Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Enamel is hardest substance in the human body.
61
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
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
Every year your body replaces 98% of your atoms.
119
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190