The human body
Bathtubs of snot? The "gross but true" guide to human anatomy
Published on January 15, 2026
Image: Tima Miroshnichenko
From the tiny, unseen creatures residing on your eyelashes to the incredible volume of mucus your nose produces annually, the inner workings of our anatomy are packed with crazy facts that sound like science fiction. Prepare to have your mind blown as we discover 10 of the most astounding, hard-to-believe truths about our very own body. Get ready to never again look at your saliva, bones, or even your earwax in the same way!
Eyes
Image: César Couto
Did you know that about 50% of people have tiny creatures living on their eyelashes? These eyelash mites are about a third of a millimetre long. They can sometimes cause allergic reactions, but most people never find out they’ve got them. We bet you're calling your ophthalmologist for a consult right now!
Ears
Image: Franco Antonio Giovanella
Earwax is produced by your body to protect the lining of your ear canal by trapping dirt and repelling water. But what will probably baffle you is that by the time it reaches the outer ear, the wax has been inside your ear for about a month. No wonder it tastes so disgusting!
Nose
Image: Andrea Piacquadio
You usually only notice snot when you’re making too much of it, that is, when you are sick. But can you guess how much mucus an average person produces in a year? The answer will shock you: about 100 gallons, enough to fill two bathtubs! While the sticky goo is rather unpleasant, you wouldn’t want to go without it. Mucus creates a layer of protection between you and the outside world, so thank God it’s there.
Mouth
Image: FUHMariaM
And what about your saliva? How many bathtubs do you think you can fill with your year's supply? Saliva helps break down and swallow food, fights bacteria, and neutralizes acid, among many benefits. So, if it is that good for you, it’s no surprise your mouth produces tons of it. In fact, it makes between 250 and 730 quarts a year, equivalent to filling a small swimming pool over a lifetime.
Brain
Image: BUDDHI Kumar SHRESTHA
That pink squidgy blob inside your head is stuffed with facts, memories, and dreams. Your brain is constantly crackling with tiny pulses of electricity, performing ten quadrillion calculations per second. They’re brilliantly complicated machines that scientists are only just beginning to understand. One thing is for sure: an average person has 1460 dreams in a year, about four dreams every night, or to put it another way, around the same as the number of miles from Denver to Nashville.
Nerves
Image: camilo jimenez
Clever as your brain is, it wouldn’t be able to do much without the network of nerves that link it to the rest of your body. Nerves bring information from your senses to your brain and deliver orders from your brain to the other organs. As you can imagine, if we were to measure that amazing network, we would end up with a lot. In fact, every person has a whopping 44 miles of nerves running through their skin. Can you imagine?
Skin
Image: Ximena Mora
The outer layer of your skin is called the epidermis and consists of dead cells that provide protection from dirt and germs. What you probably didn’t know is that your body is constantly losing and replacing these cells. Also, your dead skin cells sometimes absorb water and swell. This is the reason the ends of your fingers go wrinkly in the bath. But don’t worry, the entire surface of your skin is replaced every month.
Want to play some more? How much do you think the average adult’s skin weighs? Just under 7 pounds, or as we like to say, the same as three pineapples!
Hair
Image: Ashton Bingham
Human hair feels soft, but it’s one of the strongest fibres on the planet. The number of hairs on your head ranges from around 9,000 to 140,000, depending on what sort of hair you have.
Everyone loses about 50 to 100 hairs every day, but this process can speed up in men as they get older. Hair generally grows about half an inch a month, or 6 inches a year. Yet, if you don’t cut it regularly, it will most likely stop growing when it’s about 5 feet long.
Bones
Image: cottonbro studio
This fact is not for skeptics: the average adult’s skeleton weighs the same as one car tyre. In fact, our skeleton only makes up about 15 per cent of our overall body weight. So, next time someone tells you that big bones is the reason for them being overweight, be suspicious.
Another fun fact? Your collarbone is the last of your bones to stop growing when you become an adult. Called the clavicle, it doesn’t stop growing until you’re about twenty-five.
Muscles
Image: The Lazy Artist Gallery
Human muscles, on the other hand, make up about 40% of your body weight, and there are more than 600 of them. Yet, you use just 200 when you take a step, and almost all of them when you throw a ball.
The biggest muscle in your body is the _gluteus maximus_—a.k.a your bum. The smallest is in your ear, the stapedius, just about forty thousandths of an inch. The jaw muscle is the strongest by force, and the eye muscles are the busiest—10,000 movements an hour when reading! Our favorite muscle, though? The heart, of course!
