DIGESTIVE ORGANS. 219 



LESSON VIIL 



THE ORGANS OF DIGESTION. 



As there is a constant waste going on in our 

 bodies, it is needful that it should be regularly sup- 

 plied with nourishment. For this purpose, we take 

 food, and have a stomach and various other parts, 

 fitted for changing it into a proper form for repair- 

 ing our system. 



The changes which our food undergoes to pre- 

 pare it, constitute what is called digestion; and the 

 actual laying down of new matter by the different 

 vessels is called the process of nutrition. 



The stomach is a hollow bag, placed just below 

 the breast bone, and lying partly across the body. 

 It is large enough in a grown man to hold about 

 three pints of fluid, and is joined to the mouth by 

 a tube, or passage, called the gullet. The open- 

 ing into this is seen lying quite at the back of the 

 throat, and it receives the food after it has been 

 crushed by the teeth, or masticated, and mixed 

 with saliva. In this pulpy state it is passed into 

 the stomach by the gullet pressing it downwards. 



After the food has remained in the stomach for 

 a time, it begins to contract and pushes it through 

 an opening into the intestines. 



The intestines form one continued canal, or 

 tube, about five or six yards long, lying in a won- 

 derfully small space, and most curiously folded one 

 upon another. 



