Q: Which of the following best describes the role of the sodium-potassium pump in maintaining the resting membrane potential?

It actively transports 3 Na\textsuperscript{+} ions out and 2 K\textsuperscript{+} ions into the cell, maintaining a negative resting potential.

Question 1

Which of the following best describes the main function of astrocytes in the central nervous system (CNS)?

Accepted Answer

They maintain the blood-brain barrier and repair damaged neural tissue.

Question 2

A patient suffers a spinal cord injury that damages only the myelinated Type A fibers. Which function is most likely to be immediately impaired?

Accepted Answer

Transmission of rapid sensory information such as touch and proprioception

Question 3

During the generation of an action potential, which event occurs immediately after the membrane potential reaches threshold at the axon hillock?

Accepted Answer

Voltage-gated sodium channels open, causing rapid depolarization.

Question 4

Which of the following best explains why saltatory propagation is faster than continuous propagation?

Accepted Answer

Action potentials jump from node to node, allowing depolarization only at the nodes of Ranvier.

Question 5

A neuron receives multiple excitatory postsynaptic potentials (EPSPs) at different locations on its dendrites at the same time. This process is known as:

Accepted Answer

Spatial summation

Question 6

Which of the following statements about graded potentials is TRUE?

Accepted Answer

They can be depolarizing or hyperpolarizing, and their effect decreases with distance from the site of stimulation.

Question 7

Which type of neuroglia is responsible for forming the myelin sheath in the peripheral nervous system (PNS)?

Accepted Answer

Schwann cells

Question 8

A patient is experiencing muscle weakness due to a lack of neurotransmitter release at the neuromuscular junction. Which process is most likely impaired?

Accepted Answer

Exocytosis of synaptic vesicles at the axon terminal

Question 9

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

Accepted Answer

If the threshold is reached, an action potential of the same magnitude is always generated.

Question 10

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

Accepted Answer

Acting as phagocytes to remove debris and pathogens

Question 11

A neuron is unable to regenerate its axon after injury in the CNS. Which of the following best explains this phenomenon?

Accepted Answer

Astrocytes release chemicals that block growth and produce scar tissue.

Question 12

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

Accepted Answer

It actively transports 3 Na	extsuperscript{+} ions out and 2 K	extsuperscript{+} ions into the cell, maintaining a negative resting potential.

Question 13

Which of the following is TRUE regarding inhibitory postsynaptic potentials (IPSPs)?

Accepted Answer

They cause hyperpolarization of the postsynaptic membrane.

Question 14

A patient is exposed to a toxin that blocks voltage-gated potassium channels. What effect would this have on the action potential?

Accepted Answer

Repolarization would be delayed, prolonging the action potential.

Question 15

Which of the following best describes the difference between white matter and gray matter in the CNS?

Accepted Answer

White matter contains many myelinated axons, while gray matter contains neuron cell bodies and unmyelinated axons.

Question 16

Which neurotransmitter is most likely to be involved in the regulation of attention and emotional states in the CNS?

Accepted Answer

Serotonin

Question 17

A neuron is exposed to a drug that increases the frequency of action potentials at the axon hillock. Which of the following is the most likely effect?

Accepted Answer

The degree of sustained depolarization at the axon hillock will increase.

Question 18

Which of the following best describes the function of ependymal cells?

Accepted Answer

They secrete and circulate cerebrospinal fluid (CSF) in the brain and spinal cord.

Question 19

A patient is experiencing synaptic fatigue at a neuromuscular junction. Which of the following best explains this phenomenon?

Accepted Answer

The presynaptic neuron cannot recycle neurotransmitter fast enough to meet demand.

Question 20

Which of the following is a characteristic of Wallerian degeneration in the PNS?

Accepted Answer

Schwann cells form a path for new axonal growth and wrap the new axon in myelin.

Neural Tissue: Structure, Function, and Physiology

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