Having an erection is one of the most normal things in the world to us men, but only a handful of us can tell you exactly how an erection process works.
Men suffering from erectile dysfunction or other forms of impotence will look for the underlying cause. To find the cause we first have to understand the workings of a healthy erection.
I will give you a short explanation of the erection process in a healthy man and at the same time I will point out what often goes wrong and causes erectile dysfunction.
Table of contents
The healthy erection
What many people don’t know is that most of the erections we get have nothing to do with sex.
Men with healthy erections get them over night during the REM phase of their sleep.
We all know the morning erections. This is just the last of a series of erections. The penis regularly becomes erect during sleep phases.
This is all connected to renewing and reparation of the hormone balance, which happens in the brains where the production of some hormones is controlled.
According to the Bancroft hypothesis, one of these hormones inhibits erections, which is why the penis is mostly limp.
The penis becomes erect when the production of this erection inhibiting hormone is temporarily interrupted. That’s why we get night erections.
It happens every time a new sleep cycle sets in, about 4 to 5 times a night. The last sleep cycle ends just before we wake up, sometimes that happens when the last night erection is still ongoing.
Men tend to be easier aroused and get an erection through stimulation in the morning because the production of that erection inhibiting hormone called noradrenaline hasn’t fully started yet, so the erection is not properly inhibited yet.
The erection process
Let’s just have a look at the erection caused by sexual stimuli. A few things happen when a man is sexually aroused by stimulating images or by touch.
First of all, sexual stimulation will make the hart beat faster, which makes our blood flow faster, it is very important for this to happen to get an erection. How hard the penis becomes and how much it grows depends on the amount of blood that is being pumped into the penis during an erection. But how does faster streaming blood fill up the penis and make it swell? Why just the penis? Blood is pumped through our entire body, and this phenomenon only affects the penis.
This is because of two properties of the penis.
The roll of erectile tissue during the erection
The penis consist of, amongst other parts, two cylinder shaped parts called the corpora cavernosa.
These corpora cavernosa consist of spongy tissue. We call it erectile tissue. This erectile tissue grows when filled with blood, so when the pressure on the blood rises, more blood can be stored there. This expansion is very recognisable as part of an erection.
You’d think that’s the full story. Our heart beats faster, the erectile tissue of the corpora cavernosa fills up and expands, and we get a stiff penis. If that were true, going for a run or a cycle could become quite problematic for men, because that also makes our heart beat rise.
The PDE5 enzyme and its effect on our erection
We talked about the hormone that makes sure our penis stays limp in normal conditions.
This hormone makes sure the corpora cavernosa don’t fill up with blood, even if our heart beat rises. This is because the corpora cavernosa have to relax to grow and contain more blood.
Now it becomes slightly technical.
The corpora cavernosa stay tensed because of a certain enzyme in our body, called PDE5. The PDE5 enzyme production is switched off at the start of sexual stimulation by the previously mentioned hormone.
Now the corpora cavernosa can relax which will create enough space for blood in the erectile tissue. So this happens because sexual stimulation enables the filling of the corpora cavernosa.
When blood makes the erectile tissue expand, the erection will grow.
The more blood is collected, the more the erectile tissue will expand. During this phase the erection will grow to its maximal size. The size increase of the erectile tissue will compress the veins of the penis that take care of the blood outflow. Blood circulation will slow down; making the pressure even higher ; the penis will become even harder.
The end of the erection
Once the stimulation and arousal decrease, by lack of sexual stimulation or after an orgasm, the PDE5 enzyme is no longer inactive.
When PDE5 becomes active, the corpora cavernosa can relax, the erectile tissue will hold less blood, and will decrease in size. As soon as this happens the penile veins will stop being compressed and it will take just a few seconds to half a minute for the penis to get back to its limp state.
There are several factors that can cause erectile dysfunction. One well known factor is a vascular problem of the arteries responsible for the blood flow to the penis.
Another factor that can cause erectile dysfunction is a hormone imbalance. It will be difficult or impossible to get an erection when the PDE5 enzyme is not inhibited. The corpora cavernosa will not relax and the erectile tissue will not have enough space to expand and fill with blood. The blood circulation in the penis will not decrease and there won’t be any build-up of pressure.
There can be sexual stimulation without the penis getting stiff. This is a serious problem which often causes mental issues for men suffering from this form of impotence.
The evolutionary roll of a man during sex is a dominant one. When this roll cannot be fulfilled it often leads to insecurity and mental stress. In the long term this can create negative associations with sex, which can make the problem of impotence even worse.