How does the body primarily respond to low blood glucose levels?

The body's primary response to low blood glucose levels is the release of glucagon from the pancreas. When blood glucose levels drop, the alpha cells of the pancreas detect this decrease and secrete glucagon. Glucagon plays a crucial role in elevating blood glucose levels by promoting glycogenolysis, the process in which glycogen stored in the liver is broken down into glucose and released into the bloodstream. Additionally, glucagon stimulates gluconeogenesis, the production of glucose from non-carbohydrate sources, further helping to restore normal blood glucose levels.

The release of insulin, which lowers blood glucose by facilitating cellular uptake of glucose and promoting glycogen storage, occurs when glucose levels are high. This is the opposite response needed during hypoglycemia.

While the reduction of glycogen synthesis and an increase in lipolysis can occur during metabolic states, they do not directly respond to low blood glucose levels with the same immediacy as glucagon release. Therefore, the secretion of glucagon is the primary mechanism aimed at correcting low blood glucose levels effectively.