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
Your body is creating and killing about 2.4 million red blood cells per second.
17
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The human brain doesn't stop developing until about 25 years old.
102