RSL - GI - Regulatory substances Flashcards
Gastrin: source
G cells; Antrum of stomach, duodenum
Gastrin; regulation
(increase) Stomach distention, AA, peptides, vagal stim, chronic PPI use
Somatostatin: source
D-cells: Pancreas, GI mucosa
Somatostatin: action
Decrease: Gastric acidd and pepsinogen, pancreatic and small intestine fluid secretion, Gall bladder contractility, Glucagon/insulin
Somatostatin: regulation
Increase by acid
Decrease by vagal stim
Cholecystokinin: Source
I cells: Duodenum, jejunum
Cholecystokinin: Action
increase: pancreatic secretions, gallbladder contration, relaxation of sphincter of oddi
Decrease: gastric emtying
Cholecystokinin: regulation
INcrease by: Fatty acids, AA
Secretin: source
S cells: duodenum
Secretin: Action
Increase: HCO3- secretion, Bile secretion
Decrease: Acid secretion
Secretin: Regulation
Increase: acid, FA in duodenum
Glucose-dependent insulinotropic peptide (GIP): Source
K-cells, duodenum and jejunum
Glucose-dependent insulinotropic peptide (GIP): action
Exocrine: decrease gastric H+ secretion
Endocrine: increase insulin
Glucose-dependent insulinotropic peptide (GIP): regulation
Increased by: FA, AA, oral glucose
Motilin: source
Small intestine
Motilin: action
produces MMCs
Motilin: Regulation
increased in fasting state
VIP: source
PSNS ganglia in sphincters, gallbladder, small intestine
VIP: Action
Increase: intestinal water, and electrolytes (HCO3-, Cl-), relaxation of intestinal smooth muscle and sphincters
Decrease: H+ secretion
VIPoma
Non-alpha, non-beta islet cell pancreatic tumor:
Copious watery diahrea, hypokalemia, Achlorhydria (WDHA syndrome)
NO loss
Loss is associated with LES tone (achalasia)
Gastric acid: source
Parietal cells (stomach)
Gastric acid: Regulation
increased by: histamine, ACh, gastrin
Decreased by: Somatostatin, GIP, prostaglandin secretion
Pepsin: Source
Chief cells (stomach)
Pepsin: action
Protein digestion
Pepsin: regulation
increased by vagal stimulation and local acid
HCO3-: source
Mucosal cells (stomach, duodenum, salivary glands, pancreas) and brunners glands
HCO3-: Action
neutralizes action
HCO3-: regulation
increased by pancreatic and biliary secretion with secretin