Ask unlimited questions for free
The human body produces and destroys 15 million blood cells every second.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
The average office desk has 400 times more bacteria on it than a toilet.
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
There are 60,000 miles of blood vessels in every adult human.
For a complete list of videos, visit our video library