directly affected, and what is the consequence for neural transmission?

Accepted Answer

Oligodendrocytes; loss of myelin sheath leading to slower action potential conduction.

Question 3

Which equation best represents the Nernst equation for calculating the equilibrium potential ($E_{ion}$) of an ion across a membrane?

Accepted Answer

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

Question 4

Which of the following best explains why the inside of a neuron is negatively charged at rest?

Accepted Answer

Leak channels allow potassium ions to diffuse out of the cell, leaving behind negatively charged proteins.

Question 5

Which of the following is NOT a function of astrocytes in the central nervous system?

Accepted Answer

Phagocytosing pathogens and debris.

Question 6

A diabetic patient develops peripheral neuropathy. Which part of the nervous system is primarily affected, and what is a likely symptom?

Accepted Answer

Peripheral nervous system; numbness and tingling in extremities.

Question 7

Which of the following best describes the sequence of events during an action potential?

Accepted Answer

Sodium channels open, causing depolarization; then potassium channels open, causing repolarization.

Question 8

Which structure of the neuron is primarily responsible for receiving incoming signals from other neurons?

Accepted Answer

Dendrite

Question 9

Which of the following is a correct statement about the sodium-potassium pump?

Accepted Answer

It moves 3 Na$^+$ ions out of the cell and 2 K$^+$ ions into the cell per cycle.

Question 10

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

Accepted Answer

Graded potentials can summate and vary in magnitude, while action potentials are all-or-none.

Question 11

Which of the following neural network structures is found in the simplest animals, such as cnidarians?

Accepted Answer

Nerve net

Question 12

Which glial cell type is responsible for myelinating axons in the peripheral nervous system?

Accepted Answer

Schwann cells

Question 13

A neuron receives both excitatory and inhibitory inputs. Which of the following determines whether it will fire an action potential?

Accepted Answer

The sum of graded potentials at the axon hillock reaching threshold.

Question 14

Which of the following best describes the role of microglia in the nervous system?

Accepted Answer

They act as immune cells, removing debris and pathogens by phagocytosis.

Question 15

Which of the following is a consequence of demyelination in diseases such as multiple sclerosis?

Accepted Answer

Slower or blocked propagation of action potentials along axons.

Question 16

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

Accepted Answer

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

Question 17

Which of the following is true regarding the central nervous system (CNS) and peripheral nervous system (PNS)?

Accepted Answer

The CNS includes the brain and spinal cord, while the PNS includes nerves outside the CNS.

Question 18

Which of the following would most likely result from a mutation that causes potassium leak channels to remain closed in a neuron?

Accepted Answer

The resting membrane potential would become more positive.

Question 19

Which of the following best explains why myelination increases the speed of action potential conduction?

Accepted Answer

It allows action potentials to jump between nodes of Ranvier via saltatory conduction.

Question 20

A neuron is exposed to a toxin that blocks sodium channels. What is the most likely effect on the neuron's ability to transmit signals?

Accepted Answer

The neuron will be unable to generate action potentials.

Structure and Function of Nervous Systems: Neurons, Glia, and Membrane Potentials

Study Guide - Practice Questions