Please name the arrowed cells by morphology in the following microscopic pictures of BM aspirate smears.
Answers: 1. myeloblast; 2. metamyelocytes; 3. myelocyte; 4. promyelocyte; 5. proerythroblast; 6. polychromatophilic erythroblast; 7. orthochromatic erythroblast; 8. hematogone; 9. mast cell; 10. osteoblast; 11. nucleus of a senescent megakaryocyte; 12. osteoclast.