Question 1

Which of the following best describes the function of oligodendrocytes in the central nervous system?

Accepted Answer

They create myelin sheaths around axons, increasing the speed of action potential conduction.

Question 2

A patient presents with loss of sensation in a specific region of the skin. Which structure is most likely damaged?

Accepted Answer

A dermatome associated with a specific spinal nerve.

Question 3

During the depolarization phase of an action potential, which of the following occurs?

Accepted Answer

Voltage-gated sodium channels open, allowing Na^+ to enter the cell.

Question 4

Which neurotransmitter is released by postganglionic fibers of the sympathetic nervous system?

Accepted Answer

Norepinephrine

Question 5

A lesion in the prefrontal cortex would most likely affect which of the following functions?

Accepted Answer

Abstract intellectual processing and predicting consequences

Question 6

Which of the following best explains why the effects of adrenal medulla activation last longer than direct sympathetic nerve stimulation?

Accepted Answer

Hormones released by the adrenal medulla enter the bloodstream and affect distant tissues.

Question 7

Which of the following is TRUE regarding the sodium-potassium exchange pump?

Accepted Answer

It moves 3 Na^+ ions out of the cell and 2 K^+ ions into the cell per ATP hydrolyzed.

Question 8

A patient is unable to move their right hand but can still feel sensations in it. Which area of the brain is most likely damaged?

Accepted Answer

Left primary motor cortex

Question 9

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

Accepted Answer

It relays and filters sensory information before sending it to the cerebral cortex.

Question 10

Which of the following cranial nerves is responsible for both sensory and motor functions in the face?

Accepted Answer

Trigeminal nerve (CN V)

Question 11

A patient with damage to the dorsal root of a spinal nerve would most likely experience which of the following?

Accepted Answer

Loss of sensory input from the affected area

Question 12

Which of the following statements about graded potentials is correct?

Accepted Answer

They are local changes in membrane potential that can summate to trigger an action potential.

Question 13

Which of the following best describes the function of the cerebellum?

Accepted Answer

It adjusts postural muscles and fine-tunes voluntary and involuntary movements.

Question 14

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

Accepted Answer

Action potential arrives, $$Ca^{2+}$$ enters, ACh is released, ACh binds to receptors, ACh is broken down by AChE.

Question 15

Which of the following is a function of astrocytes in the CNS?

Accepted Answer

Maintaining the blood-brain barrier

Question 16

A person is startled by a loud noise and immediately turns their head toward the sound. Which brain structure is primarily responsible for this reflex?

Accepted Answer

Inferior colliculi

Question 17

Which of the following best describes the difference between the sympathetic and parasympathetic divisions of the autonomic nervous system?

Accepted Answer

Sympathetic postganglionic fibers release norepinephrine, while parasympathetic postganglionic fibers release acetylcholine.

Question 18

Which of the following is TRUE regarding the organization of gray and white matter in the spinal cord?

Accepted Answer

Gray matter contains cell bodies and glial cells, while white matter contains myelinated and unmyelinated axons.

Question 19

A patient is experiencing increased heart rate, dilated pupils, and decreased digestive activity. Which division of the autonomic nervous system is most active?

Accepted Answer

Sympathetic division

Question 20

Which of the following best explains why the resting membrane potential of a neuron is typically around $$-70\ \mathrm{mV}$$?

Accepted Answer

There are more K^+ leak channels than Na^+ leak channels, and the sodium-potassium pump maintains the ion gradient.

The Nervous System: Structure, Function, and Organization

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