the pancreas and diabetes Flashcards
what are the 4 cell types of pancreatic islets
1, A cells or alpha cells they secrete glucagon make up 17%
2.B cells or beta cells make up 70% secrete insulin
3. D cells or delta cells secrete somastatin make up 7%
4. f cells constitute the remainder of cells and secrete pancreatic polypeptide
explain homeostasis in regards to blood glucose
1.having low blood glucose(hypoglycaemia) stimulates alpha cells to secrete glucagon
2.
in the lover cells glycogen is converted to glucose this glucose is also formed from lactic acid and certain amino acids \3.the glucose released by the liver cell helps raise blood glucose levels to to normal but if they continue to rise you may become hyperglycaemic
4.hyperglycemia will stimulate beta cells to secrete insulin which will make blood glucose levels falls and this will inhibit glucose release
functions of insulin once secreted from beta cells
1.accelerated facilitated diffusion of glucose into cells
2.speed conversion of glucose into glycogen
3.increase uptake of amino acids and uptake of protein synthesis
4.speed synthesis of fatty acids
role of somatostatin
it is from the delta cells of pancreatic islets ,pancreatic polypeptides control the secretion
its principal is to inhibit the secretion of insulin and glucagon ,it slows the absorption of nutrients from the gastrointestinal tract
role of pancreatic polypeptides
they come from the f cells of pancreatic islets the level of secretion can be from protein based meals, fasting, exercise acute hypoglycaemia.
somostatin and elevated blood glucose levels inhibit secretion
principal role :inhibits somostatin increase,gallblader contraction, and secretion of pancreatic digestive enzymes