Sensory innervation of the palate reaches the brain via the maxillary division of the trigeminal nerve. Through which opening does that division leave the middle cranial fossa?

Correct answer: D. Foramen rotundum

• A. The foramen ovale transmits the MANDIBULAR division (V3), which supplies the lower face, mandibular teeth, anterior two-thirds of the tongue and the muscles of mastication.
• B. The superior orbital fissure transmits the OPHTHALMIC division (V1) along with CN III, IV and VI. V1 supplies the forehead, upper eyelid and nasal dorsum — not the palate.
• C. The stylomastoid foramen transmits the FACIAL nerve (CN VII) as it leaves the skull to supply the muscles of facial expression. It carries no palatal sensation.
• D. CORRECT. All palatal sensory fibres — greater palatine, lesser palatine and nasopalatine — are branches of the maxillary nerve (V2). V2 leaves the middle cranial fossa through the FORAMEN ROTUNDUM into the pterygopalatine fossa, where the pterygopalatine ganglion sits and the palatine branches arise. The palatine foramina are simply where those branches finally enter the mouth; the foramen rotundum is where the whole division enters the circuit.

Note: Quick map of the trigeminal exits: V1 → superior orbital fissure, V2 → foramen rotundum, V3 → foramen ovale.