PAR VAGUM. 



885 



appearance of this swelling depends upon fat 

 globules placed in the intervals of the plexus. 

 At the lower part of this gangliform enlarge- 

 ment the nerve becomes smaller, rounder, 

 firmer, and of a whiter colour.* This inferior 

 or second ganglion of the vagus has been long 

 known. Fallopiusf speaks of an oblong olivary 

 swelling on the vagus soon after its exit from 

 the cranium. Willis J has described it in the 

 following words : "nervi truncus, ibidem major 

 factus, in tumorem quemdam corpori calloso, 

 seu ganglio similem, attolli atque excrescere 

 videtur," and in fig. ix. he has delineated it 

 under the name of " plexus gangliformis paris 

 vagi." Vieussens also describes and figures 

 it, and terms it " plexus gangliformis cervica- 

 lis nervi octavi paris." Wmslow|| describes it 

 as " une espece de ganglion." It has also 

 been described by Prochaska,^[ Wutzer, Scarpa, 

 Bellingeri, &c. Some have considered it to be a 

 true ganglion, others only a plexus. Some re- 

 strict the term of inferior ganglion to that por- 

 tion of the enlargement of the nerve immediately 

 below the origin of the superior laryngeal nerve, 

 and have described it as being placed upon the 

 internal fibres only, so that, according to this 

 view, some of the external fibres of the vagus 

 and the strengthening fibres of the spinal ac- 

 cessory do not pass through it. 



The vagus in its passage down the neck gives 

 off pharyngeal, laryngeal, atsophageal, cardiac, 

 and vascular branches. 



Superior pharyngeal branch (ramus pharyn- 

 geus scu primus n. v.) This is by much the 

 largest and most important pharyngeal branch 

 of the vagus, and is frequently designated, par 

 excellence, the pharyngeal branch of the vagus. 

 It arises from the anterior surface of the vagus 

 shortly after its exit from the foramen lacerum, 

 and opposite the upper part of the atlas, and 

 is evidently formed by fibres, partly from the 

 internal branch of the accessory, and partly 

 from the vagus. Generally the greater part of its 

 filaments, occasionally nearly the whole, appear 

 to come from the accessory. It passes inwards 

 and a little downwards across the anterior sur- 

 face of the internal carotid artery, to which it 

 is generally pretty closely connected by cellular 

 tissue, and lies a little inferior to the glosso- 

 pharyngea Inerve.** Immediately after crossing 

 the internal carotid, it passes over the ascend- 

 ing pharyngeal artery, and after a short course 



* Oper. cit. S. 484. 



t Opera otnnia, p. 407. Francof. 1600. 



I Cerebri Anatome, p. 226. 1666. 



Neurographia Universalis, p. 118, and pi. xxiii. 

 Edit. Novissima. Lugduni, 1716. 



H Exposition Anatomique de la Structure du 

 Corps Humain, torn. iii. p. 237. Paris, 1732. 



^[ De Scructura Nervorum, 1779. 



** Cruveilhier (Anatomie Descriptive, torn. iv. 

 p. 958, 1836,) describes the pharyngeal branch as 

 passing behind (derriere) and not in front of the 

 internal carotid. Cloquet (Traite d'Anatomie De- 

 scriptive, 2de partie, p. 620,) also described it as 

 passing behind the internal carotid. No doubt this 

 nerve may occasionally pass behind the artery, and 

 similar varieties are to be found in the course of 

 all nerves ; but it is equally certain that its usual 

 course is in front of the artery, and this inaccuracy 

 must have occurred through some inadvertency. 



it reaches the surface of the middle constrictor 

 muscle of the pharynx. As it is crossing the 

 carotid it is generally joined by one, two, or 

 three small branches descending from the glosso- 

 pharyngeal, and at the point of their junction 

 a small plexus or ganglion is formed on the 

 pharyngeal. (Vide article GLOSSO-PHARYN- 

 GEAL NERVE.) At this point the pharyngeal 

 generally divides into several branches.* Two 

 of these are considerably larger than the others, 

 and one of them passes inwards and upwards, 

 and the other inwards and downwards over the 

 lateral surface of the pharynx ; while the smaller 

 branches, two or more in number, pass upon 

 the surface of the internal carotid and neigh- 

 bouring bloodvessels, especially the arteria 

 pharyngea ascendens, to assist in forming the 

 nervous plexuses surrounding them. The two 

 larger branches which pass upon the surface of 

 the pharynx are soon joined by branches from 

 the superior ganglion of the sympathetic. The 

 upper branch passes over the superior pharvn- 

 geal constrictor to its upper edge, sending 

 filaments to that muscle, to the elevator palati, 

 the palato-pharyngeus, the azygos uvulae, and 

 also to the stylo-pharyngeus, and anasto- 

 moses freely with the pharyngeal and tonsillitic 

 branches of the glosso-pharyngeal nerve and 

 twigs of the sympathetic coming from its 

 superior cervical ganglion. The lower runs 

 downwards over the surface of the middle and 

 inferior constrictors, distributes twigs to these 

 muscles, and anastomoses with the inferior 

 pharyngeal branch of the vagus, the pharyngeal 

 branches of the superior laryngeal, and with 

 some filaments of the sympathetic. 



Inferior p/iaryngeal brunch (ramus pharyn- 

 geus inferior). This branch arises a very little 

 below the last, and runs parallel to it and across 

 the anterior surface of the internal carotid. It 

 is joined by a considerable branch from the 

 superior ganglion of the sympathetic, which 

 generally forms an arch with it around the 

 ascending pharyngeal artery. It soon divides 

 itself into different branches, which are distri- 

 buted upon the lower part of the middle con- 

 strictor muscle, and over the whole of the 

 inferior constrictor, and anastomoses with the 

 twigs of the other nerves found on the surface 

 of these muscles. 



Valentin describes under the name of middle 

 pharyngeal nerves (rami phan/ngei medii seu 

 tenuiores n. v.) some small filaments arising 

 from the anterior surface of the vagus imme- 

 diately below the superior pharyngeal, and 

 which pass forwards to join the pharyngeal 

 branches of the glosso-pharyngeal. The free 

 anastomosis of the nerves we have mentioned, 

 viz. the glosso-pharyngeal and sympathetic, with 

 the numerous subdivisions of the pharyngeal 

 branches of the vagus, intermixed with a few 

 twigs from the superior laryngeal, and also 

 with some small filaments from the upper part 

 of the cervical plexus of nerves, and an occa- 

 sional twig from the hypo-glossal, form an 

 elongated and intricate plexus (plexus pharyn- 



* Wrisberg (De Nervis Pharyngis, Lud wig's 

 Script. Min. Nerv. Sel. torn. iii. p. 58) describes five 

 branches radiating from the ganglion pharyngeum. 



