Digestion in the Stomach

Flashcards based on lecture notes about the stomach and digestion.

Lower Esophageal Sphincter

The sphincter that guards the juncture between the esophagus and the stomach.

Fundus

Superior, domed region of the stomach.

Pylorus

Narrowed region of the stomach that communicates with the duodenum.

Pyloric Sphincter

Sphincter that guards the bottom portion of the stomach from the top of the small intestine.

Ruchi

Temporary folds in the mucosa of the nondistended stomach.

Gastric Pits

Infolds in the simple columnar epithelium lining the stomach.

Gastric Glands

Deeper regions of the gastric pits where secretion occurs.

Columnar Cells

Cells in the neck region of gastric pits that secrete mucus and bicarbonate ion.

Parietal Cells

Cells that secrete hydrochloric acid and intrinsic factor.

Intrinsic Factor

Chemical necessary for the absorption of vitamin B12.

Enterochromaffin-like Cells

Cells that secrete histamine, which stimulates parietal cells to secrete HCl.

Chief Cells

Cells that secrete pepsinogen (the precursor to pepsin) and gastric lipase in infants.

Pepsinogen

Precursor to pepsin. When it is secreted, it finds itself in an acidic environment becomes pepsin

G Cells

Enteroendocrine cells that secrete gastrin, a hormone that promotes acid secretion by parietal cells.

Churning

The mechanical digestion that occurs in the stomach

Chyme

The mixture of food boli and gastric juice that results from churning.

Pepsin

Enzyme that starts acting on peptide bonds and to start the digestion of proteins into smaller peptide fragments