Module 5: Digestive system: Stomach Flashcards
2 types of reduction to form chyme
mechanical
chemical
rugae
prominent longitudinal folds of mucosa
3 different zones of the stomach
cardiac
fundus and corpus
pylorus
Epithelial lining of stomach is
mucous-secreting columnar cells
Protection from acidic contents of the stomach
cardiac region
mucosal glands are small and mostly mucous secreting
Fundus and corpus region
Body of stomach
Straight tubular glands (arranged in gastric pit/foveolae) which secrete gastric juice
gastric juice
HCl and pepsin
3 types of cells in gastric glands
mucous secreting cells
parietal cells
peptic/chief cells
Mucous secreting cells
cover luminal surface of stomach and line gastric pits
Parietal cells
HCl secreting cells
Distributed along length of glands
Also produce intrinsic factor for absorption of B12 from small intestine
Peptic or chief cells
Clustered at base of gastric glands
Cytoplasm full of inactive pepsin (pepsinogen)
Pepsinogen remains inactive until it reaches the lumen of the stomach where it is activated by gastric juices (prevents auto digestion of the gastric glands)
Secretory activity of parietal and peptic cells is controlled by
autonomic nervous system and Gastrin secreted by endocrine cells in pylorus
Pyloric region
branched coiled tubular glands
Composed of mucous secreting cells ONLY (to protect entrance to duodenum)
Endocrine cells scattered as well (secrete gastrin)
what stimulates secretion of gastrin into bloodstream
presence of food
gastrin then stimulates secretion of pepsinogen and gastric mobility
Muscularis of stomach
additional layer of inner oblique smooth muscle
