In response to high blood glucose concentrations, insulin is released from the pancreas into the blood. Insulin acts on cells (especially liver cells) and causes glucose to move from the blood into these cells where it becomes converted to glycogen for storage. The removal of glucose from the blood lowers blood glucose concentration to a normal level.In response to low blood glucose concentrations, glucagon is released from the pancreas into the blood. Glucagon acts on cells, causing them to convert glycogen stored in the cell into glucose. This glucose is released into the blood to increase blood glucose levels back to normal.