- gaster
- 1. SYN: stomach. 2. Prominent part of wasp or ant abdomen, separated from the other body parts by a thin connecting segment. [G. g., belly]
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gas·ter (gasґtər) [Gr. gastēr the stomach] [TA] stomach: the musculomembranous expansion of the alimentary tract between the esophagus and the duodenum. The proximal portion is the cardia; the portion above the entrance of the esophagus is the fundus; the distal portion is the pyloric part; and the body is between the fundus and the pyloric part. The upper concave surface or edge is the lesser curvature, and the lower convex edge is the greater curvature. The stomach wall has four coats or layers: an outer, peritoneal, or serous coat (tunica serosa gastrica); a muscular coat (tunica muscularis gastrica), made up of longitudinal, oblique, and circular fibers; a submucosa (tela submucosa gastrica); and the mucosa tunica mucosa gastrica that forms the inner lining. Gastric glands, found in the mucosa, secrete gastric juice into the cavity of the stomach; it contains hydrochloric acid, pepsin, and various other digestive enzymes. Food mixed with this juice forms a semifluid substance called chyme that is suitable for further digestion by the intestine. Called also ventriculus.
Medical dictionary. 2011.