GI Hormones and Physiology Flashcards
what produces cholecystokinin (CCK)?
duodenal mucosal cells
what stimulates CCK release?
fat, protein, amino acids, HCl
what inhibits CCK release?
trypsin and chymotrypsin
what are the actions of CCK?
empties gallbladder
opens ampulla of Vater
slows gastric emptying
stimulates pancreatic acing cell growth and release of exocrine products
what is the source of secretin?
duodenal cells
- argyrophilic S cells
what stimulates secretin release?
pH <4.5 (acid), fat in the duodenum
what inhibits secretin release?
high pH in the duodenum
what is the action of secretin?
releases pancreatic bicarb/enzymes/H2O
releases bile/bicarb
decreases LES tone
decreases release of gastric acid
what is the source of gastrin?
gastric antrum G cells
what stimulates gastrin release?
stomach peptides/amino acids
vagal input
calcium
what inhibits gastrin release?
pH <3.0
somatostatin
what are the actions of gastrin?
release of HCl from parietal cells
trophic effect on mucosa of the stomach and small intestine
what is the source of somatostatin?
pancreatic D cells
what stimulates release of somatostatin?
food
what is the action of somatostatin?
globally inhibits GI function
what is the purpose of the colon?
reabsorption of H2O and storage of stool
what is the main small bowel nutritional source?
glutamine
what is the main nutritional source of the colon?
butyrate (short-chain fatty acid)
where is calcium absorbed?
duodenum actively, jejunum passively
where is iron absorbed?
duodenum
where is vitamin B12 absorbed?
terminal ileum
which hormone primarily controls gallbladder contraction?
CCK
what supplement does a patient need after removal of the terminal ileum or stomach?
vitamin B12
what is the correct diagnosis for necrotizing migratory erythema?
glucagonoma
