|
|
The familiar sounds of your heart are made by the heart's valves as they open and close.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
There are 20 feet of blood vessels in each square inch of human skin.
IgA antibodies protect body surfaces exposed to outside foreign substances. IgG antibodies are found in all body fluids. IgM antibodies are the first type of antibody made in response to an infection. IgE antibody levels are often high in people with allergies. IgD antibodies are found in tissues lining the abdomen and chest.
Congestive heart failure is a serious disorder that carries a reduced life expectancy. Heart failure is usually a chronic illness, and it may worsen with infection or other physical stressors.