The fight-or-flight response is an innate physiological reaction to perceived threats, allowing individuals to either confront the danger or flee from it. This response is largely facilitated by the secretion of adrenaline into the bloodstream, which helps the body mobilize energy reserves and enhances reaction time. For instance, in a scenario where a person encounters a venomous snake, the surge of adrenaline enables rapid decision-making and execution of evasive maneuvers.