The penis is the only organ without bones, and it needs blood to rise. But do you know exactly how much?
An erection is the result of increased blood flow to the penis. But you may be wondering how exactly this works and whether your penis needs a specific amount of blood to get an erection.
French surgeon Ronald Virag, in his book Erection mode d’emploi, says that you need no less than 130 millilitres of blood in your penis to get a hard-on. That is the equivalent of a gallon of beer for the regulars at the bar. That’s quite a lot. However, this is a small fraction of the 4,500 to 5,600 ml of blood that circulates in the adult human body at any one time.
Inside the shaft of the penis are two columns of spongy tissue called the corpora cavernosa. This tissue contains blood vessels. When your penis is flaccid, the arteries are compressed, providing just enough blood to keep the corpus cavernosum tissue healthy.
When you are aroused, the smooth muscles in the arteries of the penis relax, allowing the blood vessels to expand and fill with blood. The tissue of the corpora cavernosa also grows, making your penis larger and firmer.
Also, if your penis shrinks when it’s cold, don’t panic! It’s simply that your body will prioritise the flow of blood to your vital organs, much to the annoyance of your penis.