5 things to know about your amazing body

5 gross (and awesome) things about your body

The human body is A-MAZING! From the fact that you breath without even thinking about it, to the way we digest food and fight off diseases like superheroes, it is one amazing machine. Our bodies are also the cause of a lot of questions! What are bogies made of? Why do farts smell? Why is poo brown? Why do some people have different coloured hair? What is a burp?

1. Why do people burp and fart?

The human body is GASSY! Sometimes when we eat food, we gulp down air as well. That air gets trapped inside our digestive system but it wants to escape. The escaping air will come out as a burp! You are more likely to get burpy if you eat too fast or if you eat or drink something that already has air trapped in it, like fizzy water.

Bottom burps, farts, pops, parps, trumps and pop offs, whatever you call them, we all do them, but they happen for a different reason to burps. When we eat food, it gets broken down in your digestive system all the way from your mouth, right down into your gut, into teeny, tiny pieces. Your gut is home to whole families of different micro beasts like bacteria and yeasts (most of them are your buddies and essential for your health!) that help you to break down your food. They chomp away at the bits of food and release the nutrients that you need to stay healthy BUT they burp too! Those tiny bacterial burps build up inside your intestines, and they also need to escape, but where can they escape from? These burps happen in the depths of your digestive system, so rather than escaping back up through your mouth as a burp, the gas is pushed out through your bottom as a fart!

2. How do bones know when to stop growing?

We all know that children grow SO fast! Sometimes they seem to shoot up a whole size overnight! But we humans don’t just keep growing forever, so how does our body, and specifically our bones, know when it’s time to stop growing? To understand this, we first need to find out how our bones grow in the first place. Dr Chris and Dr Xand explain in the video below

When and how much your bones grow depends on your growth plates. Each of your bones has a growth plate and both ends and these are the gateway for layers of bone cells to be laid down, like building a tower out of lego bricks. Your body says it’s time to stop growing when chemicals called hormones, instruct the growth plate to harden up. Once the growth plate gateway is closed no new bone cell layers will be added and your bones won’t get any longer. This means, for most of us, whether you are taller, shorter or right on average, the height you are is the perfect height for you!

3. Why do we have nails?

Did you know that your finger and toe nails are made of the same stuff as your hair!!?? Keratin is a super strong protein that our body just loves to make, but how do nails grow and why do we have them at all?

Our nail cells grow from an area under the skin called the nail bed. As they grow, the cells change and become keratin. Keratin in our nails is packed together really tightly to form a shield shape that is strong, clear and waterproof. Nails help to protect our precious fingers, they also increase sensitivity of the squishy pad beneath them. Nails are useful tools, they help us to get at food, for example that delicious orange that you need to peel. Find out more about the anatomy of nails in this video:

Interestingly, keratin is also a main ingredient in scales and feathers! You may have also noticed that nails are a bit like claws on other four legged animals. If you want to find out the history of claws and nails from waaaaayyyy back in time then check out this amazing video which is FULL of incredible animal facts!

4. Why do I get hiccups?

Did you know you have a big stretchy muscle in your body that is a bit like a trampoline!? It is called the Diaphragm and it sits under your lungs. Without you even knowing about it, your diaphragm is constantly contracting and expanding to help air get in and out of your lungs, that is until… you get hiccups! Then you REALLY know about it!

Hiccups start when your diaphragm has a sudden spasm, this means the muscle contracts quickly and vigorously. This confuses your body and normal control of air into the lungs makes pockets of air get trapped. You have another special muscle in your throat that stops food and liquid getting into your lungs, this is called your Glottis. The glottis opens and shuts rapidly and the HIC you hear is actually the sound of your glottis smacking together as it shuts!

Try it! If you put a hand on your bottom and quickly clench your bottom muscles you will be able to feel what happens when a muscle contracts.

It seems that hiccups are a bit of a body glitch, they serve no obvious purpose, but they might give clues about our ancient, evolutionary link to fish! Check out this short video to find out about the fastest and longest hiccups in the world!

5. Why are veins blue when our blood is red?

You are right, blood IS red and even though it might look bluish in your veins, your blood is ALWAYS red! This is because your blood contains special cells called red blood cells (scientists are not very inventive with names sometimes!). Red blood cells have a really cool structure that looks a bit like a bowl with 4 piles of spaghetti and a tomato sitting on top of each pile like this:

The “tomato” is a bit of Iron which is bright red when it touches Oxygen. Imagine one red blood cell on its journey around your body. It starts in your heart and is pushed into your lungs where it get flooded with Oxygen from the air you breathe. Puffed up with oxygen, the red blood cell whizzes through your arteries delivering Oxygen to things like your brain and muscles. As the red blood cell offloads its Oxygen the red of the iron gets dull, and as the red blood cell makes its way back to the heart through your veins it isn’t such a vibrant red anymore.

Try it! Look at the inside of your wrists. The skin here is very thin and your veins and arteries are close to the surface of your skin. Do your veins look blue?

We know that the blood cells are red so why do the veins look blue!? Light can pass through the thin layers of skin and into your blood vessels, then that light reflects back into your eyes so you can see the blood vessels there. Blood cells with less oxygen absorb red light so the light that reflects back to your eyes doesn’t have much red in it, so the blood vessel looks bluish!

Here is a nice explanation of why your veins look blue from the team at We The Curious