The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Our eyes are always the same size from birth, but our nose and ears never stop growing.
269
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
22
If you are cold you are more likely to be hungry because you use energy to keep warm.
144
Bearing a male child can alter a woman's brain by leaving male DNA that can persist for the rest of her life, making her less likely to suffer from Alzheimer's disease, promote tissue repair, and improve her immune system.
16
Every hour one billion cells in the body must be replaced.
17
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your heart will pump about 212 million liters in its lifetime.
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