Which division of the autonomic nervous system is responsible for the "fight or flight" response?

The division of the autonomic nervous system that is responsible for the "fight or flight" response is the sympathetic nervous system. This part of the nervous system initiates physiological changes that prepare the body to respond to perceived threats or emergencies. When activated, the sympathetic nervous system increases heart rate, dilates airways, and redirects blood flow to essential muscles while inhibiting non-essential functions like digestion. These changes collectively enhance the body's ability to react quickly and effectively in stressful situations.

In contrast, the parasympathetic nervous system is often referred to as the "rest and digest" system, which serves to calm the body after the stress response has passed. The somatic nervous system controls voluntary movements of skeletal muscles while the central nervous system comprises the brain and spinal cord, processing information and coordinating responses but not directly mediating the fight or flight response.