The stomach, which is located in the upper left quadrant of the abdomen, is divided into the fundic, cardiac, body, and pyloric regions. The lesser and greater curvatures are on the right and left sides, respectively, of the stomach. The inner surface is highly convoluted, enabling the stomach to fold up when empty and expand like a balloon as it fills with food.
Functions of the stomach
Gastric secretionsThe mucosal lining of the stomach is simple columnar epithelium with numerous tubular gastric glands. The gastric glands open to the surface of the mucosa through tiny holes called gastric pits. Four different types of cells make up the gastric glands:
Regulation of gastric secretionsThe regulation of gastric secretion is accomplished through neural and hormonal mechanisms. Gastric juice is produced all the time but the amount varies subject to the regulatory factors. Regulation of gastric secretions may be divided into cephalic, gastric, and intestinal phases. Thoughts and smells of food start the cephalic phase of gastric secretion; the presence of food in the stomach initiates the gastric phase; and the presence of acidic chyme in the small intestine begins the intestinal phase.
Stomach emptyingRelaxation of the pyloric sphincter allows chyme to pass from the stomach into the small intestine. The rate of which this occurs depends on the nature of the chyme and the receptivity of the small intestine.
Related category• ANATOMY AND PHYSIOLOGY
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