Blood monocyte, SEM

Blood monocyte and phagocytosis of foreign debris on a blood vessel, scanning electron micrograph (SEM). Monocytes are derived from bone marrow monoblasts and promonocytes. They are delivered to the blood and can enter the tissues to develop into macrophages. Monocytes are a type of white blood cells (leukocytes).They are part of the innate immune system of vertebrates. They are amoeboid in shape and have an agranulated cytoplasm. They play multiple roles in immune system function, such as: 1) replenishing macrophages under static conditions and 2) under to inflammation, monocytes can move rapidly to sites of infection in the tissues and divide and differentiate into macrophages and dendritic cells to elicit an immune response. Magnification: x1,400 when shortest axis printed at 25 millimetres.