Le controle du reseau vasculaire cutane

In man, three kinds of sympathetic neurons reach the skin. Some cholinergic neurons stimulate the sweat glands, they are excited by temperature-regulating centers. Adrenergic neurons release noradrenaline and ATP to reduce cutaneous blood flow while cholinergic neurons release acetylcholine and a co-transmitter to dilate skin blood vessels. The excitation of both latter types of nerve cells depends on influences from temperature-regulating centers, baroreceptors and exercise. Moreover, in cutaneous blood vessels, a synthesis of NO is enhanced by an increase of body temperature and overall by direct heating of the skin. Burns are associated with axon reflexes and release of inflammatory mediators. The involvement of these various influences is described.