The parasympathetic innervation to the middle ear travels with which cranial nerve?

The parasympathetic innervation to the middle ear travels with which cranial nerve?

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

Answer: (A)

Parasympathetic innervation of the middle ear comes from the glossopharyngeal nerve. The preganglionic parasympathetic fibers originate in the inferior salivary nucleus and travel with the tympanic nerve into the middle ear, where they contribute to the tympanic plexus on the promontory. They then proceed as the lesser petrosal nerve to the otic ganglion; postganglionic fibers hitchhike with the auriculotemporal nerve (a branch of V3) toward targets like the parotid gland. The facial nerve handles parasympathetics to lacrimal and some salivary glands via the greater petrosal nerve and chorda tympani, not to the middle ear.

Parasympathetic innervation of the middle ear comes from the glossopharyngeal nerve. The preganglionic parasympathetic fibers originate in the inferior salivary nucleus and travel with the tympanic nerve into the middle ear, where they contribute to the tympanic plexus on the promontory. They then proceed as the lesser petrosal nerve to the otic ganglion; postganglionic fibers hitchhike with the auriculotemporal nerve (a branch of V3) toward targets like the parotid gland. The facial nerve handles parasympathetics to lacrimal and some salivary glands via the greater petrosal nerve and chorda tympani, not to the middle ear.