Control of blood glucose concentration

• How does the pancreas respond when blood glucose levels are too high?

  • pancreas secretes insulin.
  • insulin binds to receptors on the liver and muscles, causing excess glucose to be converted into glycogen and stored
• How does the pancreas respond when blood glucose levels are too low?

  • Pancreas secretes glucagon.
  • glucagon binds to liver cells, causing glycogen to be converted into glucose and released into the blood
• How is blood glucose concentration controlled using a negative feedback loop?

  • when the concentration rises or falls below the optimum, a hormone is secreted by the pancreas
  • action of either hormone helps bring back the concentration to the correct level
• What is type 1 diabetes?

  • autoimmune disorder in which the pancreas doesn’t produce enough insulin to control the blood glucose concentration
  • as a result, blood glucose levels are often very high, leading to excessive urination, tiredness and weight loss
• How can type 1 diabetes be treated?

  • insulin injections before meals - allows glucose to be converted into glycogen
  • limiting carbohydrate intake
  • attempts using pancreas and pancreatic cell transplants; investigations into genetic engineering of pancreatic cells
• What is type 2 diabetes?

  • disorder in which body’s cells stop responding to insulin, leading to an uncontrolled blood glucose concentration
  • its onset is linked with increasing age and obesity
• How can type 2 diabetes be treated?

  • following a carefully-controlled diet
  • doing regular exercise
  • losing weight
  • use of drugs which increase insulin production and effectiveness