Gastric secretion - GI system

Gastric secretion 1

Gastric secretion:
 2 litres per day
 Isotonic
 pH 0.9-1.5
 Composed of: pepsins, intrinsic factor, mucus, and HCO3-

Some cells and what they produce:
(In depth order except G)

 G-cell –gastrin
 Surface epithelial cell -Mucus & bicarbonate
 Mucous neck cells – mucus
 Parietal cell – HCl & intrinsic factor
 Chief cell – pepsinogens
 Endocrine cells
o Enterochromaffin-like (ECL) cell – histamine
o D-cell – somatostatin

Function of HCl:

 Promotes activation of peptides from pepsinogens
 Antimicrobial
 Stimulates secretion in stomach
 Helps iron and calcium absorption in the s. intestine


Active parietal cell has large number of canaliculus therefore there is a larger
secretory membrane with more H+ and Cl- channels