510 GENERAL ANATOMY. 



that this is impossible, especially in the nerves which form 

 the mesenteric or intestinal plexuses. 



807. The, sympathetic nerve,* intercostal or trisplanch- 

 nic, is a nervous and ganglionary cord, extended from the 

 head to the pelvis, connected, by anastomosing branches or 

 roots, with all the spinal nerves and the trigemini, and fur- 

 nishing numerous branches to the organs of the splanchnic 

 cavities of the trunk. 



The cephalic extremity of this nerve penetrates into the 

 cranium by the carotid canal and the cavernous sinus, where 

 it forms a plexus and often a ganglion upon the carotid artery; 

 it sends hence anastomosing filaments to the nerve of the sixth 

 pair, and communicates with 'the inferior filament of the vi- 

 dian; it sends secondary plexuses upon the branches of the in- 

 ternal carotid artery, and may be traced to a little solitary 

 ganglion placed upon the anterior communicating artery of 

 the brain. 



It consists then of three cervical ganglions, twelve thoracic, 

 five lumbar and four sacral, and of their cords of communica- 

 tion placed on each side of the anterior face of the vertebral 

 column. 



Throughout the whole length of the nerve, each ganglion 

 presents external anastomosing filaments or roots, and internal 

 filaments or branches. 



In this respect, the sympathetic nerve may be compared to 

 a subterraneous stem, or an articulated rhizoma, which, at 

 each joint,presents on one side roots, and on the other branches, 

 both of which depart at right angles, or at least at a very large 

 angle. 



The branches of the great sympathetic distribute themselves 

 to the organs situated in the face, neck, breast, the abdomen 

 properly so called, and in the pelvis. 



The pelvic extremity of the sympathetic nerve consists of a 



* Walter, tabulae, nervorum thorocis ct obdominis. Berol. 1783. H. A. 

 Wrisberg, de nervis arterios venasque comitantilus. De Nervis pharyngeis. 

 J)c Ganglio pkxuque similunari. Jh Nervis viscerum abdominalium, etc., 

 in Comment. Getting. Chaussier, Table synoptique du nerf trispktnchnique. 

 Lobstein, De ncrvi sympathetid humani fabrica, usu et morbis. Paris., 

 1823-4, cum tabulis. 



