Neutrophils, eosinophils and basophils follow a similar pattern of development. We will illustrate the neutrophil sequence. The myeloblast has one or more nucleoli and agranular cytoplasm. Cell division occurs at this stage. The next stage, the promyelocyte, still has nucleoli. Primary granules, staining red or magenta, are produced only at this stage. During cell division, primary granules carry over to the next stage, the myelocyte. Specific granules begin to appear at the myelocyte stage. The nucleus may be indented, and the Golgi region can be distinguished. Nucleoli are no longer present. Specific granules have distinct sizes and staining properties. Each myelocyte produces only one type of specific granule. The myelocyte is the last stage where mitosis occurs. In the next stage, the metamyelocyte, specific granules outnumber the primary granules remaining from the promyelocyte stage. In the band form, the nucleus is condensed and U-shaped. The cytoplasm resembles the mature form. In the mature granulocyte, the nucleus is segmented and highly condensed. Specific granules are abundant. In the basophil, the large, dense granules may obscure the nucleus in stained preparations. Although the early stages appear identical, each cell is already committed to a specific lineage.
Myeloblast, Promyelocyte, Metamyelocyte, Neutrophils, eosinophils and basophils
Ching-Jung Chen, Abraham Kierszenbaum, Robert Levy, Lena Marvin, Jazmine Rogers, Aleksandr Vinkler
The City College Libraries, New York, New York
Myeloid Cell Development by City College of New York Digital Scholarship Services is licensed under a Creative Commons Attribution 4.0 International License.