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STUDIES IN PHYSIOLOG1 



7. THE STOMACH 



Position, Size, Shape. The stomach lies about midway 

 between the upper and lower ends of the trunk, with its 

 larger end lying toward the left side of the body. It is a 



muscular pouch, shaped more 

 or less like a pear or a crook- 

 neck squash. When moder- 

 ately filled, it holds about 

 three pints. The esophagus 

 communicates with the upper 

 region of the larger end of 

 the stomach, and since this 

 opening into the stomach is 

 near the apex 'of the heart, 

 c it has received the name car'- 

 di-ac orifice (Greek Tcardia = 

 heart). The small intestine 

 is continuous with the right 

 end of this organ, the com- 

 munication between the two 

 the py-lo*rus (from Greek, 

 gate keeper) being 

 by a ring of muscle 

 'ic sphinc'ter 



FIG. 31. -Three Gastric Glands 

 (Cardiac Portion of Stomach). 



= connective tissue between called the 



(from Greek, meaning to bind 

 tight) (see Pig. 30). 



The Mucous Lining and Gastric 

 Glands. When the stomach is 

 full of food, the lining pre- 

 sents a smooth surface. This 



becomes folded into ridges as the food is forced outward 

 into the intestines. The important glands of the stomach 

 are those which secrete the gas'tric juice. This digestive fluid 

 is composed of water (over 99%), free hy-dro-chlo'ric acid, 



glands. 



e = cells lining the stomach, 

 ra = mouth of gland. 

 ov = ovoid cells (possibly secrete 



hydrochloric acid). 

 p = cylindrical cells (probably se- 

 crete pepsin) . 



