What hormone is responsible for stimulating the sympathetic nervous system?

The hormone responsible for stimulating the sympathetic nervous system is epinephrine, which is also commonly known as adrenaline. When released into the bloodstream, epinephrine prepares the body for a 'fight or flight' response, enhancing the body's ability to respond to stress. It increases heart rate, dilates air passages, and promotes the release of glucose from energy stores, among many other physiological changes. These effects make the body more efficient in handling stressful situations that require quick action.

Epinephrine is secreted by the adrenal medulla and plays a crucial role in the overall function of the sympathetic nervous system, which is activated during times of acute stress or danger. While cortisol, adrenaline, and norepinephrine are all important in the body's stress response, the specific role of epinephrine as a potent stimulator of the sympathetic nervous system positions it as the key hormone in this context.