<prompt> macrophage in the brain isSchwann cellsOligodendrocytesAstrocytesMicroglia  <response>: Answer is option 4 Microglia are considered the resident macrophages of the brain given that they are the only myeloid cells present in the CNS parenchyma. Microglia perform both homeostatic and immune-related functions and constitute about 5-20 of all cells in the CNS. Ref of img : 