For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The average sperm cell swims at 8 inches per hour.
76
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266