CHAPTER IX 



THE INTERNAL SECRETION OF THE GASTRIC 



MUCOUS MEMBRANE AND THE NORMAL MECHANISM OF 



THE SECRETION OF THE GASTRIC JUICE 



IT has been shown by Pavlov that psychical secretion, as well 

 as the results of a sham meal, are entirely abolished by division 

 of both vagi, and, further, that stimulation of the peripheral end 

 of the cut vagus (after its cardio-inhibitory fibres have been 

 allowed to degenerate) calls forth a steady secretion of gastric 

 juice. These experiments show conclusively that an important 

 probably the most important part of the gastric secretion 

 is determined by a nervous mechanism. 



On the other hand, Ducceschi finds that dogs and cats whose 

 stomachs have been severed from any nervous connections 

 either with the central nervous system or with the semilunar 

 ganglion, show no particular disturbances. 



However important the nervous influences may be, it is 

 possible that the nervous secretion does not account for the 

 whole of the gastric juice obtained as the result of a meal. 



The question as to the existence of some specific hormone in 

 relation to gastric secretion analogous to secretin was put to 

 the test by Edkins. This observer found that extracts made 

 of the pyloric mucous membrane in boiling water or HC1 04 

 per cent, contain an active substance, which, on injection into 

 the bloodvessels of an animal, leads to a secretion of gastric 

 juice. Extracts made in cold water, peptone, glucose, or 

 glycerin also contain variable amounts of this substance. 



Extracts of the fundus mucous membrane, however made, 

 do not contain this substance. The inactive condition of some 

 extracts is due to the substance being present in an undeveloped 

 state ; boiling the substance or treating with acid will lead to 

 the complete development. This is, however, only the case 

 with extracts made from the pyloric or true cardiac mucous 



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