What is the function of insulin in the body?

Insulin plays a crucial role in the body's management of glucose levels. Its primary function is to facilitate the absorption of glucose from the bloodstream into various cells, particularly muscle and fat cells. After eating, when blood sugar levels rise, the pancreas releases insulin. This hormone binds to insulin receptors on the surface of cells, signaling them to take in glucose. The glucose can then be used for energy or stored for future use.

The other options refer to functions that are not related to insulin. Generating glucose is primarily a function of the liver through processes like gluconeogenesis. Increasing heart rate is associated with the autonomic nervous system and hormones like adrenaline, while stimulating red blood cell production is primarily managed by erythropoietin produced by the kidneys in response to low oxygen levels, not by insulin. Thus, understanding insulin's specific role helps clarify the body's complex metabolic processes.