Most of the body defense elements are located in the blood and inflammation is the means by which body defense cells and defense chemicals leave the blood and enter the tissue around the injured or infected site .
Inflammation is essentially beneficial, however, excess or prolonged inflammation can cause harm.
Animation of a capillary prior to vasodilation. Animation of vasodilation. The chemokines are held on the inner surface of the endothelial cells where they interact with chemokine receptors on the surface of the rolling leukocytes. The leukocytes are then chemotactically attracted to the injured site by the chemokines and other chemotactic factors mentioned earlier. The process of diapedesis , also known as emigration, is summarized in Fig.