IX N. Glossopharyngeus
(Fig. 156, a).—The ninth or glossopharyngeal nerve takes origin (Fig. 138, IX) from the side of the medulla, as described in the account of the brain. Close to its origin its trunk bears a small enlargement, the ganglion superius. It passes along with the tenth and eleventh nerves through the jugular foramen. At its exit it has a ganglionic enlargement, the ganglion petrosum; this is connected by fine fibres with the ganglion nodosum (Fig. 156, d) of the vagus. The glossopharyngeal (Fig. 156, a) then passes craniad over the surface of the tympanic bulla (15) and mediad of the digastric muscle. It continues mediad of the carotid artery, and as it approaches the cranial cornu of the hyoid divides into two portions, one of which passes to the muscles and mucosa of the pharynx, and the other to the tongue, where it is the special nerve of taste.