View of the inner wall of the tympanum. (Grooves for tympanic plexus labeled at center.)
Plan of the facial and intermediate nerves and their communication with other nerves. (Tympanic plexus labeled at center.)
|From||caroticotympanic nerves, tympanic nerve|
|Anatomical terms of neuroanatomy|
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 gives off:
- (1) the lesser petrosal nerve
- (2) the Deep branch (small deep petrosal nerve) to join the greater petrosal nerve
- (3) branches to the tympanic cavity
The branches of the tympanic cavity provide innervation to the mucosa of the middle ear. The lesser petrosal nerve provides autonomic parasympathetic fibers that eventually innervate the parotid gland.