946 THE ORGANS OF DIGESTION. 



superior mesenteric vessels, and at its lower end it is crossed by the transverse 

 colon and its mesocolon. Behind, the head of the pancreas is in relation with 

 the inferior vena cava, the left renal vein, the right crus of the Diaphragm, and 

 the aorta. The common bile-duct descends behind, between the duodenum and 

 pancreas ; and the pancreatico-duodenal artery descends in front between the 

 same parts. 



The neck of the pancreas is about an inch long, and passes upward and forward 

 to the left, having the first part of the duodenum above it, and the termination of 

 the fourth portion below. It lies in front of the commencement of the vena portae, 

 and is grooved on the right by the gastro-duodenal and superior pancreatico-duodenal 

 arteries. The pylorus lies just above it. 



The body and tail of the pancreas are somewhat prismatic in shape, and have 

 three surfaces : anterior, posterior, and inferior. 



The anterior surface is somewhat concave, and is covered by the posterior 

 surface of the stomach which rests upon it, the two organs being separated by the 

 lesser sac of the peritoneum. At its right extremity there is a well-marked promi- 

 nence, called by His the omcntal tuber osity. 



Gastric artery. ^FSJt^*J*^ Lower end of oesophagus. 



Superior mesenteric 



Inferior mesenteric artery. 



artery. 



Spermatic vessels. ' 



FIG. 520. The duodenum and pancreas. The liver has bee"n lifted up and the greater part of the stomach 

 removed. (Testut.) 

 capsule; /, Pyloric 

 phragm ; j, Left su 

 The four portions of the duodenum. 



The posterior surface is separated from the vertebral column by the aorta, the 

 splenic vein, the left kidney and its vessels, the left suprarenal capsule, the pillars 

 of the Diaphragm, and the origin of the superior mesenteric artery. 



The inferior surface is narrow, and lies upon the duodeno-jejunal flexure and 

 on some coils of the jejunum ; its left extremity rests on the splenic flexure of the 

 colon. 



The superior border of the body is blunt and flat to the right ; narrow and sharp 



