Yawns are more contagious among people with closer relationships.
163
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If your DNA was stretched out it would reach to the moon 6,000 times.
256
One human hair can support 3 ounces.
191
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Your body is creating and killing about 2.4 million red blood cells per second.
17
The average sperm cell swims at 8 inches per hour.
76
When you take a step, you are using up to 200 muscles.
886