Volume 22, Issue 4 (October 1977)
The Use of Penile Plethysmography in a Medicolegal Evaluation
Since the pioneering research of Masters and Johnson , it has been widely recognized that sexual arousal in the human male and female is associated with a clear pattern of physiological changes. During the first part of the sexual response cycle both men and women demonstrate a vasocongestive reaction in the genital organs. In the healthy adult male a penile erection is caused by the vascular engorgement of the spongy corpora of the penis . In fact, the penis contains three cylindrical bodies of erectile tissue: the corpora cavernosa are the two dorsal cylinders, and the corpus spongiosum is the ventral cylinder through which passes the urethra. Each of these cylinders is composed of many small compartments separated by bands of smooth-muscle tissue. The arterioles supplying blood to these tissues are derived from the internal pudendal artery. Contractions of the muscles at the base of the penis appear to play a minimal role in the normal process of erection.