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The Learning Kingdom's Cool Fact of the Day for March 4, 1999
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What kind of human body cell acts like an amoeba?
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Your body contains cells that look and act very much like amoebas (see
previous Cool Fact below to learn more about amoebas). Certain kinds
of leukocytes, or white blood cells, cling to the walls of arteries
and veins, moving around by extending pseudopods (temporary
protrusions) and flowing along.
The most common white blood cells are called neutrophils. Trillions
of them are created every day by the bone marrow and released into the
blood. They are attracted to substances that are present at the sites
of injury or infection. Once they arrive, they engulf bacteria, dead
cells, and other debris.
The largest white blood cells are the macrophages, which clean up
various tissues and organs. One kind of macrophage eats dead
neutrophils.
There are many other kinds of white blood cells. All of them are part
of the human immune system, which keeps the body free of infection.
How the human immune system works:
http://www.howstuffworks.com/immune-system.htm
Previous Cool Facts about amoebas:
http://www.cool-fact.com/archive/1998/08/24.html
Previous Cool Facts about blood:
http://www.cool-fact.com/archive/1997/02/28.html
http://www.cool-fact.com/archive/1998/04/28.html
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