Our emotions have profound and measurable effects on our bodies. When we're angry, a number of bodily changes immediately begin to take place.
The autonomic nervous system controls the cardiovascular system and the endocrine system. Upon the inducement of anger, heart rate and arterial tension rises. Testosterone production increases. The stress hormone cortisol decreases.
Changes also begin to take place in cerebral activity, in the form of asymmetric activation. The brain's left hemisphere immediately receives more stimulation.
Scientists from the University of Valencia have performed research on the inducement of anger and asymmetric activation, as well as the cardiovascular and hormonal responses that anger triggers in us physically and psychologically.
"This is the first general study on emotions and more specifically on anger that examines all these different psychobiological parameters (cardiovascular, hormonal response and asymmetric activation response of the brain) in a single investigation to study the changes caused by the inducement of anger."
http://www.sciencedaily.com/releases/2010/05/100531082603.htm