DIGESTION. 97 



TABLE SHOWING DIGESTIBILITY OF VARIOUS ARTICLES OF FOOD. Continued. 



Hours Minutes. 



Liver, beef, broiled 2 30 



Sausage broiled 3 2 o 



Green corn, boiled 3 45 



Beans, boiled 2 30 



Potatoes, roasted 2 30 



Potatoes, boiled 3 30 



Cabbage, boiled 4 30 



Turnips, boiled 3 30 



Beets, boiled 3 45 



Parsnips, boiled 2 30 



INTESTINAL DIGESTION. 



The process of digestion as it takes place in the small intestine is exceed- 

 ingly important and complex, and is brought about by the action of the pan- 

 creatic juice, the bile, and the intestinal juice. 



The contents of the stomach at the close of gastric digestion consist of 

 water, inorganic salts, peptones, undigested proteins and starches, maltose, 

 cane-sugar, liquefied fats, cellulose, and the indigestible portions of meats, 

 cereals, fruits, etc. This so-called chyme is quite acid in reaction, and upon 

 its passage through the now open pylorus into the intestine it excites a reflex 

 stimulation and secretion of the intestinal fluids, which are decidedly alkaline 

 in reaction, and which have a neutralizing action on the chyme. As soon as 

 the latter becomes alkaline and gastric digestion is arrested, the various 

 phases of intestinal digestion begin which eventuate in the transformation 

 of all the remaining undigested nutritive materials into absorbable and 

 assimilable compounds. 



The small intestine is about 22 feet in length and about ij inches in 

 diameter. Like the stomach, it possesses three coats, as follows: 



1. The serous, or peritoneal. 



2. The muscular, the fibers of which are arranged for the most part circularly 

 Some of the fibers are so arranged as to form longitudinal bands. 



3. The mucous, which presents a series of transverse folds, known as the 

 valvula conniventes. 



Intestinal Glands. In that portion of the small intestine known as the 

 duodenum are to be found a number of small, branched, tubular glands (Brun- 

 ner's), the acini of which are lined by short, cylindric cells, similar to those 

 lining the pyloric glands. From the duodenum to the termination of the 



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