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GI Hormones - Physio
GI Hormones
Question | Answer |
---|---|
Gastrin | G cells (antrum) Inc H+ secretion & gastric motility Regulation: Inc via stomach distension (meal), AAs, vagus stimuli; Dec via pH < 1.5 |
CCK | I cells (duodenum, jejunum) Inc pancreatic & gallbladder secretions; Dec gastric emptying (increase metabolism time) Regulation: Inc by presence of FAs in duodenum |
Secretin | S cells (duodenum) Inc pancreatic HCO3- & bile secretion; Dec gastric H+ secretion (by dec gastrin) -Diagnostic in Zollinger-Ellison (inc gastrin levels!) Regulation: Inc by FAs in duodenum |
Somatostatin | D cells (islets) Dec gastric acid/pepsinogen, pancreatic, & gallbladder secretion; Dec insulin/glucagon & VIP (treats VIPoma) Regulation: Inc by acid; Dec by vagal stimuli |
GIP | K cells (duodenum, jejunum) Dec gastric H+ & Inc insulin Regulation: Inc by FAs, AAs, oral glucose |
VIP | parasympathetic ganglia (sphincters, gallbladder) Inc intestinal H2O/electrolyte secretion; Inc sphincter relaxation Regulation: Inc by distention & vagus; Dec by adrenergic |
NO | Endothelia Inc smooth muscle relaxation (LES) |
Ghrelin | P/D1 cells (stomach) Inc GH, ACTH, cortisol, prolaction Regulation: Inc prior to eating (regulate meal initiation!); Dec after meals |
IF | Parietal cells Bind B12; taken up in ileum |
Gastric Acid | Parietal cells Dec stomach acid Regulation: Inc by histamine, ACh, gastrin; Dec by GIP, somatostatin, prostaglandin |
Pepsin | Chief cells Protein digestion Regulation: Inc by vagal stimuli & acid (converts pepsinogen) |
HCO3- | Mucosal cells & Brunner's glands (duodenum) Neutralizes acid |