Which is the smallest cranial nerve?

Correct Answer: C

Rationale: The trochlear nerve (CN IV) is the smallest cranial nerve by axon count and diameter, innervating only the superior oblique muscle. The olfactory nerve (I) has many fibers, and oculomotor (III) and abducent (VI) are larger.

Correct Answer: B

Rationale: The sneeze reflex’s afferent path is via the maxillary nerve (V2), sensing nasal irritation, with efferent via CN VII/X. V1 senses the cornea, V3 the jaw, and vagus (X) isn’t primary here.

Correct Answer: A

Rationale: Pancreatitis referred pain is at T7-T8, due to visceral innervation from the greater splanchnic nerve (T5-T9), projecting to the epigastric region.

Correct Answer: C

Rationale: The trigeminal nerve (CN V) has its motor nucleus in the upper pons, with three divisions (V1, V2, V3). V3 has motor and sensory roles, and exits vary (e.g., V1 via superior orbital fissure).

Correct Answer: A

Rationale: The greater occipital nerve (C2) supplies the vertex and posterior scalp.