DISSECTION OF THE ABDOMEN. 327 



corresponding to the coeliac axis, the companion veins of the divisions of 

 that artery behaving as follovi's : — 



The Splenic Vein is the upward continuation of the left gastro-omental 

 vein. After receiving the posterior gastric vein, it becomes one of the 

 roots of the vena portse, previously forming a short trunk by union with 

 the posterior mesenteric vein. 



The Anterior Gastric Fern joins the vena portas in the posterior fissure 

 of the liver. 



The Right Gastro-omental Vein is continuous with the left vein of the 

 same name, in the texture of the great omentum, opposite the middle of 

 great curvature of the stomach. It receives gastric, omental, duodenal, 

 pyloric, and pancreatic branches, all of which run in company with the 

 arteries of the same names ; and then, above the pancreas, it joins the 

 portal vein. 



The CPlsoPHAGEAL Neevbs. These nerves are the backward continua- 

 tions of the vagus, pneumogastric, or 10th cranial nerves. They reach 

 the abdominal cavity by passing through the foramen sinistrum of the 

 diaphragm, in company with the oesophagus and the pleuro-oesophageal 

 branch of the gastric artery. The inferior nerve forms at the lesser 

 curvature of the stomach a plexus whose filaments pass mainly to the 

 right sac ; while the superior, after giving branches to the left sac, joins 

 the solar plexus. 



The Splanchnic Nervks. On each side there are two splanchnic 

 nerves — a great and a small. Both are formed by efferent branches of 

 the dorsal portion of the sympathetic gangliated cord, and they reach 

 the abdomen by passing between the diaphragm and the psoas parvus 

 muscle. The great splanchnic nerves terminate in the semilunar 

 ganglia ; the small nerves pass directly to the solar plexus, or they may 

 be continued to the renal or the suprarenal plexus. 



The Semilunar Ganglia are the largest in the body. They are 

 placed one at each side of the lower face of the aorta, between the 

 coeliac and anterior mesenteric arleries. Each receives the great 

 splanchnic nerve of its own side, and the two ganglia communicate by 

 transverse branches across the lower face of the aorta. The efferent 

 branches which proceed from them form the solar plexus. 



The Solar Plexus is an intricate network of nerves and ganglia. It 

 is joined on each side by the lesser splanchnic nerve, and by the 

 terminal filaments of the superior oesophageal nerve. From the plexus 

 nerves pass to the abdominal viscera, and in doing so they run in 

 company with arteries. There is thus: a coeliac plexus, whose branches 

 reach the liver, pancreas, spleen, and stomach, by accompanying 

 the divisions of the hepatic, splenic, and gastric arteries; a renal 

 and a suprarenal plexus, which pass to the kidneys aod suprarenal 

 bodies; an aortic plexus, continued backwards on the aorta to join 



