Definition of Macrophage

Macrophage: A type of white blood that ingests (takes in) foreign material. Macrophages are key players in the immune response to foreign invaders such as infectious microorganisms.

Blood monocytes migrate into the tissues of the body and there differentiate (evolve) into macrophages.

Macrophages help destroy bacteria, protozoa, and tumor cells. They also release substances that stimulate other cells of the immune system. And they are involved in antigen presentation. To do this, they carry the antigen on their surface and present it to a T cells.