Enamel is hardest substance in the human body.
61
Chewing gum boosts your brain power.
285
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Your heart will pump about 212 million liters in its lifetime.
26
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The average sperm cell swims at 8 inches per hour.
76
Your thumb is about the same size as your nose.
124
Poor eyesight (myopia) is associated with higher IQ.
232