CHAPTER VIII 

 GASTRIC DIGESTION 



Physiological anatomy of the stomach Peritoneal coat Muscular coat Mucous coat 

 Glands of the stomach Closed follicles Gastric juice Secretion of gastric juice 

 Quantity of gastric juice Properties and composition of gastric juice Saline constituents 

 of the gastric juice Pawlow's experiments on the gastric juice Action of the gas- 

 tric juice on meats Action on albumin, fibrin, casein and gelatin Action on vegetable 

 nitrogenous substances Peptones Action on fats, sugars and amylaceous substances 

 Duration of stomach digestion Conditions that influence stomach digestion Move- 

 ments of the stomach. 



PHYSIOLOGICAL ANATOMY OF THE STOMACH 



THE stomach serves the double purpose of a receptacle for food and 

 an organ in which certain important digestive processes take place. It 

 is situated in the upper part of the abdominal cavity and is held in place 

 by folds of the peritoneum and by the oesophagus. Its form is not 

 easily described. It has been compared to a bagpipe, which it resembles 

 somewhat, when moderately distended. When empty, it is flattened, 

 and in many parts its opposite walls are in contact. When moderately 

 distended, its length is thirteen to fifteen inches (33 to 38 centimeters), 

 its greatest diameter, about five inches (12.7 centimeters), and its capac- 

 ity, one hundred and seventy-five cubic inches (2868 cubic centimeters), 

 or about five pints. The parts usually noted in anatomical descriptions 

 are the following : a greater and a lesser curvature ; a greater and a 

 lesser pouch ; a cardiac, or cesophageal opening ; a pyloric opening, 

 which leads to the intestinal canal. The great pouch is sometimes 

 called the fundus. 



The coats of the stomach are three in number ; the peritoneal, 

 muscular and mucous. By some anatomists the fibrous tissue which 

 unites the mucous to the muscular coat is regarded as a distinct cover- 

 ing and is called the fibrous coat. 



Peritoneal Coat. This coat is a layer of peritoneum, similar in 

 structure to the membrane covering the other abdominal viscera. It is 

 a reflection of the membrane that lines the general abdominal cavity, 

 which, on the viscera, is somewhat thinner than it is on the walls of the 

 cavity. Over the stomach the peritoneum is -^ to gro of an i cn 

 (83 to 125 /*) in thickness. It is a serous membrane and consists of 



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