Which nervous system is responsible for the body's fight or flight response?

The nervous system responsible for the body's fight or flight response is the sympathetic nervous system. This system is part of the autonomic nervous system, which controls involuntary bodily functions. When a person faces a perceived threat, the sympathetic nervous system is activated, triggering a series of physiological changes that prepare the body to either confront or flee from the danger. These changes include an increase in heart rate, dilation of airways, and release of adrenaline, all aimed at enhancing physical performance and ensuring survival.

The other options, while related to the nervous system, do not play the same role in the fight or flight response. The peripheral nervous system includes both the sympathetic and parasympathetic nervous systems, acting as a conduit for information between the central nervous system and the rest of the body. The central nervous system, comprised of the brain and spinal cord, oversees the overall processing of information but does not directly induce the fight or flight response. The parasympathetic nervous system, on the other hand, generally promotes a state of rest and relaxation, counteracting the effects of the sympathetic system. Therefore, when discussing the body's acute stress response, the sympathetic nervous system is clearly identified as the critical component.