Orgasm is a physical reflex, usually a pleasurable one, when the muscles that were tightened during sexual arousal relax and the body returns to its pre-arousal state. During sexual arousal there is increased blood flow to the genitals and tensing of muscles throughout the body and particularly in the genitals. Orgasm reverses this process through a series of rhythmic contractions. For women, contractions occur in the lower part of the vagina, in the uterus, anus, and pelvic floor. About 10 percent of women also ejaculate fluid from the urethra at orgasm.