Pharmacology of upper GI

Question 1

Gastric juice consists of _____ and _______ which initiate hydrolysis of dietary protein and acidify stomach. it also contains ______ to protect lining from acid and lubricates food. it also has an _______ ________ which promotes transport and absorption of vitamin b12

Answer 1

HCl, pepsin, mucus, intrinsic factor

Question 2

explain the gastric proton pump that transports protons into the lumen

Answer 2

H/K ATPase on membrane of tubulovesicles translocate to can. membrane during stimulation and is activated by K to pump protons and Cl into lumen. activation is calcium-dependent and cAMP activation is required for Cl-channels

Question 3

what amino acid structure is required for gastrin activity?

Answer 3

Trp-Met-Asp-Phe-NH2

Question 4

how does acetylcholine indirectly stimulate acid output?

Answer 4

it stimulates acid output by activating G cell. cholinergic stimulation causes release of Gastrin Releasing Peptide and inhibits somatostatin (an inhibitor of acid secretion)

Question 5

how does acetylcholine activated G cells?

Answer 5

it binds to M3 Rs to increase intracellular calcium