[New findings on the physiology of erection or the concept of the active sponge]

Until these last years, erection was mainly explained by neurovascular mechanisms. The erectile bodies were assimilated as a simple sponge passively filled or emptied by an unbalance between the arterial and venous flows. In fact, the erectile bodies themselves control the erection thanks to their potent smooth musculature. By contracting, they induce both flaccidity and detumescence, since their relaxation releases the erection. The erectile bodies work really as a kind of active sponge having the property to be autonomous and distortionable. However, the contractility of the erectile bodies cannot alone explain all the erection. This complex hydraulic process requires also complementary vascular mechanisms (cavernous outflow blockade, arteriodilatation) and tissular mechanisms (extrinsic compression of erectile striated muscles, specific distortion of each erectile body) under both hormonal and neuro-psychic control. By pointing up the fact that the active and passive tissue mechanisms play a major role for erection, this active sponge concept underlines the necessity for investigating the erectile tissues and allows to reconsider both physiopathology and treatment of dyserections.