What is the role of glucagon in the body?

Glucagon plays a crucial role in maintaining blood glucose levels during fasting or when energy demands increase. It is a hormone produced by the alpha cells of the pancreas and is primarily responsible for stimulating the liver to convert stored glycogen into glucose through a process called glycogenolysis. This conversion releases glucose into the bloodstream, which is vital for providing energy, especially during periods of low intake or high physical activity.

By increasing the availability of glucose, glucagon ensures that the body has a steady source of energy to support various physiological functions, particularly for the brain and muscles. This mechanism is essential in preventing hypoglycemia (low blood sugar levels) and contributes significantly to overall metabolic regulation.

In contrast, the other options do not accurately describe the primary functions of glucagon. For instance, while insulin is indeed involved in lowering blood glucose levels, it is not stimulated by glucagon; rather, the two hormones have opposing actions. The regulation of thyroid hormones is primarily the function of the thyroid-stimulating hormone, not glucagon. Moreover, glucagon does not have a direct role in increasing muscle mass; that function is more associated with hormones like testosterone and growth hormone. Thus, the correct answer emphasizes glucagon's vital role in converting glycogen