Medical Terminology


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A humoral substance is a body fluid, or a substance related to a body fluid, especially with regard to immune responses involving antibodies in body fluids (as distinct from cells). Many of the bacteria that cause infectious diseases in humans multiply in the extracellular spaces of the body, and these extracellular spaces are protected by the humoral immune response, in which antibodies produced by B cells cause the destruction of extracellular microorganisms and prevent the spread of intracellular infections.