Pharmacology: gastric secretion Flashcards
what cells release histmaine
enterochromaffin-like cells in gastric pit
what is histamine secreted in response to
in response to stimulation by acetylcholine(ACh)
describe the action of histamine
binds to H2 receptors, with subsequent activation of adenylyl cyclase
describe the effect of histamine on gastric acid secretion
increases cAMP, which increases number of proton pumps, therefore increasing gastric acid secretion from parietal cells
what cells are responsible for secreting pepsinogen
chief cells
what is secreted from parietal cells
HCl(gastric acid)
what is secreted from mucus cells
mucous and HCO3
what is responsible for releasing acetylcholine(ACh)
parasympathetic cholinergic neurons
describe the action of acetylcholine
binds to muscarinic(M3) ACh receptors on parietal cells, with subsequent activation of phospholipase C(PLC)
describe the effect of ACh on gastric acid secretion
increase in intracellular Ca, increases number proton pumps, increasing gastric acid secretion
what do G cells release
gastrin
describe the action of gastrin
binds to CCK2 receptors on parietal cells, with subsequent activation of PLC
describe the action of gastrin on gastric acid secretion
increase in intracellular Ca results increase number of proton pumps, therefore increase in gastric acid secretion
what is secreted from D cells in the gastric glands
somastatin
describe the action of somastatin
binds to SST2R receptors, inhibiting adenylyl cyclase
