The<unk> , also called hyperarousal or the acute stress response, was first described by Walter Cannon in 1927. His theory states that animals react to threats with a general discharge of the sympathetic nervous system, priming the animal for<unk> ing or fleeing. This response was later recognized as the first stage of a general adaptation syndrome that regulates stress responses among vertebrates and other organisms.
Fight-or-flight response
Hemodynamic response
Stream of consciousness 
Hot flash
Vagovagal reflex
Cough reflex
Electric shock
Respiratory compensation