interestingasfuck

I was curious about this, so I looked it up. It's even cooler than I thought!

“It’s like going under the sea,” says Vigil, an OBGYN and a professor at Pontifical Catholic University of Chile. “You see all these little stars and seaweed-like appearances.”

But this field of fractals is no underwater scene. It’s a microscopic view of mucus from the human cervix. These shapes are created during a “fern test,” named after the distinct fern leaf structures present in cervical mucus around ovulation.

In addition to being beautiful, cervical mucus is functionally important. It lines the cervix, vagina, and vulva, creating a protective barrier between the body and the environment. The mucus also plays a major role in fostering healthy bacteria, protecting from pathogens, helping sperm reach the reproductive tract, and even signaling disease and pregnancy issues to clinicians.

“It’s a gatekeeper,” explains Katharina Ribbeck, a biochemist at MIT who studies all kinds of mucus, including cervical mucus. “It lets the right things in and [keeps] the wrong things out.”