DIGESTION OF FOOD : THE INTESTINE 



several days before. Food, after leaving the stomach, must 

 still pass through a long series of changes before it is of any 

 practical value. 



The intestine may be considered in two sections: the small 

 intestine and the large. The former is about twenty feet in 

 length, and the latter about five; the total length below the 

 stomach affords, therefore, a large amount of surface for 

 absorption; Fig. 52. 



THE SMALL INTESTINE AND ORGANS CONNECTED WITH IT 



The small intestine commences at the pyloric valve of the 

 stomach and extends, coiling much on the way, to a point in 

 the right, lower part of the abdominal cavity, where it enters 

 the large intestine. Its average diameter is about one inch. 

 It occupies practi- 

 cally all the space Arter>r i 



, r c **-Vein1otiver J. I 



m the lower half of 

 the abdominal cav- 

 ity, save that taken 

 by the large intes- 

 tine, the kidneys, 

 bladder and spleen. 

 Throughout its 

 length it is loosely 

 attached to the dor- 

 sal wall of the cav- 

 ity by a thin sheet 

 of tissue, the mesen- 

 tery. This mesentery 

 is traversed by a 

 multitude of arteries 

 and veins on their 

 way to and from the digestive tract; for it is solely through 

 these vessels that food is taken, up Jrorrytfoo^food partal 

 carried over the body; Fig, 



FIG. 53. DIAGRAM 



Showing a piece of the intestine held in the mes>tn- 

 tery and the blood and lymph vessels in it. 

 The mesentery is represented as narrower than it act- 

 ually is and hence the lymph glands as closer to the 

 intestine. 



