144 THE HUMAN BODY. 



pyloric end of the stomach is separated from the diaphragm 

 by the liver (see Fig. 4). When moderately distended the 

 stomach is about twelve inches long, and about four inches 

 across at its widest part, and would contain about three 

 pints. 



The Glands of the Stomach. The mucous membrane 

 lining the stomach is seen, when its surface is examined 

 with a common magnifying glass, to be covered with shallow 

 pits. A more powerful microscope shows on the bottom 

 of each one of these pits the openings of several minute 

 tubes, the gastric glands, which lie imbedded in the mu- 

 cous membrane, packed closely, sidrf'-by side (Fig. 48). 

 These glands secrete the gastric juice. 



The Muscular Coat of the Stomach lies outside the mu- 

 cous membrane, and is made up (Fig. 34) of plain muscular 

 tissue, whose fibres run in different directions. By its 

 contractions it stirs up the food and mixes it with the gastric 

 juice. Around the pyloric orifice of the stomach is a thick 

 ring of muscle (the pyloric sphincter)) which usually is 

 contracted, closing the passage between the stomach and 

 the commencement of the small intestine. During diges- 

 tion in the stomach the pyloric sphincter relaxes from time 

 to time, and allows food, more or less digested, to pass on 

 into the intestine. 



Palpitation of the Heart. The cardiac end of the stom- 

 ach lies close beneath the diaphragm, and the heart imme- 



What lies between the right end of the stomach and the dia- 

 phragm? What is the size of the stomach? 



What may be seen on examining the mucous membrane of the 

 stomach with a hand lens? What does a more powerful magnify- 

 ing instrument show? What is the function of the gastric glands? 



Describe the muscular coat of the stomach. What is its function? 

 What is the pyloric sphincter? Its function? What happens 

 when the pyloric sphincter relaxes during gastric digestion? 



