10 Facts About the Brain

The brain is a very complex part of your body.

It has the ability to send and receive a large amount of information.

Here are some quick facts to help you understand the most complicated organ in your body.

1. Multitasking is impossible
When we think we’re multitasking, we’re actually context-switching. That is, we’re quickly switching back-and-forth between different tasks, rather than doing them at the same time. The book Brain Rules explains how detrimental “multitasking” can be: Research shows your error rate goes up 50 percent and it takes you twice as long to do things.

2. An adult brain weighs about 3 pounds
The cerebrum makes up 85% of the brain’s weight, and the brain makes up about 2% of a human’s body weight. The texture of the brain is like a firm jelly. The heaviest normal human brain weighed 4.43 pounds. It belonged to the Russian Writer Ivan Turgenev. And the smallest brain, just 2.41 pounds, belonged to a woman.

3. About 75% of the brain is made up of water
This means that dehydration, even as small as 2%, can have a negative effect on brain functions. Dehydration and a loss of sodium and electrolytes can cause acute changes in memory and attention. To prevent any loss of body or brain function, take steps to keep your body properly hydrated.

4. The human brain will triple its size the first year of life
 A two year old baby will have an 80% fully grown brain. It will continue to grow until you’re about 18 years old. It isn’t until about the age of 25 that the human brain reaches full maturity. The human brain is the largest brain of all vertebrates relative to body size.

5. Headaches are caused by a chemical reaction
Chemical activity in your brain, the nerves or blood vessels surrounding your skull, or the muscles of your head and neck (or some combination of these factors) can play a role in primary headaches. Serotonin is a chemical necessary for communication between nerve cells. When serotonin or estrogen levels change, the result for some is a headache or migraine. Serotonin levels may affect both sexes, while fluctuating estrogen levels affect women only.

6. The human brain contains approximately one hundred billion neurons 
This is about the same as the number of stars in the Milky Way galaxy. These neurons are connected by trillions of connections, or synapses. Experts call this a “neuron forest”. Information runs between these neurons in your brain for everything we see, think, or do. These neurons move information at different speeds. The fastest speed for information to pass between neurons is about 250 mph. That being said, neurons only make up 10% of the brain.

7. It is a myth that humans only use 10% of our brain
We actually use all of it. We’re even using more than 10 percent when we sleep. Although it’s true that at any given moment all of the brain’s regions are not concurrently firing, brain researchers using imaging technology have shown that, like the body’s muscles, most are continually active over a 24-hour period.

8. Cholesterol is key to learning and memory
The brain has a higher cholesterol content than any other organ.  In fact, about 25% of the body’s cholesterol resides within the brain. The brain is highly dependent on cholesterol, but its cholesterol metabolism is unique. Because the blood-brain barrier prevents brain cells from taking up cholesterol from the blood, the brain must produce its own cholesterol. The brain’s cholesterol is much more stable than the cholesterol in other organs, but when it breaks down, it is recycled into new cholesterol right in the brain.

9. Dreams are believed to be a combination of imagination, physiological factors, and neurological factors
The limbic system in the mid-brain deals with emotions in both waking and dreaming and includes the amygdala, which is mostly associated with fear and is especially active during dreams. Dreams are proof that your brain is working even when you are sleeping. The average human has about 4-7 dreams per night.

10. Short term memory lasts about 20-30 seconds
This has to do with your brain’s capacity for holding small amounts of information in the active mind. The brain keeps this information in an available state for easy access, but only does so for about a minute and a half. Most people hold memory for numbers around 7 seconds, and memory for letters around 9 seconds. In addition, the brain can store up to 7 digits in its working memory. That is why the telephone numbers in the United States are 7 digits long.