Complement System

∞ generated and posted on 2016.03.19 ∞

Various blood proteins associated with innate immunity that together are involved in effecting the destruction of microorganisms.

Though antibodies can be involved in complement cascades (particularly re: the classical pathway), and antibodies are indeed blood proteins (i.e., IgM and IgG), in fact antibodies are not considered to be complement proteins. Instead, complement was named due to the ability of these blood proteins to "complement" the antimicrobial activities of antibodies.

The following video shows complement's classical pathway in "all" of its glory – in simple cartoon form – from antibody binding trough membrane attack complex formation:

The following video provides a nice illustration, without sound, of complement's classical pathway, stopping prior to "late" stages: