A
megakaryocyte ( + + , "large-nucleus cell") is a large
bone marrow cell with a lobulated nucleus responsible for the production of blood
thrombocytes (
platelets), which are necessary for normal blood
clotting. Megakaryocytes normally account for 1 out of 10,000
bone marrow cells but can increase in number nearly 10-fold during the course of certain diseases. Owing to variations in
combining forms and spelling, synonyms include
megalokaryocyte and
megacaryocyte.