#HUMAN скачать в хорошем качестве

#HUMAN

The stomach is a J-shaped, muscular organ in the upper abdomen, vital for digestion, acting as a temporary food reservoir, breaking down food mechanically through churning and chemically with gastric juices (acid & enzymes) into a semi-liquid called chyme, which then slowly empties into the small intestine via the pyloric sphincter. It has four main parts (cardia, fundus, body, pylorus) and strong muscular walls that mix food with acid and enzymes, killing bacteria and starting protein breakdown before passing it to the duodenum.   Location & Structure Location:  Upper-left abdomen, below the diaphragm, between the esophagus and small intestine (duodenum). Parts:  Cardia (entrance), Fundus (top), Body (main mixing area), Pylorus (lower end). Sphincters:  Lower esophageal sphincter (top) and Pyloric sphincter (bottom) control food entry/exit. Layers:  Walls have four layers: mucosa, submucosa, muscularis externa, and serosa, allowing for expansion and strong contractions.  Functions Storage: Temporarily holds food, expanding to accommodate volume.  Mechanical Digestion: Muscular walls contract rhythmically (churning) to mix and break down food into smaller pieces.  Chemical Digestion: Secretes gastric juice (hydrochloric acid & enzymes like pepsin) to kill microbes and start protein breakdown.  Produces Chyme: Mixes food with gastric juices to form a semi-liquid mixture called chyme.  Regulates Release: The pyloric sphincter slowly releases chyme into the duodenum (small intestine).