The complement system helps or ??complements? the ability of antibodies and phagocytic cells to clear pathogens from an organism. Complement is part of the innate immune system that is not adaptable and does not change over the course of an individual's lifetime. Complement can be recruited and brought into action by the adaptive immune system. The following are basic functions of complement: 1. Opsonisation - enhancing phagocytosis of antigens 2. Chemotaxis - attracting macrophages and neutrophils 3. Cell Lysis - rupturing membranes of foreign cells 4. Clumping of antigen-bearing agentsSynonyms: Complement system, tissue macrophages, blood monocytes, protease C3-convertase, mannose-binding lectin pathway, C3, C3a, C3b, C5a, C5b, C6, C7, C8, and polymeric C9, cascade cleavage and activation events, recruit inflammatory cells, anaphylatoxin.