At what stage will specific (secondary) granules of polymorphonuclear cells appear?

The appearance of specific (secondary) granules in polymorphonuclear cells is a crucial aspect of myeloid cell development. This process begins during the myelocyte stage of maturation. The myelocyte is characterized by the formation of specific granules containing enzymes and proteins that are essential for the functions of mature granulocytes, such as neutrophils, eosinophils, and basophils.

During earlier stages, specifically during the promyelocyte stage, the cells primarily contain azurophilic granules. It is at the myelocyte stage that specific granules start to form and accumulate, leading to a distinct shift in the composition of the granules within the cell. The presence of these granules is important for the cell's functionality in immune response and pathogen defense.

In subsequent stages like the metamyelocyte and band cell stages, the granule types continue to evolve, but the specific granules are already established by the time the cell reaches the myelocyte stage. Understanding this developmental timeframe is essential for recognizing the functions and characteristics of different stages in granulocyte maturation.