Ask unlimited questions for free
Your heart beats over 36 million times a year.
Today, nearly 8 out of 10 pregnant women living with HIV (about 1.1 million), receive antiretrovirals.
In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.
It is difficult to obtain enough calcium without consuming milk or other dairy foods.
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.
For a complete list of videos, visit our video library