increase in blood glucose

• Increase in blood glucose concentration

  1. Blood glucose increases to above normal range

  2. Detected by B cells in the pancreas

  3. High glucose molecules enter B cells by facilitated diffusion

  4. Cells respire glucose and produce ATP

  5. High concentration of ATP causes potassium channels to close

  6. Change in membrane potential occurs

  7. Voltage-gated calcium channels open

  8. Influx of calcium ions causes beta cells to secrete insulin

  9. Insulin containing vesicles move towards cell surface membrane

  10. Release insulin into capillaries

  11. Insulin circulates around the body
• When blood glucose increases to above the normal range

  B cells in the pancreas detect it
• High concentration of ATP

  Causes potassium channels in the B cells to close
• This change in the membrane potential

  Causes voltage-gated calcium channels to open
• Influx of calcium ions

  Causes beta cells to secrete insulin
• Insulin containing vesicles move towards the cell surface membrane

  Release insulin into the capillaries
• Insulin

  A hormone secreted by beta cells in response to high blood glucose levels
• Insulin's effects

  • Stimulates the uptake of glucose by muscle cells
  • Stimulates the uptake of glucose by fat cells
  • Stimulates the uptake of glucose by the liver