DISSECTION OF THE ABDOMEN. 317 



organ, beyond which it is continued as the left gastro-omental artery, 

 From its convex side it gives off many large splenic branches ; and from its 

 concave side it emits gastric branches, which pass in the gastro-splenic 

 omentum to reach the great curvature of the stomach, where they 

 bifurcate to be distributed to both surfaces of the left sac. 



The Left Gastro-omental Artery is the continuation of the splenic 

 artery beyond the tip of the spleen. It passes in the texture of the 

 great omentum to meet, and inosculate with, the right gastro-omental 

 artery, advancing in the opposite direction. Besides omental branches, it 

 emits gastric branches, which bifurcate at the great curvature of the 

 stomach to be distributed to both its surfaces. 



The Portal Vein (Plates 43 and 44) is the trunk which collects the 

 blood from the stomach, intestines, spleen, and pancreas, and conveys 

 it to the liver, where, as will afterwards be described in connection with 

 the liver structure, the vessel comports itself after the manner of an 

 artery. The vessel is formed behind the pancreas, by the junction of 

 the anterior mesenteric vein with a short trunk resulting from the union 

 of the posterior mesenteric and sj^lenic veins. It gains the upper face of 

 the pancreas by passing through its substance, the perforation being 

 termed the pancreatic ring; and descending in the gastro-hepatic 

 omentum to the posterior fissure of the liver, it penetrates the substance 

 of the gland in company with the bile duct and hepatic artery. 



Anterior and Posterior Mesenteric Veins, satellites of the arteries of the 

 same names, have already been described ; but there is no venous trunk 

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

 that artery behaving as follows : — 



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

 vein. After receiving the j)osterior 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 Vein joins the vena portae in the posterior fissure 

 of the liver. 



The Eight 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 gasti'ic, 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 Qi^soPHAGEAL Nerves. These nerves are the backward continu- 

 ations 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 cESophagus and the pleuro-oesophageal 

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

 cui-vature of the stomach a plexus whose filaments pass mainly to the 



