890 



PAR VAGUM. 



which Valentin* has termed plexus gastricus 

 anterior et superior. 



Rig/it vagus. .-As the right vagus is entering 

 the abdomen it sends numerous branches upon 

 the posterior part of the termination of the 

 oesophagus and of the cardiac extremity of the 

 stomach. Part of these disappear in the mus- 

 cular fibres of the cesophagus and stomach ; 

 others anastomose with the branches of the left 

 vagus, while others proceed downwards and to 

 the left side upon the posterior surface of the 

 large cul-de-sac of the stomach, sending fila- 

 ments into the muscular coat, and also anas- 

 tomosing with the filaments of the splenic 

 plexus accompanying the vasa brevia. The 

 right vagus also sends some branches upon the 

 posterior surface of the stomach, to be distri- 

 buted in that part of the organ, a few of which 

 proceed as far as the large curvature, and 

 coui'se along it from left to right. It also 

 sends two or three branches along the smaller 

 curvature, which anastomose with the coronary 

 plexus and branches of the left vagus. A 

 considerable portion of the right vagus, so 

 large as generally to present the appearance 

 of being the continuation of the trunk of the 

 nerve, proceeds from the posterior surface of 

 the cardiac region of the stomach, backwards 

 and downwards to the left side of the cceliac 

 axis, sending branches to the splenic, the coro- 

 nary, and to the superior mesenteric plexuses, to 

 the plexus surrounding the pancreatic branches 

 of the splenic artery ; and it ultimately termi- 

 nates in the left semilunar ganglion. The 

 branches of the right vagus running upon the 

 posterior surface of the lower part of the 

 cesophagus and cardiac orifice of the stomach 

 have been termed the posterior cardiac plexus.f 

 Dr. Kemak has discovered numerous small 

 ganglia upon the filaments of the cardiac 

 nerves, as they are ramified upon the surface 

 of the heartjj also upon some of the filaments 

 of the pulmonary plexus, and upon some of 

 the finer branches of the superior laryngeal 

 nerve. These ganglia can scarcely be seen by 

 the naked eye, and it is only when examined 

 by the microscope that we can satisfactorily 

 determine their nature. These ganglia appear 

 to be placed upon the filaments of the sympa- 

 thetic, conjoined with the branches of the vagi, 

 and not upon those of the vagi. 



According to Volkmann and Bidder the 

 vagus nerve contains, in all vertebrated animals, 

 a greater number of sympathetic than cerebro- 

 spinal filaments; and this preponderance of the 

 sympathetic over the cerebro-spinal is more 

 marked in the lower than in the higher verte- 

 brata. This remark is in conformity with the 

 observations of E. II. Weber upon the relative 

 size of the vagus and sympathetic in the diffe- 

 rent families of the vertebrata, from which it 

 appears that in the lower vertebrata the vagus 



* Opus cit. S. 503. 



t Many anatomists describe the branches given 

 off hy both vagi near the cardiac orifice of the 

 stomach as forming a single cardiac plexus, the 

 larger portion of which is formed by the right vagus. 



J Casper's Wochenschrift fiir die gesammte Heil- 

 kunde den 9ten JNlarz, 1839. 



Mcdicinisthc Zeitung. Berlin, 8 Jan. 1840. 



increases, the sympathetic diminishes, in size. 

 The branches of the vagus distributed in the 

 cesophagus, heart, lungs, stomach, liver, and 

 gills, are chiefly composed of sympathetic 

 filaments, while the recurrent one of the motor 

 branches is chiefly composed of cerebro-spinal 

 filaments.* 



Connection of the vagus and spinal accessory. 

 We have seen that, as the vagus and accessory 

 emerge from the foramen lacerum posterius, 

 the internal branch of the accessory joins 

 itself to the vagus, and that while part of its 

 filaments go to assist in forming the superior 

 pharyngeal branch of the vagus, the rest pro- 

 ceed downwards with the trunk of the vagus, 

 and become incorporated with it. Bischoff 

 statesf that he has not been able to trace the 

 filaments of the accessory into any of the 

 branches of the vagus except the pharyngeal, 

 while BendzJ has been more successful. He 

 states that the portion of the accessory which 

 accompanies the vagus down the neck sends a 

 few filaments to the upper part of the inferior 

 ganglion of the vagus, and then joins itself to 

 some of the posterior and external fibres of the 

 vagus which do not pass through the ganglion. 

 Below the ganglion these fibres form part of 

 the trunk of the nerve, being enclosed in the 

 same neurilema with those which pass through 

 the ganglion. At the lower edge of the gan- 

 glion, or sometimes a little lower, the accessory 

 portion sends off some filaments which often 

 join the external branch of the superior laryn- 

 geal, but more frequently give twigs to the 

 sterno-thyroid muscle. Other fibres of the 

 accessory portion accompany the vagus into the 

 thorax, and some of them assist in forming the 

 recurrent nerve. Some small twigs from the 

 accessory join the pulmonary and cardiac plex- 

 uses ; the remainder accompany the vagus to 

 the stomach, where they are lost. Mr. Spence 

 states that those fibres of the vagus which do 

 not pass through the superior ganglion are 

 joined bv the internal branch of the accessory; 

 and that these together form a small fiat band, 

 which may be traced among the other fibres of 

 the vagus to the lower part of the neck, where 

 it is joined by some of the other fibres of the 

 vagus which have passed through the ganglion, 

 and seems to go principally to the formation of 

 the recurrent nerve. 



We have seen that the vagi are distributed 

 over a large space and upon many organs. 

 They send branches to the external ear, to the 

 pharynx, the larynx, the cesophagus, the trachea, 

 the thyroid body, the heart, the lungs, the 

 stomach; also to the liver, the spleen, the 

 pancreas, the small intestines, and probably to 

 other viscera of the abdomen. In their course 

 they communicate very freely and extensively 

 with the sympathetic, and to a greater or less 



* Die Selbststandigkert dcs Sympathischen Ker- 

 vensystems, by Bidder and Volkmann. Also the 

 article Nervenphysiologie in Wagner's Handwor- 

 terbuch der Physiologic, p. 584. 



t Oper. cit. p. 25. 



J Oper. cit. p. 20,21,23. 



In many of the mammalia the cervical portion 

 of the sympathetic joins the trunk of the vagus 

 immediately below the infcriorganglioa of the vagus. 



