Tympanic plexus
In the tympanic cavity, the tympanic nerve (a branch of CN IX) divides into branches which, along with sympathetic fibres from the carotid plexus, form the tympanic plexus. This plexus is located on the surface of the promontory. This tympanic plexus branches into: The branches to the tympanic cavity provide sensory innervation to the mucosa of the tympanic cavity and the internal surface of the tympanic membrane. The cell bodies of these neurons are found in the superior ganglion of the glossopharyngeal nerve.