Which hormone is primarily involved in increasing blood sugar levels?

Glucagon is the primary hormone responsible for increasing blood sugar levels. Produced by the alpha cells of the pancreas, glucagon plays a crucial role in glucose metabolism, particularly when blood sugar levels drop. It stimulates the liver to convert stored glycogen into glucose, a process known as glycogenolysis. Additionally, glucagon promotes gluconeogenesis, which is the synthesis of glucose from non-carbohydrate sources. This action helps to elevate blood sugar levels back to a normal range, ensuring that the body has a sufficient supply of glucose for energy, particularly for vital organs like the brain.

The other hormones listed interact with blood sugar but do not primarily function to raise its levels. For example, insulin, secreted by the pancreas, lowers blood glucose levels by facilitating the uptake of glucose by cells for energy or storage as glycogen. Cortisol, while it can raise blood sugar levels during stress responses, primarily acts to increase blood sugar through its effects on metabolism and has a more complex role. Adrenaline, also known as epinephrine, raises blood sugar levels quickly during stress or 'fight or flight' responses, but it does not have the primary role that glucagon does in regulating blood sugar levels during periods of fasting or low glucose avail