Emotions begin inside two almond-shaped structures in the brain called the
amygdala<1>. The amygdala is responsible for identifying
threats, and for sending out alarms when threats are identified. The
amygdala is so efficient at warning about threats, that it causes us to react before the cortex (the part of the brain responsible for thought and judgment) is able to check on the reasonableness of the reaction. In other words, the brain is networked in such a way as to implement the action before its consequences are logically considered.
As one becomes angry the body''s muscles tense up. Inside the brain, neurotransmitter chemicals known as catecholamines are released causing an experience of a burst of energy lasting up to several minutes. At the same time the heart beat increases, the blood pressure rises, and so does the rate of breathing. The face may flush as increased blood flow enters the limbs and extremities in preparation for physical action. In quick succession, additional brain neurotransmitters and hormones, adrenaline and noradrenaline are released which trigger a lasting state of arousal.
The emotional progression to rage is usually stopped before getting out of control. The
prefrontal cortex of the brain keeps emotions in proportion to the stimulus. The amygdala initiates emotion, the prefrontal cortex moderates emotion through judgment. The left prefrontal cortex can switch off the emotions. It serves to keep things under control. Getting control of the emotion of anger means learning ways to help the prefrontal cortex get the upper hand over the amygdala so that the angry person has control over the reactions to anger feelings.
If anger has a physiological preparation phase during which the body resources are mobilized for a fight, it also has a wind-down phase as well. The body starts to relax back towards its resting state when the target of the anger is no longer accessible or an immediate threat. It is difficult to relax from an angry state very quickly. The adrenaline-caused arousal that occurs during anger lasts a very long time (many hours, sometimes days), and lowers the anger threshold, making it easier for the person to get angry again later on. It takes a rather long time for the body to return to the resting state. During this slow cool-down period the angered person is more susceptible to anger in response to even minor irritations.