Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The human body contains over a billion miles of DNA.
147
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The largest cell in the human body is the female egg and the smallest is the male sperm.
682