What system controls the fight or flight reaction?

The sympathetic nervous system is the primary system responsible for controlling the fight or flight reaction. This physiological response prepares the body to confront or flee from perceived threats or harmful situations. When faced with stress, the sympathetic nervous system activates a range of bodily responses: heart rate increases, blood pressure rises, respiratory rate quickens, and energy is mobilized to prepare muscles for action.

This reaction involves the release of hormones such as adrenaline (epinephrine) and norepinephrine, which enhance these effects, ensuring that the body can respond effectively to immediate challenges. The sympathetic system's role in managing stress responses is crucial for survival, as it enables quick and decisive actions during danger.

In contrast, the parasympathetic nervous system is more associated with rest and digestion, calming the body down after the threat has passed. The cerebral cortex is involved in higher-order functions, including decision-making and complex thought processes, but it does not directly manage the fight or flight response. The somatic nervous system is responsible for voluntary movements and reflexes, but it doesn't control the automatic responses involved in fight or flight.