For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain uses approximately as much energy as a 10 watt light bulb.
120
The human brain doesn't stop developing until about 25 years old.
102
The human body contains over a billion miles of DNA.
147
Yawns are more contagious among people with closer relationships.
163
The average person's skin weighs twice as much as their brain.
131