Stomach

The **stomach** is a muscular, hollow organ located between the esophagus and duodenum in the upper abdomen. It is a key component of the gastrointestinal tract responsible for mixing ingested food with gastric secretions to form chyme, initiating protein digestion through pepsin and hydrochloric acid, and regulating controlled release of partially digested contents into the small intestine. The stomach wall consists of four main layers from inside outwards—mucosa, submucosa, muscularis externa (with unique oblique muscle layer), and serosa. The mucosal layer contains specialized cells including surface mucous cells that secrete protective mucus; parietal cells that produce hydrochloric acid and intrinsic factor; chief cells that secrete pepsinogen; and neuroendocrine cells releasing hormones. Anatomically, it is divided into regions called cardia, fundus, body, and pylorus[1][4][7][9]. Note on correctness: "Stomach anatomy" refers to an anatomical structure rather than a specific molecule or therapeutic target such as a receptor or enzyme. Therefore, **this entry is not considered a valid molecular or pharmacological target** for drug discovery purposes—it describes an organ system rather than an actionable biomolecule[1][4].

Other names

Gastric anatomyHuman stomachStomach organGastric wall