Final answer:
Glycogenolysis maintains stable blood glucose levels during fasting by breaking down stored glycogen into glucose, which is then used as an energy source for cells.
Step-by-step explanation:
When glucose levels fall between meals, glycogen is broken down in a process called glycogenolysis, maintaining a steady serum glucose. In the postabsorptive state, or fasting state, the body relies initially on stored glycogen to maintain blood glucose levels within the normal range of 80-120 mg/dL.
As glucose levels drop, glucagon is released from the alpha cells of the pancreas, stimulating the breakdown of glycogen in the liver, ensuring that the blood glucose levels remain stable.
During this process, the enzymes that break down glycogen become active. This enzymatic action results in the release of glucose into the bloodstream, which is then available as an energy source for the body cells. Glycogenolysis is one of the critical mechanisms that support glucose homeostasis in the human body.