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31 Cards in this Set
- Front
- Back
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What pancreas cells make insulin?
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Beta
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What pancreas cells make glucagon?
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Alpha
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what pancreas cells make somatostatin?
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Delta
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What do pancreas cells make pancreatic polypeptide?
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F cells
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What is insulin syntheized from?
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a prohormone
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what is ratio of release for C peptide to insulin?
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it is 1-1, pro insulin is cleaved of its C peptide to form insulin and C peptide
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How does glucose stimulate insulin release?
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binds glut 2
ATP is produced, closes K+ channels. Depolarizes cell. Opens Ca2+ channels, causing exocytosis |
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What is the release of insulin like?
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insulin spike within seconds of glucose infusion
then about 10 min later, a second, sustained release |
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What has a greater insulin reponse, oral, or IV?
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oral does, due to incretin
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what is incretin? what does it do?
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This cause 60% of insulin released after a mean, resultant from GLP-1 and GIP release (GIP= glucose dependent insulinotropic peptide)
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What are the two sections of the insulin receptor? what do they do?
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alpha- binds insulin
beta- tyrosine kinase, causes autophosphorlyation when insulin binds also activates insulin receptor substrates-> activates other enzymes |
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How does insulin affect carbohydrate metabolism?
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stimulates:
glucose transport glycogen synthesis glucose oxidation |
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what does insulin affect lipid metabolism?
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stimulates:
lipogenesis FFA uptake cholesterol synthesis |
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How does insulin affect protein metabolism?
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stimulates:
aa uptake protein synthesis inhibits: proteolysis |
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What is the rapid effect of inuslin?
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increase transport of glucose/aa/K+ into cells
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what is the intermediate time effect of insulin?
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stimulation of protein and glycogen synthesis
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what is the delayed effect of insulin?
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lipogenesis
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what does amylin do? what produces it?
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this made by Beta Cells (insulin)
it delays gastric emptying |
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what does pancreastatin do? what makes it?
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this is made by beta cells (insulin)
this is autofeedback regulation of insulin release |
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How does insulin affect Other things? (list of 5)
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inotropic effect on heart
diet induced thermogenesis increases energy expenditure decrease NPY synthesis (suppressing appetite) increase K+ and PO4 reabsorption |
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What form is glucagon synthesized as?
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it is made as a prohormone by alpha cells
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where does preproglucagon synthesis occur?
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in intestinal cells and primarily alpha cells in the pancreas
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What is the role of glucagon?
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this is used to increase circulating glucose levels.
promotes mobilatization of fuel! |
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What stimulates the release of glucagon?
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hypoglycemia
and AA's (which are turned into glucose) |
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What suppresses the release of glucagon?
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lots of glucose, FFA, and ketones in the blood
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How does glucagon affect carbohydrate metabolism?
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stimulates glycogenolysis
gluconeogenesis ALSO- epi induced hyperglycemia |
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How does glucagon affect lipid metabolism?
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stimulates lipolysis
increases plasma FFAs ketogenesis can cause acidosis without insulin |
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how does glucagon affect protein metabolism?
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stimulates AA uptake, and gluconeogenesis from it.
increases urinary nitrogen. inhibits protein synthesis |
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What 4 things lower blood sugar?
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Glucagon
Cortisol GH Epiniphrine these all promote glucose mobilization |
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What is the normal I to G ratio? how does it change?
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it is normally 2:1
during exercise, can become 1:2 (i:G) during high sugar meal can be 10:1 |
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What are the actions of somatostatin?
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inhibits insulin and glucagon secretion
inhibits GH secretion inhibits GI hormone secretions/motility/pepsin/blood flow |
