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How does an erection develop?

In order to fully answer that question a person must understand the anatomy of the male penis. The penis consists of penile root, shaft and the glans. The penis is made of cavernous tissue, which allows to develop an erection, when the male is aroused. The fundamentals of normal sexual function consist in normal penile innervation and penile blood flow.

When the penis is relaxed the small arteries which are located in the cavernous body of the penis are constricted, thus the blood flow is low and the penis is relaxed. The process of erection development starts when the male is sexually stimulated, and nervous impulses are being sent to the nervous ends in the penile tissue, thus the vessels are dilated and the cavernous body is filled with blood.

The second essential component of maintaining an erection is the venous drainage system. In any part of the human body veins are vessels through which the body flows out of an organ. In the penis the process is altered significantly. As when the penis begins to become erect and the cavernous body is filled with blood, it presses the small veins, thus preventing the blood to flow out of the penis. Due to the above mechanism the venous blood outflow is blocked and is resumed only, when the inflow of blood to the cavernous body through the arteries is stopped, or in other words after the sexual stimulation is stopped.

And so in general, when a male is aroused, his brains sends impulses to the nerve endings located in the tissues of the penis, which leads to dilation of the arteries and increased blood flow into the cavernous tissue. At the same time veins of the penile tissues are constricted, thus the out flow of blood from the penis is blocked. When sexual stimulation is stopped, the blood rapidly leaves the cavernous body and the penis becomes relaxed.

As a conclusion the mechanism of erection is ensured by the following processes:

• Sexual stimulation and transmission of nerve impulses from the brain to the penile tissue
• Dilation of arteries in the cavernous body and inflow of blood
• Block of blood outflow in the veins of the penis

If any of the above mentioned processes is somehow altered, a man suffers from erectile dysfunction.