Explain the Phagocytosis

Phagocytosis includes the ingestion of particulate material including complete pathogenic microorganisms. The plasma membrane expands around the particulate material to form large vesicles known as phagosomes. It is performed either by neutrophils or macrophages. Neutrophils are very effective against pus forming (pyogenic) bacteria. We already know that macrophages are tissue phagocytes and are derived from circulating monocytes. These monocytes and macrophages together contribute to the phagocytic system (reticulo endothelial system). Macrophages are most effective against those microorganisms which live within the cells.