Monocyte

A monocyte is a white blood cell.

Monocytes are large blood cells (from 20 to 40 micrometres in diameter) which are mobile and produced by the bone marrow from haemopoietic stem cells, specifically from monoblasts.

These are young leukocytes, which are involved in phagocytosis and haemostasis (coagulation). When monocytes leave the circulating blood, they then evolve into different types of phagocytes:

• macrophages in connective tissue;
• microglial cells in the central nervous system;
• osteoclastes in bone.