Yawns are more contagious among people with closer relationships.
163
If your DNA was stretched out it would reach to the moon 6,000 times.
256
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
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
The average person's skin weighs twice as much as their brain.
131
Enamel is hardest substance in the human body.
61
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99