The Mechanical Factors of Digestion Book

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 edition. Excerpt: ...been in part suggested. As other observations to the same effect are to be described, however, a brief restatement of the experiments previously mentioned will not be out of place, and will serve to bring all the evidence together. 1. Acid in the duodenum inhibits gastric discharge. In 1893, Hirsch, as already noted, found that inorganic acids left the stomach slowly. When he isolated the stomach, however, the acids departed as rapidly as any other fluid. He explained this difference by assuming that the stomach is controlled by acid reflexes from the duodenum. Serdjukow modified Hirsch's experiment by introducing through a duodenal fistula small quantities of acid solutions or pure gastric juice. By repeated injections it was possible to prevent discharge from the stomach for an unlimited time. Tobler's observations were closer to the normal conditions. He allowed a dog with duodenal fistula to eat 100 grammes of lean beef. The chyme as it emerged was caused to leave the duodenum through the artificial opening. The stomach was thus emptied in about two hours and fifteen to thirty minutes. The next day the dog was given the same amount of the same kind of food, but whenever a portion of the chyme came through the fistula from the stomach, a similar portion of the chyme of the day before was injected through the fistula towards the intestines. The result was that the chyme left the stomach at considerably longer intervals, and was more thoroughly digested. The time of digestion thus became lengthened to three hours and three hours and a half. Tobler's observations have been completely confirmed by Lang.34 The experiments of Hirsch, Serdjukow, Tobler, and Lang prove definitely that acid chyme in the duodenum checks the outgo from the...