The nurse is assessing the sensory function of the cranial nerves. The nurse recalls that which nerve has only sensory function?

Correct Answer: C

Rationale: CN VIII (vestibulocochlear) is purely sensory (hearing, balance). Facial, vagus, and trigeminal are mixed nerves with sensory and motor functions.

Correct Answer: B

Rationale: The three primary brain vesicles during early development are the prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain). Telencephalon and diencephalon are subdivisions of the prosencephalon, while metencephalon and myelencephalon are subdivisions of the rhombencephalon.

Correct Answer: D

Rationale: The basal ganglia include the putamen, caudate nucleus, and globus pallidus, involved in motor control. The infundibulum is a hypothalamic structure connecting to the pituitary gland, not part of the basal ganglia.

Correct Answer: C

Rationale: The hypothalamus monitors osmotic concentration (thirst), blood glucose, and amino acids for homeostasis, but PCO₂ (carbon dioxide) is primarily regulated by the medulla oblongata’s respiratory centers, not the hypothalamus.

Correct Answer: A

Rationale: The pia mater is the innermost meninx, directly adhering to the brain and spinal cord. The dura mater is outermost, arachnoid is middle, and 'perineural mater' is not a standard term.