Tympanic plexus present in -

B i.e. Medial projection of middle ear cavity Tympanic nerve arises from the glossopharyngeal nerve, just below the jugular foramen. It passes through the floor of middle ear and reaches onto the mucous membrane covering the promontory(2, where it splits into branches and joint branches of internal carotid plexus to form tympanic plexus. Promontary is round bulging in the medial or labyrinthine wall of middle ear cavityQ produced by the first turn of cholea.