Which hormones are primarily involved in normal metabolism during resting and light activity?

Insulin and glucagon are two critical hormones that play a primary role in regulating metabolism, especially during periods of rest and light activity. Insulin is produced by the pancreas in response to elevated blood glucose levels, such as after a meal. Its primary role is to facilitate the uptake of glucose by the cells, promote the storage of glucose as glycogen in the liver and muscle tissue, and stimulate the synthesis of fats. This action leads to a decrease in blood glucose levels, promoting an anabolic state that supports growth and energy storage.

On the other hand, glucagon acts as a counter-regulatory hormone, being released when blood glucose levels are low. Its main function is to stimulate the liver to break down glycogen into glucose (glycogenolysis) and initiate gluconeogenesis, the process of producing glucose from non-carbohydrate sources. This ensures a continuous supply of glucose for energy, particularly important during fasting states and between meals.

Together, insulin and glucagon work in tandem to maintain blood glucose homeostasis and provide a stable energy supply, which is crucial during resting and light activity. The interplay of these hormones allows the body to efficiently utilize energy substrates based on metabolic needs, making them essential players in normal metabolic processes.