Body

Your heart is a strong little muscle in your chest that pumps blood all around your body, day and night. The blood carries food and air to every part of you, even your toes.

When you run and play, your muscles need more air to keep going, so your heart beats faster to send it to them quickly. As soon as you rest, it slows back down again.

Every time you breathe in, you pull in air that has something called oxygen, which your body needs to work and grow. When you breathe out, you push out the part your body is finished with.

Blood is like a busy little delivery driver inside you, carrying food and air to every part of your body and taking away the bits you do not need. It also helps you heal when you get a scrape.

Your eyes work like tiny windows that let light in from everything around you. Your eyes turn that light into little messages and send them to your brain, which turns them into the pictures you see.

Having one ear on each side helps you tell where a sound is coming from. A sound reaches the ear that is closer just a tiny bit sooner, and your brain uses that to point you the right way.

Your tongue is covered in tiny bumps that pick up flavours like sweet, salty and sour. They send the news up to your brain, which decides if that bite is yummy or not.

A sneeze is your nose's way of blowing out something that tickles or bothers it, like dust or pepper. The air rushes out so fast that it clears your nose in one big puff.

Sleep is your body's time to rest, fix itself and grow, a bit like charging up for a brand new day. Your brain also uses the night to tidy up everything you learned and did.

While you sleep, your brain keeps playing quietly and mixes up things you saw, felt and imagined into little stories called dreams. Some dreams are fun, some are strange, and most float away by morning.

A yawn is a big, slow breath that gives your body a gulp of fresh air, often when you are tired or just waking up. Nobody knows every reason, but it may help your brain wake up a little.

When you run, think and play all day, your body slowly uses up its energy, like a toy whose battery is running low. Feeling tired is your body's gentle way of asking for rest and sleep.

Your body is made of billions of tiny building blocks called cells, and they keep making more of themselves so you get taller and stronger. Good food, sleep and play all help you grow.

Your first little teeth make room for bigger, stronger grown-up teeth that are pushing up from underneath. When a new tooth is ready, the baby tooth gets wobbly and then falls out to let it through.

Hair grows out of tiny pockets in your skin called roots, pushing up a little longer all the time. That is why a haircut does not hurt, because the ends of your hair are not alive like your skin is.

Food is the fuel your body turns into energy for running, thinking and growing, a bit like petrol for a car. Different foods give you different things, which is why eating a colourful mix keeps you strong.

When you swallow, food slides down a stretchy tube into your stomach, where it gets mashed and mixed into a soupy mush. From there it moves into your intestines, long winding tubes that soak up the good bits your body needs and send the leftovers out as poop.

That rumbling sound comes from your stomach and intestines squeezing air and juices around inside you. It often gets louder when your stomach is empty, which can be its way of reminding you it is nearly time to eat.

After your body has soaked up all the good parts of your food, the bits it cannot use are left over. Your body packs those leftovers together and pushes them out as poop, which is a normal and healthy way to keep the inside of you clean.

Your body is mostly made of water, and you lose a little all the time when you sweat, breathe and go to the toilet. Feeling thirsty is your brain's clever way of telling you to drink and top your body back up before it runs low.

Your brain is like the busy control room of your body, and it talks to every part of you through a network of tiny wires called nerves. When you decide to wiggle a toe, your brain fires off a message that races down the nerves so fast that your toe moves almost the instant you think it.

Pain is your body's alarm system, and it is actually trying to help you. When you touch something too hot or bump your knee, tiny sensors send an urgent message to your brain saying stop, and that hurt makes you pull away before you get harmed more.

That quick kick is called a reflex, a move your body makes all by itself without waiting for your brain to decide. Some messages take a shortcut straight through your spine so your body can react in a flash, which keeps you safe when there is no time to think.

Deep inside your ears is a tiny bit of liquid that sloshes about as you move and helps your brain know which way is up. When you spin fast and stop, the liquid keeps swirling for a moment, so your brain thinks you are still turning and the room seems to spin.

Your bones are hard and strong on the outside, but they are alive and growing just like the rest of you. Inside many of them is a soft, spongy centre called marrow, which is a busy little factory that makes new blood for your body.

Muscles are soft bundles that are joined to your bones, and they move you by squeezing shorter and then relaxing again. They usually work in pairs, so one muscle pulls your arm up while its partner gets ready to pull it back down.

The places where two bones meet are called joints, and they work like tiny hinges that let you bend and twist. Smooth, slippery padding and a bit of stretchy rope called ligaments hold the bones together and help them glide without scraping.

When you bump into something hard, tiny blood tubes just under your skin can break and leak a little blood inside. That trapped blood shows through as a bruise, and its colour slowly changes from red to purple to yellow as your body cleans it up and heals.

A fever means your body has turned up its own heat on purpose to fight off germs that are making you unwell. Many germs do not like the warmth, so your body raises the temperature to slow them down while it works to get you better.

Germs are living things far too tiny to see, and a few of them can make you poorly if they get inside your body. The good news is that your body has clever defences, and simple habits like washing your hands wash most germs away before they cause trouble.

A cough is a sudden burst of air that your body uses to blast something out of your throat or lungs, like dust, a crumb that went the wrong way, or gunk when you have a cold. It is one of your body's quick ways of keeping your airways clear so you can breathe easily.

The moment you get a small cut, your blood quickly turns sticky and forms a plug to stop the bleeding, which dries into a scab. Under that scab your body is busy building brand new skin, and once it is ready the scab drops off on its own.

Your whole body is built from tiny living building blocks called cells, far too small to see without a microscope. You have trillions of them, and different kinds do different jobs: muscle cells pull, blood cells carry oxygen, and brain cells send messages. Together they make all of you.

Inside almost every cell is a set of instructions called DNA, a bit like a recipe book for building and running your body. It decides things like the colour of your eyes and how tall you might grow. Your DNA is a mix from your parents, which is why you share features with your family.

You look like your family because you inherited a mix of their DNA, half from each parent. That mix decides features like your hair, eye colour and the shape of your face. Since the blend is different for everyone, even brothers and sisters do not look exactly alike.

Your body grows and repairs itself because cells can copy themselves. One cell splits neatly into two, each with the same instructions, then those split again. This is how a small scrape heals over and how you grew from a single tiny cell into the whole of you.

When something happens, your brain cells form new connections that store it as a memory. Every time you think about it or practise it, those connections grow stronger, which is why repeating something helps you remember it. Your brain is always deciding what to keep and what to let go.

Emotions are your brain's way of helping you understand the world and what to do. Fear can keep you safe, joy pulls you toward good things, and sadness tells others you need care. Feelings are not weaknesses, they are useful signals, and naming them helps you handle them.

Every time you learn something new, brain cells reach out and build fresh connections with each other. Practising makes those links stronger and faster, like wearing a clear path through tall grass. That is why something hard at first, like riding a bike, becomes easy once your brain has built the path.

Your brain cannot keep everything, so it lets go of details it does not use, a bit like clearing space on a full shelf. Forgetting is not broken, it helps you focus on what matters. Things you repeat, care about or connect to other memories are the ones most likely to stay.

When you eat, your body breaks food down into tiny fuel bits and carries them in your blood to every cell. Each cell combines that fuel with the oxygen you breathe to release energy, a little like a slow, gentle fire with no flame. That energy powers everything you do.

Sweating is your body's clever way of cooling down. When you get hot, tiny glands push salty water onto your skin, and as it dries into the air it carries heat away, leaving you cooler. That is why you sweat more when you run or when the day is hot.

Hormones are tiny chemical messengers that travel in your blood to tell parts of your body what to do. One hormone gets you ready to run fast when you are scared, another makes you feel sleepy at night, and others quietly help you grow. They keep your body working smoothly without you thinking about it.

Your body works hard to stay around the same cosy temperature all the time. When you get cold you shiver, which makes heat, and your skin traps warmth close. When you get hot you sweat to cool down. A part of your brain acts like a thermostat, keeping the balance just right.

Blood is a busy mix of parts floating in a pale liquid called plasma. Red cells carry oxygen to your body, white cells fight germs, and tiny platelets rush to plug any cuts. All of it flows through your body to deliver, defend and repair, over and over.

Blood is red because of the red cells that fill it, and those cells carry a special substance that grabs onto oxygen. When it is loaded with fresh oxygen from your lungs it turns bright red, and after it drops the oxygen off it becomes a darker red. That is why veins can look bluish through your skin.

Your body has a built-in defence team called the immune system. Special white blood cells patrol your body, spot invading germs and destroy them, and they even remember germs they have beaten before. That memory is why you often catch some illnesses only once.

A vaccine gives your immune system a safe practice run. It shows your body a harmless piece or copy of a germ, so your defences learn to recognise it without you getting sick. Then, if the real germ ever turns up, your body already knows how to beat it fast.