Explain how the body responds to increases and decrease in blood glucose concentration:

When the concentration of glucose in the blood increases, insulin (a hormone) is secreted by the pancreas. It binds to cells, stimulating them to increase their uptake of glucose, hence decreasing the amount in the blood. In contrast, when the concentration of glucose decreases, glucagon (another hormone) is secreted by the pancreas. Glucagon stimulates cells to breakdown glycogen into glucose, which is then released into the blood.