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the giant cell of bone marrow; it is a large cell with a greatly lobulated nucleus, and is generally supposed to give rise to blood platelets.


A large cell (as much as 100 mcm in diameter) with a polyploid nucleus that is usually multilobed; megakaryocytes are normally present in bone marrow, not in the circulating blood, and give rise to blood platelets.
[mega- + G. karyon, nut (nucleus), + kytos, hollow vessel (cell)]