Sex in the MRI?! #shorts

Added: 2026-05-05

[00:00:00]Did you know scientists once had sex inside an MRI machine? In 1999, one of the world's most prestigious medical journals published this study about couples having sex inside of an MRI machine. And here's why. For centuries, doctors relied on guesses, sketches, and assumptions about what actually happened inside a woman's body during sex. There were no real images or proof, just ideas. Since the 1490s, when Leonardo da Vinci sketched this reproductive tract, medicine assumed that the vagina was a straight tunnel and the penis moved straight in and out. Here's another illustration where you can see the penis is sort of going straight into a tunnel.

[00:00:37]But in 1991, a Dutch scientist realized we had never actually looked at the female anatomy during intercourse to fact-check this. And he wanted to do it in real time using an MRI machine. Then he put couples inside an MRI machine and took the first ever real images of what happens during sex. Along with seven other couples, an anthropologist named Ida and her boyfriend Jeff volunteered to do the deed inside the scanner in the name of science. Now, if you've ever had an MRI, you know it's essentially a cramped, narrow plastic tube filled with clanging metal coils making it incredibly loud. The space was so small that they couldn't even fit in the standard missionary position. Instead, they had to lie side by side and hold perfectly still for minutes at a time while the machine took images and three male researchers told them what to do.

[00:01:24]Not the ideal setup for arousal. But it was worth it in the end because the scans basically rewrote our understanding of genital anatomy and Leonardo was wrong. Now, these are the actual MRI images and you can see here that the penis is actually going in sort of a boomerang type shape at about a 120° angle. And about a third of the penis is behind the pubic bone, showing that it's actually not visible to the naked eye. They also looked at women during arousal and they saw that the woman's uterus actually rises in the pelvis and the front wall of the vagina lengthens. And they uncovered something else really surprising. See this big white blob here? This is actually the bladder and in every single scan, the woman's bladder rapidly filled during arousal, even if they had just emptied it beforehand. Now, the scientific hypothesis is that this is simply evolution's way of prompting women to urinate after sex to help prevent UTIs.

[00:02:15]I suspect it's also why women squirt, even if they've urinated right before sex. If you found that piece of medical history fascinating like I did, make sure to follow and share it with a friend who might find it interesting, too.