Synonyms
Erectile dysfunction (ED)Erectile dysfunction in men occurs when a man is unable or only rarely able to bring his penis to the fully erect (stiff) state required for sexual intercourse, or to maintain this state. However, if this is only occasionally the case or only for a short time, it is not called erectile dysfunction. Erectile dysfunction has nothing to do with a reduction in the man’s fertility.
In the case of existing impotence, the ability to ejaculate and produce semen is retained with few exceptions. According to studies, the incidence of erectile dysfunction is about 20% in Germany and internationally. In men over 70 years of age, however, it is already 70%, which shows that this disease is strongly dependent on age.
Under 40 year old men this disorder is about 5% complete and about 17% moderate. Furthermore, recent studies show that 20 – 70% of all patients with diabetes mellitus, hypertension or lipometabolic disorders will one day suffer from erectile dysfunction requiring treatment. In order to achieve an erection in men, several systems interact with each other.
Important for their development are functioning blood vessels, nerves, certain parts of the penis as well as a healthy psychological starting situation. In order to understand an erection and thus also its disorder, it is important to know its physiology, as well as an idea of the anatomy of the penis: The penis has three so-called erectile tissue corpus cavernosum, which can swell and shrink. Their filling with blood, and thus the condition of the penis, is controlled by blood vessels that run along the penis.
An important blood-supplying vessel is the arteria dorsalis penis, which runs in pairs under the upper side of the penis. From there, small branches go into the two large erectile tissue layers and fill them with blood as needed. Inside these two corpora cavernosa there is another vessel, the arteria profunda penis, which performs the same task.
The third erectile tissue surrounds the urethra and is fed by its own artery. However, all three vessels are connected to each other. In the flaccid state of the penis, these arteries supply it with oxygen, and the blood flowing into them is carried away by the associated veins without the erectile tissue being able to fill.
This is achieved by small muscle fibers that surround the fluid stores (sinusoids) of the erectile tissue. One can therefore imagine them similar to a sponge. These muscles are tense in a flaccid state, so that the arteries have a narrow diameter and there is not much room for blood in the caverns of the erectile tissue.
Through certain nerve impulses, the muscle fibers slacken when an erection is to be achieved. This causes the above-mentioned arteries to increase in diameter, allowing more blood to be pumped into the erectile tissue. This blood then collects in the caverns (sinusoids), which causes the veins that carry it away to become narrower in diameter.
They have a much softer wall than the arteries. This results in what is known as positive feedback: the more blood flows in, the more the corpus cavernosum fills up, the less blood flows out. The shaft of the penis becomes longer, it increases in diameter and becomes stiff. The nerve impulses necessary for this come from the autonomous (vegetative, involuntary) nervous system, more precisely from the so-called parasympathetic nervous system. The parasympathetic nervous system is particularly active when we are sleeping, digesting or generally relaxed.