DIGESTION 



i ii in iv v 



in iv v vi vii vm i ii in iv v vi 



vous mechanism, which, although it does not take part in the 

 excitation of the pancreatic secretion by acid, may yet exist 

 for the performance of other offices. It is more probable, how- 

 ever, that it is due to the passage of some of the gastric contents 

 through the pylorus ; for when oil is introduced into the small in- 

 testine, it causes the production of secretin, although, unlike dilute 

 acid, it is quite ineffective in forming secretin when rubbed up 

 with the scraped- 

 off mucous mem- 52 

 brane. 



The pancrea- & 

 tic, like the gas- 

 tric, juice is said 

 to vary as regards 

 its digestive pro- 

 perties with the 

 nature of the 36 

 food. On a diet 

 of bread the juice ^ 

 is very poor in 3 28 

 fat-splitting fer- ' ( 

 ment, while on a '1 24 

 diet of flesh it is 

 richer, and on a 20 

 diet of milk rich- 

 est of all. With 

 bread the juice is L 

 relatively rich in 

 amylolytic fer- ! g 

 ment. When we 

 take the quan- i 

 tity of the juice 

 as well as its ' l 

 strength in fer- 

 ments into con- 

 sideration, it is 

 stated that bread 

 occasions the se- 

 cretion of a juice with a greater quantity of proteolytic ferment 

 than either milk or meat, although it is relatively dilute (Fig. 150). 

 The vegetable proteins require more ferment to digest them 

 than proteins of animal origin. There is no more evidence that 

 the adaptation of the pancreatic juice to the nature of the food 

 is due to a specific sensibility of the duodenal mucosa to the 

 various food-stuffs than there is in the case of the adaptation of 

 the gastric juice. If the volume of the chyme and its acidity 



Flesh, 100 grm. Bread, 250 grm. Milk, 600 grm. 



FIG. 150. SECRETION OF PANCREATIC JUICE WITH 

 DIFFERENT DIETS (PAWLOW). 



The hours are in roman numerals. 



