Digestion 0.5% hydrochloric acid (HCl), which lowers the pH to the desired pH of 1-3. Acid release is also triggered by acetylcholine and histamine. The intestinal phase has two parts, the excitatory and the inhibitory. Partially digested food fills the duodenum. This triggers intestinal gastrin to be released. Enterogastric reflex inhibits vagal nuclei, activating sympathetic fibers causing the pyloric sphincter to tighten to prevent more food from entering, and inhibits local reflexes. Protein digestion occurs in the stomach and duodenum in which 3 main enzymes, pepsin secreted by the stomach and trypsin and chymotrypsin secreted by the pancreas, break down food
Stomach in the maintenance of oro-oesophageal and gastric tissue integrity. The biological effects of salivary EGF include healing of oral and gastroesophageal ulcers, inhibition of gastric acid secretion, stimulation of DNA synthesis, and mucosal protection from intraluminal injurious factors such as gastric acid, bile acids, pepsin, and trypsin and from physical, chemical, and bacterial agents. The human stomach can "taste" sodium glutamate using glutamate receptors and this information is passed to the lateral hypothalamus and limbic system in the brain as a palatability signal through the vagus nerve. The stomach can also sense, independently of tongue and oral taste receptors, glucose,