The Brain

Brain Facts

The Brain [brān]

An organ of soft nerve tissue contained in the skull of vertebrates.

The Brain

Education, writing or girl in a house thinking of solutions, learning math problem solving or child

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

  • Read printed words
  • Regulate our breathing
  • Remember colors
  • Manage the rhythm of our heart
  • Control our body temperature
  • Remind us to blink
  • Remember how to play a game
  • Ride a bike
  • Determine what the soft fur on a dog's back feels like
  • 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.

Brain image made out of little cogwheels

In the book, The Great Brain Book: An Inside Look At The Inside Of Your Head, author HP Newquist says, “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 head. 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.”

Where Is Your Brain Located?

Human Physiology - Model of human head and brain

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! Altogether, there are 28 bones in your skull, and your brain is tucked safely inside, protecting it from most minor bumps and blows. Learn more about the skull at this Neuroscience For Kids site.

Fascinating Facts

Adorable kid girl sleeping on bed

Here are some interesting pieces of information about the brain:

  • 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!
  • A human brain is larger than that of most other animals'. See how it compares.
  • 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.

Here are some more fun facts about the brain.

What does your brain look and feel like?

human brain on white background

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.

What are the major areas of the brain and what do they do?

Brain coloed sections

CerebrumCerebellumBrain 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.Divided into three parts: Medulla, Pons, and Midbrain.
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, and digestion, as well as reflexes such as sneezing, swallowing, and coughing.

How does the brain connect to the rest of the body?

X-ray with brain and spinal cord concept

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 inches) long in adults. It is protected by 33 bones called vertebrae. The brain and the spinal cord together are called the central nervous system. The central nervous system is one part of the nervous system. The rest, mostly nerves, is called the peripheral nervous system.

How are all the parts of the nervous system connected?

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.

Neurons Electrical Pulses

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, via neurons, through your spinal cord and nerves to the muscles in your arm to pull your hand away. Neurons can send signals to thousands of other neurons at a rate of up to 270 miles per hour.

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

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

  • Your brain contains approximately 100 billion neurons. Each neuron links 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.

You can take a look at some neurons at this online Gallery of Neurons.

Find out more at the Science Trek Nervous System site.

Your brain and your senses

adorable child in chef hat smiling and looking away in kitchen

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 sense organs — fingers, ears, eyes, nose, and tongue — gather information about your surroundings and send this information through sensory neurons to special areas in the cerebral cortex. Visit Lobes of the Brain to take a closer look at where the different kinds of sensory signals go to in the cerebral cortex.

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

Our Science Trek Five Senses site has more information.

Exercise Your Brain

boy scratches his head thoughtfully the child looks up and is thinking about something

Although scientists used to believe that the brain could not repair itself, they are starting to discover ways in which brains can indeed do this. Despite this great news, brains don't heal as easily as a cut, scraped skin, or torn and broken bones. So 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 at this Brain Fitness guide for ways to keep your brain healthy.

Top 10 Questions

January 2011

Thanks to Dr. David Bettis, pediatric neurologist, St. Luke's Regional Medical Center; Dr. Mikaela Sebree, pediatric neuropsychologist, St. Luke's Regional Medical Center for the answers.

  1. How many cells are there in the brain?

    There are about 100 billion nerve cells in one human brain. To put that in perspective, there are 300 million people in the United States. There are 100 times more cells in the human brain. (From Connor in Mrs. Schweitzer's class at Riverside Elementary School in Boise)

  2. How big is your brain?

    A full size brain weighs about three pounds. (From Tyler in Mrs. Schweitzer's class at Riverside Elementary School in Boise)

  3. Why can't the brain be located somewhere else in the body?

    The brain is the information center for the body. The head is a perfect place because it is on top. We have a neck that can swivel, so we can see things in different places and the brain is well protected by the skull. (From Dakota in Mrs. Schultz's class at Dalton Elementary School in Dalton Gardens)

  4. How does the brain help us see?

    The brain helps us see through a system that is in charge of our senses. We use our eyes and sense light. The brain has pathways that go to the back part of the brain, the visual cortex, where the light signal is processed. This is where we are able to recognize what we are seeing. (From Gabriel in Mrs. Pokington's class at Sunset Falcon Elementary School)

  5. How much of our brain do we actually use?

    In theory, we don't use all of it, but we do need all of it. We use different parts of our brain at different times for different things. (From Hannah in Pocatello)

  6. How does the brain get information to the body?

    We get information to parts of our body through nerves. These nerves control many things like movement, sensation, sweating and temperature. It's a dense and complex network of nerves that goes to all parts of our body. (From Cooper at Riverside Elementary School in Boise)

  7. How does one side of your brain control the other side of your body?

    Some time back in evolution, the right side pathway to the brain crossed over. So the right side of the brain controls the left side of your body and the left side of the brain controls the right side of your body. Why that happened, people are still trying to understand. Then there's the cerebellum, a part of the brain that controls balance and coordination. (From Megan who is homeschooled in Kuna)

  8. How does the brain think of all these thoughts?

    The brain is able to think fast through neurotransmitters and the brain's connections. Chemicals create our thoughts, but it's also the organization of the networks in our brain that allows us to have the thoughts that we have. (From Clara at Longfellow Elementary School in Boise)

  9. How does the brain store thoughts?

    Scientists are trying to figure out exactly how that process happens. There's a really important part of our brain that's in the limbic system. It helps store and create new memories. However, information is generally stored in a network. It's not like we have one part of the brain where every memory is stored. Memories are actually stored throughout the brain. This helps us create new learning and new memories. (From Randy in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens)

  10. Why do we need wrinkles in our brain?

    The brain has lots and lots of wrinkles. This has to do with the complexity of the brain. These folds allow there to be a lot more surface area. If we took a brain and flattened it out, it would be the size of a double section of a newspaper. There's a lot of surface area and it has a lot to do with the functions of the brain. If the brain does not form properly, and the wrinkles don't occur, it can really affect how the brain works. (From Korynn at Temple View Elementary School in Idaho Falls)