You can’t fault a man for thinking his penis a single use tool. But it’s more like a Leatherman or a good Swiss Army knife. One great use is as a barometer for gauging the health of a man’s heart and blood vessels.
The structure of the penis is basically a sponge with a tiny artery that supplies blood. The sponge fills with blood, and the penis becomes erect. (It’s actually a really impressive piece of engineering, with veins at the outer edge of the sponge that are pressed closed as the penis fills, trapping the blood and holding the erection.) The artery supplying the sponge is very small, only about half the diameter of the coronary blood vessels supplying the heart. If the arteries are getting clogged, the arteries in the penis go before the heart ones do, giving a man a two to five years heads-up that something bad is happening, not just to the penis, but that may be life-threatening.
Recently published guidelines recommend that if a man is experiencing problems with erections, that he be evaluated for high cholesterol and other artery clogging problems, and that if the labs are out of whack, he be treated aggressively with medication.
As important as the penis is, the heart’s kind of necessary.