Ask unlimited questions for free
Drying your hands with a paper towel will reduce the bacterial count on your hands by 45–60%.
The human body produces and destroys 15 million blood cells every second.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
People about to have surgery must tell their health care providers about all supplements they take.
For a complete list of videos, visit our video library