THE DUODENUM 



1285 



denalis for the second part of the duodenum; behind, with the inner part of the right 

 kidney, to which it is connected by loose areolar tissue, the renal vessels, and the 

 inferior vena cava; at its inner side is the head of the pancreas and the common 

 bile duct; to its- outer side is the hepatic flexure of the colon. The common bile 

 duct passes downward behind the first portion of the duodenum, descends to the 



Lesser amentum 



Hepatic Artery 

 Portal Vein 



G rente 



r 



Greater 



omentum -Transverse Mesocolon 



FIG. 1008. Diagram of cross-section of the first 

 part of the duodenum, to show its peritoneal 

 relations. 



FIG. 1009. Diagram of cross-section of the second 

 part of the duodenum, to show its peritoneal rela- 

 tions. (Gerrish.) 



inner side of the second portion, is joined by the pancreatic duct, and the two 

 together perforate the inner side of this portion of the intestine obliquely, and empty 

 into the duodenum by a common opening or by two openings at the summit of 

 a papilla, some three and a half or four inches (9 to 10 cm.) below the pylorus. 



SECOND 



LUMBAR 



VERTEBRA 



FIG. 1010. Diagram of the third part of the 

 duodenum, to show its peritoneal relations. 

 (Gerrish.) 



FIG. 1011. Diagram of the fourth part of the duodenum, 

 to show its peritoneal relations. (Gerrish.) 



The relations of the second part of the duodenum to the right kidney present con- 

 siderable variations. 



The third, preaortic, or transverse portion (pars horizontal-is inferior) (Figs. 

 1007 and 1010) is from two to three inches in length. It commences at the 

 right side of the upper border of the fourth lumbar vertebra and passes from right 



