Abstract
Macrophages are mononuclear phagocytes that are widely distributed throughout the body. These cells can contribute to development and homeostasis and participate in innate and adaptive immune responses. The physiology of macrophages can vary tremendously depending on the environment in which they reside and the local stimuli to which they are exposed. Macrophages are prodigious secretory cells, and in that role can promote and regulate immune responses and contribute to autoimmune pathologies. Macrophages are highly phagocytic, and in this capacity have long been considered to be essential immune effector cells. The important roles of macrophages in maintaining homeostasis and in contributing to tissue remodeling and wound healing is sometimes overlooked because of their vital role in host defense.