Yawns are more contagious among people with closer relationships.
163
Every year your body replaces 98% of your atoms.
119
Enamel is hardest substance in the human body.
61
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
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The average sperm cell swims at 8 inches per hour.
76
The largest cell in the human body is the female egg and the smallest is the male sperm.
682