Enamel is hardest substance in the human body.
61
The average sperm cell swims at 8 inches per hour.
76
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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
When you take a step, you are using up to 200 muscles.
886
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22