Which body system is responsible for preparing the body for fight or flight?

The sympathetic nervous system, part of the autonomic nervous system, also known as the involuntary system, is in charge of the fight-or-flight response, a response to the stress that leads to a hormonal cascade that boosts alertness and heart rate to prepare the body to respond.

Explanation:

Rapid heart rate and breathing: Heartbeat and respiration rate increase to provide the body with the energy and oxygen needed to fuel a rapid response to danger. 2  Trembling: The muscles tense and become primed for action, which can cause trembling or shaking.