Yawns are more contagious among people with closer relationships.
163
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
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Your thumb is about the same size as your nose.
124
The human body contains over a billion miles of DNA.
147
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266