During tympanotomy, a surgeon elevates a nerve plexus lying over the promontory of the middle ear. This plexus is formed chiefly by which nerve?

• A Tympanic branches of the facial nerve
• B Greater petrosal nerve
• C Nerve of the pterygoid canal
• D Tympanic branch of the glossopharyngeal nerve ✓

Explanation

The tympanic plexus on the promontory is formed mainly by Jacobson's nerve, the tympanic branch of the glossopharyngeal nerve, reinforced by caroticotympanic sympathetic fibres. It supplies middle ear mucosa and gives the lesser petrosal nerve to the otic ganglion. The greater petrosal nerve carries parasympathetic fibres of VII and runs in the middle cranial fossa, never reaching the promontory.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.