During the absorptive state, what is the primary hormone involved in metabolism regulation?

• A. Adrenaline
• B. Insulin
• C. Cortisol
• D. Glucagon

Answer: (B)

During the absorptive state, the primary hormone involved in the regulation of metabolism is insulin. This hormone is secreted by the beta cells of the pancreas in response to elevated blood glucose levels after food intake. Insulin plays a critical role in facilitating the uptake of glucose into tissues, particularly muscle and adipose tissue, where it can be used for energy or stored as glycogen and fat, respectively.

Insulin also promotes the synthesis of proteins and lipids, enhancing nutrient storage during this state. Its effects help to lower blood sugar levels after meals, ensuring that glucose is not only utilized but also stored for future energy needs. This hormone essentially signals the body's cells to absorb nutrients and indicates that there are ample resources available for energy and growth, which is characteristic of the absorptive state.

In contrast, the other hormones listed have different roles. Adrenaline is primarily involved in the fight-or-flight response and typically elevates blood glucose levels. Cortisol plays a significant role in stress response and can promote gluconeogenesis and lipolysis. Glucagon, secreted by alpha cells of the pancreas, typically functions to raise blood glucose levels, especially during fasting or between meals, making it less relevant in the context of the absorptive state.