Do you think your little brother can grow longer?

Do you think your penis can grow longer? Of course, maybe you have never thought about the possibility of your penis growing longer. But for men who have thought about this, here's a warning: "All surgeries, medications and techniques are ineffective, and some are not safe," says Karen Elizabeth Boyle, MD, director of male reproduction at Shadewood Reproductive Sciences in Rockville, Maryland. That's because the length of the corpora cavernosa — the two blood-filled "chambers" that produce an erection — is fixed and won't change with implants, vacuum devices or herbal supplements. The surgical solution is to make the flaccid penis look a little longer by shortening the ligament, with the result that the penis points downward instead of upward when erect. The good news is that most men don't need this kind of "penis enlargement surgery" - if your penis is 4-6 inches long when erect, it's normal.

On the other hand, nocturnal erections are controlled by the parasympathetic nervous system. This system controls our "rest and digest" response through a series of movements in the smooth muscle between the liver and the blood vessel walls. In a healthy penis, the parasympathetic nerves release nitric oxide, which relaxes the smooth muscles in the penile arteries. This causes excess blood to flow into two spongy, parallel "chambers" - the corpora cavernosa (literally, tubular bodies) - and cause them to become engorged with blood. During this process, the veins that normally drain blood out of these sacs are squeezed, causing blood to rush into the penis and become trapped there, creating that wonderful feeling in your penis.

These two nervous systems coordinate with each other, one is like the accelerator and the other is like the brake, and vice versa. A doctor friend explained that this is why you don't get an erection when a gun is pointed at your head. Conversely, you get a spontaneous erection when the nerves that control your ability to move your body are shut down by REM sleep.

This may solve some of the researchers' puzzle, but other researchers believe that nocturnal erections are so dramatic and persist throughout a man's life - from birth to old age - that they must be more than just a physiological accident.

"I think a flaccid penis is like an unstable oxygen supply, while an erect penis is more

It's kind of like charging a battery. "Said Irving Goldstein, MD. To study the possibility of this statement, Professor Goldstein and his colleagues injected samples of penile smooth muscle into different concentrations of oxygen. The result was: under low concentrations of oxygen, as the penis wilts, the smooth muscle will be damaged and turned into scar tissue; under high concentrations of oxygen, during the penile erection, the human body will naturally produce enzymes and will not cause damage to the smooth muscle.

Professor Goldstein said: "The penis is a very interesting balance, it forms scar tissue and then later in the same day it 'digests' that scar tissue at the same rate."

If Professor Goldstein's theory is correct, it could help drug researchers find a new way to treat erectile dysfunction. Today, we are comforted to learn that the human body is smart enough to keep us healthy even when we sleep. This discovery was soon put into practice.