Ask unlimited questions for free
There are more nerve cells in one human brain than there are stars in the Milky Way.
There are 60,000 miles of blood vessels in every adult human.
Blood in the urine can be a sign of a kidney stone, glomerulonephritis, or other kidney problems.
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
For a complete list of videos, visit our video library