Cranial Nerves and Foramina Flashcards

Which foramen transmits the facial nerve (CN VII) as it exits the skull?

Answer: Stylomastoid foramen

The facial nerve exits the skull through the stylomastoid foramen before branching in the parotid gland.

A patient cannot move their eyes upward or medially and has a dilated, non-reactive pupil. Which cranial nerve is most likely damaged?

Answer: CN III (Oculomotor)

CN III controls most extraocular muscles and carries parasympathetic fibers to the pupillary sphincter; its injury causes the classic 'down and out' eye with mydriasis.

The lesser petrosal nerve (parasympathetic to the parotid gland) exits the skull through which foramen?

Answer: Foramen ovale

The lesser petrosal nerve, carrying GVE fibers from CN IX, exits through the foramen ovale (or a small canal nearby) to reach the otic ganglion.

Which cranial nerve carries taste sensation from the anterior two-thirds of the tongue?

Answer: CN VII (Facial)

The chorda tympani branch of CN VII carries special visceral afferent (taste) fibers from the anterior two-thirds of the tongue.

Which structure passes through the foramen lacerum in life?

Answer: Only the cartilaginous plug (nothing functional)

The foramen lacerum is filled with fibrocartilage in living individuals; the internal carotid artery passes over (not through) it via the carotid canal.

Damage to which cranial nerve would result in loss of the afferent limb of the corneal reflex?

Answer: CN V1 (Ophthalmic)

The ophthalmic division (V1) of the trigeminal nerve carries corneal sensation; CN VII mediates the efferent (blink) response.

The trochlear nerve (CN IV) is unique among cranial nerves because it:

Answer: Exits from the dorsal brainstem and crosses before exiting

CN IV is the only cranial nerve to exit from the dorsal surface of the brainstem and decussates before emerging, making it the longest intracranial cranial nerve.