Enamel is hardest substance in the human body.
61
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
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
Yawns are more contagious among people with closer relationships.
163
The human body contains over a billion miles of DNA.
147
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118