[Chyme homeostasis in the gastroduodenal portion of the digestive tract under different nutritional diets]

The concentration of chyme ingredients and volumetric velocity of the chyme transfer from the duodenum to the jejunum were investigated in experiments on normal preoperated dogs with fistulas implanted into the stomach, duodenum and jejunum after feeding different diets throughout the entire process of active digestion. It has been established that as a result of exchange between the medium filling the gastroduodenal part of the alimentary tract and blood, an enteral medium is formed in the duodenum, with the composition of this medium being relatively constant as regards the concentration and constituent ingredients. It has been also shown that the direction of the balanced flows of the nutrients depends on their concentration in the diet and that both immediate exchange of substances between the enteral and internal media, which is effected according to the concentration gradient, and regulatory alterations in the secretion are involved in homeostasis of the enteral medium.