Yawns are more contagious among people with closer relationships.
163
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
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human body contains over a billion miles of DNA.
147
Enamel is hardest substance in the human body.
61
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190