Final answer:
Blood glucose homeostasis is mainly regulated by insulin, which decreases blood sugar levels by enhancing glucose uptake by cells, and glucagon, which raises blood sugar levels by converting glycogen back into glucose in the liver.
Step-by-step explanation:
Blood glucose homeostasis is regulated primarily by two key hormones: insulin, which helps to move glucose from the blood into the cells, and glucagon, which brings glucose out of storage when necessary. When blood glucose levels are high, insulin is secreted by the beta cells of the pancreas, prompting cells to absorb glucose and use it for energy in the form of ATP, or storing it as glycogen in the liver. Glucagon is secreted by the alpha cells of the pancreas when blood glucose levels are low, triggering the liver to convert stored glycogen back into glucose and release it into the bloodstream.