DISSECTING MANUAL. 



of the pancreas, and then bends forward to become the jeju- 

 num. It has three parts. The first portion runs from the py- 

 lorus to the right and backward, ending at the neck of the gall 

 bladder where it turns downward; it is an inch and a half to 

 two inches long. Peritoneum covers its first inch entirely, but 

 only the front beyond this point. Above and in front of it is 

 the quadrate lobe; below are the neck and head of the pan- 

 creas; and behind are the portal vein, bile duct, and (to the 

 right) vena cava. [1065] 



The second (descending) portion is three and a half or four 

 inches long and descends to the right side of the third or fourth 

 lumbar vertebra; peritoneum covers it in front, except under 

 the colon. In front of it are the gall bladder above, small in- 

 testine below, and the transverse colon crossing it mesially; 

 behind it is the right kidney ; externally is the liver and inter- 

 nally the vena cava and pancreas, with the common bile duct 

 intervening. [1068] 



The third portion runs transversely (transverse part) for an 

 inch or two across the vena cava, then ascends (ascending 

 terminal part) in front of the aorta and Psoas to the lower edge 

 of the pancreas, and then bends (duodeno-jejunal flexure) 

 sharply forward to become the jejunum. Peritoneum covers 

 it anteriorly, except under the mesentery and superior mesen- 

 teric vessels and also on the left side of the ascending terminal 

 part. The mesentery and superior mesenteric vessels cross it 

 anteriorly; behind it are the vena cava, aorta, left renal ves- 

 sels, and left Psoas; above it is the pancreas. The duodeno- 

 jejunal flexure is fixed by a band of unstriped muscle (suspen- 

 sory muscle of duodenum, or muscle of Treitz) running from i j ; 

 to the connective tissue around the coeliac axis. [1068] 



Duodenal Fossce. On drawing the ascending terminal part 

 to the right, two peritoneal folds are generally seen at its left, 

 extending from it to the parietal peritoneum. The upper 

 (superior duodenal fold) has its lower edge free and under it is 

 the superior duodenal fossa, which opens downward; the lower 



[218] 



