OLOSSO-PHARYNGEAL NERVE. 



437 



portions. One or generally more of these pha- 

 ryngeal brandies perforate the stylo-pharyngeus 

 muscle, and can be traced partly downwards up- 

 on the middle constrictor, partly upVards upon 

 the superior constrictor and mucous membrane 

 of the fauces, and also partly forwards upon the 

 surface of the tonsils. I have traced one of 

 the^e pharyngeal branches through the posterior 

 part of the hyo-glossus muscle into the mucous 

 membrane at the side of the posterior part of 

 the tongue. These pharyngeal branches, by 

 their anastomoses with the pharyngeal branches 

 of the par vagum and pharyngeal branches of 

 the sympathetic, form what is called the^a- 

 ryngeal plexus of nerves.* A distinct swelling 

 is frequently found over the internal carotid 

 artery, formed by the confluence of the princi- 

 pal pharyngeal branches of the glosso-pharyn- 

 geus, of the superior pharyngeal branch of the 

 par vagum, and the pharyngeal branches of the 

 superior ganglion of the sympathetic. This 

 swelling varies considerably in size and appear- 

 ance. Hubert describes a small ganglion in 

 the pharyngeal plexus. HaaseJ shortly de- 

 scribes this swelling as a gangliform enlarge- 

 ment. \Vrisberg states that a ganglion, of the 

 size of the ophthalmic, is placed at the conflu- 

 ence of these nerves. Scarpajj describes and 

 figures it as a gangliform plexus more particu- 

 larly, connected with the pharyngeal branch of 

 the par vagum. Wutzerlf states that he has 

 been unable to detect this pharyngeal ganglion. 

 Kilian** and Arnold,ft but more particularly 

 Kilian, figure it as a plexus. Though I would 

 not deny the occasional existence of a small 

 ganglion in this region, yet I believe it will be 

 found that this swelling is generally formed by 

 the cellular tissue binding together these 

 branches as they anastomose with and cross 

 each other.Jt 



Lingual branches. After the trunk of the 

 nerve has furnished the pharyngeal branches, it 

 sends off from its concave side some small 

 twigs upon the surface of the tonsils. It then 

 forms the lingual portion of the nerve, passes 

 into the base of the tongue below the stylo- 

 glossus and posterior margin of the hyo-glossus 

 muscle, where it divides into three or four 

 branches. The superior of these is principally 

 distributed upon the posterior part of the sides 

 of the tongue, and sends some twigs backwards 

 upon the palato-glossus muscle and mucous 

 membrane of the fauces, where they anastomose 

 with the other tonsillitic twigs. The middle 

 part of the termination of the nerve passes 



* A small twig from the hypo-glossal nerve can 

 sometimes be traced into this plexus. As the su- 

 perior pharyngeal branch of the par vagum is partly 

 formed by the spinal accessory, this last nerve must 

 assist in the formation of this plexus. 



t Op. cit. p. 18. 



$ De Nervo phrenico dextri lateris duplici, 

 &c. Ludwig, torn. iii. p. 115. 



$ Op. cit. p. 58. 



jj Tabulae Neurologies, plate 2. 



1 Op. cit. p. 91. 



** Op. cit. tab. ii. fig. 5. 



tt Op. cit. tab. iv. 



t$ The glosso-pharyngeal in the dog is generally 

 considerably increased in size where th'e principal 

 pharyngeal branches are given off. 

 VOL. II. 



through the lingualis and hyo-glossus muscles 

 to reach the mucous membrane and papillae at 

 the side of the base of the tongue. The re- 

 mainder of the nerve perforates the genio-hyo- 

 glossus to reach the mucous membrane and 

 papillae in the middle of the base of the tongue. 

 The distribution of these twigs is confined to 

 the mucous surface at the base of the tongue, 

 and do not extend beyond an inch in front of 

 the foramen coecum. They pass through the 

 muscles of the tongue without giving any fila- 

 ments to them.* 



Tonsillitic twigs. The different twigs of this 

 nerve which we have described as passing to 

 the tonsils, form an intricate plexus, posterior 

 to and around these bodies, which has been 

 called the circulus tonsillaris. These tonsillitic 

 twigs are ultimately intermixed with the as- 

 cending filaments of the pharyngeal branch of 

 the par vagum, and pass in considerable num- 

 bers to the isthmus of the fauces and soft 

 palate. They anastomose also with the pos- 

 terior palatine branches of the second branch 

 of the fifth pair, and, according to Wrisberg,f 

 with a filament from the third branch of the 

 fifth. 



In repeated dissections, both upon the hu- 

 man subject and the dog, I have found, in 

 tracing the branches of this nerve to their ulti- 

 mate distribution upon the pharynx and fauces, 

 that those branches of the glosso-pharyngeal 

 which do not anastomose with the pharyngeal 

 branch of the par vagum are principally distri- 

 buted upon the mucous membrane, and that 

 comparatively a small number of these fila- 

 ments seem to terminate in the muscular fibre. 

 The uncombined twigs of the pharyngeal 

 branches of the par vagum are, on the other 

 hand, distributed entirely to the muscular fibre. 

 In a dissection of this kind care must be taken 

 to select those twigs only which proceed to 

 their distribution without exchanging filaments 

 with any other nerve. It can be made more 

 favourably in the dog than in the human spe- 

 cies. The glosso-pharyngeus is still distri- 

 buted upon the tongue in birds, in the frog, 

 and certain of the amphibia, while this organ 

 receives no branch from the fifth pair, and from 

 this circumstance it has been considered the 

 nervus gustatorius of these animals.} In 

 fishes there is a branch of the par vagum 

 called glosso-pharyngeal, which escapes from 

 the base of the cranium by a separate opening, 

 and is distributed upon the gills, and also upon 

 the tongue as far as the skin of the mouth. 



Physiology. It is only to the labours of 

 anatomists and physiologists within the last 

 few years that we are to look for any thing 



* In tracing these nerves, it has appeared to me 

 that a few minute filaments terminate in the mus- 

 cles of the tongue, but these are exceedingly few 

 and small. The statement of Wrisberg, that the 

 deep branches of the lingual portion of the glosso- 

 pharyngeal are distributed to the muscles of the 

 tongue, is opposed to the observations of the best 

 anatomists, who have since his time examined the 

 ultimate distribution of this nerve. 



f Op. cit. p. 51. 



i Handbuch der Physiologic, etc. Erster Band, 

 p. 590, 772. 



2 L 



