關於陰莖你不知道的事情

Use it or lose it

You need regular erections to keep your penis in shape. It must be intrinsically exercised.

To maintain healthy tone, the smooth muscles of the penis must be regularly replenished with oxygen through blood flow, engorging the penis with blood and allowing it to become erect.

If a man is physically capable of erections but never gets one during the day—and perhaps finds himself in very unsexy situations for long periods of time—there is no need to worry. The brain has automatic penis maintenance built into it.

Impulses from the brain can cause an erection during the dreaming stage of sleep, known as the rapid eye movement stage. Whether you're having sexy sex dreams or zombie apocalypse nightmares, your penis gets hard during this time in your sleep cycle.

But some men are physically unable to achieve an erection, such as those who have suffered trauma to their nerves or damage to nerves or blood vessels caused by diabetes.

If nothing is done to maintain a normal erection, the penis will shorten. Without a normal erection, the penile tissue becomes less elastic and shrinks, making the penis shorter by 1-2 cm.

Devices like a vacuum pump, which forces the penis to swell with blood, can help men with erection problems maintain a healthy penis.

There is no consistent relationship between the size of a flaccid penis and its fully erect length

In a study of 80 men, researchers found that the increase in length from flaccid to erect was substantial, from less than a quarter of an inch to 3.5 inches longer.

Whatever the clinical significance of these data, the implications in the locker room are considerable. You can't assume that a guy with a big, soft penis will get even bigger when erect. People with seemingly small penises may develop surprisingly large erections.

An analysis of more than a thousand measurements shows that shorter flaccid penises tend to be twice as long as longer flaccid penises.

Data suggests that most penises are not extreme show-offs or growers. About 12 percent of penises increase in length by one-third or less when erect, and about 7 percent double in length when erect.

Happy Zone

Many men believe that the underside of the glans penis (head) and the underside of the penile shaft are most sensitive to sexual pleasure.

Researchers asked 81 healthy men to rate the sexual sensitivity of different parts of their bodies, including not just the penis but also the scrotum, anus, nipples and neck.

For most men, sensitivity is highest on the underside of the glans penis and under the body of the penis, followed by the upper side of the glans penis, the left and right sides of the glans penis, both sides of the penis, the upper side of the shaft of the penis, and the foreskin (for the uncircumcised minority) of men). The findings were reported in the British Journal of Urology International in 2009.

Sensitivity decreases with age

Research shows that as men age, they gradually lose sensitivity in their penis, although it's difficult to say exactly how much. This is because different researchers use different methods to stimulate the penis and measure sensitivity.

Generally speaking, penile sensitivity is measured by the minimum amount of stimulation a man can feel. This is the so-called "sensory threshold".

Although there are differences between studies, the data show clear trends when taken together. Starting at age 25, sensitivity begins to decline. The greatest decrease in sensitivity occurs between the ages of 65 and 75.

Vibrators also work on the penis

Vibrators aren’t just for women. They also work on the penis. In fact, vibrations are so effective on the penis that men with spinal cord injuries can often ejaculate with the help of special medical vibrators. For this treatment, the vibrator is usually placed against the underside of the glans penis.

Most men don't need a medical vibrator to induce orgasm. When patients come to him about delayed ejaculation (difficulty reaching orgasm), he recommends they try a store-bought vibrating personal massager.

Although vibrators can often help men with ejaculation problems, no medical condition is required to use one. You can do this just for fun.

There's more to your penis than meets the eye

Most men would be proud to know that their penis is twice as long as they thought it was.

That's because half the length of your penis is inside you. Just like you can't see all of a large oak tree above ground, you can't see the base of your penis hidden within your pelvis and attached to your pubic bone.

As you can see from the MRI photo, the erect penis is shaped like a boomerang.

Your penis is a habitat

The skin of the penis is home to a diverse bacterial community.

Research shows that a total of 42 unique species of bacteria live on the skin of the penis.

The human body is essentially an ecosystem.

Research shows that uncircumcised and circumcised penises have different types and amounts of bacteria. The researchers first analyzed penis samples from 12 men scheduled to undergo circumcision. After the men were circumcised, samples were collected again and analyzed.

After circumcision, men have fewer types of bacteria on their penis. Many bacteria that are less common or absent after circumcision are anaerobic, meaning they don't need oxygen to grow.

The inner folds of the foreskin are mucous membranes, just like the inside of a human eyelid. Certain anaerobic bacteria thrive in this environment, but not on dry skin.

The types of bacteria found in men in other parts of the world vary.

Research may help explain why circumcision is associated with a lower risk of HIV infection. One theory is that anaerobic bacteria may prompt an immune system response that makes cells more susceptible to HIV infection.

Most men are not circumcised

Globally, approximately 37% to 39% of males aged 15 and older have been circumcised, according to a 2016 report by Population Health Metrics.

The report noted that costs vary widely based on religion and nationality. Nearly all Jewish and Muslim men in the world are circumcised, and together they account for almost 70% of all circumcised men worldwide.

Some studies suggest that circumcision may have health benefits. For example, circumcised men are less likely to transmit sexually transmitted diseases to their female partners or to develop penile cancer.

A 2012 policy statement from the American Academy of Pediatrics (AAP) affirms that “an evaluation of the available evidence indicates that the health benefits of neonatal male circumcision outweigh the risks and that the benefits of the procedure justify families who choose the procedure.” The procedure. Specific benefits identified include prevention of urinary tract infections, penile cancer, and the spread of certain sexually transmitted infections, including HIV." This claim is also endorsed by the American College of Obstetricians and Gynecologists.

In recent years, several studies have shown that circumcised men are less likely to contract HIV. The World Health Organization and the United Nations Program on AIDS now recommend male circumcision as an HIV prevention measure. The World Health Organization states that "there is compelling evidence that male circumcision reduces the risk of HIV infection in heterosexual men by approximately 60%."

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