Impotence information

How Does Erection Occur?

During sexual arousal, the genital organs relax and become engorged with blood. In men, transmission of nerve impulses from the brain to the penis causes an increased blood flow to the male organ. This sudden influx of blood expands the muscles of the penis and produces an erection by straightening and stiffening its muscles. Continued sexual arousal maintains a higher rate of blood flow into the genital organ and limits the blood flow out of it, causing firmness of the penis. After ejaculation or sexual climax, the excess blood drains out, and the penis returns to its non-erect size and shape.

In women, the enlargement of the clitoris and the surrounding tissues are comparable to the erection of the penis. Physiology of orgasm in female can be categorized in four distinct stages. The first stage is the excitement stage. The heart and respiration rates increase, and the blood pressure goes up. The clitoris swells and the vagina begins to lubricate itself. The blood vessels narrow, and when this is coupled with an increased heart rate, flushing of the skin occurs. Breasts may swell and the nipples harden and taut. The entire excitement process can happen in a matter of seconds from the onset of sexual stimulation. Stage two is called the plateau. The body continues to experience the aforementioned changes. Further stimulation will cause the inner lips of the vagina to darken due to the increased blood flow to the genital area. By the end of this stage, the pulse and respiration rates have peaked, pushing the body into the third stage. The third stage is the actual orgasm, when the clitoris retracts and the vagina tightens and lengthens. Spasms of the vaginal and anal muscle occur rhythmically like wavelike contractions that move from the top of the uterus to the cervix. Other changes related to the female orgasm include muscle contractions throughout the body, more notably in the neck, pelvis, arms and legs. The fourth and final stage of the physiology of orgasm is often referred to as the resolution stage. The excess blood will drain from the genital area, and the clitoris returns to its normal size. The body returns to its previous, non-stimulated state.