PHYSIOLOGY OF AN ERECTION

When a man is sexually excited, the chemicals he secretes allow extra blood to be pumped into the erectile tissue of his penis. At the same time the erection itself presses on the veins, reducing outflow. An erect penis is a penis engorged with blood. Which is why the comic Robin Williams once said, "God gave us all a penis and a brain, but only enough blood to run one at a time."

Penises grow erect from base to head. One man described the feeling to me—"There's a faint warmth and sense of well-being, as if the sun has just moved over and covered you." The angle of erection varies from man to man but in general the younger a man is, the more his erections point up. As a man gets older he takes longer to reach a full erection and he may need direct stimulation of his penis.

During sex a man's testicles also increase in size and in most men at a certain point they elevate, pressing up against the pelvis. This elevation means ejaculation is near.

Ejaculation happens in two stages. Semen is formed during the first stage, when rhythmic contractions propel sperm from the testicles into the urethra to mix with seminal fluid from the seminal vesicles and the prostate. A man who experiences these contractions may say, "I'm coming" he feels he's on the verge of orgasm, and at the point of no return.

During the second stage of ejaculation, contractions of the urethra, the prostate and the pelvic muscles propel the semen out the opening of the urethra. About a tea-spoonful, containing 100 to 600 million sperm, is ejaculated at one time.

Here in the West we assume that orgasm, the intensely pleasurable feeling that accompanies ejaculation, can only occur during ejaculation—but this is not the case. Ejaculation is possible without orgasm (boys do it when they have wet dreams), and orgasm is possible without ejaculation. According to Chinese and Indian philosophies, orgasm without ejaculation is the path to ecstasy and superior health.

Orgasm can feel localized in the penis and testicles, or it can be more of a whole body experience. In the Hite Report on Male Sexuality one man says the sensation travels "down the back of my legs to the knees, up around my arms into my deep insides. The penis is only the focus for all this, the trigger." Another says, "I feel like my cock has roots that extend down the backs of my legs, and coming draws juice from clear down there."

After ejaculation the erection subsides, either at once or gradually, and for a short time a man's penis and balls may be very tender.

If a man becomes highly excited and doesn't ejaculate, his erection takes longer to go away and he may feel a heaviness and discomfort in his testicles. However, this condition, known as "blue balls," is not at all as painful as teenage boys, trying to seduce teenage girls, like to claim it is.



Source: The Book of the Penis by Maggie Paley