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
If your DNA was stretched out it would reach to the moon 6,000 times.
256
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
The human brain doesn't stop developing until about 25 years old.
102
Yawns are more contagious among people with closer relationships.
163
Every year your body replaces 98% of your atoms.
119