What controls the fight or fight response?

The fight or flight response is primarily controlled by the autonomic nervous system, specifically the sympathetic division. When faced with a perceived threat, the brain's amygdala activates, sending signals to the hypothalamus, which in turn stimulates the adrenal glands to release stress hormones like adrenaline and cortisol. These hormones prepare the body for immediate action by increasing heart rate, blood flow to muscles, and energy availability. This physiological response enhances survival by enabling quick reactions to danger.