GLOSSO-PHARYNGEAL NERVE. 



495 



nal jugular vein, which lie in the order here 

 enumerated. As the nerve issues from the 

 lower part of the foramen lacerum it forms a 

 small rounded chord, close to, but still quite 

 separate from the par vagum, and is situated 

 between the internal jugular vein and internal 

 carotid artery. It now leaves the trunk of the 

 par vagum, proceeds downwards, inwards, and 

 forwards, passing in front of the internal carotid 

 artery and behind the styloid muscles, and 

 joins itself to the stylo-pharyngeus muscle. It 

 runs at first along the lower margin of this 

 muscle, and rests on the superior constrictor 

 of the pharynx which separates it from the 

 tonsil ; it then mounts on the anterior surface 

 of the stylo-pharyngeus muscle, and passes be- 

 tween it and the stylo-glossus to reach the base 

 of the tongue, upon which it is ultimately dis- 

 tributed. Occasionally, instead of turning over 

 the lower edge of the stylo-pharyngeus, it per- 

 forates this muscle. In following the course 

 here described, it forms a slight curve, the con- 

 vexity of which looks downwards, and it sends 

 off several branches, which are principally dis- 

 tributed to the pharynx and isthmus of the 

 fauces. These branches vary very considerably 

 in size and in number in different subjects, but 

 the general distribution of the nerve is in all 

 cases nearly the same. When the branches 

 are few in number, this is compensated for by 

 their increased bulk, and when they are more 

 numerous they are of diminished size. This 

 nerve generally anastomoses with the par vagum 

 within the cranium by a pretty distinct branch.* 

 As the nerve lies within the foramen lacerum it 

 presents two swellings or ganglia upon it, and 

 gives off some small branches. The superior of 

 these two ganglia is considerably smaller than the 

 inferior, and has been termed the ganglion ju- 

 gularebyJ. Miiller, (Jig. 225). It is described 

 by Mullerf as generally present, though small, 

 placed upon the posterior or external side of 

 the nerve, and situated at the cranial end of 

 the foramen lacerum. It can only be distinctly 

 seen after the dura mater has been removed, 

 and the upper margin of the opening chiseled 

 away. I have repeatedly observed this gan- 

 glion jugulare in the human subject. In one 

 case which I lately dissected, where it was 

 comparatively large, very distinct, and pre- 

 sented undoubtedly all the appearance of a 

 true ganglion, it appeared to me, after careful 

 examination, that this swelling does not include 

 the whole of the nerve, but is confined, as 

 Miiller states, to the posterior filaments. These 

 posterior filaments do not seem to differ other- 

 wise in appearance from the anterior. This 

 ganglion was first pointed out by Ehrenritter, 

 and mentioned by Soemmerring on his autho- 

 rity.]: Very little attention seems to have been 

 paid to this ganglion, so that when it was lately 

 re-described by Miiller, it was supposed that 



Op. cit. p. 114. 



t Handbuch der Physiologic des Menschen. 

 Erster Band, p. 589. 



i Arnold in Tiedemann's Zeitschrift fur Physio- 

 logic, vol. ii. p. 175, and J. Muller, in his Archiv. 

 fur Anat. und Phys. &c. 1837. No. ii. p. 275. 



$ In Vergl. Jahresbericht Von 1833, Archiv. fur 

 Anatomic und Physiol. 1834, p. 11. 



its existence in the human subject had been 

 hitherto unknown.* Mayer, of Bonn, had, 

 previous to this (1833), described two small 

 swellings upon the root of the glosso-pharyn- 

 geal in the ox, but he failed to detect any 

 similar ganglion in the human species. No 

 nervous filaments either leave or join that part 

 of the trunk of the nerve upon which the gan- 

 glion jugulare is placed. The inferior ganglion 

 (ganglion petrosum, ganglion of Andersch) is 

 considerably larger than the superior, is of an 

 oblong shape, and includes all the filaments of 

 the nerve. It is described by Anderschf as 

 about five lines in length, and commencing 

 about four lines below the place where the 

 nerve perforates the dura mater. No doubt, if 

 we include all that portion of the trunk of the 

 nerve which appears to be somewhat increased 

 in size, it may sometimes measure five lines, 

 but the true gangliform enlargement is consi- 

 derably less. As WutzerJ remarks, it is rarely 

 found to exceed two lines in length. This gan- 



Fig. 225. 



Natural size. Magnified about four times. 



glion lies in a distinct depression in the pe- 

 trous portion of the temporal bone, which 

 Andersch terms receptaculum ganglioli petrosi. 

 Some branches both proceed from and join 

 that portion of the nerve occupied by this gan- 

 glion petrosum. The most important of these 

 is a small branch which proceeds from the 

 ganglion into the tympanum (ramus tympani- 

 cus nervi glosso-pharyngei ; nerve of Jacobson). 

 The course and distribution of this branch were 

 partly known to Schmiedal, Andersch, Ehren- 

 ritter, and Comparetti,|| but were more fully 



* I find that Wutzer, in his Monograph " De 

 Corporis Humani Gangliorum Fabrica atque Usu," 

 p. 92, after describing the inferior ganglion of the 

 glosso-pharyngeal, says, " secundarium ganglion 

 quod nonnumquam adesse Ehrenritter contendit 

 mihi non sub oculos cecidit." 



t If Andersch is not to be considered the disco- 

 verer of this ganglion, it cannot be denied that he 

 first gave a full and clear description of it. (Op. 

 cit. p. 115.) Kilian (Op. cit. p. 30 and 75) con- 

 tends that the existence of this ganglion was known 

 to Winslow. In evidence of this he quotes the 

 following sentence from his Exposit. Anatom. torn, 

 iii. " les deux portions (nervus glosso-pharyngeus 

 et nervus vagus) sont edroitement collees ensemble 

 et communiquent de pan et d'autre par des filamens 

 qui grossissent un peu la petite portion (glosso- 

 pharyngeal.)'" 



[This figure is taken from a dissection by Mr. 



t Op. cit. p. 91. 



[This figure is 



Walker in the Webb-street School of Anatomy. 

 The Editor is indebted for it to the kindness of his 

 friend Mr. Grainger.] 



|| Vide Muller's Archiv. fur Anat. und Physiol. 

 &c. No. ii. 1837. p. 281. 



