The granulocytes, also called polymorphonuclear leukocytes because of their multilobed nuclei, are three short lived cell types including eosinophils, basophils, and neutrophils.
A granulocyte differentiates into a distinct cell type by a process called granulopoiesis.
This promyelocyte gives rise to a unique myelocyte that for the first time can be classified as an eosinophil, basophil, or neutrophil progenitor based on the histological staining affinity (eosinophilic, basophilic, or neutral granules).
[3] The unique myelocyte next differentiates into a metamyelocyte and then a band cell, with a C-shaped nucleus, before becoming a mature eosinophil, basophil, or neutrophil.
Macrophages come from monoblast progenitors that differentiate into promonocytes, which mature into monocytes.