What is the primary function of glucagon?

The primary function of glucagon is to stimulate glycogen breakdown in the liver. When blood glucose levels are low, glucagon is released from the alpha cells of the pancreas. Its role is to promote glycogenolysis, the process by which glycogen stored in the liver is converted back into glucose and released into the bloodstream. This action effectively raises blood glucose levels, ensuring that the body has an adequate supply of glucose for energy, especially critical during fasting or between meals.

This is a crucial counter-regulatory mechanism to insulin, which lowers blood glucose levels by facilitating glucose uptake into cells. By stimulating glycogen breakdown, glucagon plays an essential role in maintaining glucose homeostasis and ensuring that the body can access energy as needed.