Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human body contains over a billion miles of DNA.
147
Every year your body replaces 98% of your atoms.
119
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Your heart will pump about 212 million liters in its lifetime.
26