Enamel is hardest substance in the human body.
61
Poor eyesight (myopia) is associated with higher IQ.
232
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The average sperm cell swims at 8 inches per hour.
76
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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human body contains over a billion miles of DNA.
147
It takes about 20 seconds for a red blood cell to circle the whole body.
102