The average sperm cell swims at 8 inches per hour.
76
Every year your body replaces 98% of your atoms.
119
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Enamel is hardest substance in the human body.
61
Yawns are more contagious among people with closer relationships.
163
Your thumb is about the same size as your nose.
124
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127