Final answer:
The hormone glucagon is released to raise blood sugar levels when we are hungry, while cortisol aids in breaking down fats and proteins for energy. Leptin, a satiety hormone, also adjusts with changes in energy stores, influencing hunger and energy balance.
Step-by-step explanation:
When we are hungry and our blood glucose levels are low, the hormone glucagon is released by the pancreas. Glucagon's primary function is to increase blood sugar levels by signaling the liver to convert stored glycogen into glucose, which is then released into the bloodstream. This process helps preserve and increase the body's energy levels during times of fasting or starvation.
In addition to glucagon, the hormone cortisol also plays a role in maintaining energy homeostasis during periods without food. Cortisol increases the breakdown of fats and proteins, which can be used as alternative energy sources to glucose.
Leptin is another hormone, primarily produced by adipose (fat) tissues, that can influence our sense of satiation. Although leptin primarily plays a role in signaling satiety and is usually associated with the prevention of overeating, its levels do fluctuate in response to changes in body fat and energy stores. When body fat decreases, leptin levels drop, which can increase hunger, encouraging food intake to restore energy balance.