What division of the Autonomic Nervous System is responsible for the "flight or fight" response?

The sympathetic nervous system is the division of the autonomic nervous system that is responsible for the "fight or flight" response. This response is a physiological reaction that occurs in response to a perceived threat or danger, triggering various bodily changes to prepare for either confronting the threat or fleeing from it.

When the sympathetic nervous system is activated, it releases adrenaline and other stress hormones that increase heart rate, dilate airways, expand blood vessels in the muscles, and redirect blood flow from non-essential functions, like digestion, toward essential systems that facilitate quick physical responses. This cascade of changes enables an individual to react swiftly in high-stress situations, either by fighting against a threat or fleeing from it.

The parasympathetic nervous system, on the other hand, is involved in the "rest and digest" functions and works to conserve energy by slowing down the heart rate and enhancing digestion after a stressful event has passed. The cognitive nervous system is not a recognized division, and while the central nervous system encompasses the brain and spinal cord, it does not specifically mediate the fight or flight response. Therefore, the sympathetic nervous system is clearly the correct choice for its role in activating the body's acute stress response.