Gastric secretion begins during the cephalic stage and ends during the intestinal phase. The regulation of stomach secretion is divided into three phases which are cephalic, gastric and intestinal. The cephalic stage occurs when the food is been eaten. Gastric secretions are stimulated by three chemicals which are acetylcholine, histamine and gastrin. The gastric phase occurs in the stomach while the intestinal phase occurs in the small intestines.