Final answer:
Glucagon raises blood glucose levels by promoting the synthesis of glucose, stimulating glycogen breakdown, and stimulating gluconeogenesis.
Step-by-step explanation:
Glucagon is a hormone that raises blood glucose levels by promoting the synthesis of glucose, stimulating the breakdown of liver glycogen, and stimulating gluconeogenesis. When blood glucose levels are low, glucagon is released from the pancreas and acts on liver and muscle cells to release glucose into the bloodstream. Glucagon also stimulates the breakdown of stored glycogen in the liver and promotes the synthesis of glucose from amino acids via gluconeogenesis.