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
Your body is creating and killing about 2.4 million red blood cells per second.
17
Every year your body replaces 98% of your atoms.
119
The human body contains over a billion miles of DNA.
147
Enamel is hardest substance in the human body.
61
The human brain has the capacity to store everything that you experience.
4k
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266