Enamel is hardest substance in the human body.
61
The human brain has the capacity to store everything that you experience.
4k
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
Poor eyesight (myopia) is associated with higher IQ.
232
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
The average sperm cell swims at 8 inches per hour.
76
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266