Enamel is hardest substance in the human body.
61
One human hair can support 3 ounces.
191
Chewing gum boosts your brain power.
285
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
Yawns are more contagious among people with closer relationships.
163
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Your body is creating and killing about 2.4 million red blood cells per second.
17
Your heart will pump about 212 million liters in its lifetime.
26