Tympanikanerven

The tympanic nerve, also known as Jacobson's nerve, is a small nerve originating from the glossopharyngeal nerve (cranial nerve IX). It arises in the inferior ganglion of the glossopharyngeal nerve and travels through a small canal in the temporal bone to enter the tympanic cavity, the middle ear.

Within the tympanic cavity, the tympanic nerve branches extensively over the inner surface of the tympanic membrane and the ossicles. It also contributes fibers to the tympanic plexus, a network of nerves on the promontory of the middle ear. From this plexus, postganglionic parasympathetic fibers arise and travel with the lesser petrosal nerve to the otic ganglion. The otic ganglion is a parasympathetic ganglion located just below the foramen ovale, responsible for innervating the parotid salivary gland.

The tympanic nerve carries sensory fibers from the mucous membrane of the tympanic cavity and the auditory tube. It also transmits taste sensation from the posterior third of the tongue, although this function is primarily associated with the main trunk of the glossopharyngeal nerve. The parasympathetic fibers conveyed by the tympanic nerve stimulate secretion from the parotid gland. Damage to the tympanic nerve can lead to altered taste sensation, changes in salivation, and potential disruptions in the sensory perception of the middle ear.