Lecture 71 Flashcards
_________ and _________ work together to regulate blood glucose after a meal and during fasting
insulin and glucose
_________ regulates blood glucose, FA, and AA metabolism
liver, adipose tissue, muscle
Pancreatic _________ synthesize hormones
islets of Langerhans
_________ is the major source of insulin inside the cell and makes up 65%
b cells
20 percent of this cell inside the pancreatic cell makes glucagon and most are around the outer rim of islet
a-cells
10 percent of this cell is interspersed b and a cells and it produces somatostatin
delta-cells
somatostain inhibits _________ cells?
a and b cells
endocrine pancreas is _________ percent of pancreatic mass
1-2 percent
some cells around the pancreatic islet release _________ to self regulate
pancreatic polypeptide
Hormones secreted into pancreatic veins and reach the liver via portal vein. The liver can control?
How much hormones from the pancreas reaches periphery
Central core of islet is _________
beta-cells
_________ connect a- cells to each other, B cells to each other and A to B cells
Gap junctions
Blood supply to the pancreas arranged so that venous blood from each cell type _________ other cell types
bathes
Small arteries enter islet core and capillaries are distributed throughout. Coverage at rim to form _________
veins
Islets innervated by adrenergic, cholinergic and _________ neurons.
peptidergic
first hormone isolated from animal sources, first to have structure determined and mechanism of action described
Insulin
Amino acid sequence varies by _________ but certain segments highly conserved within vertebrates
species
Segments of AA: location of disulfide bonds include end of A chain, c-terminal residues of _________
B-chain
_________ two species have the same sequence of insulin
dog and pig
usually injecting insulin of one species into another causes antibody formation- not a huge issue in _________ and _________ injected with insulin from other species
Dogs and cats
peptide hormone with 2 chains
A chain: 21 AA and B chain: 30 AA
_________ peptide hormone is longer and is biologically active
B chain
_________ are the 3 disulfide bridges
2 link A and B chain and 3rd is in A chain
Insuliin synthesis: Synthesized as _________ with four peptides
prehormones
_________ are the four peptides that comes with insulin synthesis?
Signal peptide bond cut out early, A+ B chains and C chain (comeding peptide)
Insulin synthesis: Proinsulin sent to ER, insulin folds and _________ forms
disulfide bridge
Insulin synthesis: Golgi packages into granules, proteases cut
C peptides
Insulin synthesis: Once golgi packages into granules and proteases cut C-peptudes, secretion happens via exocytosis and releases
Insulin and C-peptide together