It takes about 20 seconds for a red blood cell to circle the whole body.
102
Yawns are more contagious among people with closer relationships.
163
The human eye blinks an average of 4,200,000 times a year.
233
The average sperm cell swims at 8 inches per hour.
4
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
In ancient Egypt, priests plucked EVERY hair from their bodies, including their eyebrows and eyelashes.
130
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
The human body contains over a billion miles of DNA.
147