We have described how the stress response is mediated via different chemicals, notably noradrenaline, adrenaline and cortisol, so that different body actions can take place. It is possible to identify those signs in the body and mind which are produced by the action of noradrenaline, adrenaline or cortisol.
Noradrenaline is associated with aggression and fighting behaviour as shown by changes in facial muscle tenseness and drawing back of lips to show the teeth which are clenched together. The back and shoulder muscles tense (hunched shoulders) and the fists clench. Hairs stand more erect; this is seen as goose pimples’ since humans have relatively little body hair compared to other animals. All this action is to make us look more threatening and hostile. Also, the skin blood vessels constrict, and the palms of the hands, the feet and the upper lip become sweaty. The pupil of the eye dilates, mental alertness increases, thinking and decision-making become quicker and performance improves. Noradrenaline produces a feeling of pleasantness and excitement in the absence of irritation, anger and hostility.