Question 1

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

Accepted Answer

They support and brace neurons, regulate the chemical environment, and participate in information processing.

Question 2

A patient suffers a spinal cord injury that damages only the dorsal root ganglia. Which function is most likely to be impaired?

Accepted Answer

Transmission of sensory information to the CNS

Question 3

Which of the following is TRUE regarding the difference between graded potentials and action potentials?

Accepted Answer

Graded potentials operate over short distances, while action potentials are long-distance signals that do not decay.

Question 4

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

Accepted Answer

Schwann cells

Question 5

A person is exposed to a toxin that blocks voltage-gated sodium channels in neurons. What is the most immediate effect on neural signaling?

Accepted Answer

Action potentials cannot be generated, preventing nerve impulse transmission.

Question 6

Which of the following best explains why the blood-brain barrier is essential for brain function?

Accepted Answer

It selectively allows nutrients and fat-soluble substances while blocking toxins and most drugs.

Question 7

During a 'fight-or-flight' response, which of the following physiological changes is most likely to occur due to sympathetic nervous system activation?

Accepted Answer

Dilated pupils, increased heart rate, and glucose release from the liver

Question 8

Which sequence correctly represents the components of a reflex arc?

Accepted Answer

Receptor → Sensory neuron → Integration center → Motor neuron → Effector

Question 9

A patient is given atropine before eye surgery. What is the expected effect of this drug on the nervous system?

Accepted Answer

It blocks muscarinic acetylcholine receptors, causing pupil dilation.

Question 10

Which of the following best describes the role of the thalamus in the brain?

Accepted Answer

It acts as the main relay station, sorting and relaying sensory and motor information to the cerebral cortex.

Question 11

If a neuron is hyperpolarized, which of the following statements is TRUE?

Accepted Answer

The inside of the cell becomes more negative, reducing the probability of producing a nerve impulse.

Question 12

Which of the following is a function of ependymal cells in the CNS?

Accepted Answer

They circulate cerebrospinal fluid with their cilia and form a barrier between CSF and CNS tissue.

Question 13

Which of the following best explains why most CNS nerve fibers do not regenerate after injury?

Accepted Answer

Oligodendrocytes produce growth-inhibiting proteins and astrocytes form scar tissue that blocks regrowth.

Question 14

Which of the following is a correct pairing of a sensory receptor type with its stimulus?

Accepted Answer

Photoreceptor – responds to light energy

Question 15

Which brain region is primarily responsible for conscious awareness, voluntary movement, and memory storage?

Accepted Answer

Cerebral cortex

Question 16

A person is experiencing difficulty with voluntary muscle movements and loss of learned motor skills. Which brain region is most likely affected?

Accepted Answer

Premotor cortex

Question 17

Which of the following best describes the effect of neostigmine in the treatment of myasthenia gravis?

Accepted Answer

It inhibits acetylcholinesterase, increasing acetylcholine at the neuromuscular junction.

Question 18

Which of the following is a characteristic of the parasympathetic division of the autonomic nervous system?

Accepted Answer

It promotes digestion, diuresis, and defecation during rest.

Question 19

Which of the following best explains why myelinated axons conduct nerve impulses faster than nonmyelinated axons?

Accepted Answer

Myelin allows for saltatory conduction, where action potentials jump between nodes of Ranvier.

The Nervous System: Structure, Function, and Cellular Organization

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