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25 Cards in this Set
- Front
- Back
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What is the range of normal glucose in plasma?
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4-8mmol/l
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Which hormones are involved in levels of adequate nutrition?
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Insulin
Glucagon |
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Which hormones are involved during levels of stress/exercise
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Cortisol
Adrenaline (GH) |
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Which hormones are involved during levels of starvation?
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Cortisol
GH |
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What are the actions of insulin?
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Promotes uptake of glucose by cells
Promotes glycolysis Promotes formation of glycogen Inhibits glycogenolysis Inhibits gluconeogenesis (OVERALL counteracts increase in plasma glucose/amino acids) |
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How does insulin promote the uptake of glucose into cells?
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Upregulation of GluT4 transporter protein
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On which types of cell is the GluT4 transporter protein found?
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Adipose tissue
Skeletal and cardiac muscle |
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What happens to GluT4 protein when insulin is present and absent?
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Insulin absent - usually sequestered - kept in cells
Insulin present - brought to plasma membrane and glucose enters cell by facilitated diffusion down a concentration gradient |
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How does insulin affect the levels of TAGs?
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Promotes the synthesis and storage of TAGs and inhibits the breakdown of them
Promotes uptake of fatty acids by adipose and formation of glycerol from glucose |
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How does insulin affect the levels of proteins?
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Promotes protein synthesis and amino acid uptake while inhibiting protein degradation
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Does insulin promote catabolism or anabolism?
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ANABOLISM
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Why do insulin levels decrease during the postabsorptive phase?
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To prevent hypoglycaemia
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Why is it important to feed diabetics insulin when they are feeding?
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Absorptive phase - insulin should be high otherwise hyperglycaemia (high sugar level in blood)
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Alpha cells in the pancreas make:
Beta cells make: |
Glucagon
Insulin |
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What effects does glucagon have?
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Opposite of insulin - liver and adipose tissue
Increases glycogenolysis Increases gluconeogenesis Increases lipolysis Decreases glycogen synthesis |
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What happens to glucose plasma levels in each circumstance?
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1. Decrease plasma glucose levels
2. Increase plasma glucose levels |
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What is the insulin:glucagon ratio after a) a high carb meal and b) postabsorptive state?
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a) High
b) Low |
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What is the insulin:glucagon ratio like in ruminants?
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Fairly low and fairly constant
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Which precursors do ruminants use during feeding and during postabsorptive state?
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Propionate, amino acids
Amino acids, glycerol |
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How do high protein meals affect insulin and glucagon?
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Stimulate release of both, preventing hypoglycaemia
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What happens to plasma glucose levels during physical activity?
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They stay constant because:
Physical activity stimulates Sympathetic nervous system which stimulates Glucagon increase, insulin decreases Keeps glucose in plasma |
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How does muscle take up glucose during exercise?
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Insulin-independently
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What effect does adrenaline have on blood glucose levels during exercise?
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Increases glucagon, decreases insulin
Increases glucose release to plasma, increase lipolysis Catabolic |
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What effect do glucocorticoids have on metabolism?
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Increase amino acids in blood
Increase lipolysis Increase blood glucose Catabolic |
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What effect does GH have on metabolism?
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Anabolic on protein (and breakdown)
Breakdown of fats Promotes insulin secretion but gluconeogenesis and uptake of glucose by tissues |
