Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The human brain uses approximately as much energy as a 10 watt light bulb.
120
The human body contains over a billion miles of DNA.
147