Every year your body replaces 98% of your atoms.
119
Yawns are more contagious among people with closer relationships.
163
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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 thumb is about the same size as your nose.
124
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human body contains over a billion miles of DNA.
147
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197