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23 Cards in this Set
- Front
- Back
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Name the pancreatic endocrine hormones?
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Insulin
Glucagon Somatostatin |
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Insulin is a polypeptide hormone. TRUE/FALSE
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TRUE
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What are the steps of insulin synthesis?
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Preproinsulin---Proinsulin(C-peptide joins chains A and B)---Insulin + C peptide.
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What is the importance of C- peptide?
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It distinguishes an endogenous source of insulin from an exogenous source.
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Where is insulin secreted?
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Into portal circulation.
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How are the effects of insulin mediated?
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Through insulin receptors on various tissues.
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What is insulins second messenger system?
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Insulin receptor is a tyrosine kinase, which phosphorylates itself and other proteins.
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Name 5 actions of insulin in skeletal and cardiac muscle.
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1. Increase glucose uptake via Glut4(insulin sensitive glucose transporter)
2. Increase active transport of amino acids 3. Increase protein synthesis 4. Decrease protein degradation 5. Increase K+ into cells |
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Name the actions of insulin on the liver.
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1. Decrease gluconeogenesis
2. Decrease glycogenolysis 3. Increase glycogenesis |
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Regarding adipocytes, insulin will increase triglyceride sysnthesis, and decrease lipolysis. TRUE/FALSE
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TRUE.
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What is the overall effect of insulin on serum levels of:
Glucose Amino acids Fatty acids Ketoacids K+ |
Glucose- decrease
Amino acids-decrease Fatty acids-Decrease Ketoacids-Decrease K+- Decrease |
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What factors regulate insulin secretion?
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Increase blood glucose
Increase amino acids(leucine, arginine) Increase fatty acids Gastric inhibitory peptide(GIP) Vagus nerve stimulation GH SS(inhibitory effect) |
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How do the pancreatic beta cells sense serum glucose?
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Via Glut2(glucose sensor glucose transporter)---Glucose binds Glut2 on Beta cells---Glucose metabolized to ATP--- Beta cell membrane depolarization---Insulin release from pancreas.
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Describe insulin receptor regulation in the starvation state and in Obesity.
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Starvation-Up regulation
Obesity- Down regulation |
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What is Glucagon?
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A single chain polypeptide hormone
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Where is glucagon secreted?
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Into portal circulation
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What is Glucagons second messenger system?
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cAMP
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name the actions of glucagon on the liver.
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1. Increased glycogenolysis
2. Increased gluconeogenesis 3. Increased Lipolysis 4. Decreased protein degradation 5. Decreased protein synthesis On adipocytes- Increased lipolysis |
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What is the overall effect of glucagon on serum levels of, Glucose, fatty acids and Ketoacids?
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All are increased.
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What factors regulate glucagon secretion?
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Decrease blood glucose
Increased amino acids(arginine, leucine) Epi NE Glucocorticoids Cholecystokinin SS(inhibitory |
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Where is SS synthesized?
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Delta cells of islets of Langherhans
Intestines Nervous system |
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What is SS/
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A polypeptide hormone-secreted in 2 forms
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Name the actions of SS(pancreatic form)
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1. Decreased insulin
2. Decreased glucagon 3. Decreased secretion of many other GI hormones |
