regulation of blood glucose and insulin secretion
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?- Created by: vezting
- Created on: 21-04-16 19:03
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- regulation of blood glucose and insulin levels
- the pancreas
- haa both endocrine and exocrine functions
- majority of cells manufacture and release digestive enzymes
- the cells that manufacure the enzymes are found in tiny tubules, these tubules join to make the pancreatic duct
- the pancreatic duct carries enzymes to the small intestine
- cells in the pancreas
- the islets of langerhans are small patches of tissues which have endocrine function
- alpha and beta cells are found in the islets of langerhans
- alpha secrete glucagon and beta secrete insulin
- insulin causes blood glucose to decrease and glucagon causes it to increase
- glucose levels too high
- 1: B cells secrete insulin into blood, they target hepatocytes and some muscles cells.
- 2: the insulin binds to receptors and activates adenyl cyclase which converts ATP into cAMP
- 3: ore glucose channels move to cell surface membrane more glucose enters the cells, more glucose converted to glycogon more glucose converted to fats and used in respiration
- glucose levels too low
- 1:a cells secret glucagon
- 2: it targets hepatocytes and converts glycagon into glucose.
- 3: also uses more fatty acids in respiration
- terms needed to know
- glyconoegenesis is fats into glucose
- glycogenolysis is glycogen to glucose
- glycogenesis is glucose to glycogen
- insulin levels
- 1: cell membrane has K and Ca channels
- 2: K channels normally open and K ions flow out
- 3: when blood glucose conc. too high glucose moves into cell
- 4: glucose metabolised to produce ATP
- 5: ATP closes K channels, accumulation of K ions alters pot.diff. inside is less negative
- 6: causes Ca channels to open
- 7: Ca ions cause vesicles containing insulin to fuse with cell surface mebrane and release insulin via exocytosis
- the pancreas
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