Complement also helps to rid the body of antigen-antibody complexes. In carrying out these tasks, it induces an inflammatory response.
Complement proteins circulate in the blood in an inactive form.
But both pathways end in creation of a unit known as the membrane attack complex. Inserted in the wall of the target cell, the membrane attack complex constitutes a channel that allows fluids and molecules to flow in and out. The target cell rapidly swells and bursts. Meanwhile, various fragments flung off during the course of the cascade can produce other consequences. One byproduct causes mast cells and basophils to release their contents, producing the redness, warmth, and swelling of the inflammatory response.