Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your heart will pump about 212 million liters in its lifetime.
26
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
When you take a step, you are using up to 200 muscles.
886
The human body contains over a billion miles of DNA.
147
The average person's skin weighs twice as much as their brain.
131
Yawns are more contagious among people with closer relationships.
163
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118