SYMPATHETIC NERVE. 



429 



substance of the diaphragm, where they com- 

 municate with branches of the phrenic nerve. 



(b) The superior coronary plexus accom- 

 panies the left coronary artery of the stomach, 

 along its upper border, and is distributed to 

 the anterior and posterior walls of the organ, 

 its filaments uniting with the branches sup- 

 plied by the pneumogastric nerves, chiefly 

 with those which are distributed to the 

 posterior wall of the stomach. It extends to 

 the pyloric orifice, where it joins branches of 

 the hepatic plexus. 



(c) The hepatic j/'exus, of considerable 

 size, ascends along with the hepatic artery ; it 

 receives some filaments from the pneumo- 

 gastric nerve, and also communicates, as has 

 been already mentioned, with the superior 

 coronary plexus of the stomach. Branches 

 leave it for the duodenum and head of the 

 pancreas ; and others pass with the right gastro- 

 epiploic artery, along the greater curvature of 

 the stomach, forming the inferior coronary 

 plexus of the stomach. On entering the trans- 

 verse fissure of the liver, the hepatic pli MS 

 divides into a right and a left portion, wnich 

 accompany the divisions of the hepatic artery 

 and vena portae, ramifying upon them an oif- 

 set from the hepatic plexus passes to tb~J. 

 gall-bladder, along with the cystic artery. 



(d) The splenic plexus surrounds the 

 artery of the same name, passing with it and 

 its branches to the spleen. Offsets pass from 

 the splenic plexus to the pancreas, and to the 

 stomach, which form the pancreatic and left 

 gastro-epiploic plexuses. 



2. The superior mesenteric Plexus appears as 

 a prolongation downwards of the cceliac 

 plexus, and is the largest of the offsets fur- 

 nished by it : it also receives some filaments 

 from the right pneumogastric nerve. It sur- 

 rounds the superior mesenteric artery, form- 

 ing for it a clo-ie plexifonn sheath, and sends 

 offsets along its branches, which accompany 

 them as they pass between the layers of the 

 mesentery to the duodenum, small intestine, 

 ccecum, and ascending and transverse colon. 

 The highest of these unite with the nerves 

 which pass along the pancreatico-duodenal ar- 

 tery, while those which are distributed to the 

 transverse colon communicate with the nerves 

 derived from the inferior mesenteric plexus. 

 The nerves which accompany the arteries to 

 the intestines present at first a plexiform 

 arrangement but in their course through the 

 mesentery, several of them are seen to run 

 alongside the vessels, sometimes separated a 

 short distance from them. Communicating 

 branches pass between them in the same way 

 as between the arteries. On reaching the 

 intestine they enter it at the part where the 

 mesentery is attached, and dividing into finer 

 twigs, soon disappear in the substance of its 

 coats. Many appear to become lost in the 

 muscular coats, while some may be traced 

 through these, ending apparently in the mu- 

 cous coat, or in the sub-mucous cellular 

 tissue. 



3. Renal Plexuses. The right and left renal 



plexuses are formed by branches which pro- 

 ceed from the coeliac and superior mesenteric 

 plexuses, and likewise derive filaments from 

 the aortic plexus. In their course along the 

 renal arteries they receive filaments, which 

 are sent oft'from the smaller splanchnic nerves, 

 and others from the superior lumbar ganglia. 

 Several small ganglia are present in the nerves 

 of the renal plexus. They divide along with 

 the branches of the renal artery, each arterial 

 branch being generally accompanied by two 

 nervous twigs. From the renal plexus fila- 

 ments are sent off, which, with others derived 

 from the cceliac and phrenic plexuses, form the 

 supra-renal plexus destined for the supply of 

 the supra-renal capsule. 



4. Spermatic Plexuses. The right and left 

 spermatic plexuses consist of some delicate 

 nervous filaments, which are derived from the 

 renal plexus. As they pass downwards with 

 the spermatic arteries, they receive some ad- 

 ditional filaments from the aortic plexus, and 

 appear to give off several filaments to the 

 ureters ; in their course to the testes they are 

 connected with the nerves which accompany 

 the vas deferens. In the female they are dis- 

 tributed to the ovaries and uterus. 



5. The aortic plexus, situated along the abdo- 

 minal aorta, and extending from the superior 

 to the inferior mesenteric arteries, consists of 

 filaments derived from the superior mesenteric 

 and renal plexuses. In its course downwards 

 it also receives branches from the lumbar gan- 

 glia : it terminates in the inferior mesenteric 

 and superior hypogastric plexuses, and also, 

 as has been already stated, contributes to the 

 formation of the spermatic plexus. 



6. Inferior Mesenteric Plexus. The inferior 

 mesenteric plexus, formed by the left lateral 

 portion of the aortic plexus, is less dense and 

 less distinct than the superior plexus of the 

 same name: its fibres present, however, the 

 same whitish aspect and firm consistence, and 

 sometimes have small ganglionic enlargements 

 developed upon them. It accompanies the 

 inferior mesenteric artery, dividing along with 

 it, and forming secondary plexuses around its 

 branches, which pass with them to the de- 

 scending colon, higmoid flexure, and upper 

 half of the rectum. Above, the branches of 

 the inferior mesenteric plexus form communi- 

 cations with those derived from the superior 

 mesenteric, and below, with others derived 

 from the superior hypogastric plexus of the 

 left side. 



7. Hypogastric Plexus. The hypogastric, a 

 single plexus, situated in front of the fifth 

 lumbar vertebra and promontory of the sacrum, 

 between the two common iliac arteries, pre- 

 sents an irregularly quadrilateral and flattened 

 aspect. Nervous branches, about twelve in 

 number, pass down to it on each side from 

 the aortic plexus, and additional filaments are 

 derived from the lumbar ganglia. From the 

 plexus small offsets proceed along the common 

 iliac arteries, and a few join the hemorrhoidal 

 filaments derived from the superior mesenteric 

 plexus : it then divides into a right and left 



