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10 Cards in this Set
- Front
- Back
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Somatostatin |
i. Stimulation: Secreted in response toacidity throughout the GI tract ii. Function: inhibits the release ofall GI hormones and gastric acid secretion. |
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Histamine |
i. SGI peptidesecreted from ECL cells ii. Function: acts on H2 receptors onparietal cells and stimulates gastric acid secretion. |
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GI peptides |
Regulate the functions of the GItract a. Contraction and relaxation of thesmooth muscle wall and the sphincters b. Secretion of enzymes for digestion c. Secretion of fluid and electrolytes d. Trophic (growth) effects on thetissues of the GI tract e. Regulate the secretion of other GIpeptides |
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Gastrin |
a. Stimulated: ingestion of ameal, small peptides and amino acids in the stomach, distention of the stomach,vagal stimulation b. Inhibited by increased acidity ofthe stomach (< pH 3) c. Function: stimulate acid secretion and mucosal growth. Secreted in randomlayers and areas. Histamine release and acid secretion. *** Gastrin and CCK are homologous in structuremeaning they can act on the same receptors CCK1 And CCK2 receptors. |
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parietal cells |
stimulate acid secretion |
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Cholecystokinin (CCK) |
a. Secreted by I cells in the duodenumand jejunum b. Stimulated by fatty acids andmonoglycerides in the intestine, and amino acids, and small peptides. b. Functions: contract the gallbladderto force the bile material out into the duodenum. Cause the relaxation/openingof the sphincter of Oddi to release the contents of the pancreas (mucous).Reduces the emptying in the stomach, increases nutrient delivery, digestion,and absorption. *** Gastrin and CCK are homologous in structure meaning they can act onthe same receptors. CCK can only act on CCK2 receptors |
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Secretin |
a. Secreted by the S-cells of theduodenum, act on G-protein coupled receptors of cells. b. Stimulation for release: entry ofgastric juice into the small intestine (acidity of the duodenum and fatty acidsin the duodenum). c.Function: Stimulate pancreatic andhepatic bicarbonate secretion to neutralize the acid. Inhibition of acid production and releaseof the stomach decreasing the contents entering the small intestine. **** Secretin and glucagon and GIP are homologous |
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Glucose dependent insulinotropic peptide (GIP) |
a. Secreted by K cells in the duodenumand jejunum b. Stimulated by: fatty acidmonoglycerides, glucose, and amino acids. c. Functions: increase insulin releasefrom the pancreas, and decrease acid secretion (not a major role since it needsto be secreted in more than physiological levels. **** Secretin and glucagon and GIP are homologous) |
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Motilin |
a. Secreted by M cells of the duodenumand the jejunum during fasting. Is released cyclically b. Stimulation: we don’t really know. c. Function: control the pattern ofsmooth muscle contraction in the upper GI tract. Limited to motor effects ofthe GI system. Induced gastric emptying and migrating myoelectric complex. *** Ghrelin is homologous to motilin |
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Ghrelin |
a. mainly released from the stomach andpancreas, and can be secreted along the complete gut. Receptors in all majororgans. b. Functions: same as motilin.Stimulates gastric acid secretion, appetite and feeding. Travels to the brainand has downstream effects before you start eating. *** Ghrelin is homologous to motilin |
