Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Every year your body replaces 98% of your atoms.
119
The average person's skin weighs twice as much as their brain.
131
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your thumb is about the same size as your nose.
124
It takes about 20 seconds for a red blood cell to circle the whole body.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515