Which hormone is associated with the fight-or-flight response?

The hormone associated with the fight-or-flight response is adrenaline. This response is part of the body's acute stress response, which prepares an individual to either confront or flee from a threat. When faced with a stressful situation, the adrenal glands release adrenaline into the bloodstream, leading to various physiological changes. These changes include an increase in heart rate, heightened blood pressure, and the release of energy stores from the body, all of which enhance physical capabilities to react quickly in emergencies.

Adrenaline's role is critical because it enables rapid responses to stress by preparing the body for immediate action. This is distinct from the roles of insulin, oxytocin, and cortisol, as they do not directly mediate the immediate physiological changes required for a fight-or-flight reaction. Insulin is primarily involved in regulating blood sugar levels, oxytocin is related to social bonding and reproduction, and cortisol is a stress hormone that responds to prolonged stress rather than immediate threats.