Wk2 Gastric secretion Flashcards
Location of parietal cells:
body of stomach
Cell type in gastric pit:
simple columnar
cells that make up gastric gland:
parietal
mucous
chief
Cell type and location where gastrin is secreted from:
G cells
antrum
Gastrin receptors in which cells?
Where are they found?
parietal (stimulates acid secretion)
body (corpus) / fundus
Mechanism for gastrin secretion from seeing food?
vagus –> Gastrin-releasing peptide –> GRP receptor in G cell
Three molecules that stimulate acid secretion from parietal cells:
gastrin
histamine
Ach
Histamine pathway for H+ secretion:
cAMP dependent pathway
Ach pathway for H+ secretion:
M3 receptor –> Ca2+ release
Gastrin pathway for H+ secretion:
CCK2 receptor –> Ca2+ release
Parietal cell pump that secretes acid?
H+ / K+ ATPase
Cells that release histamine:
What triggers it?
ECL cells
gastrin from blood
Look at slide
13
Describe “alkaline tide”:
HCO3- leaves basolateral parietal cell via Cl- / HCO3- exchanger and goes into blood
**HCO3- can also leave via vesicular fusion
Inhibitor of gastrin release:
somatostatin
**released when pH is less than 3