Which division of the autonomic nervous system is often referred to as 'fight or flight'?

The sympathetic division of the autonomic nervous system is often referred to as the "fight or flight" system because it is responsible for preparing the body to respond to perceived threats or emergencies. When activated, this division triggers a series of physiological changes that enable the body to react quickly and effectively in stressful situations. These changes include increased heart rate, dilated pupils, and redirected blood flow toward the muscles while inhibiting non-essential functions like digestion.

This division functions by releasing neurotransmitters such as norepinephrine, which amplifies the body's alertness and energy levels, providing the necessary resources for quick action. In contrast, the parasympathetic division promotes the "rest and digest" state, which conserves energy and restores the body to a calm state after the stressor has passed. The other options, such as centripetal and somatic divisions, do not relate to the autonomic nervous system's response to stress. The centric division is not a recognized part of the autonomic system, and the somatic division is responsible for voluntary muscle movements rather than autonomic processes. Therefore, the sympathetic division's role in managing immediate and intense stress responses is what makes it synonymous with "fight or flight."