FH& LlVm. 149 



meters) long. The colon commences on the right side of 

 the abdominal cavity where the small intestine communi- 

 cates with the large, runs up for some way on that side 

 (ascending colon), then crosses the middle line (transverse 

 colon) below the stomach, and turns down (descending colon) 

 on the left side, and there makes an S-shapcd bend known 

 as the sigmoid flexure; from this the rectum proceeds to 

 the opening by which the intestine communicates with the 

 exterior. The mucous coat of the large intestine possesses 

 no villi nor valvulse conniventes; it contains numerous closely 

 set glands much like the crypts of Lieberkuhn of the small 

 intestine. 



The Ileo-Colic Valve. Where the small intestine joins 

 the large there is a valve formed by two flaps of the mucous 

 membrane sloping down into the colon, and so arranged as 

 to allow matters to pass readily from the ileum into the 

 large intestine, but not the other way. 



The Liver. Besides the secretions formed by the glands 

 imbedded in its walls, the small intestine receives those of 

 two large glands, the liver and pancreas, which lie in the 

 abdominal cavity. The ducts of both open, by a common 

 aperture, into the duodenum about 4 inches (10 centime- 

 ters) from the pylorus. 



The liver is the largest gland in the body, weighing 

 from 50 to 60 ounces (1400 to 1700 gr; JIB). It is 



Describe the colon. What is the sigmoid flexure? What is the 

 terminal portion of the alimentary canal named? How does the 

 mucous lining of the large intestine differ from, and how does it re- 

 semble that of the small ? 



Where is the ileo-colic valve? How is it formed? What is its 

 function? 



What large glands pour their secretion into the small intestine? 

 Where are they situated? Where do their ducts open? 



What is the largest gland in the body? What is its weight? 

 Where is it placed? 



