How Does Viagra Work?
Dec 14th, 2007 by admin
The name recognition of Viagra is so good that nearly every adult in America has heard of the drug and can tell you what it does. What Viagra does is simple: When it works as intended, Viagra causes a man who is sexually stimulated to get an erection.
How does Viagra do that? And why does Viagra work only if the man is sexually stimulated? For that matter, what causes an erection in the first place? Are Cialis and Levitra the same as Viagra? In this article, we’ll answer all of those questions and more.
This is actually a fascinating story - it involves the technology of the human body and the techniques that scientists use to control different parts of the body with drugs. And in the case of Viagra, the story starts with the technology of the penis…
Probably the easiest way to understand how the penis becomes erect is to think about a balloon. If a balloon has no air in it, it is limp. As you inflate a limp balloon with just a little air, it becomes elongated and rigid.
The penis uses a similar mechanism, but instead of using pressurized air to become rigid, the penis uses pressurized blood. The penis contains two cigar-shaped structures, called corpora cavernosa (singular - corpus cavernosum), that it uses to become erect.
To solve an erection problem when the cause is poor blood flow, you need to open the arteries. Let’s take a look at how this can be done — and how it was done before Viagra.
Starting in the mid-1980s, it became common for men with erectile dysfunction to inject smooth-muscle-relaxing drugs as a treatment for the problem.
Viagra eliminate the PDE that is decomposing the cGMP, so cGMP builds up in the penis and has a larger effect on the artery walls. The greater the amount of cGMP the greater the blood flow, and the greater the blood flow the greater the degree of the erection. The reason that Viagra uses this technique is because of an interesting quirk of PDE.
Viagra contains sildenafil citrate packaged as a pill. When a man takes a Viagra pill, the sildenafil citrate flows throughout his body, but it really only affects the PDE5 enzyme in the penis. The drug stays in the bloodstream for about four hours, and then it is washed out of the blood by the liver and kidneys.
In other words:
- A man takes a Viagra pill.
- The sildenafil citrate enters his bloodstream and flows throughout his body.
- The sildenafil citrate attaches to the PDE5 enzyme in his penis and disables most of it.
- When the man becomes sexually aroused, the brain sends the normal message to the NANC cells in his penis, which produce nitric oxide as usual.
- The nitric oxide creates cGMP, which starts relaxing the arteries in his penis.
- Since the PDE5 has been disabled, the cGMP in the penis does not break down. Instead, it builds up and lets the arteries in the penis fully dilate.
- His penis inflates with blood, and the man gets a full erection.
Read the full version of this article “How does Viagra work”.
