THE INTESTINES. 



291 



inner walls are millions of tiny glands which are known as gastric 

 glands. These little glands become excited, and pour out a 

 sticky juice, which is known as gastric juice. It oozes out, just 

 like perspiration upon the skin. The muscular walls of the 

 stomach are meanwhile twisting, writhing, and turning, with 

 the object of swishing and swirling the food round its inner walls, 

 so that the gastric juice may be washed off. This gastric juice 

 mingles with the food, 

 and begins to break it 

 up. The churning 

 process goes on for 

 four to five hours, 

 until the whole of the 

 food has been broken 

 up into a creamy- 

 looking, liquid mass. 

 It then passes out into 

 the first part of the 

 intestine, called the 

 duodenum. Its pre- 

 sence excites certain 

 nerve ends, which 

 cause the bile from the 

 gall bladder to run 

 out into the food. 

 The secretion known 

 as the pancreatic j nice, 

 manufactured by the 

 pancreas or melt, is 

 also poured into the 

 food for the purpose 

 of completing its 

 digestion. 



Fig. 121. — The organs of the human body, iw situ, the 

 abuse of which induces disease, suffering and pre- 

 mature death. (From Blackie's Physiology.) 



The Intestines. 



By a sort of squeezing process performed by the muscular walls 



of the intestines or bowels, and which is known as the peristaltic 



movement, the food is worked slowly down. As it proceeds, more 



juices are poured out to complete the digestion of any parts of 



