DIGESTION AND ABSORPTION IN THE STOMACH. 775 



make separate fistulous openings to the exterior. Under these con- 

 ditions, when the animal ate and swallowed food it was discharged 

 to the exterior instead of entering the stomach. The animal thus 

 had the enjoyment of eating without actually filling the stomach. 

 Eating in this style forms what the author called a fictitious 

 or sham meal (Scheinf utter ung) . It was found that it causes 

 an abundant flow of gastric juice as long as the vagi are intact, 

 but has no effect on the secretion when these nerves are cut. 

 Evidently, therefore, the sensations of taste, odor, etc., developed 

 during the mastication and swallowing of food, set up reflexly 

 a stimulation of secretory fibers in the vagus. Pawlow desig- 

 nates a secretion produced in this way as a psychical secretion, 

 a term which implies that the reflex must be attended by 

 conscious sensations. In favorable cases the fictitious feeding has 

 been continued for five or six hours and a large amount of gastric 

 juice (700 c.c.) has been collected from a fistula, although no food 

 actually entered the stomach. It is important to note, also, that a 

 psychical secretion, once started, may continue for a long time after 

 the stimulus (the eating) has ceased. Experiments have been made 

 upon human beings under similar conditions. Thus, Hornborg* 

 reports the case of a boy with a stricture of the esophagus and a 

 fistula in the stomach. Food when chewed and swallowed did not 

 reach the stomach, but was regurgitated; it caused, nevertheless, 

 an active psychical secretion in the empty stomach. 



Normal Mechanism of the Secretion of the Gastric Juice. 

 During a meal the gastric juice is secreted, under normal conditions, 

 as long as the food remains in the stomach. The modern explana- 

 tion of the origin, maintenance, and regulation of this flow of secre- 

 tion is due chiefly to Pawlow. Contrary to a former general belief, 

 he showed that mechanical stimulation of the gastric mucous mem- 

 brane has no effect on the secretion of the tubules. This factor may 

 therefore be eliminated. In an ordinary meal the secretion first 

 started is due to the sensations of eating that is, it is a psychical 

 secretion. The afferent stimuli originate in the mouth and nostrils; 

 the efferent path, the secretory fibers, is through the vagus nerve. 

 This reflex insures the beginning at least of gastric digestion, but its 

 effect is supplemented by a further action arising in the stomach 

 itself. It seems that some foods contain substances designated as 

 secretogogues, that are able to cause a secretion of gastric juice 

 when taken into the stomach. Thus, meat extracts, meat juices, 

 soups, etc., are particularly effective in this respect; milk and water 

 cause less secretion. In other foods these ready-formed secreto- 

 gogues are lacking. Certain common articles of food, such as 



* Hornborg, "Skandinavisches Archiv f. Physiologic," 15, 209, 1904; see 

 also Bickel, "Verhandl. Kongr. f. innere Medizin," 23, 491. 



