Control of blood glucose concentration

• Insulin

  Hormone used to control the blood glucose concentration
• How insulin controls blood glucose concentration

  1. Pancreas senses rise in blood glucose after meal

  2. Pancreas produces insulin

  3. Insulin triggers body cells to take up glucose from blood

  4. Insulin triggers liver and muscle cells to store excess glucose as glycogen

  5. Blood glucose concentration returns to normal
• Type 1 diabetes

  Pancreas does not produce enough insulin
• Type 1 diabetes

  • Blood glucose concentration rises and stays high
  • Patients monitor blood glucose and inject insulin
• Type 2 diabetes

  Body cells stop responding to insulin produced by pancreas
• Type 2 diabetes

  • Blood glucose levels can rise too high
  • Treated with diet containing controlled carbohydrates
  • Patients advised to exercise
  • Obesity is a major risk factor
• Glucagon

  Hormone released by pancreas when blood glucose concentration falls
• How glucagon controls blood glucose concentration

  1. Pancreas senses fall in blood glucose

  2. Pancreas releases glucagon

  3. Glucagon triggers liver cells to convert glycogen to glucose

  4. Glucose released into blood

  5. Blood glucose concentration returns to normal
• Insulin and glucagon

  • Have opposite effects on blood glucose concentration
  • Form a negative feedback cycle
• Blood glucose concentration in a person without diabetes rises and falls slightly over the course of the day