Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
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
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
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266