Erections: An Underappreciated Scientific Journey
Da Vinci knew a thing or two about male anatomy
Ancient physicians were surprisingly advanced in their medical knowledge. As far back as 500 B.C. Chinese physician Bian Que was taking the pulse of patients to diagnose disease. Only a few years later Sophocles was writing in praise of Greek surgical techniques. And ancient Roman physicians used sophisticated techniques to distill medicines from plants. However, even the greatest ancient physicians were stumped when it came to understanding how erections work.
The ideas of the second century Greek philosopher, scientist, and all around genius Galen dominated medicine for over a thousand years. He pioneered the technique of dissection and mapped the circulatory system. But even his genius failed when it came to explaining erections. Despite knowing more about the circulatory system than anyone alive at the time, he incorrectly believed that it was differences in air pressure that allows a man to achieve an erection.
The medical community unquestioningly accepted Galen’s ideas about most things, including erections, until the renaissance. Thankfully the original renaissance man, Leonardo Da Vinci, cast his critical eye on the human body and revolutionized the way science understood erections. Da Vinci’s Vitruvian Man may be his most famous contribution to male anatomy, but his most important is arguably his conclusion that erections are the result of blood becoming trapped in the penis.
But Da Vinci’s discovery was only part of the equation. What physical mechanisms cause blood to flow into the penis and stay there? By the 19th a few doctors in Central Europe thought they had the answer. A group of Austrian, German and Swiss doctors collectively discovered that the relaxation of a special type of muscle, called smooth muscle, was key to allowing blood to flow into the penis. Unfortunately, they wrote their findings exclusively in German, which could be one reasons why their ideas were slow to trickle down to the scientific mainstream. In fact, it wasn’t until a century later, during a landmark international meeting of urologists convened in Paris in 1984, that the smooth muscle hypothesis was considered universally accepted among physicians.
But questions still existed about smooth muscle’s role in erectile health. Scientists remained unsure why smooth muscle sometimes fails to relax, and why this happens more frequently in men as they age. Over the last three decades research has focused on the signaling molecules that keep smooth muscle healthy and tell it when it needs to allow greater blood flow. They discovered that the body needs a good supply of these molecules in the right tissue to maintain strong erectile function.
These new discoveries have provided today’s physicians with an unprecedented understanding of how erections work on the molecular level, opening the door to new research on potential methods for improving men’s sexual health. It may have taken a couple of thousand years, but the mystery behind erections is finally (mostly) solved.