Which nerve innervates the internal surface of the tympanic membrane?

Which nerve innervates the internal surface of the tympanic membrane?

• A. Vagus nerve
• B. Trigeminal nerve
• C. Glossopharyngeal nerve
• D. Facial nerve

Answer: (C)

The inner surface of the tympanic membrane is innervated by a branch of the glossopharyngeal nerve that passes into the middle ear as the tympanic nerve and forms the tympanic plexus on the promontory. From this plexus, sensory fibers supply the mucosa of the middle ear and the inner surface of the tympanic membrane. That’s why glossopharyngeal nerve is the correct choice. The other nerves don’t provide this specific innervation: the vagus nerve mainly contributes to other ear structures and the outer surface of the tympanic membrane, while the trigeminal and facial nerves are not responsible for sensory innervation of the inner tympanic membrane.

The inner surface of the tympanic membrane is innervated by a branch of the glossopharyngeal nerve that passes into the middle ear as the tympanic nerve and forms the tympanic plexus on the promontory. From this plexus, sensory fibers supply the mucosa of the middle ear and the inner surface of the tympanic membrane. That’s why glossopharyngeal nerve is the correct choice. The other nerves don’t provide this specific innervation: the vagus nerve mainly contributes to other ear structures and the outer surface of the tympanic membrane, while the trigeminal and facial nerves are not responsible for sensory innervation of the inner tympanic membrane.