THE INTESTINAL CANAL. 



1015 



of the kidney and on the renal vessels at the hilus. Sometimes it only abuts 

 against the inner margin, not covering its surface at all. This is thought to be 

 due to a changed position of kidney and not of duodenum. The adhesion by con- 

 nective tissue between the duodenum and kidney is especially close where the 

 hepatic flexure crosses the kidney and then crosses the duodenum as transverse 

 colon (Fig. 636). 



In case the duodenum descends very low to the fifth lumbar vertebra, it then 

 borders the lower extremity of the kidney. The relations of the ascending por- 



yon-peritoneal part 

 Peritoneal part 



Left suprarenal 

 capsule 



Right suprarenal 

 capsule 



Duodenum 



Duodenum 



Mesocolic area 



Descending 

 'colon 



Mesocolic area 

 FIG. 636. Diagram to show relations of duodenum to both kidneys. 



tion with the left kidney are much more variable. A light traction from left 

 to right displaces them. There are no adhesions, and the ascending duodenum 

 glides ^asily over the subjacent tissue. 



The annular or the U-shaped duodenum usually overlies the inner margin of 

 the lower third or half of the left kidney ; with the V-shaped duodenum, only the 

 ascending portion or the duodeno-jejunal angle may touch the lower part of its 

 inner margin. Ureters and spermatic vessels are covered on the two sides by the 

 duodenal arch. 



Between the duodenum and pancreas there exists not only a relation of con- 

 tiguity but one of continuity of tissue, which is explained by the duodenal origin 

 of the pancreas. The head of the pancreas fills the space limited by the duode- 

 nal arch and then escapes as the neck by the opening of the intestinal ring. It is 

 to be noted that the head is always proportional in extent to the duodenum, and 

 assumes the form allowed by that intestine. In the adult the head of the pancreas 

 embraces the duodenum much as the parotid gland embraces the ramus of the 

 lower jaw. It advances in front and behind, covering about one-half of the cir- 

 cumference of the intestinal wall, generally more anteriorly than posteriorly. 



The second portion is much more enveloped than any other. Union between 

 the intestine and pancreas is established by cellulo-fibrous tissue, by pancreatico- 

 duodenal vessels, by excretory ducts, and perhaps by longitudinal muscular fibres 

 from the intestines which run between the lobules of the gland. Yerneuil and 

 Treitz believe the duodenum holds the pancreas in place and not vice versd. 



By lifting all the viscera from the abdominal cavity, the vertebral column 

 with its prevertebral vessels are disclosed behind the duodenum. There is the 

 aorta, often a little to the left of the median line, which nearly always divides 



