The Immune system is the bodys main
defense against all foreign substances. The largest organ in the Immune system
is the skin. The skin acts as a protective barrier for the rest of the body, keeping
out literally billions of microscopic bacteria cells. Some of which are disease
causing pathogens. Also involved in the immune system is the bloodstream which carries billions of tiny
cells specializing in the removal of pathogens. These cells include white blood
cells, platelets, and antibodies.