Which nervous system prepares the body for "fight or flight" responses?

The sympathetic nervous system is responsible for preparing the body for "fight or flight" responses, which are crucial for survival in stressful or threatening situations. When activated, this system increases heart rate, dilates airways, and redirects blood flow away from non-essential functions (like digestion) towards muscles and the brain, enhancing the body’s ability to respond to stressors. This response is mediated through the release of hormones such as adrenaline and norepinephrine, which contribute to heightened alertness and physical readiness.

In contrast, the central nervous system consists of the brain and spinal cord and is primarily responsible for processing information and coordinating responses, rather than directly regulating "fight or flight" mechanisms. The somatic nervous system controls voluntary movements of skeletal muscles and is not directly involved in autonomic stress responses. The parasympathetic nervous system, on the other hand, promotes "rest and digest" activities, counteracting the sympathetic nervous system's effects by calming the body down and conserving energy after a stressful event. Therefore, the sympathetic nervous system is the correct choice for initiating the body's acute stress response.