erection
Eva Rudolf-Müller is a freelance writer in the medical team. She studied human medicine and newspaper sciences and has repeatedly worked in both areas - as a doctor in the clinic, as a reviewer, and as a medical journalist for various specialist journals. She is currently working in online journalism, where a wide range of medicine is offered to everyone.
More about the experts All content is checked by medical journalists.The erection is the most noticeable sign of sexual arousal in men. The penis fills with blood, becomes stiff and straightens up. Possible triggers for this are, for example, touch, smells, images, sexual fantasies and much more. An erect penis is a prerequisite for sexual union. Read everything you need to know about erection!
What is the erection?
A penile erection is the result of a complex interplay of nerve stimuli, messenger substances, blood circulation and muscles. As long as the penis is flaccid, its three erectile tissue contain little blood. This is ensured by permanently contracted smooth muscle strands in the arteries. The tense muscles prevent the veins from expanding and too much blood from flowing into the erectile tissue. These muscles are controlled by the sympathetic nervous system that originates in the upper thoracic spine and radiates into the genital region.
How does an erection come about?
In the event of sexual arousal (e.g. through a touch, an attractive sight, a stimulating smell or an erotic dream), a complex biochemical mechanism is set in motion. The brain sends the "erotic stimulus" signal and the parasympathetic nervous system takes control of what is happening. It is the antagonist of the sympathetic nervous system and ensures that the muscles in the arterial walls in the penis relax: the vessels expand, causing the erectile tissue to fill with blood. At the same time, the venous outflow of blood is prevented. The blood builds up in the erectile tissue, the penis becomes hard and erect. At the same time, the testicles move towards the abdomen and perineum.
With this erection, the so-called pleasure droplet can also form. This is a small amount of a clear secretion from Cowper's glands, which are located in the prostate area. Sometimes the "pleasure droplet" can also contain sperm.
The four stages of the sexual response cycle
According to Johnson and Masters, the male sexual response cycle has four phases:
- Excitement phase with erection of the penis
- Plateau phase with maximum penile erection
- Orgasm phase with ejaculation
- Relaxation phase with a decrease in penile erection
Chemical reaction chain that leads to an erection
When touched, the highly sensitive penile nerves send the sexual stimulus directly to the medulla of the lumbar spine, where it is amplified in a kind of feedback loop and radioed back to the genital organs. The nerve signals trigger a chemical reaction chain, in the course of which first nitrogen oxide (NO), then cyclic guanine monophosphate (cGMP) is released.
This messenger substance plays a key role in the development of an erection: it activates the so-called protein kinase G, which in turn relaxes the muscle cells in the arterial walls by reducing the calcium level. The increasing influx of blood presses the small veins in the erectile tissue, so that the blood outflow is reduced. In this way, up to 40 times more blood accumulates in the erectile tissue than in the flaccid state - the erectile tissue becomes three to four times as large. How strong the erection is depends on the cGMP level. The more of it is available, the more permanent and harder the erection will be.
Chemical reaction that causes the erection to deteriorate
The enzyme phosphodiesterase 5 (PDE-5) is necessary to reduce the erection again (so that an excited penis relaxes again). It acts as an opponent to the "stiffener" cGMP. That means: PDE-5 ensures that the cGMP molecules are broken down and the blood supply is reduced until the penis is back in its relaxed state.
What is the function of the erection?
The penile erection has a primary goal due to evolution: the union of male and female mature sex cells. In order to achieve this goal, not only must fertilizable sperm be present, they must also get into the woman's posterior vaginal vault. This requires an erect penis. Only an excited penis can release seminal fluid (ejaculation) through further mechanical irritation of the skin of the penis.
What problems can erection cause?
Erectile dysfunction or erectile dysfunction is a man's inability to achieve an erection sufficient for sexual union. The problem persists for at least six months and in three quarters of all attempts. Such “impotence” can have very different reasons.
In around 50 percent of cases, arteriosclerosis (hardening of the arteries) is present, which prevents sufficient blood flow into the erectile tissue (for example in diabetics).
Erectile dysfunction can also result from nerve damage to the sacral cord (for example in the case of paraplegia), traumatic brain injury or diseases such as dementia, multiple sclerosis, Parkinson's disease, epilepsy, a stroke or a brain tumor.
After an operation on the prostate or injuries / operations in the pelvic area, erection disorders are also common. Other possible causes are excessive alcohol consumption and drugs such as psychotropic drugs, antihypertensive drugs, lipid lowering drugs, diuretics, hormones and cytostatics.
In the case of hormone disorders such as a testosterone deficiency in older men ("menopause of men") and disorders of hormone production, the ability to function in an erection can also be impaired.
The fact that cycling can also impair the ability to achieve an erection is only understandable at second glance: Minimal damage to nerves can cause sensory disorders in the genital area.
In addition, erection disorders can also be psychological (e.g. fear of failure).
Tags: symptoms parasites healthy feet
