three major functions of stomach?
1. bulk storage of ingested matter; 2. mechanical breakdown of resistant materials; 3. chemical digestion through the absorption of chemical bonds using acids and enzymes
four regions of stomach?
cardia, fundus, body, pylorus
what does pyloric sphincter do?
guards the exit from the stomach
what are rugae?
longitudinal folds in the stomach, which the mucosa and submucosa are thrown into
what forms the muscularis layers of the stomach?
three bands of smooth muscle - longitudinal layer, circular layer, inner oblique layer
what are the mesenteries of the stomach?
greater omentum and lesser omentum
where is greater omentum?
hangs from the greater curvature
where is lesser omentum?
attached to the lesser curvature and is the medial surface of the stomach
what do the branches of celiac trunk do?
supply blood to the stomach
what are the branches of the celiac trunk?
left gastric artery; splenic aretery; common hepatic artery
what lines all portions of the stomach?
simple columnar epithelia
what are shallow depressions in the stomach?
what do gastric pits contain?
gastric glands of the fundus and body
what do parietal cells secrete?
intrinsic factor and hydrochloric acid
what do chief cells secrete?
what is pepsin?
an enzyme formed by conversion from pepsinogen by acids in gastric lumen
what do G cells of the stomach secrete?
the hormone gastrin
what controls the production and secretion of gastric juices?
the CNS (the vagus nerve [parasympathetic innervations] and the celiac plexus [sympathetic innervations])
what does the release of hormones secretin and cholecystokinin do?
inhibits gastric secretion but stimulates secretion by the pancreas and liver