THE INTESTINAL CANAL. 1017 



Below : 



Neck of pancreas ; 

 Head of pancreas. 



Descending, or Second Portion. 



Anterior!// : 



Right lobe of liver (impressio duodenalis) ; 



Right end of transverse colon ; 



Two layers of transverse mesocolon ; 



Small intestine ; 



Right leaf of mesentery. 



Posteriorly : 



Right kidney and suprarenal capsule (at times) ; 



Structures at hilus ; 



Common bile and pancreatic ducts ; 



Vena cava inferior ; 



Spermatic vessels. 



Internally : 



Head of pancreas ; 



Pancreatico-duodenal vessels ; 



Common bile and pancreatic ducts ; 



First, second, third, fourth, or fifth lumbar vertebras. 



Pre-aortic, or Third Portion. 



Superiorly : 



Head of pancreas ; 

 Superior mesenteric vessels. 



Anterior!// : 



Root of mesentery ; 

 Right and left layers of mesentery ; 

 Superior mesenteric vessels ; 

 Small intestine. 



Posteriori'/ : 



Vena cava inferior ; 



Aorta ; 



Crura of diaphragm ; 



Third or fourth lumbar vertebra. 



Ascending, or Fourth Portion. 

 Anteriorly : 



Antrum pylori (at times) : 



Transverse colon ; 



Transverse mesocolon (lower layer); 



Small intestine ; 



Left layer of mesentery. 



Posteriorly : 



Left Psoas muscle ; 

 Left renal vessels ; 

 Spermatic vessels ; 

 Lower part of inner edge of left kidney. 



