Identify the hormone that will dominate in the post absorptive state
The correct answer and explanation is:
The hormone that dominates in the post-absorptive state is glucagon.
The post-absorptive state, also known as the fasting state, occurs after the absorption of nutrients from a meal is complete. During this state, the body shifts from using nutrients obtained from food to relying on stored energy. In this phase, glucose levels in the blood begin to drop since food has been digested and absorbed, and insulin, which helps store glucose, decreases its activity. Glucagon, which is secreted by the alpha cells of the pancreas, takes on a dominant role in regulating blood sugar levels.
Glucagon works by stimulating the liver to break down glycogen into glucose through a process called glycogenolysis. This glucose is then released into the bloodstream to maintain blood sugar levels within a normal range. Additionally, glucagon promotes gluconeogenesis, the production of new glucose from non-carbohydrate sources like amino acids and lactate. These processes ensure that the body has a continuous supply of glucose, which is essential for energy, particularly for the brain and muscles, which rely heavily on glucose.
In the post-absorptive state, the body must prevent blood sugar from dropping too low. Glucagon counters this by increasing glucose production and preventing its excessive use. This balance between glucagon and insulin helps to maintain homeostasis. The actions of glucagon are opposed by insulin, which is more active during the absorptive state (when the body is digesting food and absorbing nutrients). Therefore, as insulin levels decrease after a meal and blood glucose levels start to fall, glucagon levels increase to help regulate energy production from stored reserves.