158 



THE VITAL PROCESSES 



The Large Intestine. The large intestine is a tube from 

 five to six feet in length and averaging about one and one 

 half inches in diameter. It begins at the lower right side 

 of the abdominal cavity, forms a coil which almost com- 

 pletely surrounds the coil of small intestine, and finally 



terminates at the surface of 

 the body (Figs. 2, 71 and 73). 

 It has three divisions, known 

 as the caecum, the colon, and 

 the rectum. 



The ccecum is the pouch- 

 like dilatation of the large 

 intestine which receives the 

 lower end of the small in- 

 testine. It measures about 

 two and one half inches in 

 diameter and has extending 

 from one side a short, slender, 

 and blind tube, called the 

 vermiform appendix. This structure serves no purpose 

 in digestion, but appears to be the rudiment of an organ 

 which may have served a purpose at some remote period 

 in the history of the human race. The caecum gradually 

 blends into the second division of the large intestine, 

 called the colon. 



ikThe colon consists of four parts, described as the as- 

 cending colon, the transverse colon, the descending 

 colon, and the sigmoid flexure, or sigmoid colon. The 

 first three divisions are named from the direction of the 

 movement of materials through them and the last from 

 its shape, which is similar to that of the Greek letter 

 sigma (2). 



The rectum is the last division of the large intestine 



FIG. 73. Passage from small 

 into large intestine. At the ileo- 

 caecal valve is the narrowest constric- 

 tion of the food canal. 



