The familiar sounds of your heart are made by the heart's valves as they open and close.
Did you know?
More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.
Did you know?
Acetaminophen (Tylenol) in overdose can seriously damage the liver. It should never be taken by people who use alcohol heavily; it can result in severe liver damage and even a condition requiring a liver transplant.
Did you know?
Giardia is one of the most common intestinal parasites worldwide, and infects up to 20% of the world population, mostly in poorer countries with inadequate sanitation. Infections are most common in children, though chronic Giardia is more common in adults.
Did you know?
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
American Alsatian
Young American Alligators basking
In American Progress (1872), John Gast depicts a feminized (and eroticized) America moving westward,
Native American casinos remain a topic of both controversy and envy. Shown here is Corey Two Crow as ...