An erection is the ability to achieve and maintain the hardness of the penis, sufficient for the successful conduct and completion of sexual intercourse.
The male penis (penis) consists of two parallel longitudinal rollers of erectile tissue, the so-called cavernous bodies (corpora cavernosa), and one small tube – the spongy body (corpus spongiosum), which surrounds the urethra and forms the head of the penis (glans penis). Cavernous and spongy bodies consist of spongy tissue surrounded by a dense protein shell. The flow and outflow of blood in the cavernous and spongy bodies are regulated by special mechanisms, so that the penis can very quickly fill with blood, increase in volume and become hard. This condition is called erection.
How Does An Erection Occur and Why?
Erection is a consequence of complex nervous and vascular interactions, usually associated with sexual arousal.
When excited, signals are transmitted from the brain to the sacral part of the spinal cord, and then to the local nerves, which causes the relaxation of smooth muscles in the wall of the arteries of the penis. This provides an increase in blood flow and filling it with the spongy tissue of the cavernous and spongy bodies. Filled with blood, the cavernous and spongy bodies compress the veins that drain blood, so the outflow of blood decreases. The penis is filled with blood, swells and becomes hard.
As long as the erection lasts, the blood remains “captured” in the penis.
The erection stops after ejaculation (ejaculation) oras a result of any violation the stops the flow of the signals that caused it.
The blood flow and pressure of the cavernous bodies on the blood-draining veins decreases, the blood flows from the cavernous and spongy bodies, and the penis returns to its usual sluggish state.
During an erection, there is 6 times more blood in the penis than in a relaxed state.