A patient with a deep laceration at the stylomastoid foramen loses lacrimal secretion on that side along with ipsilateral facial paralysis. Which nerve, interrupted by this injury, carried the secretomotor fibres to the lacrimal gland?

• A Greater petrosal nerve ✓
• B Lesser petrosal nerve
• C Deep petrosal nerve
• D Zygomatic branch of the facial nerve

Explanation

Parasympathetic secretomotor fibres to the lacrimal gland leave the facial nerve at the geniculate ganglion as the greater petrosal nerve, join the deep petrosal nerve to form the nerve of the pterygoid canal (Vidian nerve), relay in the pterygopalatine ganglion, and reach the gland via the zygomatic and lacrimal nerves. B lesion proximal to the geniculate ganglion abolishes lacrimation. The lesser petrosal nerve carries parasympathetics to the parotid gland via the otic ganglion.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.