376 THE SYMPATHETIC NERVES. 



Cceliac plexus. This plexus is of large size, and is derived from the fore part 

 of the great epigastric plexus. It surrounds the coeliac axis in a kind of fenestrated 

 sheath, and subdivides, with the artery, into coronary, hepatic, and splenic plexuses, 

 the branches of which form communications corresponding with the arches of the 

 arterial anastomosis. The plexus receives on the left side a considerable offset from 

 the right pneumo-gastric nerve. 



The coronary plexus is placed with its artery along the small curvature of the 

 stomach, and unites with the nerves which accompany the pyloric artery, as well as 

 with branches of the pneumo-gastric nerves. The nerves of this plexus enter the 

 coats of the stomach, after running a short distance beneath the peritoneum. 



The hepatic plexus, the largest of the three divisions of the coeliac plexus, ascends 

 with the hepatic vessels and the bile duct, and, entering the substance of the liver, 

 ramifies on the branches of the portal vein and the hepatic artery. Offsets from the 

 left pneumo-gastric nerve join the hepatic plexus at the left side of the vessels. 

 From this plexus filaments pass to the right suprarenal plexus, as well as other 

 secondary plexuses which follow the branches of the hepatic artery. Thus there is 

 a cystic plexus to the gall-bladder; and there are pyloric, gastro-epiploic, and pan- 

 creatico-duodenal plexuses, which unite with coronary, splenic, and mesenteric 

 nerves. 



The splenic plexus (plexus linealis), continued on the splenic artery and its 

 branches into the substance of the spleen, is reinforced at its beginning by branches 

 from the left semilunar ganglion, and by filaments from the right vagus nerve. It 

 furnishes the left gastro-epiploic and pancreatic plexuses, which course along the 

 corresponding branches of the splenic artery, and, like the vessels, are distributed to 

 the stomach and pancreas. 



Superior mesenteric plexus. The plexus accompanying the superior 

 mesenteric artery, whiter in colour and firmer than any of the preceding offsets, is 

 mainly given off from the lower part of the solar plexus and the superior mesenteric 

 ganglion, but it also receives fibres from the right pneumo-gastric nerve at its 

 junction with the cceliac plexus. Surrounding the trunk of the superior mesenteric 

 artery, it divides into secondary plexuses which agree in name and distribution with 

 the branches of that vessel. In their progress to the intestine some of the nerves 

 quit the arteries which first supported them, and are directed forwards in the 

 intervals between the vessels. As they proceed they divide, and unite with lateral 

 branches, like the arteries, but without the same regularity ; they finally pass upon 

 the intestine along the line of attachment of the mesentery. 



Aortic plexus. The aortic or intermesenteric plexus (plexus aorticus 

 aldominalis}, placed along, the abdominal aorta, occupies the interval between the 

 origins of the superior and inferior mesenteric arteries. It consists, for the most 

 part, of two lateral cords, which are connected above with the semilunar ganglia and 

 renal plexuses, and extend downwards on the sides of the aorta, meeting in several 

 communicating branches over the front of that vessel. The cords receive branches 

 from some of the lumbar ganglia, and at the spots where these join there are often 

 small ganglionic enlargements, which are more distinct in the infant. Several 

 filaments pass to the root of the inferior mesenteric artery to form the plexus on 

 that vessel, and in connection with these is the inferior mesenteric ganglion, placed 

 below the origin of the artery. 



The aortic plexus furnishes the inferior mesenteric plexus and part of the 

 spermatic, gives some filaments to the lower vena cava, and ends below in the 

 hypogastric plexus. 



Inferior mesenteric plexus. This plexus is derived principally from the left 

 lateral part of the aortic plexus, and closely surrounds with a network the inferior 

 mesenteric artery. It distributes nerves to the left or descending and the sigrnoid 



