GI Hormones Flashcards
Gastrin released from
G cells in gastric antrum + duod
Gastrin stimulation
intragastric peptides + gastric distention
Gastrin site of action + effect (3)
- gastric parietal and chief cells - H+ and pepsinogen secretion
- pancreatic acinar cells - enzyme secretion
- stomach, duod, pancreas - growth (can cause gastric hypertrophy)
CCK released from
I cells in duod + jej
CCK site of action (4) + fxn
- GB - contraction
- sphincter of Oddi - relaxation
- panc - enzyme secretion + growth
- stomach - inhibition of gastric emptying
CCK stimulation
duod fatty acids, AA, H+
Secretin released from
S cells in SI
Secretin stimulation
Duod H + fatty acids
Secretin site of action + fxn (2)
- panc duct cells - bicarb + water secretion
- biliary epithelium, duod - bicarb + water secretion
Enteroglucagon secreted by
L cells in terminal ileum/colon and cleaved into 3 hormones
Oxyntomodulin source
break down of enteroglucagon
GLP-1 + -2 source
break down of enteroglucagon
Oxyntomodulin stimulation
Ileal/colonic glucose + lipid
Oxyntomodulin site of action and function
gastric parietal cells - inhibition of H+ secretion
GLP-1 stimulation, site of action, effect
Duod FAs, acts on panc B cells, stimulates insulin secretion (incretin during euglycemia)
-ileal FAs, site of action on stomach, inhibition of gastric emptying
GLP-2 stimulation
carbs, lipids, SCFA
GLP2 site of action + effect
SI, colon - inhibits gastric emptying (ileal brake) and secretion.
crypt cell proliferation, suppression of apoptosis. reduces gut permeability + bacterial translocation
gastric inhibitory polypeptide released from
prox SI
gastric inhibitory polypeptide stimulus
FAs, glucose, AAs
gastric acid polypeptide site of action + effect
duod, jej, ileum - inhibition of gastric + intestinal motility
stimulates insulin secretion during euglycemia
somatostatin released from
D cells throughout GI
somatostatin stimulus
lipids, protein, bile
somatostatin site of action + effect
stomach, intestine, panc - inhibition of gastric, intestinal, panc secretion
Motilin released from
prox SI
Motilin stimulus
H+ and lipids
Motilin site of action and effect
stomach, duod, jej - increases gastroesophogeal sphincter pressure, stimulates propulsive motility
stimulates gastric, pancreatic, biliary secretion
panc polypeptide stimulation
protein, cholinergic reflexes
panc polypeptide site of action + effect
panc - inhibition of panc enzyme + fluid secretion
5-hydroxytryptamine (aka serotonin) released from
enterochromaffin cells + enteric neurons in GIT
5-hydroxytryptamine (aka serotonin) stimulus
H+
5-hydroxytryptamine (aka serotonin) site of action and effect
intestine + colon - stimulation of motility and secretion
Ghrelin released from
stomach
Ghrelin stimulus
dietary protein
Ghrelin site of action + effect
pituitary - stim of GH secretion
