Macrophages are scavenger cells and an essential component of the immune system.
Macrophages are leukocytes (white blood cells) and are cells of the immune system. They recognize foreign protein structures, enclose pathogens that have entered the body, phagocytise them into their cell interior and break them down there.
They can also destroy living tumour cells.
Macrophages are large, mobile, mononuclear cells and are the essential cellular component of the monocyte-macrophage system. They therefore belong to the innate immune system.
Macrophages are present in all tissues under steady state conditions. They develop from the monocytes circulating in the blood, which have a half-life of about 72 hours.
For further details see below. Macrophages (Allergology)