In the bone marrow, multipotential hematopoietic stem cells (HSCs) are produced. These HSCs are the common ancestors of all blood cell elements. Under various cellular signals, HSCs differentiate into either lymphoid or myeloid progenitor cells.
- Lymphoid progenitor cells become B and T lymphocytes, as well as natural killer (NK) cells.
- Myeloid progenitor cells have many more options. They can become a:
- Myeloblast and differentiate into neutrophils, eosinophils, basophils, or monocytes/macrophages
- Megakaryocyte which then produces platelets
- Erythroblast which differentiates into erythrocytes
- Mast cell which contains histamine and heparin and participates in allergic and inflammatory responses
Aspirating bone marrow for microscopic examination can be significant when diagnosing hematopathology.
