- : The stomach is part of the digestive system. It is located in the upper abdomen, under the ribs. The upper part of the stomach connects to the esophagus, and the lower part leads into the small intestine. When food enters the stomach, muscles in the stomach wall create a rippling motion that mixes and mashes the food. This motion is called peristalsis. At the same time, juices made by glands in the lining of the stomach help digest the food. After about 3 hours, the food becomes a liquid and moves into the small intestine, where digestion continues.
* * *A large irregularly piriform sac between the esophagus and the small intestine, lying just beneath the diaphragm; when distended it is 25–28 cm in length and 10–10.5 cm in its greatest diameter, and has a capacity of about 1 L. Its wall has four coats or tunics: mucous, submucous, muscular, and peritoneal; the muscular coat is composed of three layers, the fibers running longitudinally in the outer, circularly in the middle, and obliquely in the inner layer. SYN: gaster (1) [TA], ventriculus (1) [TA]. [G. stomachos, L. stomachus]- bilocular s. SYN: hourglass s..- cascade s. a radiographic description: when contrast material is swallowed while the patient is in the upright position, the gastric fundus acts as a reservoir until contrast overflows (cascades) into the antrum; a normal variant in a horizontal s..- drain-trap s. SYN: water-trap s..- hourglass s. a condition in which there is a central constriction of the wall of the s. dividing it into two cavities, cardiac and pyloric. SYN: bilocular s., ectasia ventriculi paradoxa.- leather-bottle s. marked thickening and rigidity of the s. wall, with reduced capacity of the lumen although often without obstruction; nearly always due to scirrhous carcinoma, as in linitis plastica. SYN: sclerotic s..- miniature s. SYN: Pavlov pouch.- powdered s. the dried and powdered defatted wall of the s. of the hog, Sus scrofa; it contains thermolabile factors including native vitamin B12 and intrinsic factor; has been used in the treatment of pernicious anemia.- thoracic s. a condition in which part or all of the s. is contained within the thorax because of a paraesophageal hiatus hernia.- wallet s. a form of dilated s. in which there is a general baglike distention, the antrum and fundus being indistinguishable.- water-trap s. a ptotic and dilated s., having a relatively high (though normally placed) pyloric outlet which is held up by the gastrohepatic ligament. SYN: drain-trap s..
* * *stom·ach 'stəm-ək, -ik n1 a) a saclike expansion of the alimentary canal of a vertebrate communicating anteriorly with the esophagus and posteriorly with the duodenum and being typically a simple often curved sac with an outer serous coat, a strong complex muscular wall that contracts rhythmically, and a mucous lining membrane that contains gastric glandsb) one of the compartments of a ruminant stomach <the abomasum is the fourth \stomach of a ruminant>2) a cavity in an invertebrate animal that is analogous to a stomach
* * *n.a distensible saclike organ that forms part of the alimentary canal between the oesophagus (gullet) and the duodenum. It communicates with the former by means of the cardiac sphincter and with the latter by the pyloric sphincter. The stomach lies just below the diaphragm, to the right of the spleen and partly under the liver. Its function is to continue the process of digestion that begins in the mouth. gastric juice, secreted by gastric glands in the mucosa, contains hydrochloric acid and the enzyme pepsin, which contribute to chemical digestion. This - together with the churning action of the muscular layers of the stomach - reduces the food to a semiliquid partly digested mass that passes on to the duodenum.
* * *stom·ach (stumґək) [L. stomachus; Gr. stomachos] 1. gaster. 2. in ruminants, any of four expansions of the alimentary canal between the esophagus and the duodenum; the first three, the rumen, reticulum, and omasum, are called forestomachs, and the fourth, the abomasum, is analogous to the stomach of a nonruminant. 3. the midgut of an invertebrate.
Medical dictionary. 2011.