Enamel is hardest substance in the human body.
61
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Every year your body replaces 98% of your atoms.
119
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111