CHAPTER VII 

 GASTRIC DIGESTION 



GASTRIC digestion takes place in the stomach and is promoted by 

 the gastric juice, which is secreted by the glands of the stomach mucosa. 

 These glands are of two kinds, fundus glands and pyloric glands which 

 are situated, as their names imply, in the regions of the fundus and 

 pylorus. The principal foods acted upon in gastric digestion are the 

 proteins which are so changed by its processes as to become better pre- 

 pared for further digestion in the intestine and for their final absorption. 



From reliable experiments made upon lower animals and man it is 

 evident that the gastric juice is secreted as the result of stimuli of two 

 forms, i.e. , psychical stimuli and chemical stimuii . The psychical form of 

 stimuli may be produced by the sight, thought, or taste of food, and the 

 chemical stimuli may be produced by certain substances, such as water, 

 milk, the extractives of meat, etc., when coming in contact with the 

 stomach mucosa. The stimulatory power of water has been very 

 strikingly demonstrated. 1 y^he claim that the drinking of water with 

 meals is harmful because such a procedure causes a dilution of the gastric 

 juice, has no basis in fact. The drinking of water with meals by normal 

 individuals has been found to be accompanied by a more economical 

 utilization of the ingested proteins, fats and carbohydrates. Various 

 other desirable and no undesirable features have been demonstrated 

 as accompanying or following such a dietary procedure. 2 No experi- 

 mental evidence has been submitted which can justly be interpreted as 

 showing any harmful influence to accompany or follow the drinking, 

 by normal persons, of large quantities of water at meal time./ 



The volume of gastric juice secreted during any given period of 

 digestion varies with the quantity and kind of the food. These con- 

 clusions were deduced principally from a series of so-called delusive 

 feeding experiments. A dog was prepared with two esophageal open- 

 ings and a gastric fistula. When thus prepared and fed foods of various 



1 Foster and Lambert: Journ. Exper. Med., 10, 820, 1908. 

 Bergeim, Rehfuss and Hawk: Jour. Biol. Chem., 19, 345, 1914. 



Ivy: Proceedings Amer. Physiol. Soc. (Amer. Jour. Physiol) 45, 561, 1918. 

 King and Hanford: Ibid., 562. 

 Sutherland: Ibid., 563. 



2 Hawk: University of Pennsylvania Medical Bulletin, 18, i, 1905. 

 Fowler and Hawk: Jour. Exper. Med., 12, 388, 1910. 

 Hattrem and Hawk: Arch. Int. Med., 7, 610, 1911. 



Mattill and Hawk: Jour. Am. Chem. Soc., 33, pp. 1978, 1999, and 2019, 1911. 

 Hawk: Arch. Int. Med., 8, 382, 1911. 

 Hawk: Proceedings Soc. Exp. Biol. and Med., 8, 36, 1910. 

 Fairhall and Hawk: Jour. Am. Chem. Soc., 34, 546, 1912. 

 Howe and Hawk: Jour. Biol. Chem., n, 129, 1912. 

 Hawk: Biochem. Bull., 3, 420, 1914. 



