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

Question 1

Which of the following best describes the function of the sodium-potassium pump in maintaining the resting membrane potential of a neuron?

Accepted Answer

It actively transports 3 Na\^+ ions out of the cell and 2 K\^+ ions into the cell, using ATP hydrolysis.

Question 2

A patient is experiencing muscle weakness due to demyelination of axons in the peripheral nervous system. Which glial cell is most likely affected?

Accepted Answer

Schwann cell

Question 3

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

Accepted Answer

$$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion}]_{	ext{out}}}{[	ext{ion}]_{	ext{in}}} ight)$$

Question 4

Which of the following neurotransmitters is primarily inhibitory in the central nervous system and is associated with the treatment of epilepsy?

Accepted Answer

GABA (gamma-aminobutyric acid)

Question 5

During an action potential, what is the primary cause of depolarization?

Accepted Answer

Opening of voltage-gated Na\^+ channels

Question 6

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

Accepted Answer

Action potentials in myelinated axons jump from one node of Ranvier to the next, a process called saltatory conduction.

Question 7

A drug that blocks acetylcholinesterase would have which effect at the neuromuscular junction?

Accepted Answer

Increase the duration of muscle contraction by preventing acetylcholine breakdown

Question 8

Which of the following is a characteristic of graded potentials but NOT action potentials?

Accepted Answer

They can summate and vary in amplitude depending on stimulus strength.

Question 9

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

Accepted Answer

Astrocyte

Question 10

A patient with Parkinson's disease has a deficiency of which neurotransmitter, and in which brain region is this most critical?

Accepted Answer

Dopamine in the substantia nigra

Question 11

Which of the following best describes the effect of selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression?

Accepted Answer

SSRIs inhibit the reuptake of serotonin, increasing its concentration in the synaptic cleft.

Question 12

Which of the following pathways is responsible for voluntary control of skeletal muscles?

Accepted Answer

Somatic motor division of the peripheral nervous system

Question 13

Which of the following ions has a higher concentration inside the neuron compared to outside, contributing to the resting membrane potential?

Accepted Answer

K\^+

Question 14

Which of the following best describes the absolute refractory period of an action potential?

Accepted Answer

It is the period when voltage-gated Na\^+ channels are inactivated and no new action potential can be generated.

Question 15

Which neurotransmitter is involved in both excitatory and inhibitory signaling in the CNS and is affected by drugs used to treat anxiety?

Accepted Answer

GABA

Question 16

Which of the following is a function of ependymal cells in the central nervous system?

Accepted Answer

Produce and circulate cerebrospinal fluid

Question 17

Which of the following best describes spatial summation in neuronal signaling?

Accepted Answer

Graded potentials from different synapses combine at the trigger zone to reach threshold.

Question 18

Which of the following is true regarding the effect of barbiturates on GABA receptors in the treatment of epilepsy?

Accepted Answer

Barbiturates enhance GABA binding, increasing Cl\^- influx and neuronal inhibition.

Question 19

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

Accepted Answer

They regulate the composition of the extracellular fluid and help form the blood-brain barrier.

The Nervous System: Structure, Function, and Neural Communication

Study Guide - Practice Questions