Physiology, Stomach

Excerpt

The stomach is a hollow organ that is part of the gastrointestinal system, and it is responsible for functions including the formation of chyme, synthesis of proteins necessary for vitamin absorption, microbial defenses, and propagates the peristaltic reflex. Contrary to popular thought, the stomach does not contribute to the absorption of any nutrients. This organ can is in the peritoneal cavity, located in the left upper abdominal quadrant or in the epigastric abdominal region that acts to relay ingested food between the nervous system and the endocrine system. Gastric acid secretion, peristaltic propulsion, and other physiologic functions of the stomach are finely controlled by the integration of the enteric nervous system, parasympathetic nervous system, and the secretion of various neurohormonal molecules (i.e., gastrin, HCl acid, intrinsic factor, bicarbonate, mucus, etc.)

As a component of the alimentary canal (i.e., the tubal passageway for ingested food to be digested, absorbed, then excreted as waste), the stomach's physiological function is structured around creating an environment where the food ingested can be safely acted on by proteolytic enzymes and acidic solutions. There are pathologic consequences that can develop with the failure of the gastric mucosa to isolate the lumenal contents from the surrounding peritoneal cavity.