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 adult human brain weighs about 3 pounds (1,300-1,400 g).
99
One human hair can support 3 ounces.
191
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
It takes about 20 seconds for a red blood cell to circle the whole body.
102
If your DNA was stretched out it would reach to the moon 6,000 times.
256