Which functional division of the nervous system would be responsible for the physiological changes seen during exercise (e.g., increased heart rate and sweating)?

Correct Answer: B

Rationale: The autonomic nervous system regulates involuntary functions like heart rate and sweating, which increase during exercise. The somatic system controls voluntary movements, the enteric system governs digestion, and the central nervous system (CNS) includes the brain and spinal cord but isn’t a functional division in this context.

Correct Answer: C

Rationale: During the relative refractory period, the membrane is hyperpolarized (more negative than resting potential, -70 mV) due to potassium efflux, but recovering. -45 mV is plausible, as it’s below threshold (-55 mV) but above full hyperpolarization.

Correct Answer: A

Rationale: The blood-brain barrier (BBB) is a protective feature of the CNS, but the anterior pituitary lacks a complete BBB, allowing hormone exchange with the bloodstream. The posterior pituitary, pineal body, and area postrema have weaker or no BBB to facilitate their functions (e.g., hormone secretion or vomiting trigger).

Correct Answer: C

Rationale: The oculomotor nerve (CN III) supplies medial rectus, ciliary body, levator palpebrae superioris, and inferior oblique. The lateral rectus (option e) is innervated by the abducent nerve (CN VI), not CN III.

Correct Answer: B

Rationale: The anterior spinal artery (singular) arises from the vertebral arteries, supplying the anterior spinal cord. There are two posterior spinal arteries, typically from the posterior inferior cerebellar arteries, not superior cerebellar.