BIO 211 Lecture Notes - Lecture 28: Pylorus, Stomach, Gastric Glands
1 Dec 2020
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Gastric phase contents and (c) presence of undigested materials in stomach. Cephalic phase stomach being controlled by brain. Intestinal phase stomach being controlled by small insetsine. Stimuli that initiate this phase: (a) distension of stomach, (b) increase of ph of gastric. Period in which swallowed food and semi-digested protein activates gastric activity. Ingested food stimulates gastric activity in two ways: Gastric secretion is stimulated by three chemicals: By increasing the ph of its contents. Acetylcholine (ach) secreted by parasympathetic nerve fibers of both reflexes. Bistamine a paracrine secretion from enteroendocrine cells in the gastric glands. Gastrin a hormone produced by the enteroendocrine g cells in pyloric glands. Two-thirds of gastric secretion occurs in this phase. Intestinal phase absorptive functions of small intestine can proceed with reasonable efficiency. Controlling the rate of gastric emptying to ensure that the secretory, digestive and. Stage in which the duodenum responds to arriving chyme and moderates gastric activity.
