What is the primary action of glucagon?

Glucagon's primary action is to promote glucose release from the liver. This hormone is produced by the alpha cells of the pancreas and plays a crucial role in maintaining glucose homeostasis, particularly when blood sugar levels drop. When the body experiences low blood glucose levels, glucagon is released into the bloodstream and targets the liver, where it stimulates the breakdown of glycogen into glucose through a process known as glycogenolysis. Additionally, glucagon also promotes gluconeogenesis, which is the production of glucose from non-carbohydrate sources. This multifaceted approach ensures that adequate glucose is available to meet the energy needs of the body, particularly for vital organs like the brain.

This action is critical in situations like fasting or intense exercise when blood glucose levels may fall, ensuring that the body has a continuous supply of energy.