The human body is a weird and wonderful place, full of gross and cool stuff! It's time to find out how many of these interesting facts about the human body you already knew! Join us for a journey all around the human body and the amazing ways it works! Find out why you can surivive with just one kidney, how many bones you have, and which body part is unique to humans! And if you liked this, check out more awesome facts here! How about these 53 totally random facts? Or if you're looking for a way to gross your mates out, try these disgusting facts! Or for more science, check out these facts about Mars!

1. Your Largest Organ Covers Your Whole Body

Can you guess what it is? That's right it's the...skin! Yup, you're skin is an organ (along with your heart, liver, lungs, brain, kidneys and a few other things) and it's also your largest organ! Your skin is really important, not just because it stops your insides falling out, but because it helps you do things like protect yourself from disease, regulate your temperature and sense things that you touch.

2. Your Hair and Nails Are Made of The Same Thing

One might seem soft and silky and the other hard and brittle (we're not telling you which!) they are both made of the same substance, a protein called keratin. Keratin is also the substance that makes up skin. In order to keep your nails and hair healthy, you need to make sure you're eating a lot of foods with vitamins C, E and A.

3. You Have Over 200 Bones

You have over 200 bones in your body - 213, to be exact. The largest is your thigh bone, the femur, and the smallest is a teeny tiny bone inside your ear, the stapes, which helps your to hear properly!

4. ...But You Used To Have More

That's right, when you were a newborn baby, you actually had MORE bones than you do now! (Unless you're a baby reading this, in which case...wow). You actually had 300 bones! The reason? As you develop, your bones, which are quite soft when you're born, fuse together to make bigger bones, mostly in your skull. Some of these baby bones are also not really bones at all, but cartilage.

5. Your Heart's In The Right Place

Everyone always pictures their heart in their left chest, but that's not completely correct - it's actually in the middle, underneath your sternum (breast bone). The reason we can hear it beating more loudly on the left is because it protrudes slightly to the left because of its shape. If you ever ask a Dr to put their hand on their heart, they'll probably put it right in the middle of their chest!

6. Your Eyebrows Have A Very Special Job

Your eyebrows aren't just there to make you look cool (and sometimes angry), they also serve a special function. They keep sweat out of your eyes! If your eyebrows weren't there, you'd have sweat and other dirt and grime getting in them all the time! Your eyelashes serve a similar function, they help keep tiny bits of dirt out of your eyes. Clever!

7. We're Not Exactly Sure What The Appendix Does

If you've ever had your appendix out, you'll find this fact extra annoying, because there's a chance you never needed it in the first place! To be honest, we're still not entirely sure what the appendix is meant to do - that is, if it's meant to do anything! Some scientists think it might be left over from previous stages of evolution, a sort of extra bit of colon. Maybe one day we'll find out for sure!

8. Your Nose and Ears Never Stop Growing

If you're already worried about the size of your ears, look away now, because they're going to keep growing forever! And so does your nose! In actuality, they don't grow exactly, it's the cartilage substance they're made of that grows - and what's worse, your earlobes are also getting pulled down by gravity! So pray you don't live to a 1,000 and end up with a ginormous conk and ears that drag on the ground!

9. Only Humans Have Chins

Ok this one sounds really weird but think about it, it's true! Can you think of ANY other animal with a chin? An aardvark? A sparrow? A butterfly? Even our closest living relatives, chimps, don't have chins - they're neck starts where their mouth ends! The chin is more than just the jaw (which lots of animals have) it's a special jutty-out bit that is unique to us! Is there a special reason humans have chins? Probably just to make us look extra beautiful.

10. Your Small Intestine Is Very Long

Have a guess - how long do you reckon it is? Well, it's longer! Honest, it's really long! If it was laid out on the floor (which we don't advise) it would reach a whopping 20 feet long! That's about half a bus! This is because it needs a lot of surface area in order to absorb nutrients and break down food.

11. You Can Survive With Only One Kidney

The human body is amazing - so amazing that it doesn't even need to be fully there to function! Everyone is usually born with 2 kidneys, but if one gets ill, it can be removed without doing much to the way your body functions. That's why people can donate a kidney to someone in need and still be fine! Your kidneys are really important for filtering bad stuff out of your system, so it's vital we've all got at least one good one!

12. You DON'T Lose The Most Body Heat From Your Head

It's time for some myth busting! You might have heard that you lose most of your body heat from the top of your head, which is why it's extra important to wear a hat when it's cold. Although it IS important to wear a hat, this idea came from one scientific study where people wrapped up warm - but left their heads bare! So of course they lost the most heat through their heads! In actually, your head is only 10% of your body's surface area, so it's unlikely to be losing more heat than the rest!

13. Sweating Is Very Important

Getting sweaty might feel gross, but it's really important, and much better than not sweating at all! When we sweat, it helps us regulate our body temperature, cooling the surface of the skin in hot weather. If you didn't sweat, you'd die!

14. Most of Your Bones Are In Your Feet

Out of the 200-odd bones in your body, most of them are actually in one place - the foot! In fact, a whopping 26 of them! That's 52 if you've got 2 feet, almost a quarter of all your bones! The foot also has lots of joints - 33 in total - and is basically a piece of super complex mechanical engineering - it takes a lot of things moving in the right places to help you stand and walk!

15. Babies Blink Less Than Adults

If you've ever wondered why that baby is staring at you, it's probably not their fault! Babies blink way less than adults, who blink about 15 times a minute. Babies, on the other hand, only blink a few times. Once theory behind this is that babies need to take in more information than adults, as their eyes aren't fully functioning yet. Or maybe they're just really cool.

16. It's Good For You To Have Some Bacteria

Bacteria has a reputation as being bad and icky, but actually your body needs certain bacteria to function properly! Some bacteria will give us diseases and make us sick, but others are really important for things like gut function. Lots of bacteria live naturally in your gut, where they help you digest food and absorb nutrients. And they start living there pretty much as soon as your born! Thanks, germs!

17. Your Spine Is Like A Superhighway

Your spine is important for lots of things - for one thing, you couldn't stand up without it! But one of it's most important functions is the spinal cord, your nervous systems way of travelling around the body. Your spinal cord is what links your brain to all the nerve centres in the body, and the neurons that carry messages along it are like tiny cars, full of information!

18. There Are 600 Muscles In The Human Body

Yup, 600! There are three types of muscle in the human body - skeletal, smooth and cardiac. Skeletal are the muscles that help you move and holds your skeleton together. Smooth muscle is found around your organs, where it moves them when the brain once. Cardiac muscles are muscles related to the heart - they keep your blood pumping and are involuntary (they work without you making them).

19. You Can't Breathe and Swallow at the Same Time

And it's dangerous to try, so please don't! The reason you can't do both at once is because when you breathe a valve, the epiglottis, flaps open to allow air into the lungs, and when you eat it closes to allow food into the stomach. So if you tried to breathe in while you were eating, your food could end up in your lungs, choking you or causing infection! You might also swallow lots of air into your stomach, which causes, amongst other things...lots of farts! It's best avoided!

20. Doctors Used to Have Some Weird Ideas About the Body

In Ancient Rome and Greece, and then in Medieval Europe, there was a common belief that the body was made up of four 'humours' - fluids inside you that influenced your emotions. If you had too much of one fluid, it would affect your personality. They were; phlegm, blood, black bile and yellow bile. Too much blood would make you restless, too much phlegm made you serious, too much black bile made you depressed, and too much yellow bile made you angry. Which one are you?

21. You Get A New Skeleton Every 10 Years

How? By Going to the body shop! No, ok, that's just a joke. But you really do get a brand new skeleton - because your bone cells regenerate! Roughly every ten years every bone cell you have will have been replaced by a new one, meaning you're totally new! But still you...if you get us.

22. Your Brain Doesn't Fully Develop Until You're 25

If you've ever been told to 'grow up', the good news is that you've got a while to go before you have to be properly mature! Even though we legally reach adulthood between 18-21 in most countries, your brain is actually still growing and developing during that time. It's not until you hit 25 that your brain has finished doing everything it needs to do to turn you into a proper adult who can do boring things like bleed radiators and buy asparagus.

23. You Lose Taste Buds As You Get Older

Every wondered why great uncle George loves smelly cheese so much? There's actually a scientific reason! As we age, our taste buds start to die off, meaning that our sense of taste gets slowly weaker over time. So older people tend to prefer very strong flavours in order to get the most out of their food! Who knows, maybe you'll love stinking bishop one day too!

24. You Can't Sneeze With Your Eyes Open

You probably shouldn't try this one either, but we doubt you'll be able to do it! Yup, it's pretty much impossible to sneeze with your eyes open. Scientists aren't completely sure why we close our eyes, but they think it's probably to protect them from whatever gross germs just came out of the nose! Makes sense!

25. You're Taller in the Morning

Have you ever felt taller in the morning? That's probably because you are! Over the day, the pressure caused by moving and walking impacts on your body, meaning that you lose height (about ) over the course of your waking hours. When you're asleep and resting, your spine has the chance to decompress. So if you want to look your tallest, make sure to measure yourself in the morning!

26. Your Biggest Muscle is Your Butt

Ok, no giggling - it's true! And it's a very important muscle as well. Properly, your bum is called the gluteus maximus, and as well as being great to laugh at, it also does a lot of important things like helping you sit down, keeping your core centered and holding your torso together!

27. Tongue Prints Are Like Fingerprints

If you ever want to take part in a diamond heist, wear gloves and don't pick up any jewels with your mouth...because your tongue has a unique print! That's right, no two tongues are the same, though we can't see any law enforcers getting excited about the idea of tongue printing criminals - probably best to stick to fingers!

28. Everyone is Born With Lighter Eyes

If you've ever wanted blue eyes, the good news is you've already got them! Or at least, you might have done when you were born. That's because when babies are born, they have very little melanin (a pigment responsible for colour in the human body) in their eyes, leaving them a appearing a much paler colour. As you age, your eyes may develop more melanin and darken, or they may stay light, depending on your genetics.

29. Your Eyes Are Better Than The Fanciest Camera

You might wish you could get your hands on the latest digital camera or phone on the market, but the good news is you've already got something better - your eye! Yup, the human eye is around 4x better than the best camera, which is why when you take a picture it might not come out exactly how you see it with your naked eye.

30. You're Unique!

The human body is truly a weird and wonderful place, and the best thing about it is yours is completely and utterly unique! No one else on the planet has your body, so remember what an awesome job it does of keeping you going and take the best care of it you can!