What is the brain?
The human brain is an organ that lives inside the skull. It is about the same size as your fists and weighs about 1.3kg. It is covered in wrinkles and protected by fluid inside the head. It’s sometimes nicknamed the ‘grey matter’ because it is grey.
You might not think about your brain often, but it’s pretty amazing when you think about it. The human brain is in charge of everything your body does – even the things you don’t think about, like breathing or keeping your heart pumping. It’s like a potent computer, storing memories and controlling our thoughts and bodies.
The brain is the signal box that receives information from the rest of your body. Every time you use any of your senses, all that information is transmitted to your brain, where it is processed. It is also where all of our thinking and feeling take place. For example, people sometimes talk about the heart as the place where our feelings happen – like when they talk about heartbreak – but actually, it all takes place inside the brain!
The brain explained for kids
The brain is part of the nervous system. Along with the spinal cord, it connects to all the nerves that travel throughout the body. So, for example, when you touch something hot or see something beautiful, that information travels through your body and into your brain. This helps us understand what is happening around us, informing us how to respond.
The brain also uses those nerves to tell our muscles what to do. This is how we move. Our brain sends the signals, our muscles receive them, and suddenly we walk, talk, or stretch.
The nervous system is made up of millions of neurons, which are microscopic cells. They can join together with other neurons to form connections called pathways that transmit information. These pathways can get stronger the more that they are used.
For example, learning how to ride a bike shows how neurons form pathways. The first time someone gets on a bike, they must think carefully about how they move. How do they pedal? How do they balance? It’s a lot of hard work. But after a lot of practice, it becomes much more manageable. Eventually, they don’t have to think about it all. That’s because the neurons have successfully formed a pathway that tells their body how to ride the bike without consciously thinking about it.
The brain also keeps working while we are asleep. It controls our dreams and sorts through everything we have learned and experienced that day to decide what is essential and what we can forget.
The brain keeps growing until we are about 20 years old. This doesn’t mean that we stop being able to learn new things, though! The neurons in the brain can keep forming pathways throughout our lives.
Doctors and scientists still don’t understand everything there is to know about the brain. This is partly because it is complicated and partly because it’s pretty tricky to experiment on something that keeps us alive and functioning. So the brain still has lots of secrets hidden inside it.
Main parts of the brain and their functions
Cerebrum
This is the most significant part of the brain. There are two halves of the cerebrum on each side of your head. It controls your voluntary muscles, which move when you want them to, giving you motor skills. For example, your cerebrum tells you how to proceed when playing sports or dancing.
It is also the home of your memory and logic. You have short-term memory, which helps you remember things that happened recently (like the name of someone you have just met), and long-term memory, which stores memories from long ago (like your tenth birthday party). The cerebrum also helps you with reasoning and making decisions.
Cerebellum
The cerebellum is much smaller than the cerebrum. It controls your muscles, movement, and coordination. Without it, you wouldn’t be able to stand upright, balance, or move.
It also helps us to learn how to do things with our bodies so that we no longer have to think about them. If you’ve learned how to ride a bike, your cerebellum stores all of the information so that each time you get on a bike isn’t like the first, shaky time. So it is an essential part of the brain!
Brain stem
The brain stem is also known as the medulla. It connects your brain to the spinal cord. It controls lots of involuntary muscles and processes. For example, the brain stem keeps your heart beating to move blood around your body. It also tells your stomach to digest your food to give you energy.
The brain stem also receives all of the information sent from nerves in the rest of the body. Then, it decides what to do with them. This is a big task – we have so much information whizzing around our bodies all the time that even a supercomputer couldn’t keep up with it.
How to keep your brain in shape
- Drink lots of water to keep your brain hydrated.
- Work out at the Brain Gym! This is a program of physical movements and exercises that help you to engage your brain. It can help to reduce stress and improve your ability to learn.
- Try mental workouts, too. Things like puzzles and reading are great for keeping your brain fit and strong. And you don’t even need to get off the sofa to get a great brain workout!
- Eat healthy foods. The brain needs lots of vitamins and minerals to function correctly. So fatty fish, like salmon, is delicious, like blueberries and broccoli. Maybe not all at the same time, though.
- Look after your head! Make sure to wear a helmet when you ride your bike or scooter. Hurting your head can also be bad for your brain, so keep it safe.
- Get plenty of sleep. Although your brain never entirely switches off, sleep gives your brain a chance to rest and remove toxins from your brain that have built up during the day. A lack of sleep can make you grumpy and distracted. It can also make you more likely to get sick because it affects how well your immune system works.
Fun facts about the brain for kids
- Your brain produces enough electricity to power a lightbulb. You might have seen cartoons where lightbulbs pop up above someone’s head to show that they have had an idea. Well, your brain could light up a lightbulb!
- The brain is 80% liquid. This is why we have to drink lots of water. If we get dehydrated, our brains don’t work as well.
- The brain is divided into two halves, called hemispheres. The left side of the brain controls the right side of the body and vice versa. So, for example, if you are left-handed, the right side of your brain is in charge.
- Every time you learn something new, your brain changes its structure. This is because the neurons form new pathways to make accessing and using new information faster and easier.
- Neurons are incredibly speedy – they transmit information to and from the brain at more than 240kmph. This is because sometimes our bodies need to react very quickly to situations. For example, if you touch something straight out of the oven, you will flinch before you have even thought about it. These speedy reflexes help to keep us safe.
- The brain uses around 20% of its energy from food and oxygen. So it needs a lot of power to do everything it needs to keep us going.
- Humans have the most significant brain-to-body ratio of all animals. This might be part of why we have been able to invent and create so many complicated things, like cars and rockets.
