BIOL 3070 Lecture Notes - Lecture 27: Ranitidine, Zymogen, Pernicious Anemia
Document Summary
Motility in stomach: gastric filling: helps with stretching the stomach when it"s full of digested, gastric storage: along length of digestive tract, have special pacemakers food matter (20-fold increase in volume of stomach) Receptive relaxation = reflex relaxation of the walls of the stomach so it can accommodate the food that"s ingested called ___ of cahal that generate slow-wave action potentials. Normally, these interstitial cells of cahal generate these potentials without generating ap (hormonal/neural/mechanical stimulation pushes it to threshold) When threshold is reached, peristaltic contractions occur to push chyme from body of stomach to antral cavity (gastric mixing) amounts of water/fluid, but difficult for chyme to pass through) Peristaltic contractions become more forceful due to thick antral cavity wall. Regulatted by factors in stomach + small intestine. Gastric secretion: 2 main regions of mucosa, oxyntic: pepsinogen is inactive enzyme precursor to pepsin (zymogen, pyloric gland area: lines antrum; many of these cells secrete gastrin hormone.
