Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your thumb is about the same size as your nose.
124
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Your heart will pump about 212 million liters in its lifetime.
26
Enamel is hardest substance in the human body.
61
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266