Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain uses approximately as much energy as a 10 watt light bulb.
120
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Poor eyesight (myopia) is associated with higher IQ.
232
When you take a step, you are using up to 200 muscles.
886
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197