....The Immune System is the body's defense against infection. The
Immune System consists of the Adenoids, Tonsills, Lymph Nodes, Spleen,
Bone Marrow, Appendix, Thymus,and the Lymphatic Vessels. Through a
series of steps called the "immune response", the Immune System attacks
organisms and substances that invade our systems and cause disease.
It protects us against disease by identifying and killing pathogens.
It detects pathogens ranging from viruses to parasitic worms and tells
them apart from the organism's normal cells and tissues.

....Finding pathogens is complicated because pathogens adapt and evolve,
or change, and come up with new ways to infect the organism.

Video Clip: ........How does the Immune System work?

.... Mr.Video ClVVidideoii

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