sympathetic nervous system
The sympathetic nervous system initiates the flight-or-flight response in response to a perceived threat or harmful event.
During this response, the adrenal gland sends out signals to secrete norepinephrine and epinephrine. These hormones have many effects on the body during the fight-or-flight response, including:
- increase of blood flow to muscles
- pupil dilation
- increase in blood pressure
- increased awareness
- release of glucose into the blood stream