7 Amazing Facts About Your Brain, the Boss of Your Body

Realistic Human Brain Anatomy Picture

Get ready to learn lots of cool and fun facts about your brain!

Your brain can do so many amazing things whether or not you even notice. That’s because the human brain is powerful. It controls everything in your body. Thinking and drinking; resting and digesting; moving and grooving; and much, much more.

Although your brains give you unique ideas and personalities, your brain also has a lot in common with other human brains.

Keep reading to learn about interesting brain facts. Then share with your friends at school or family at home!

Human Brains Look Wrinkly…But They Start Off Smooth

The normal human brain is crinkled with lots of hills and valleys. But it wasn’t always this way.

Before you were born, when you were a tiny fetus, your brain looked smooth. Around the halfway point of pregnancy, the fetal brain was supposed to start folding and wrinkling as it grows bigger. Why is folding process is so important? More brain tissue can fit into the skull. Folding also separates your brain into different sections, and it helps each part of your brain work properly.

Check out this 3-D gel model of fetal brain from a lab at Harvard University that shows how a brain might grow and fold.

Your Eyes Are Like Windows To Your Brain

Brain anatomy connected to eye by optic nerve

You can learn so much about a person, just by looking at the eyes. That’s because the long optic nerves connect the brain to the back of each eyeball. Plus, the back of the eye – the retina – is actually made of brain tissue.

Pupils – the opening in the middle of your eyes – get wider when you get excited or scared. They also seem to dilate when you’re thinking or focusing on something, like a tricky math problem.

Through the pupils, doctors also use a special magnifying glass to look at the retina and optic nerve at the back of the eye. For example, if the retina’s blood vessels have problems, their might be problems with the brain’s blood vessels. If the optic nerve looks swollen, then the brain might have a problem causing pressure to build-up.

A Baby’s Brain Weighs Less Than 1 Pound (0.5 Kilograms)

Have you ever noticed how a baby’s head is pretty large compared to the body?

Even though the head looks relatively big, the newborn brain weighs less than 1 pound (0.5 kilograms).

After a baby is born, the neck is not yet strong enough to hold up that big head on its own. Grown-ups need to carefully support a baby’s head and carry them around until the baby grows stronger.

dad holding newborn baby's head for support

Your Brain Keeps Developing Until Age 25

The human brain does most of its growing during the toddler years. By the time that a kid is 5 years old, the brain actually almost the size of the adult brain.

But that’s still just part of the beginning!

During the childhood and teenage years, the human brain grows more gradually as it absorbs tons of information.

Around age 25, the brain is fully formed and weighs around 3 pounds (1.3 kilograms).

brain inside skull

Your Brain Cells Talk to Each Other

neuron axon

Your brain is made of billions of nerve cells called neurons. Because neurons are so small, you have to use a microscope to see them. Under a microscope, they look like little trees with branches and roots.

Just like anything in life, if neurons want to work together, they need to communicate. Neurons talk to each other by sending important signals called neurotransmitters. Because your brain has so many different jobs to do, like thinking, remembering, and feelings emotions, it has lots of different neurotransmitters. More than 100 actually!

Have you ever heard of dopamine? This neurotransmitter is famous for making us feel good after we do something.

Your Brain Has a Bridge

person holding two halves of a human brain

Nerves are a bunch of neurons that are bundled together. You can actually see them without a microscope! The corpus callosum is an incredibly important nerve bundle, and it acts like a bridge in your brain. But why does your brain need a bridge?

When you look at a human brain, it looks like it has been cut in half. Without the corpus callosum bridge, the left half and right half of the brain wouldn’t be able to communicate and work together.

Your Brain Shrinks as You Get Older

It’s true: Just like any part of the body, the brain naturally gets older. Around age 40, the human brain starts to shrink as it losing some cells and the connections between cells. You can slow down that process though! Exercising, eating healthy, sleeping well, and spending time with friends can help keep your brain as sharp as possible.

Learn More About Your Amazing Body!


Updated on September 2, 2022 by Betty Choi, MD

Updated on September 2, 2022

by Betty Choi, MD