GI hormones Flashcards
Gastrin
released from: G cells (Antrum)
in response to: nerve (GRP), dietary, secretagogues
actions: increase acid secretion, increase gastric motility, and pepsin secretion
cholecystokinin
released from: duodenum (I cells)
in response to: fatty acids, peptides
actions: pancreatic enzyme secretion, gall bladder contraction, decreased gastric motility/ secretion satiety
secretin
released from: duodenum (S cells)
in response to H+
actions: pancreatic bicarbonate secretion, biliary bicarbonate secretion, decrease gastric secretion
gastric inhibitory peptide
released from: duodenum (K cells)
in response to: fatty acids, glucose
actions: decrease gastric secretion, increase insulin secretion
motilin
released from: small intestine
in response to: lack of nutrients
actions: migrating motor complex
GI transmitters - ACh
released from: reflex (PNS & ENS)
in response to: food
actions: increase secretion, increase motility,
somatostatin
released from: D cells (stomach)
in response to acid (endocrine/ paracrine)
actions: decrease gastrin secretion
vasoactive intestinal peptide
released from: reflex
in response to: ENS nerves
actions: relaxation of sphincters, increased intestinal secretion, vasodilation of arterioles
histamine
released from: ECL cells (stomach)
in response to: ACh, gastrin
actions: increase acid secretion
serotonin
released from: enterochromaffin cells (intestine)
in response to: mechanoreceptor, chemoreceptor
actions: stimulates nerves of the ENS
nitric oxide
released from: reflex
in response to: ENS nerves
actions: relaxation of sphincters, vasodilation of arterioles
gastrin releasing peptide
released from: reflex
in response to: ENS nerves
actions: increase gastrin secretion
noradrenaline
released from: fight or flight
in response to sympathetic nervous system
actions: general inhibition
