Enamel is hardest substance in the human body.
61
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
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
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Yawns are more contagious among people with closer relationships.
163
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Chewing gum boosts your brain power.
285