Question 1

Which of the following best describes the role of Schwann cells in the peripheral nervous system?

Accepted Answer

They wrap around axons to form myelin sheaths, increasing the speed of nerve impulse conduction.

Question 2

A patient presents with slowed nerve conduction velocity. Which structure is most likely damaged?

Accepted Answer

Myelin sheath

Question 3

Which equation correctly represents the resting membrane potential of a neuron?

Accepted Answer

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

Question 4

During an action potential, which ion's influx is primarily responsible for depolarization?

Accepted Answer

Sodium ($$Na^+)$$

Question 5

Which of the following best explains the 'all-or-none principle' of action potentials?

Accepted Answer

Once the threshold is reached, an action potential is always generated with the same amplitude.

Question 6

If the extracellular concentration of $$K^+$$ increases, what effect would this have on the resting membrane potential?

Accepted Answer

It would become less negative (closer to zero).

Question 7

Which cell type is responsible for forming the blood-brain barrier?

Accepted Answer

Astrocytes

Question 8

A toxin blocks voltage-gated sodium channels. What is the most likely effect on neuronal signaling?

Accepted Answer

Action potentials will not be generated.

Question 9

Which of the following best describes saltatory conduction?

Accepted Answer

Action potentials jump from one node of Ranvier to the next, increasing conduction speed.

Question 10

Which equation best represents the Nernst equation for calculating equilibrium potential for an ion?

Accepted Answer

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

Question 11

Which glial cell type acts as phagocytes in the CNS, removing debris and pathogens?

Accepted Answer

Microglia

Question 12

A patient has a demyelinating disease affecting the CNS. Which cell type is most likely involved?

Accepted Answer

Oligodendrocytes

Question 13

Which of the following is NOT a function of the autonomic motor division?

Accepted Answer

Controlling voluntary movement of skeletal muscles

Question 14

Which process occurs during hyperpolarization of a neuron?

Accepted Answer

Efflux of $$K^+$$ ions

Question 15

Which of the following best describes the function of Nissl bodies in neurons?

Accepted Answer

They are sites of protein synthesis and contain rough endoplasmic reticulum.

Question 16

If a neuron receives more excitatory post synaptic potentials (EPSPs) than inhibitory post synaptic potentials (IPSPs), what is the likely outcome?

Accepted Answer

The neuron will reach threshold and fire an action potential.

Question 17

Which of the following best describes the role of the axon hillock?

Accepted Answer

It is the site where action potentials are initiated.

Question 18

Which equation best represents the change in membrane potential during depolarization?

Accepted Answer

$$\Delta V = V_{final} - V_{rest}$$, where $$V_{final} \u003e V_{rest}$$

Question 19

Which of the following is TRUE regarding the propagation of an action potential in a myelinated axon?

Accepted Answer

It occurs via saltatory conduction, jumping from node to node.

Question 20

Which cell type lines the ventricles of the brain and helps circulate cerebrospinal fluid?

Accepted Answer

Ependymal cells

Introduction to the Nervous System: Structure, Function, and Physiology

Study Guide - Practice Questions