Yawns are more contagious among people with closer relationships.
163
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Your body is creating and killing about 2.4 million red blood cells per second.
17
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
It takes about 20 seconds for a red blood cell to circle the whole body.
102
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
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