What are interesting facts about the human brain?

The brain is one of the body's most powerful organs. It helps people talk, move, feel, see, hear and even smell. The brain controls almost everything the body does, including things that people don’t even have to think about, like growing and breathing.

Mrs. Marjorie Nolan Cohn
Nutrition & Dietetics Specialist

The average brain weighs about 3 pounds, and has approximately 100 billion neurons. There are about 100,000 billion miles of blood vessels in the brain. The brain uses about 20 percent of the total oxygen at rest. While awake your brain generates 10 to 23 watts of power- or enough energy to power a light bulb. The brain is 75 percent water.

Here are some cool facts about the human brain:

  • The brain accounts for only 2 percent of the body's weight but uses 20 to 25 percent of the body's oxygen and energy supply.
  • Messages travel between neurons at different speeds. Some seem like they're walking (one and a half feet per second), while others are fighter-jet fast (400 feet per second).
  •  In utero, the brain has no pain receptors, so it can feel no pain. Newborns feel pain with the same sensitivity as adults, but the sensation may be less localized (they don't know where the pain is coming from), and they may have a delayed response.
  • While awake, the brain generates up to 23 watts of power, enough to light up a room.
  • Simply opening your eyes activates 75 percent of your brain's energy.
  • Children who learn two languages before the age of five have much denser gray matter as adults. They literally build bigger brains. Muy bueno!
YOU: Raising Your Child: The Owner's Manual from First Breath to First Grade

More About this Book

YOU: Raising Your Child: The Owner's Manual from First Breath to First Grade

There’s little doubt that parenting can be one of the most rewarding and satisfying experiences you’ll ever have. But it can be plenty tough, too: Around the clock, you’re working to keep your...
Dr. Daniel G. Amen, MD
Psychiatrist (Therapist)

A piece of brain tissue the size of a grain of sand contains 100,000 neurons and one billion connections—all talking to one another! You continue to make new neurons (brain cells) throughout life in response to mental activity and new learning (physical exercise helps too!). The human brain is over three times as big as the brain of other mammals that are of similar body size. The human skull is made up of 22 bones that are joined together. Your brain is very delicate, about the consistency of soft butter. Your brain is 80 percent water. Hydration is critical to its health. The brain weighs around 3 pounds, of which 60 percent of its dry weight is fat. Even though your brain is only 2 percent of your body’s weight, it uses 20 to 30 percent of the calories you consume. Your brain uses 20 percent of the oxygen and blood flow in the body and it never rests (even during sleep). It is thought that a yawn is your body’s way of cooling down and “waking up your brain” by sending in more oxygen. There are approximately 100,000 miles of blood vessels in your brain. Your brain’s “grey matter” is made up of neurons, or brain cells. Your brain’s “white matter” is made up of dendrites and axons, which create the network by which neurons communicate with each other. On average, your brain is 60 percent white matter and 40 percent grey matter. Children who learn two languages before the age of 5 have more grey matter by the time they are adults. During sleep, your cerebrospinal fluid washes away harmful waste proteins that build up between brain cells during waking hours. At times during pregnancy, the baby’s brain makes 250,000 new nerve cells per minute.

Continue Learning about Brain Health

Think Smarter with a Handful of This
Think Smarter with a Handful of This
The perfect brain food fits oh so neatly in the palm of your hand. Know what it is? It's a handful of Dr. Mao's Anti-aging Brain Mix, from his book Se...
Read More
How does blood get to the brain?
Natalia S. Rost, MDNatalia S. Rost, MD
Blood delivers fuel and nourishment to the brain through a complex system of blood vessels that reac...
More Answers
4 Foods Your Brain Will Love
4 Foods Your Brain Will Love4 Foods Your Brain Will Love4 Foods Your Brain Will Love4 Foods Your Brain Will Love
Nourish your noggin for stronger brainpower.
Start Slideshow
Drink Hot Cocoa to Boost Your Brain Power
Drink Hot Cocoa to Boost Your Brain Power

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.