Secretion of glucagon from the pancreas results in break down of glycogen, which causes an increase in blood glucose levels. Glucagon is a hormone that is produced by alpha cells in a part of the pancreas known as the islets of Langerhans. It is released in response to low blood glucose levels and to events where the body needs additional glucose, such as in response to vigorous exercise. It stimulates break down of glycogen, activates gluconeogenesis (the conversion of amino aids to glucose) and break down of stored fats into fatty acids. This results to high blood glucose levels.