Q: Which of the following equations correctly represents the movement of ions by the sodium-potassium pump?

$$3\ \mathrm{Na}^+_{\text{in}} + 2\ \mathrm{K}^+_{\text{out}} + \mathrm{ATP} \rightarrow 3\ \mathrm{Na}^+_{\text{out}} + 2\ \mathrm{K}^+_{\text{in}} + \mathrm{ADP} + \mathrm{P}_i$$

Question 1

Which of the following best describes the main function of the nervous system in maintaining homeostasis?

Accepted Answer

It regulates and coordinates voluntary and involuntary responses, including respiratory rate, blood pressure, and body temperature.

Question 2

A patient suffers a spinal cord injury at the level of the first lumbar vertebra. Which anatomical division of the nervous system is most directly affected?

Accepted Answer

Central nervous system (CNS)

Question 3

Which of the following is TRUE regarding the difference between the CNS and PNS?

Accepted Answer

The CNS is protected by the skull and vertebral column, while the PNS is not.

Question 4

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

Accepted Answer

Astrocytes

Question 5

A patient is diagnosed with multiple sclerosis, which results in the loss of myelin in the CNS. What is the most likely effect on action potential conduction?

Accepted Answer

Action potentials will slow down or fail due to increased current leakage.

Question 6

Which of the following best describes the function of the sodium-potassium pump in neurons?

Accepted Answer

It moves three sodium ions out and two potassium ions into the cell per ATP hydrolyzed, maintaining the resting membrane potential.

Question 7

A local anesthetic such as lidocaine blocks voltage-gated sodium channels. What is the physiological consequence of this action?

Accepted Answer

Neurons cannot depolarize, so action potentials are not generated and pain signals are not transmitted.

Question 8

Which of the following equations correctly represents the movement of ions by the sodium-potassium pump?

Accepted Answer

$$3\ \mathrm{Na}^+_{	ext{in}} + 2\ \mathrm{K}^+_{	ext{out}} + \mathrm{ATP} ightarrow 3\ \mathrm{Na}^+_{	ext{out}} + 2\ \mathrm{K}^+_{	ext{in}} + \mathrm{ADP} + \mathrm{P}_i$$

Question 9

Which of the following best explains why action potentials are unidirectional along an axon?

Accepted Answer

The refractory period prevents the action potential from traveling backward toward the cell body.

Question 10

A neuron receives simultaneous excitatory postsynaptic potentials (EPSPs) from several presynaptic neurons. This is an example of:

Accepted Answer

Spatial summation

Question 11

Which of the following neurotransmitters is most associated with the regulation of mood and is targeted by selective serotonin reuptake inhibitors (SSRIs)?

Accepted Answer

Serotonin

Question 12

Which of the following is a correct sequence of events at a chemical synapse?

Accepted Answer

Action potential arrives at axon terminus, neurotransmitter is released, neurotransmitter binds to receptors, local potential occurs in postsynaptic cell

Question 13

Which of the following best describes the effect of opening ligand-gated chloride channels on the postsynaptic membrane?

Accepted Answer

It causes hyperpolarization and an IPSP.

Question 14

Which of the following is a property of action potentials but NOT local potentials?

Accepted Answer

They are all-or-none and nondecremental.

Question 15

A patient is exposed to a neurotoxin that prevents postsynaptic sodium channels from closing. What is the most likely effect?

Accepted Answer

The postsynaptic neuron will remain depolarized and continue to fire action potentials.

Question 16

Which of the following best describes the role of astrocytes in the CNS?

Accepted Answer

They anchor neurons and blood vessels, regulate the extracellular environment, and help form the blood-brain barrier.

Question 17

Which of the following is TRUE regarding the difference between saltatory and continuous conduction?

Accepted Answer

Saltatory conduction occurs in myelinated axons and is faster because action potentials jump from node to node.

Question 18

Which of the following best explains why the CNS has limited ability to regenerate damaged neurons compared to the PNS?

Accepted Answer

Oligodendrocytes do not form regeneration tubes and the environment inhibits axon regrowth.

Introduction to the Nervous System and Nervous Tissue: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards