Final answer:
Insulin is the hormone prominently secreted during the absorptive state to regulate blood glucose levels by facilitating glucose uptake into cells and storage, whereas glucagon plays the opposite role in the post-absorptive state.
Step-by-step explanation:
The major hormone secreted during the absorptive state is insulin. The absorptive state, also known as the fed state, occurs shortly after eating when nutrients from the food are absorbed into the bloodstream from the gut. During this time, blood glucose levels rise, which signals the pancreas to secrete insulin. Insulin plays a pivotal role by facilitating the uptake of glucose into cells and promoting the storage of excess nutrients. It not only helps to lower blood glucose levels by enhancing glucose utilization and storage but also inhibits the breakdown of fat (lipolysis), thus supporting the body's anabolic processes.
Conversely, glucagon is secreted during the post-absorptive state or fasting state, when blood glucose levels decline. It functions to raise blood glucose levels by promoting the conversion of stored glycogen into glucose in the liver and the formation of new glucose via gluconeogenesis. The secretion of insulin by the pancreas is a classic example of a negative feedback loop triggered by an increase in blood glucose levels.