SCIENTIFIC FACTS

Bone Facts 
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- The smallest bone in the human body is the stapes bone which is located in the ear.

- There are 54 bones in your hands including the wrists.

- The only bone fully grown at birth is located in the ear.

- The human face is made up of 14 bones.

- Enamel is hardest substance in the human body.

- Adult human bones account for 14% of the body's total weight.

- Humans are born with 300 bones in their body, however when a person reaches adulthood they only have 206 bones. This occurs because many of them join together to make a single bone.

- Although the outsides of a bone are hard, they are generally light and soft inside. They are about 75% water.

- Fingernails grow nearly 4 times faster than toenails!

- Your thigh bone is stronger than concrete.

- The strongest bone in your body is the femur (thighbone), and it's hollow.
Brain Facts 
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- The human brain has about 100,000,000,000 (100 billion) neurons.

- From all the oxygen that a human breathes, twenty percent goes to the brain.

- Your brain is 80% water.

- Your brain is move active and thinks more at night than during the day.

- People who ride on roller coasters have a higher chance of having a blood clot in the brain.

- Once a human reaches the age of 35, he/she will start losing approximately 7,000 brain cells a day. The cells will never be replaced.

- In America, the most common mental illness is Anxiety Disorders.

Blood Facts 
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- Two million red blood cells die every second.

- The average life span of a single red blood cell is 120 days.

- The kidneys filter over 400 gallons of blood each day.

- A woman has approximately 4.5 liters of blood in her body, while men have 5.6 liters.

- Blood accounts for about 8% of a human's body weight.

- Each day 400 gallons of recycled blood are pumped through the kidneys.

- By donating just one pint of blood, four lives can be saved.

- Blood is such a good stain that Native Americans used it for paint.

- Your blood takes a very long trip through your body. If you could stretch out all of a human's blood vessels, they would be about 60,000 miles long. That's enough to go around the world twice.

- Half your body’s red blood cells are replaced every seven days.

- If all the blood vessels in your body were laid end to end, they would reach about 60,000 miles. 

Eyes Facts
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- The eyeball of a human weighs approximately 28 grams.

- The eye of a human can distinguish 500 shades of the gray.

- The cornea is the only living tissue in the human body that does not contain any blood vessels.

- The conjunctiva is a membrane that covers the human eye.

-Our body has some natural protection for our eyes. Our eyelashes help to keep dirt out of our eyes. Our eyebrows are made to keep sweat from running into our eyes.

- Around the pupil is a colored muscle called the "iris." Our eyes may be blue, brown , green , gray or black , because that is the color of the iris.

- Our eyes have many parts. The black part on the front of our eye is called the "pupil." It is really a little hole that opens into the back part of our eyes.

- Your eyes blinks over 10,000,000 times a year.

- A human eyeball weighs an ounce.

- Babies' eyes do not produce tears until the baby is approximately six to eight weeks old.

- The most common injury caused by cosmetics is to the eye by a mascara wand.

- Some people start to sneeze if they are exposed to sunlight or have a light shined into their eye.

- It is impossible to sneeze with your eyes open.

- The space between your eyebrows is called the Glabella.

- Inside our eye, at the back, is a part called the "retina." On the retina are cells called "rods" and "cones." These rods and cones help us to see colors and light.

- Just behind the pupil is a lens. It is round and flat. It is thicker toward the middle.

- Over the front of our eye is a clear covering called the "conjunctiva."

-The white part of our eye is called the "sclera." At the front, the sclera becomes clear and is called the "cornea."

- We should never put anything in or near our eyes, unless we have a reason to use eye drops. We would only do that if our doctor or parent told us to use them.

- Our eyes are very important to us, and we must protect them. We don't want dirt, sand, splinters or even fingers to get in our eyes. We don't want our eyes to get scratched or poked. That could damage our sight!

- The shark cornea has been used in eye surgery, since its cornea is similar to a human cornea.

- The number one cause of blindness in adults in the United States is diabetes.

- People generally read 25% slower from a computer screen compared to paper.

- Men are able to read fine print better than women can.