THE LARGE INTESTINE 135 



called the vermiform appendix. It has no useful function. If 

 food collects in the appendix, it is not easily drained out. This 

 food may decay, which causes an inflammation commonly known 

 as appendicitis. 



The large intestine is divided into the ascending colon, trans- 

 verse colon, descending colon, and sigmoid flexure (see page 119). 

 The colons and the sigmoid flexure inclose the folds of the small 

 intestine. The sigmoid flexure ends in the rectum. The rectum 

 is six to eight inches long and leads into the anal canal, having 

 an external aperture, the anus. This opening has an internal 

 sphincter muscle of the involuntary type, and an external sphinc- 

 ter that is voluntary. These sphincters control the passage of solid 

 waste from the body. 



The process of digestion is continued to a slight degree in the 

 large intestine, due to the presence of the digestive fluids with 

 which the food became mixed in the small intestine. The indi- 

 gestible waste materials associated with all foods, are removed 

 from the body through the large intestine by means of peristaltic 

 movements. The chief waste product is the cellulose of vegetable 

 food and the fiber of meat. 



Bacteria are abundant in the large intestine. They cause the 

 putrefaction of unabsorbed proteins. Some of these products of 

 putrefaction are absorbed from the intestine by the blood, while 

 the others are eliminated from the body. If an excessive amount 

 of toxic products from this putrefaction is absorbed into the blood, 

 a headache or feeling of lassitude will usually result. Normally, 

 the rectum is empty until just before defecation or the elimination 

 of solid waste. 



ABSORPTION 



After foods have been refined, split, and standardized in the 

 digestive process into the simplest forms ; namely, amino-acids 

 from proteins, glucose and galactos from carbohydrates, and fatty 



