<unk>  is the aspect of immunity that is mediated by macromolecules - including secreted antibodies, complement proteins, and certain antimicrobial peptides - located in extracellular fluids.<unk>  is named so because it involves substances found in the humors, or body fluids. It contrasts with cell-mediated immunity.<unk>  is also referred to as antibody-mediated immunity. The study of the molecular and cellular components that form the immune system, including their function and interaction, is the central science of immunology. The immune system is divided into a more primitive innate immune system and an acquired or adaptive immune system of vertebrates, each of which contain both<unk>  and cellular immune elements.<unk>  refers to antibody production and the coinciding processes that accompany it, including: Th2 activation and cytokine production, germinal center formation and isotype switching, and affinity maturation and memory cell generation. It also refers to the effector functions of antibodies, which include pathogen and toxin neutralization, classical complement activation, and opsonin promotion of phagocytosis and pathogen elimination.
Humoral immunity
Immune response
Intrinsic immunity
Contact immunity
Social immunity
Histocompatibility
Immunity 
Immune tolerance