PHI 8101 OOS OF Till DIG! BTH I '.l \ 



I fistula. This experimenl ia known as thai 



Within a £ev» minutes after <_ r i\in«_: food the gastric juia ind t.. 

 be secreted actively, and if the Eeedii • was kepi ap, which ••• >ul< 1 



be done almost indefinitely since 1 1 1 * - animal never became ed, the 



secretion continued to flow. Thus, in one instance l'a\ 1 in 



collecting about 700 c.c. of gastric juice after Bham feeding an animal 

 for five or six hours in the manner abovi 



After the stomach has emptied itself of thi en with tin- p 



vious meal, it is said by Pavlov to contain only a little alkali 

 The more recenl \\ ork of < larlson, how ever, shov» s that this i 

 the case, there being more or less of a continuous secretioi 



in the entire absence of E 1. The amount varies Erom 



60 c.c. per hour, more secretion being produced when it is collei 

 five or icn minutes than it' it is collected every thirty thus 



indicating that, ordinarily, some escapes through the pylorus ii I 

 duodenum. The secretion contains both pepsin and hydrochli 

 As to the cause of this continuous secretion, little is known [1 i 

 an example of the periodic activities of the digestive glai 

 Boldyreff, or it may in part be due to a psychic stimulation dep< 

 upon the thought of food. That the latter is probably not the cans.-. is 

 indicated by the fact that, at least in Carlson's patient, the psychic 

 could not be made to flow short of giving £ 1. 



The sham feeding causes stimulation of the gastric tion tl 



impulses transmitted to the stomach along the vagus nervt 



n found, in animals in which the vagus nerve has I.. •. that the 



sham feeding no longer induces a Becretion rtric juice l 



tion therefore arises as to how the nerve cent stimulated. I 



possible causes may be considered: 1 mechanical stimulation 

 sensory nerves of the mouth; 2 chemical stimulation of these nen 

 (3) the agreeable stimulation of the taste buds and 



concerned in the tasting of f 1. In investigating th< 



mechanical stimulation was readily ruled oul by Bhowing thai 

 taking of solid matter in the mouth did nol excite anj 

 it might cause a flov» of saliva. .Mere chemical stimulation could 

 the cause, for no secretion was induced by placing sub 



acetic acid or mustard oil in the mouth. B tlusion, then, it would 



appeal- that the adequate stimulus mui sist in th. 



tion of the taste buds, etc. thai is to Bay, in thi 



Further justification for this conclusion was readily 

 that foodstuffs for which the animal had no p 

 tite failed to excite the Becretion Mosl dogs, althot 



they ma\ lake it, are nol particularly fond I d. and w 



