An American text-book of physiology . be takenin a single meal to last for a day, the flow of secretion is intimately connectedwith the reception of food into the stomach and its subsequent digestivechanges. The time relations of the secretion to the ingestion of food areshown in the accompanying chart (Fig. 78). The secretion begins immedi-ately after the food enters the stomach, and increases in velocity up to a cer-tain maximum which is reached some time between the first and the third hourafter the meal. The velocity then diminishes rapidly to the fifth or sixthhour, after which there may
An American text-book of physiology . be takenin a single meal to last for a day, the flow of secretion is intimately connectedwith the reception of food into the stomach and its subsequent digestivechanges. The time relations of the secretion to the ingestion of food areshown in the accompanying chart (Fig. 78). The secretion begins immedi-ately after the food enters the stomach, and increases in velocity up to a cer-tain maximum which is reached some time between the first and the third hourafter the meal. The velocity then diminishes rapidly to the fifth or sixthhour, after which there may be a second smaller increase reaching its maxi-mum about the ninth to the eleventh hour. From this point the secretion SECRETION. 177 diminishes in quantity to the sixtoentli or seventeenth hour, when it haspractically reaclucl the zero point. In man, in whom the meals normallyoccur at intervals of five to six hours, this curve of course would have a dif-ferent form. The interestincr fact, however, that the secretion starts very soon. o—, -^ 3 -^—s—b—y s 9 io~^ /2 15 /v 15 Jb 17 a Fig 78 -Curve of the secretion of pancreatic juice during digestion. The figures along the abscissarepresent hours after the beginning of digestion; the figures along the ordinate represent the quantityof this secretion in cubic centimeters. Curves of two experiments are given (after Heidenhain). after the beginning of gastric digestion is probably true for human beings, andgives strong indication that the secretion is a reflex act. Recently a number of experiments have been reported which strengthenthe view that the normal secretion of the pancreas is reflexly excited bystimuli acting upon the mucous membrane of the stomach or ^ finds that in rabbits the pancreatic secretion is very greatly accel-erated by stimulants such as oil of mustard, pepper, acids, or alkalies intro-duced into the stomach or duodenum, and Dolinsky,^ working upon dogsunder more c
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