534 MECHANISM OF SECRETION OF GASTRIC JUICE. 



This he cut across, and tested the reaction of the fluid in its cavity. He 

 found it as strongly acid as the secretion inside the stomach cavity. 

 This experiment may be taken to show that the acid is secreted in the 

 glands, but is continually being carried away by the stream of secretion. 

 It might be objected against this experiment, that the fluid in the cavity 

 of the compound gland is in communication with the stomach cavity 

 and is acid by reason of admixture, but the communicating duct is too 

 small to make this probable ; moreover, there must be a continual 

 stream flowing during secretion in the opposite direction from gland 

 cavity to stomach cavity. That the gland cavity is not passively filled 

 with secretion from the general stomach cavity, is also shown by the 

 fact that some of these glands are swollen out with secretion while 

 others are empty. It may be taken, thfen, that the gastric juice is acid 

 as secreted by the gland-cells, and does not first become acid in the 

 stomach. 



Such observations as have been made in order to ascertain whether 

 the border cells yield an acid reaction have not been successful. 

 Though the mass of evidence is very greatly in favour of the view that 

 the border cells are the origin of the acid of the juice, there are not 

 wanting those who deny it entirely. Contejean 1 observed, as had 

 previously been shown by Langley, 2 that the stomach cells of the frog, 

 although they secrete acid, also secrete pepsin. But a more remarkable 

 statement is that the pylorus cells secrete an acid juice. This is so 

 much at variance with the results of the majority of investigations, that 

 it cannot be accepted as correct. If it were true, a conclusive proof 

 would be furnished against the view that the border cells originate the 

 acid. 



As regards the functions of the different regions of the stomach, it 

 may be stated that the fundus and the greater curvature form in most 

 animals pepsin, hydrochloric acid, and other constituents of the gastric 

 juice. But considerable discussion has taken place as to the functional 

 importance of the pyloric region. That an extract can be made from 

 the pyloric region containing pepsin is generally agreed, but such an 

 extract, in comparison with one prepared from the rest of the stomach, 

 has very small digestive value. Langley, 2 in one experiment on the 

 mucous membrane of the mole, found that if the digestive power of 

 the pyloric region be taken as 1, that of the fundus would be 73. 

 What then is the source of the pepsin that can be obtained from 

 the pyloric mucous membrane ? Is it pepsin formed by the gland 

 cells in the pyloric region, or is it absorbed pepsin that has 

 passed with the absorbed food into the mucous membrane of this 

 region ? 



Wassmann 3 and v. Wittich 4 have held that the pepsin was merely 

 infiltrated pepsin, and Wassmann stated that it was removable by 

 repeated washing with water. On the other hand, Ebstein and 

 Griitzner 5 found that washing the mucous membrane of the pylorus 

 causes but a very slow loss of pepsin. If, then, the cells of the mucous 



1 "Contribution a 1'etude de la physiologic de 1'estomac," CentralbL f. PhysioL, 

 Leipzig u. Wien, 1892. 



2 Proc. Roy. Soc. London, 1881, No. 212. 



3 " De digestione nonnulla," Berolini, 1839. 



4 "Ueber die Pepsinwirknng der Pylorusdriiscn," Arch. f. d. gcs. Physiol., Bonn, 1873, 

 Bd. vii. 



5 "Ueber den Ort der Pepsinbildung in Magen," ibid., 1872, Bd. vi. 



