What hormone is responsible for stimulating glucose production to increase blood sugar levels?

Glucagon is the hormone responsible for stimulating glucose production, primarily from the liver, thereby increasing blood sugar levels. When blood glucose levels drop, glucagon is released from the alpha cells of the pancreas. This hormone promotes glycogenolysis, which is the breakdown of glycogen into glucose, and gluconeogenesis, the process of synthesizing glucose from non-carbohydrate sources.

This action helps to counteract low blood sugar levels, ensuring that the body has a sufficient supply of glucose, especially when it's needed for energy between meals or during physical activities. The secretion of glucagon is particularly important during fasting or when the body requires a quick release of glucose into the bloodstream to maintain normal physiological functions.

In contrast, insulin, produced by the beta cells of the pancreas, has a lowering effect on blood sugar levels by facilitating the uptake of glucose into cells for energy or storage. Thyroxine is primarily involved in metabolic processes and regulating metabolism, while cortisol is a stress hormone that can influence glucose metabolism but is not the primary regulator of blood sugar levels like glucagon.