Enamel is hardest substance in the human body.
61
Your thumb is about the same size as your nose.
124
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Every year your body replaces 98% of your atoms.
119
The average sperm cell swims at 8 inches per hour.
76
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The largest cell in the human body is the female egg and the smallest is the male sperm.
682