For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human brain doesn't stop developing until about 25 years old.
102
The average sperm cell swims at 8 inches per hour.
76
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193