Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
The human brain doesn't stop developing until about 25 years old.
102
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
The human body contains over a billion miles of DNA.
147