1226 A MANUAL OF ANATOMY 



Summary of the Glosso-pharyngeal Nerve — i. Cutaneous Distribution. — 



It supplies (a) the mucous membrane of the tympanum, the posterior third 

 of the tongue, the pillars of the fauces, and the pharynx ; and (b) the tonsil. 

 2. Muscular Distribution. — It supplies the stylo-pharyngeus. 3. Glandular 

 Distribution. — Through means of (i ) its tympanic, subsequently small super- 

 ficial petrosal, branch, {2) the otic ganglion, and (3) the auriculo-temporal nerve, 

 it furnishes secretory branches to the parotid gland. 



The Pneumogastric Nerve. 



The pneumogastric (vagus) or tenth cranial nerve is a mixed 

 nerve, consisting of both afferent and efferent fibres. It emerges 

 from the cranial cavity through the middle compartment of the 

 jugular foramen, being enclosed in the same sheath of dura mater 

 as the spinal accessory, and, with that nerve, lying on the inner 

 side of, and slightly posterior to, the glosso-pharyngeal. In the 

 foramen it presents a small enlargement, called the ganglion of the 

 root. After emerging from the foramen, it is joined by the accessory 

 portion of the spinal accessory nerve, and it here presents another 

 enlargement, called the ganglion of the trunk. This ganglion is 

 larger and longer than that of the root, measuring fully | inch in 

 length, and presenting a somewhat plexiform appearance. In 

 this part of its course the nerve lies between the internal carotid 

 artery and the internal jugular vein, the glosso-pharyngeal nerve 

 being in front of it, and the spinal accessory behind it. The hypo- 

 glossal nerve lies at first deeply behind it, but subsequently turns 

 round the outer side of the ganglion of the trunk. The pneumo- 

 gastric then descends within the carotid sheath, lying at first between 

 the internal carotid artery and the internal jugular vein, and then 

 between the common carotid artery and the internal jugular vein, 

 being on a plane posterior to both vessels. Within the sheath the 

 nerve occupies a special compartment, situated in the back part of 

 the septum which separates the artery from the vein. Beyond the 

 root of the neck the right and left nerves present important differ- 

 ences in their course and relations (see p. 964). 



Branches — A. Ganglion of the Root — i. Branches of Communi- 

 cation. — (a) It receives two filaments from the bulbar or accessory 

 portion of the spinal accessory nerve, (b) It communicates by a 

 small twig with the petrous ganglion of the glosso-pharyngeal nerve, 

 (c) It communicates with the facial, and with the posterior auricular 

 branch of the facial, through means of its auricular branch of dis- 

 tribution (Arnold's nerve), (d) It receives a twig from the superior 

 cervical ganglion of the sympathetic. 



2. Branches of Distribution. — (a) The meningeal branch takes a 

 recurrent course, and, after entering the cranial cavity, supplies the 

 dura mater which lines the cerebellar fossa of the occipital bone. 

 {b) The auricular branch, or nerve of Arnold, is of small size, and is 

 soon reinforced by a twig from the petrous ganglion of the glosso- 

 phar5mgeal. It enters the auricular canaliculus through an aperture 

 on the posterior part of the outer wall of the jugular fossa. In this 



