Final answer:
Following a meal, blood glucose levels increase, leading to the release of insulin, which promotes glucose uptake and conversion to glycogen, thus reducing glucose levels. During fasting, the hormone glucagon is released to raise glucose levels by breaking down glycogen and synthesizing new glucose, ensuring that blood glucose remains within a normal range.
Step-by-step explanation:
After eating, blood glucose levels rise, prompting beta cells in the pancreas to secrete insulin. This hormone facilitates the uptake of glucose by liver, fat, and muscle cells, where it's converted into glycogen or fats. Insulin also inhibits the production of glucose in the liver, which helps to lower the elevated blood glucose levels. When the body is in a fasting state, such as between meals or during exercise, and blood glucose levels drop, alpha cells in the pancreas release glucagon. This hormone triggers the breakdown of glycogen into glucose in the liver and muscles through a process called glycogenolysis, and it initiates gluconeogenesis, where new glucose is synthesized from amino acids. Additionally, glucagon encourages the release of fatty acids from adipose tissue. Together, insulin and glucagon maintain glucose homeostasis in the body.