Both epinephrine and norepinephrine are released by adrenal medulla when the body comes under stress. They are the fight and flight hormones of the body and in stress condition, the sympathetic nervous system becomes activated which trigger the release of these hormones from the adrenal gland.
They alert the mind and prepares the body to make a quick decision in stress conditions like in anger or fear. Their release cause increase of heart rate, breath rate, blood flow.
So epinephrine and norepinephrine prepares the body to cope up with stress by fighting with the stress or by flighting away from stress.
