Physiology Endocrine Pancreas Flashcards
What is the role of Insulin in liver?
Increased glycogenisis Increased Protein Synthesis Decreased Glycogenolysis Decreased Gluconeogensis decreased ketogenesis Decreased Ureogenesis
What is the role of insulin in Adipose Tissue
Increased Lipogenesis
Decreased Lipolysis
What is the role of insulin in Muscle
Increased Glycogenesis Increased proteinsyntehsis Increased glucose oxidation Decreased glycogenolysis Decreased Proteolysis
What tissues does Insulin help increase glucose uptake?
Liver, muscle, and adipose tissue
OTher tissues EXCEPT CNS (brain, spinal cord), RBC, kidney tubuels, intestinal mucosa, and beta cells of the pancreas
How does insulin increase uptake of glucose in most tissue, esp ,sucle and adipose tisseu?
By increasing the number of glucose transproters (GLUT4) in cell membrane
Also increase glucose-uptake by liver , but NOT by glucose transporters
How do you incrase glucose uptake by liver by Insulin
Insulin promotes intracellular conversion of glucose into glycogen
This lowers the intraecllular glucose concetraiton, thus facilitating glucose-uptake
Activity of glucose-transproter of the liver (GLUT2) is NOT increased by insulin
Insulin promotes teh intracellular conversion of glucose into glycogen
What does insulin do with liver and muscle
Increasing glycogen synthesis in liver and muscle
What is the role of insulin in fat cells? Which enzyme is activated
increase triglyceride uptake by fat cells. Does this by increaseing LIPOPROTEIN LIPASE
Lipoprotein lipase clears chylomicrons from blood
How does insulin incrase triglyceride syntehsis (lipogenesis) in adipose tissue and liver?
by increasing glucose uptake
INsulin makes triose phsopahte available for triglyceride syntehsis in adipose tissue
Insulin stimulates rate limiting step for FA synethesis, carboxylation of acetly coA to malonyl CoA
What does high concentratino of ATP do in a beta cell
closes ATP- regulated K chanels on teh cell membrane
Decreased K+ conductance caues cell membrane to partially depolarize which , in turn, caues voltage-gated Ca channels to open.
Leads to furtehr membrane depol and to an ass. influx of extraceelular Ca as wella s to relese of intracellular Ca from sequestered locatiosn
Increased Ca causes microtubuels to contract moving insulin-containng secretory granules to beta cell surface where contents of granule are secreted
What does HYPOKALEMIA do to secretion of insulin?
it diminishes secretion of sinsulin
Oral hypoglycemic agents (sulfonylurease) decrease capacity to increase insulin secretion
What does intestinal hormones, sucha s GIP (GLP) do to insulin secretions?
promotes insulin secretion. Accoutsn for fact tha oral dose of glucose evokes much mroe insulin secretion than does sae dose of glucose administered itravensouly
What is the affect of glucagon on insulin secetion
Elicits insulin secretion
has amino acid homology with gut hormone, secretin!
What dos alpha adrenergic stimulation do to insulin secretion?
This is sympathetic …this inhibits insulin secretion . Therefore, during exercise, decrease in insulin secretion
How does exercise modify insulin?
Glucose entry into exercisign muscle is adequate evne though plasma concentraiton of insulin during exercise is low
This is b/c high rate of glucose utilization within teh workign musclees keep the itnracellular concentration of glucose and G6P low, thus maintaining favorable concenration gradient for gluocse transprot into teh cell
Adequate uptake of gluocse occurs weven without recruitment of add. Glut 5 transproters
