Question 1

Which brain structure acts as the principal sensory relay center, and what is its primary function?

Accepted Answer

The thalamus; it relays and processes sensory information on its way to the cerebral cortex.

Question 2

A patient suffers a stroke that damages the cerebellum. Which of the following symptoms is most likely to result?

Accepted Answer

Impaired balance and coordination during movement.

Question 3

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

Accepted Answer

It produces cerebrospinal fluid, which cushions and supports the brain and spinal cord.

Question 4

Which pathway is responsible for voluntary motor control, and what is its main function?

Accepted Answer

Corticospinal tract; carries motor commands from the cerebral cortex to skeletal muscles.

Question 5

Which of the following correctly matches a protective membrane of the CNS with its description?

Accepted Answer

Dura mater: the tough, outermost membrane providing mechanical protection.

Question 6

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

Accepted Answer

It restricts harmful substances while allowing selective passage of nutrients and gases.

Question 7

During an action potential, what is the sequence of voltage-gated sodium channel states?

Accepted Answer

Closed at rest, open during depolarization, inactivated at peak, closed during repolarization.

Question 8

Which ion is primarily responsible for triggering synaptic vesicle fusion and neurotransmitter release at the presynaptic terminal?

Accepted Answer

Calcium (Ca\^{2+})

Question 9

A neuron receives several excitatory postsynaptic potentials (EPSPs) in rapid succession at the same synapse. What is this process called, and what is its effect?

Accepted Answer

Temporal summation; increases the likelihood of reaching threshold for an action potential.

Question 10

Which of the following best describes saltatory conduction in myelinated axons?

Accepted Answer

Action potentials jump from one node of Ranvier to the next, increasing conduction velocity.

Question 11

Which neuroglial cell is responsible for myelinating axons in the central nervous system (CNS)?

Accepted Answer

Oligodendrocyte

Question 12

A patient with multiple sclerosis experiences slowed nerve conduction. Which of the following best explains this phenomenon?

Accepted Answer

Loss of myelin increases membrane capacitance and decreases conduction velocity.

Question 13

Which of the following is a distinguishing feature of the medulla oblongata?

Accepted Answer

It contains centers that regulate heart rate and respiration.

Question 14

Which of the following best describes the difference between the dorsal and ventral horns of the spinal cord?

Accepted Answer

Dorsal horns process sensory input; ventral horns contain motor neuron cell bodies.

Question 15

Which of the following best explains why the inside of a resting neuron is negative relative to the outside?

Accepted Answer

Potassium ions diffuse out of the cell more readily than sodium ions enter, creating a negative charge inside.

Question 16

Which of the following is true regarding the absolute refractory period of an action potential?

Accepted Answer

It occurs because voltage-gated sodium channels are inactivated and cannot reopen immediately.

Question 17

Which of the following best describes the organization of the autonomic motor pathway?

Accepted Answer

Two neurons in series connect the CNS to the target organ, with a synapse in an autonomic ganglion.

Question 18

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

Accepted Answer

They maintain the extracellular environment and support the blood-brain barrier.

Question 19

Which of the following is a correct statement about the nodes of Ranvier?

Accepted Answer

They are gaps in the myelin sheath where action potentials are regenerated.

Question 20

Which of the following best explains the difference between ionotropic and metabotropic neurotransmitter receptors?

Accepted Answer

Ionotropic receptors directly open ion channels for rapid signaling; metabotropic receptors activate second messenger systems for slower, longer-lasting effects.

Anatomy & Physiology Unit 3 Exam Study Guide: Step-by-Step Guidance

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