A platelet is a fragment of the cytoplasm of which cell?

1. A platelet is not a cell but a fragment of cytoplasm surrounded by a plasma membrane. 2. The parent cell is the megakaryocyte, a large myeloid cell that stays in the marrow. 3. The megakaryocyte pushes platelet-precursor extensions through marrow capillary walls and sheds fragments into the circulation. 4. This is why calling platelets thrombocytes is inaccurate, since the suffix suggests a cell rather than a fragment. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.4 Leukocytes and Platelets_