Henry Gray (18251861). Anatomy of the Human Body. 1918.
The Tympanic Nerve (n. tympanicus; nerve of Jacobson) arises from the petrous ganglion, and ascends to the tympanic cavity through a small canal on the under surface of the petrous portion of the temporal bone on the ridge which separates the carotid canal from the jugular fossa. In the tympanic cavity it divides into branches which form the tympanic plexus and are contained in grooves upon the surface of the promontory. This plexus gives off: (1) the lesser superficial petrosal nerve; (2) a branch to join the greater superficial petrosal nerve; and (3) branches to the tympanic cavity, all of which will be described in connection with the anatomy of the middle ear.
The Carotid Branches (n. caroticotympanicus superior and n. caroticotympanicus inferior) descend along the trunk of the internal carotid artery as far as its origin, communicating with the pharyngeal branch of the vagus, and with branches of the sympathetic.
The Pharyngeal Branches (rami pharyngei) are three or four filaments which unite, opposite the Constrictor pharyngis medius, with the pharyngeal branches of the vagus and sympathetic, to form the pharyngeal plexus; branches from this plexus perforate the muscular coat of the pharynx and supply its muscles and mucous membrane.
The Muscular Branch (ramus stylopharyngeus) is distributed to the Stylopharyngeus.
The Tonsillar Branches (rami tonsillares) supply the palatine tonsil, forming around it a plexus from which filaments are distributed to the soft palate and fauces, where they communicate with the palatine nerves.
FIG. 793 Course and distribution of the glossopharyngeal, vagus, and accessory nerves. (See enlarged image)
The Lingual Branches (rami linguales) are two in number; one supplies the papillæ vallatæ and the mucous membrane covering the base of the tongue; the other supplies the mucous membrane and follicular glands of the posterior part of the tongue, and communicates with the lingual nerve.