Yawns are more contagious among people with closer relationships.
163
Enamel is hardest substance in the human body.
61
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Your heart will pump about 212 million liters in its lifetime.
26
One human hair can support 3 ounces.
191
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13