Midterm 2 - Importance of Insulin and Glucagon Flashcards
what kind of gland is the pancreas
endocrine and exocrine
what is the endocrine pancreas
islets of Langerhans - scattered throughout pancreas
what is the conformation of islets
B cells secrete insulin (70%)
alpha cells secrete glucagon (20%)
what kind of effects do insulin and glucagon have on glucose metabolism
opposite effects
what is insulin when produced
produced as a preprohormone and converted to proinsulin
what happens to proinsulin before secretion
converted to active insulin by removing a connecting C-peptide
what is the major anabolic hormone of the body
insulin
what does insulin lead to through its tyrosine kinase receptor
up regulation of membrane glucose transporters which leads to the CELLULAR UPTAKE OF GLUCOSE in muscles/adipose
what does insulin stimulate
incorporation of glucose in energy storage molecules
where goes glycogen go for energy storage
liver
muscle
where does triglycerides go for energy storage
adipose tissue
what does insulin promote
uptake of aa
what is the overall effect of insulin
a decrease in blood glucose and amino acid levels
what does glucagon activate through its G-protein coupled receptor
activates enzyme responsible for glycogenolysis which leads to the release of glucose from glycogen by liver
what does glucagon stimulate
gluconeogenesis in the liver (synthesis of glucose)
release of fatty acids from triglycerides in adipose tissue
what is the major mechanism of regulation of insulin and glucagon
the blood glucose concentration
what is the lesser mechanism of regulation of insulin and glucagon
amino acid conentration
what is the role of the autonomic nervous system with glucagon/insulin
during meals, PNS activates insulin secretion
SNS inhibits insulin secretion and stimulates glucagon release
what is stress hyperglycaemia
when SNS inhibits insulin secretion and stimulates glucagon release
what is diabetes
hyperglycaemia
what occurs during insulin-dependent diabetes
the insulin secretion is impaired
what is type 1 diabetes
insulin-dependent diabetes
what occurs in insulin-independent diabetes
insulin secretion is normal but tissues are insensitive
what is type 2 diabetes
insulin - independent diabetes
