Sex under X-Ray eyes

Herbert Blankesteijn

What exactly happens, anatomically speaking, when two people have sexual intercourse? What would you see if you really had X-ray eyes? We all know, don't we? Or we think we do.

The truth is, nobody ever bothered to find out. Leonardo da Vinci thought he knew, and made drawings that survive to this day. It even turns out that the information on the subject in most medical textbooks can be traced back to Leonardo's speculations. After him, some research was done in the 20th century by inserting glass test tubes in women's vaginas, and also using ultrasound, the same technique that is used to picture fetuses during pregnancy. But none of this led to a clear, sharp picture of what takes place during sex.

In the Netherlands, one medical researcher wasn't satisfied with this state of affairs. As far back as 1991, dr. P. (Pek) van Andel realized, that in principle it should be possible to let people have sex in an MRI apparatus and meanwhile take pictures of their insides. An MRI (Magnetic Resonance Imaging) device makes photographs of the interiors of a human body using radio waves; this technique has, contrary to X-rays, no known unhealthy side effects.

Van Andel started inquiring about the practical possibilities of doing this kind of research, and immediately ran into difficulties. He wasn't taken seriously; his colleagues wouldn't risk their careers working with him; universities and hospitals weren't willing to let him use an MRI apparatus. Besides, wasn't it all in the textbooks? Why investigate what you already knew? What use could such an experiment possibly have? And how in the world was he going to find people willing to go inside the narrow tube of an MRI machine and have sex? Who, come to think of it, would be able to do such a thing?

Undeterred, Van Andel found out that MRI equipment wasn't in use 24 hours a day. But it would never be switched off, because starting the machine would cost more than leaving it on, even on weekends. With help of friends and unknown to administrators, he could use an MRI device a number of times. Who were his guinea pigs? A friend of his and her husband agreed to do it. The lady friend was an anthropologist interested in gender matters and therefore easy to convince of the importance of this kind of sexuological experiment. And also both the friend and her husband were slim - a vital property, considering the width of the tube in which they had to perform.

The first experiment led to historical pictures - the first ever of this kind - and to an article that was rejected by the scientific press. The respectable British Medical Journal said: more observations were needed to draw scientific conclusions. So: more people would have to go in there and have sex.

Okay, at least Van Andel could now show his experiments were taken seriously by a leading scientific journal. His research gained official status; to get more human guinea pigs he made an appeal on local TV - causing quite a stir in the press nationwide. Why use valuable time on expensive medical equipment when patients with serious illnesses were on waiting lists? one popular newspaper argued - not realizing that Van Andel was using the machine when the doctors weren't on the job anyway.

The experiments went on nonetheless. Some people that went into the MRI apparatus had a hard time getting sexually aroused in these unusual surroundings. But in the meantime Viagra had been invented, and it was used succesfully to get those who had difficulties in the right mood.

Finally all pictures were taken and conclusions could be drawn. The British Medical Journal published a nicely illustrated article in their 1999 Xmas issue. The most striking results were, that the erect male penis has a much larger root than anybody thought - the root being the part of the penis inside the body. The root takes account of about 1/3 of the total length of the penis. Also it turned out that during intercourse the penis is shaped much like a boomerang, with an angle of about 120 degrees between the root and the external part of the penis. As far as women are concerned, it used to be thought that the uterus becomes larger during sexual arousal, because of increased blood flow. But in Van Andels experiments this appeared not to happen.

All of this proved the fundamental scientific importance of the experiments. Much of our anatomical knowledge is obtained by dissecting dead bodies. But dead bodies ar not sexually aroused, and they certainly don't have sex. What happens to the penis and the uterus during intercourse was unknown to medical science so far, and could not have been found any other way.

Are these results going to change our lives? Not immediately. But this kind of research could help find the cause of sexual problems, and that could show some people the way to happier lives. One person who is a bit happier know is for sure dr. van Andel. He had a crazy idea, fought a battle to pursue it, and he won. An article in the famous British Medical Journal is a reward that not many medical scientists ever get.