Glucose Metabolism
Control of Glucose Metabolism The pancreas is both an exocrine and endocrine gland. It secretes digestive enzymes into the duodenum (exocrine) and 3 specific hormones into the bloodstream (endocrine). gallbladder pancreas pancreatic duct duodenum common bile duct
Control of Glucose Metabolism The hormones are produced by specialized cells called pancreatic islets. There are 3 classes of cells that influence blood sugar glucose levels. pancreatic islet (islets of Langerhans) microscopic view of pancreatic tissue
Control of Glucose Metabolism The hormones are produced by specialized cells called pancreatic islets. There are 3 classes of cells that influence blood glucose levels. Cell type Alpha (α) Beta (β) Delta (δ) Hormone secreted - secretes glucagon which acts to convert glycogen (animal starch) to glucose - secretes insulin which promotes glucose uptake by the liver, muscles and fat tissue - secretes somatostatin which can block the secretion of both glucagon and insulin Effect on Blood Glucose Level Increases Decreases Stabilizes
Control of Glucose Metabolism The endocrine cells of in the pancreas maintain blood sugar levels through a negative feedback system. A normal blood glucose is about 0.9 mg/ml. After a meal, glucose enters the bloodstream, at the small intestine, raising the blood glucose level.
Reaction to high blood glucose levels. The High hypothalamus blood glucose stimulates beta cells to produce insulin. Blood glucose levels levels decrease decrease liver, as muscle liver, and muscle fat and cell take fat cell in take glucose. in glucose. As blood As glucose blood glucose levels drop, levels drop, the beta the beta cells cells become less less active. Insulin production stops before blood glucose levels return to normal.
Reaction to low blood glucose levels. Between meals, blood glucose levels decrease as the cells of the body consume glucose through respiration. This The stimulates hypothalamus alpha senses cells to this secrete and stimulates glucagon..the alpha glucagon cells to causes secrete muscle glucagon. and liver The glucagon cells to convert causes their muscle stored and glycogen liver cells into to glucose, convert their thereby stored raising glycogen the blood into glucose, level. thereby raising the blood glucose level. glycogen (starch) glucagon glucose (sugar) Various samples of glycogen have been measured at 1,700-600,000 units of glucose
Control of Glucose Metabolism Nelson Biology 12 Teacher Resources
Control of Glucose Metabolism In both cases, a change in blood glucose levels away from the normal causes a negative response that is fed back on the system until the normal value is reached. People with diabetes have difficulty regulating their blood glucose levels.
Diabetes There are 3 types of diabetes: Type 1 In type 1 diabetes, the body does not make insulin.
Diabetes There are 3 types of diabetes: Type 1 The beta cells are mistakenly destroyed by an immune system response. The pancreas loses its ability to produce sufficient insulin. insulin. In type 1 diabetes, the body does not make insulin.
Diabetes There are 3 types of diabetes: Type 1 Type 2 In type 2 diabetes, the body has become insulin resistant.
Diabetes There are 3 types of diabetes: Type 1 Type 2 The beta cells produce insulin, but the cells of the body do not respond to it (insulin resistance). In type 2 diabetes, the body has become insulin resistant.
Diabetes There are 3 types of diabetes: Type 1 Type 2 Gestational Most women have a 3.5% chance of getting gestational diabetes during pregnancy. The symptoms and treatment are very similar to type 2 diabetes. Women who have had gestational diabetes are at a greater risk of getting it again. Studies have shown that breast feeding reduces this risk.
Diabetes There are 3 types of diabetes: Type 1 Type 2 Gestational People with diabetes are at a greater risk of circulatory and nervous system disorders, especially at the feet. Other organs are also at risk.
Read pgs. 483-485 Do Q#1-5, 7 pg. 487 Complete the Mini Investigation pg. 486 parts A-G Due: Feb. 15 Closure: Feb. 19