Читать книгу Sex For Dummies - Pierre Lehu A., Dr. Ruth K. Westheimer - Страница 33

Basically, a penis is composed of three structures (see Figure 2-1), which are made of a spongelike material that can fill with blood.

 The two corpus cavernosa contain the central arteries and lie on the top half of the penis. They are cylindrical tubes and are larger than the other spongy structure.

 The corpus spongiosum, which is under the two corpus cavernosa and surrounds the urethra, is the pipeline for both urine and sperm.

Illustration by Kathryn Born

FIGURE 2-1: The penis: not as simple as it looks!

When a man becomes excited — and I’m not talking about watching his team score the winning touchdown here — the nerves surrounding his penis become active, causing the muscles around the arteries to relax and more blood to flow into the penis. The spongelike material then absorbs the additional blood, making the penis stiff and hard, or erect. This erection tightens the veins so the blood can’t leave the penis, enabling the penis to remain erect. After a man ejaculates or if his arousal fades, detumescence occurs, in which the brain sends a signal to allow the blood to leave the erect penis, and it returns to its flaccid state.

At the base of the penis, the two corpus cavernosa split to form a Y, where the two ends connect to the pubic bone. This ligament controls the angle of the erect penis. I get many questions from men, each asking me if something is wrong with him because the angle of his erect penis isn’t straight out, parallel to the floor. I tell all of them not to go hanging any weights in an effort to change the angle, because they have nothing to worry about!

Penises become erect at all different angles — and the angle doesn’t have any effect on the way the penis performs. As a man gets older, the ligament at the base of his penis stretches, and the angle changes. A man of 70, for example, may have an erection that points downward instead of upward, the way many a young man’s erection does.