384 CLINICAL APPLIED ANATOMY. 



left lumbar region that the submesocolic region bears to the 

 right. 



5. The Lesser Sac of the Peritoneum. This is a diverticulum 

 of the greater sac arising in the region of the right kidney. 



6. The Kegion of the Pelvis. 



The mesocolon and mesentery constitute peritoneal partitions 

 of which the mesocolon is more complete and important. The 

 transverse mesocolon is attached to the posterior abdominal wall 

 at the level of the second lumbar vertebra. Traced from right 

 to left across the abdomen it first ascends as it crosses the lower 

 part of the right kidney, the second part of the duodenum, and 

 the head of the pancreas, after which it runs to the left with less 

 upward inclination, along the anterior border of the body of the 

 pancreas. The projection of the lumbar spine and a small 

 upward prolongation of the superior layer of the mesocolon in 

 this region sharply separate the right and left halves of the fold. 

 Consequently extravasations of fluid above the right half are 

 directed downwards towards the depression around the upper 

 part of the right kidney. 



The root of the mesentery springs from the posterior abdominal 

 wall along an oblique line which extends from the left side of the 

 second lumbar vertebra to the right iliac fossa. Starting at 

 the duodeno-jejunal flexure, the line of attachment crosses the 

 front of the terminal part of the duodenum, the aorta, the inferior 

 vena cava, the right ureter, and the right psoas muscle to reach 

 a variable point in the right iliac fossa. The direction may be 

 indicated on the surface by drawing a diagonal line from a point 

 on the transpyloric line, an inch to the left of its middle point, 

 to the right iliac region. The mesentery is not so efficient in 

 separating the submesocolic from the submesenteric regions as 

 the transverse mesocolon is in cutting off the subdiaphragmatic 

 space from the regions below. 



Subdiaphragmatic Region. The viscera in relation with this 

 part of the greater sac are the stomach, spleen, liver, gall 

 bladder, bile ducts, part of the duodenum, and upper part of the 

 right kidney. An abscess in this region may be due to disease 



