Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Every year your body replaces 98% of your atoms.
119
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13