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Brain Facts

The Brain

The brain is one of the most amazing parts of your body. Everyday it allows us to do activities that we determine and many that we don't. Our brain can:

  • read printed words
  • cause us to breathe
  • remember colors
  • determine the rhythm of our heart
  • control our body temperature
  • remind us to blink
  • remember how to play a game
  • ride a bike
  • help us feel the soft fur on our dog's back
  • and many, many other things

It's true! Inside your skull your brain controls everything you do!!! It is more powerful and faster than any computer. Your brain is the most important part of you and it is very complicated.

In the book, The Great Brain Book: An Inside Look At The Inside Of Your Head, (Scholastic Reference, 2002) author, HP Newquist said, "Understanding the brain is one of the biggest challenges facing scientists. We're just now beginning to figure out how all the pieces of the brain work, but we have a long way to go. We still don't know how it creates thoughts or how it stores pictures in your hear. It's not a photo album or a CD player that just files your favorite images and songs. It's a complicated organ that does billions of things every second that you're alive. That makes it the most powerful organ on earth."

SkullWhere Is Your Brain Located?

Your brain fills the upper part of your bony head which is called the skull. The top part of the skull, called the cranium, is made of 8 bones. The rest of your skull includes 14 bones in the face and 3 small bones in each ear. How about that! There are 28 bones in your skull and your brain is tucked safely inside, protected by this vast number of bones. Learn more about the skull here.

  • The brain is always working, even while you sleep.

  • Your brain can go without oxygen for 3-5 minutes before injury will occur.

  • Scientists aren't sure how many brain cells you lose each day because of decay and misuse but you don't need to worry. You have enough to last for your whole lifetime!

Here are some more fascinating facts about the brain.

Examining the brain

How does a human's brain size compare with other animals' brain sizes?


The right hemisphere controls the left side of the body, the left hemisphere controls the right side. These two hemispheres are connected by nerves through the corpus callosum.


Your brain is the size of a large grapefruit but it looks like a large pinkish-gray walnut. There are many folds and creases and it feels soft and squishy. It weighs about 1 pound at birth, 2 pounds at elementary age, and 3 pounds as an adult.

Brain tissue



Cerebrum Cerebellum Brain Stem

The cerebrum is the largest part of the brain the outer part is called the cerebral cortex

The cerebellum is about the size of a pear

The brain stem is located at the bottom of the brain, above the neck where it connects the brain to the spinal cord

divided into 2 parts called the right and left hemispheres

tucked under and behind the cerebrum

controls reflexes such as sneezing, swallowing, coughing

responsible for: thinking, senses, producing and understanding language, memories, eating, emotions, body temperature, drinking, sleeping, hormones

controls muscle movement, balance, coordination

responsible for automatic survival functions such as breathing, heartbeat, digestion, and keeping your body alive while you sleep

Diagram of a brain


You can't understand what the brain does without knowing about the spinal cord. The spinal cord is an extension of the brain that runs down the middle of the back. The spinal cord is about 44 cm (19 in) long in adults. It is protected by 33 bones called vertebrae. The brain and the spinal cord are called the central nervous system. The central nervous system is one part of the nervous system. The rest is called the peripheral nervous system.


The wires of the nervous system are called neurons. The brain and the spinal cord contain billions of neurons. They send and receive information throughout your body.

All kinds of messages travel in neurons. If you touch a hot stove, neurons send a pain message from your finger to your brain. Your brain then sends a message through neurons, and through your spinal cord to the muscles in your arm to pull your hand away. Neurons can send signals to thousands of other neurons at a rate of about 200 miles per hour.

Nerve cell

The point of connection between two neurons is called a synapse - from the Greek word "synaptein" meaning to fasten together. Chemicals and/ or electricity flow across this connection to communicate with the brain.

We don't really know how all parts of the brain work together. Scientists, called neuroscientists, are doing experiments every day to try to solve these and other mysteries of the brain.

You can take a look at some neurons by clicking here.

  • Your brain contains approximately 100 billion neurons. They each link to as many as 10,000 other neurons.

  • If you could line up all the neurons in your body end to end, they would stretch almost 600 miles.

  • More than 30,000 neurons can fit on the head of a pin.


Here's some additional information about your senses.

check markCheck out D4K's site on senses.

Be Amazed by Amazing Animal Senses from The University of Washington.


Your Senses Work For Your Brain

Some areas of the cerebral cortex are important for thinking and reasoning, some for voluntary movements and speech. There are also areas for your senses. You see, hear, smell, taste and feel because of your brain. Your senses; touch, ear, eye, nose, and tongue gather information about your surroundings and send this information through sensory neurons to special areas in the cerebral cortex. Take a closer look at the cerebral cortex to see where the signals go to from each sense.

Some parts of the body such as your hands and lips have more sensory neurons than other parts. They are for detecting touching, pressure, roughness, smoothness, dry, wet, cold, hot, and pain. This body map, called an homunculus shows you how much of the cerebral cortex is responsible for processing touch receptor information.

ThinkUnlike a cut, some scraped skin, or torn and broken bones that can heal and mend, your brain cannot repair itself. It is very important for you to keep it healthy and to take care of it. Protecting your brain from accidents is very important. Take a look here for ways to keep your brain healthy.

Exercise your brain...THINK

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