Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
Your heart will pump about 212 million liters in its lifetime.
26
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Every year your body replaces 98% of your atoms.
119
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197