Which hormone is most commonly associated with the sympathetic nervous system activation?

The hormone most commonly associated with the activation of the sympathetic nervous system is adrenaline, also known as epinephrine. When the sympathetic nervous system is activated, such as in response to stress or danger, the adrenal glands release epinephrine into the bloodstream. This hormone plays a crucial role in the "fight or flight" response, leading to various physiological changes such as increased heart rate, dilation of the airways, and increased blood flow to muscles. These changes prepare the body to respond to immediate threats by enhancing physical performance and alertness.

In contrast, cortisol is primarily linked to the body’s long-term stress response rather than immediate sympathetic activation. Dopamine is a neurotransmitter involved in various functions including mood regulation and reward pathways but is not directly tied to sympathetic nervous system activation. Insulin, produced by the pancreas, regulates blood glucose levels and is more associated with metabolic processes rather than the physiological changes induced by the sympathetic nervous system.