− | Macrophages are large, round cells that contain a central round nucleus and have abundant clear, often vacuolated, cytoplasm. Macrophages acts as sentinel cells; they have a role in destroying bacteria, protozoa and tumour cells, and release substances that act upon other immune cells. Macrophages are phagocytic, long lived and are found throughout the body. | + | Macrophages are large, round cells that contain a central round nucleus and have abundant clear, often vacuolated, cytoplasm. Macrophages acts as sentinel cells; they have a role in destroying bacteria, protozoa and tumour cells, and release substances that act upon other immune cells. Macrophages are [[Phagocytosis|phagocytic]], long lived and are found throughout the body. |