Flashcards in Gastric Secretion Deck (21):
Name the 6 cell types involved in gastric secretion
parietal (oxyntic) cells
What do parietal cells secrete?
What do chief cells secrete?
What do mucous cells secrete?
What do endocrine cells secrete?
What do mast cells secrete?
What do epithelial cells secrete?
Name the 5 functions of gastric secretion
protein digestion - acid and pepsin
inactivation of bacteria, viruses, and parasites
iron absorption - Fe2+ + H+ = Fe3+
intrinsic factor - vitamin B12 absorption
prostanoids - mucosal barrier cyto-protection
Name the 4 phases of gastric secretion
that which occurs in the absence of all cephalic, gastric, and intestinal stimulation
that mediated by sight, smell, taste, swallowing
that mediated by gastric distension and protein concentration
that mediated by duodenal amino acid concentration
Explain the cephalic phase of gastric secretion
vagal nerve stimulates parietal cells via Ach to secrete H+
vagal nerve stimulates G cells via Ach to release gastrin, which stimulates parietal cells to release H+
Explain the gastric phase of gastric secretion
distension stimulates G cells to produce gastrin, which stimulates parietal cells to release H+
amino acids and peptides from the food stimulates parietal cells to produce H+
distension also stimulates parietal cells to produce H+
Name the 3 receptors in a parietal cell
Where does feline intrinsic factor originate?
(mediates ileal cobalamin absorption - vitamin B12)
Name the 7 different mechanisms for inhibiting gastric acid secretion
dietary management (decrease gastric distention and protein content)
chemical diffusion barriers (sucralfate)
acetylcholine receptor antagonists (pirenzepine)
histamine receptor antagonists (ranitidine)
gastrin receptor antagonists (proglumide)
H+, K+, ATPase inhibitors (omeprazole)
Name the 5 parts of the gastric mucosal barrier
mucosal cell renewal
mucosal blood flow
5 things that can cause damage to the mucosal barrier