Fight-or-flight response: A physiological reaction triggered by the sympathetic nervous system that prepares an individual to either confront or flee from a perceived threat.
Sympathetic nervous system: The part of the autonomic nervous system responsible for activating the fight-or-flight response during stressful situations.
Adrenaline: A hormone released by the adrenal glands during moments of stress or excitement, which increases heart rate and provides a burst of energy.