controlling blood glucose

• Blood glucose concentration


  The amount of sugar in our bloodstream
• We need a decent amount of sugar in our blood so that our cells have a constant supply of glucose for respiration
• If the blood glucose concentration gets too high it can start to damage our tissues
• What happens when we eat a big meal with lots of carbohydrates

  1. Carbohydrates broken down in intestines into glucose

  2. Glucose absorbed into bloodstream

  3. Blood glucose concentration increases
• Pancreas


  • Organ that sits just behind the stomach
  • Releases insulin and glucagon hormones
• How insulin regulates high blood glucose

  1. Pancreas detects high glucose

  2. Releases insulin into bloodstream

  3. Insulin binds to cells (liver, muscle)

  4. Cells take up glucose from blood

  5. Blood glucose concentration decreases
• Glycogen


  Long-term storage form of glucose
• How glucagon regulates low blood glucose

  1. Pancreas detects low glucose

  2. Releases glucagon into bloodstream

  3. Glucagon binds to liver cells

  4. Liver breaks down glycogen into glucose

  5. Glucose released into blood

  6. Blood glucose concentration increases
• Insulin and glucagon


  Create a negative feedback loop to keep blood glucose at the right level
• Our bodies constantly release insulin and glucagon to ensure blood glucose is kept at the right level