The Brain: Your Control Center

By Alida Cataldo

That wrinkled gray matter in your head is what makes you speak, see, hear, taste, smell, move and feel things. If not for your brain, you couldn't blink, breathe, think or learn. Your heart couldn't beat. Your brain controls everything you do all the time and it never stops, even when you sleep.

The Need for Speed

Brains receive electrical and chemical signals from tiny cells called neurons that travel on tiny highways throughout the body at more than 150 miles per hour. Neurons that control movements transmit information even faster: more than 220 miles per hour! There's enough electricity in a person's brain to light a light bulb, and all of the telephones in the world don't transmit as many messages as a human's neurons do!

What Is That "Gray Matter?"

Every brain is made up of mostly water, 77-78 percent in fact, so drink up! It also contains about 100 billion neurons, weighs about 3 pounds and is about the size of a cantaloupe. That "cantaloupe" is divided in two: The left side controls the right side of your body and vice-versa.

No other animal has a brain as complex as a human's. But there are bigger brains: The sperm whale's brain weighs about 78.2 pounds. And the smallest brain — weighing in at less than 0.03 ounces — belongs to the green lizard.

Changing Your Brain

No one can trade it in, but anyone can improve brain power by learning and practicing; as a person learns new things, the structure of the brain changes. Remember the first time you tried to ride a two-wheel bike? It didn't work the first few times, but you kept trying, and now you do it well. While you were practicing, your brain and neurons were building new highways to transmit bike-riding information. Exercise helps improve brain power, too. It makes the body produce a chemical that makes a person's brain more open to learning. (Remember that when you can't concentrate or solve that math problem.)

Classroom Discussion

• Because your brain controls your entire body, it needs to be well protected. How does it protect itself? How can you protect it?
• When you learn, your brain changes so that it can keep and use that new information. What else can change the structure of your brain?