Term
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Definition
| what are the 3 sources of energy for the body? |
|
|
Term
1) maintaining body temp
2)muscle contraction
3) biosynthesis
4) cell transport
5) growth |
|
Definition
| how is energy expended by the body? |
|
|
Term
1)ATP generation
2) storage as glycogen
3) biotransformation (lipid deposition) |
|
Definition
| what are the 3 ways glucose is used by the body? |
|
|
Term
1)biosynthesis of peptides, and proteins
2)gluconeogenesis |
|
Definition
| what are amino acids used for? |
|
|
Term
1)energy storage
2)energy generation(beta oxidation)
4)gluconeogenesis |
|
Definition
| how is fat utilized in the body? |
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Term
|
Definition
| how many grams of islet cells are in the body? |
|
|
Term
alpha
beta = most prevalent 50-60%
delta |
|
Definition
| what are the 3 major cell types in islets of langerhans? which is most prevalent? |
|
|
Term
alpha: synthesize and secrete glucagon (increase glucagon and blood sugar)
beta: synth & secrete insulin (increase insulin to decrease blood sugar)
delta: synth & secrete somatostatin
(somatostatin inhibits alph and beta cells) |
|
Definition
| what do alpha cells do? beta? delta? |
|
|
Term
1)increase in glu
2)increase in FA and amino acids
3) incretins (GIP) |
|
Definition
| what causes an increase in insulin secretion? |
|
|
Term
1)increases glu transport into cells
2)stimulates a.a. uptake into cells |
|
Definition
| what does insulin do within a matter of seconds? |
|
|
Term
| increases activity of metabolic enzymes inside of cells |
|
Definition
| what are the actions of insulin within a few minutes? |
|
|
Term
1) increases protein formation and prevents protein degradation
2) promotes growth(with help of growth hormone) |
|
Definition
| what are the effects of insulin within hours to days? |
|
|
Term
1)glucose enters a beta cell or hepatocyte via facilitated diffusion down its concentration gradient (GLUT-2 transporter)
2) glucose is converted to glucose-6-phosphate via glucokinase (this prevents the molecule from leaving the house because it is impermeable to the membrane)
3) G6P is oxidized creating ATP which closes ATP sensitive K+ channels |
|
Definition
| describe how glucose enters a (beta) cell (the cellular mechanisms) |
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|
Term
1) K+ channels closing causes the membrane to depolarize and open calcium channels
2) calcium enters and helps the insulin out somehow |
|
Definition
| Once ATP sensitive K+ channels close, what happens to the beta cell to cause insulin secretion? |
|
|
Term
aa: augment effect of glucose
FA: augment effect of glucose, may be toxic
hormones: growth hormone stimulates secretion, and cortisol is secreted by tumors
(something to do with gigantism and acromegaly) |
|
Definition
| how do amino acids, fatty acids, and hormones stimulate insulin secretion? |
|
|
Term
| Incretins, ensure similar glucose excursions regardless of the glucose load |
|
Definition
| why does the blood glucose concentration over time change about the same whether glucose is ingested in varying amounts, or orally versus intravenously? |
|
|
Term
oral glucose stimulates more insulin secretion than IV glucose.
no difference really(oral SLIGHTLY higher), because incretins amplify insulin secretion so glucose excursions are kept constant |
|
Definition
| which stimulates more insulin secretion? oral intake of glucose, or intravenous intake? in the end is there a noticeable difference? |
|
|
Term
|
Definition
| what percent of post-glucose insulin secretion is due to the incretin effect? |
|
|
Term
| after oral glucose intake, via gut hormones |
|
Definition
| where is incretin secreted? |
|
|
Term
| GIP and GLP-1, they both augment the effect of glucose on insulin secretion |
|
Definition
| incretins are released from the small intestine in response to glucose by enteroendocrine cells, what are the incretins? what do they do to insulin? |
|
|
Term
there are structural changes and tyrosine kinase autophosphorylates, leading to a phosphorylation cascade with (IRS) insulin receptor substrates that
1) increase glucose transport(uptake), and
2) increase synthesis |
|
Definition
| what happens when insulin binds to a cell membrane? |
|
|
Term
all most all tissues
especially skeletal musc, liver, and fat but NOT CNS |
|
Definition
| where does insulin induce glucose uptake? especially? not at all? |
|
|
Term
insulin increases transporter production in muscle/fat
in the liver insulin tells the cells to make more glucokinase |
|
Definition
| what does insulin do to the GLUT-4 transporter in muscle and fat cells? what does insulin do in the liver mainly? |
|
|
Term
1)increases glu uptake
2)increases glycogen formation
3)decreases use of glycogen for energy |
|
Definition
| what 3 things does insulin do to skeletal specifically? |
|
|
Term
1) increases glu uptake
2) decreases uses of fats for energy
3) enhances synth/storage of fat |
|
Definition
| what 3 things does insulin do in adipose tissue? |
|
|
Term
1)increases glu uptake
2) increases glycogen formation
3) increase FA formation (from glu)
4) decreases use of glycogen for energy
5) decreases formation of new glucose |
|
Definition
| what 5 things does insulin do to the liver? |
|
|
Term
| low blood glucose, or increase in blood amino acids |
|
Definition
| what stimulates glucagon secretion by alpha cells? |
|
|
Term
1)increases breakdown of glycogen(glycogenolysis)
2)increases glucose production (gluconeogenesis)
-> increase blood glu levels, and increases breakdown of fat |
|
Definition
| what does glucagon do in the liver? |
|
|
Term
| glucagon starts taking effect |
|
Definition
| when we eat, insulin starts taking effect, what happens 2 hours later? |
|
|
Term
increase in blood glucose, amino acids, and fatty acids
somatostatin decreases moth insulin and glucagon secretions because it inhibits alpha and beta cells (feedback loop) |
|
Definition
| when are delta cells stimulated to secrete? what does this do to insulin and glucagon? |
|
|
Term
glucagon(panc), growth hormone(petuitary), cortisol(adrenal gland), and epi(adrenal gland) are increased
insulin(panc) is decreased |
|
Definition
| what hormones are increased to switch from carb metabolism to lipid? which decrease? |
|
|
Term
1)hormone sensitive TAG lipase activated -> TAG's are hydrolyzed to GA and glycerol
2) there is a hepatic conversion of FA to phospholipids, and cholesterol
3) this can lead to ketosis or acidosis that can be toxic in a few hours because FA->acetoacetic acid-> betahydroxybutyric acid->acetone |
|
Definition
| what does insulin do in fat metabolism? |
|
|
Term
| polyuria, polydypsia, polyphagia |
|
Definition
| what are 3 symptoms of diabetes mellitus? |
|
|
Term
1) increases blood glucose
2) carb metabolism switched off
3) fat metabolism switched on |
|
Definition
what does diabetes do to 1) blood glucose
2) carb metabolism 3) fat metabolism |
|
|
Term
juvenile (age 14) onset
complete lack of insulin due to destruction of beta cells
5-10% of diabetics |
|
Definition
| when does type 1, T1DM, or IDDM onset and what happens to insulin? what percent of diabetics does this account for? |
|
|
Term
adult onset, insulin resistance (insensitivity to insulin, relative lack of insulin)
90-95% of diabetics |
|
Definition
| when does type 2, T2DM, or NIDDM onset and what happens to insulin? what percent of diabetics does this account for? |
|
|
Term
1) genetic suceptibility
2) chronic autoimmune damage
3) environmental precipitation (viral infection) |
|
Definition
| what are the 3 things that are supposed causes of T1DM? |
|
|
Term
1)decreased # of insulin receptors
2)toxic effects of lipid in muscle or liver
3) late loss of insulin secretory capacity |
|
Definition
| what are the possible causes of T2DM? |
|
|
Term
T1DM: insulin administration
T2DM: weight loss & exercise, insulin sensitivity, decrease in hepatic glucose production, increase in insulin secretion |
|
Definition
| what is the treatment for T1DM? T2DM? |
|
|
Term
1) marked hyperglycemia
2) dehydration
3) metabolic acidosis
4) coma, death |
|
Definition
| what are the acute complications of T2DM? |
|
|
Term
microvascular problems: renal, retinal, neural
macrovascular: cardiovasc disease, stroke, peripheral vascular disease |
|
Definition
| what are the chronic complications of T2DM? |
|
|
Term
|
Definition
| what causes 60% of blindness? & 1/2-1/3 of all renal problems? |
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