Enamel is hardest substance in the human body.
61
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Your thumb is about the same size as your nose.
124
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Poor eyesight (myopia) is associated with higher IQ.
232
One human hair can support 3 ounces.
191