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
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Poor eyesight (myopia) is associated with higher IQ.
232
Your body is creating and killing about 2.4 million red blood cells per second.
17
It takes about 20 seconds for a red blood cell to circle the whole body.
102