After not eating since breakfast 6 hours ago, a student taking a test notices a period of hunger and fatigue. He doesn't have access to food because he is taking the test. About 10 minutes later, though, he begins to feel ok again and finishes the test with flying colors. What has happened in his body

Glycogenolysis occurred in his body as a compansatory mechanism to provide him energy to complete the test.

Explanation:

Glycogenolysis is a process involving the breakdown of glycogen, stored in the liver and muscle cells into glucose to provide immediate energy and maintain blood glucose levels during fasting. This process is mediated by the hormones glucagon and adrenaline. In the case of adrenaline however, the fight or flight mechanism is the trigger for its release and function in glycogenolysis while glucagon is released in the case of physiologic drop in blood glucose levels.

Upon physiologic drop in blood glucose levels, glucagon secretion in the pancreas is increased, reducing the secretion of insulin which stores up glucose in the body. The secreted glucagon then travels to the liver where it begins the process of glycogen breakdown to glucose.

Glucose-1-phosphate is formed, the reaction catalyzed by the enzyme glycogen phosphorylase. This molecule is then converted in the liver, kidneys, and intestines, to glucose-6-phosphate by the enzyme phosphoglucomutase. After the conversion, the enzyme glucose-6-phosphatase converts glucose-6-phosphate into free glucose that is secreted into the blood causing a restoration of the blood sugar levels and providing energy to the body.