Yawns are more contagious among people with closer relationships.
163
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The human body contains over a billion miles of DNA.
147
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Every year your body replaces 98% of your atoms.
119
The average person's skin weighs twice as much as their brain.
131
Enamel is hardest substance in the human body.
61