The Basics of Male Anatomy and ED
The Penis
The penis is the male sexual organ.
The shaft is the longest part of it. The head or glans is at the end of the shaft. The opening at the tip of the head, where urine and semen come out, is called the meatus.
Inside, two cylinder-shaped chambers called the corpora cavernosa run the length of the penis. They have a maze of blood vessels, tissue, and open pockets.
The urethra, the tube that urine and semen flow through, runs along the underside of them, in the spongy tissue of the corpus spongiosum.
Two main arteries (one in each of the corpora cavernosa) and several veins move blood in and out. Nerves relay messages to and from other parts of your body.
What Happens When You Get an Erection?
The corpora cavernosa – the erection bodies - are made of spongy tissue and have the ability to gain blood volume and grow in size.
Throughout the day, arteries supplying blood to your penis are only partially open. This provides the blood flow needed to keep your tissue healthy.
In response to sexual (physical or mental) stimulation, your brain sends signals to trigger a hormonal response that allows those same arteries to open completely.
Open arteries allow more blood to enter the corpora cavernosa. The blood enters faster than it can leave through the veins. The veins get compressed, trapping blood in your penis. This chain reaction lets you achieve and maintain an erection.
When your brain stops sending signals that indicate sexual arousal, the hormonal response ends. Your arteries go back to their normal state and your penis returns to a flaccid state.
As such, in order for men to achieve an erection, a number of things need to be functioning correctly:
• The nerves in the penis and those “signalling” the sexual stimulus to the penis must be functioning properly;
• The blood circulation to the penis must be adequate and the internal erection mechanism must be intact;
• The veins must be able to “trap and keep” the blood inside the penis; and
• There must be sexual stimulus from the brain.
Interference with any of these systems may result in sporadic or permanent erection problems.
It is often said that ED can have an organic cause – something is physically wrong - or a psychogenic cause i.e. it is in your head. The reality is that most patients suffering from ED will have a mixed aetiology i.e. an organic cause that is usually exacerbated by performance anxiety and stress. In our experience very few men suffer from pure psychogenic ED, bearing in mind that irrespective of the underlying reason you initially suffer from ED it is very likely that this will make you stressed (this phenomenon is often called performance anxiety), which will in turn exacerbate the problem.