How does glucagon affect blood glucose concentration?

Glucagon increases blood glucose concentration by stimulating the conversion of stored glycogen into glucose in the liver.

Glucagon is a hormone produced by the alpha cells in the pancreas. It plays a crucial role in maintaining the body's energy balance by regulating blood glucose levels. When blood glucose levels drop, for instance during periods of fasting or between meals, the pancreas releases glucagon into the bloodstream.

Once in the bloodstream, glucagon travels to the liver where it stimulates the conversion of stored glycogen into glucose. This process is known as glycogenolysis. The newly formed glucose is then released into the bloodstream, thereby increasing blood glucose concentration. This ensures that the body's cells have a constant supply of glucose to use as fuel, even when dietary intake is low.

In addition to stimulating glycogenolysis, glucagon also promotes the production of glucose from non-carbohydrate sources, such as amino acids and fats. This process, known as gluconeogenesis, further contributes to the increase in blood glucose concentration.

It's important to note that glucagon and insulin work together in a sort of 'see-saw' effect to maintain blood glucose levels. When blood glucose levels are high, the pancreas releases insulin to promote the uptake of glucose by cells and reduce blood glucose concentration. Conversely, when blood glucose levels are low, the pancreas releases glucagon to increase blood glucose concentration. This balance between insulin and glucagon ensures that the body's cells always have access to the energy they need to function properly.