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
When you take a step, you are using up to 200 muscles.
886
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Your thumb is about the same size as your nose.
124