Hematopoesen
Hematopoesen, often spelled hematopoiesis in English, is the biological process by which all cellular components of blood are produced, developed, and maintained. In vertebrates it begins during embryonic life and continues throughout adulthood. Blood cells originate from hematopoietic stem cells (HSCs) in the bone marrow, which can self-renew and differentiate into progenitor cells that commit to either the myeloid or lymphoid lineages.
During development, hematopoiesis shifts sites: it starts in the yolk sac, then the fetal liver and spleen,
Lineages: Myeloid differentiation yields erythrocytes, megakaryocytes (platelets), and granulocytes and monocytes; lymphoid differentiation yields T cells,
Clinical relevance: Abnormal hematopoiesis can cause anemia, immunodeficiency, or bleeding disorders. Malignant transformation of hematopoietic cells