Megakaryosyyttejä

Megakaryosyyttejä are large bone marrow cells that are the source of platelets in the blood. They originate from hematopoietic stem cells, undergoing a complex differentiation process. As they mature, megakaryocytes increase significantly in size and their cytoplasm becomes filled with granules containing clotting factors. This maturation involves repeated DNA replication without cell division, leading to polyploidy, where the cell contains multiple sets of chromosomes. The mature megakaryocyte then extends long cytoplasmic projections called proplatelets into the bloodstream. These proplatelets fragment into thousands of individual platelets, which are essential for hemostasis, the process of stopping bleeding. Megakaryocyte production is regulated by various growth factors, most notably thrombopoietin, which stimulates their proliferation and differentiation. Disruptions in megakaryocyte development or function can lead to bleeding disorders or abnormal platelet counts.