Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Enamel is hardest substance in the human body.
61
Your body is creating and killing about 2.4 million red blood cells per second.
17
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The largest cell in the human body is the female egg and the smallest is the male sperm.
682