Enamel is hardest substance in the human body.
61
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
One human hair can support 3 ounces.
191
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
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
It takes about 20 seconds for a red blood cell to circle the whole body.
102