Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain doesn't stop developing until about 25 years old.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
Enamel is hardest substance in the human body.
61
Every year your body replaces 98% of your atoms.
119
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
When you take a step, you are using up to 200 muscles.
886