The main effect of glucagon is to increase blood glucose levels.
How Glucagon Increases Blood Glucose
Glucagon achieves this primarily through three mechanisms:
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Increased liver glucose production: Glucagon stimulates the liver to produce more glucose from stored glycogen and other precursors. This process is called gluconeogenesis.
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Decreased liver glucose consumption: Glucagon reduces the liver's uptake and use of glucose, making more available for release into the bloodstream.
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Increased glycogen breakdown (glycogenolysis): Glucagon promotes the breakdown of glycogen, the storage form of glucose in the liver, releasing glucose molecules into the bloodstream.
These actions are crucial in maintaining blood sugar levels, especially during periods of fasting or low blood glucose. Glucagon acts as a counter-regulatory hormone to insulin, which lowers blood glucose.
The reference states: "The function of glucagon is primarily to raise blood glucose levels. It does this by increasing liver glucose production, decreasing liver glucose consumption, and increasing glycogen (a glucose storage molecule) breakdown." This directly supports the answer.
