One of the most terrifying things that can be found in our bodies is teratomas. They are tumors that can be both benign and malignant. What makes them something out of a body-horror story is that they can have hair, nails, teeth, or even contain remnants of organs like the lungs, liver, brain, or thyroid gland.
Teratomas are considered a rare type of tumor, with ovarian teratomas, for example, occurring in about 1.2 to 14.2 per 100,000 women a year. In newborns, on the other hand, one in 30,000 to 40,000 babies may have a sacrococcygeal teratoma. The tumors develop when there is a disruption in our cell differentiation process. Essentially, cells that don't have a specific task yet turn into muscle cells, nerve cells, or blood cells. That's why they sometimes contain remnants of random body parts.
Sleep is essential for us, and experts say that you need seven to nine hours of sleep a day. But what if you suddenly couldn't fall asleep at all? Some people actually have this condition, and it's called fatal familial insomnia. Essentially, a person's sleep becomes so disrupted that they lose basic functions, such as the ability to speak, develop dementia, and eventually fall into a coma from which they don't wake up.
Almost half of all people experience regular insomnia, but fatal insomnia is very rare: only about 70 families in the world carry the gene. Despite its name, it's not actually a sleep disorder but a degenerative nerve disease. It's genetic, so people inherit the mutation of the prion protein (PRNP). The average cycle of the disorder from first symptoms to the end is about 18 months, although sometimes the end might come as shortly as in seven months.
Kissing is a pleasant activity that people engage in daily, yet few ever think about the germs that they exchange with the person they're smooching. Researchers who did a study in a zoo in Amsterdam found that couples exchange 80 million bacteria during one long kiss.
Interestingly, the participants, who were intimate partners, didn't have significantly different microbiotas. The researchers suggest that it was because most couples have similar lifestyles, diets, and live in the same environment.
Humans are not snakes, but we do kind of shed our skin too. We also leave our expired skin cells around in the environment: we shed from 30,000 to 40,000 skin cells every hour, almost a million an hour. But don't worry, you won't become skinless; new skin cells regenerate every 28 days.
"Why can't I see it then?" you may ask. You do actually see it: it's in the dust on your tables, shelves, windowsills, monitors, and keyboards. Extra fun gross fact: these tiny former bits of yourself also get eaten by dust mites.
Do you know what "immune privilege" is? There are a few sites in our bodies that trigger no immune response. Those sites are the testicles, central nervous system, placenta or fetus, and the eyes. Basically, our immune system doesn't attack injuries and foreign objects in the eye, for example, without causing swelling and inflammation to protect our vision. This makes our eyes the perfect candidates for medical studies where researchers can implant cells and biological treatments into the eyes without them rejecting the treatment instantly.
Have you ever had a really big dinner that you had trouble digesting? If you're worried that your stomach acid won't be able to do its job, don't worry: it's capable of dissolving materials such as bone, teeth, and even certain metals. In comparison, battery acid has a pH of 0. In turn, stomach acid has a pH of 1 to 2 and can dissolve thin steel and razor blades.
