Yawns are more contagious among people with closer relationships.
163
The average person's skin weighs twice as much as their brain.
131
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain doesn't stop developing until about 25 years old.
102
Enamel is hardest substance in the human body.
61
One human hair can support 3 ounces.
191
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137