Myelocyte

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A myelocyte is a young cell of the granulocytic series, occurring normally in bone marrow, but not in circulating blood (except when caused by certain diseases).

Contents 1 Histology 2 Precursor 3 Measurement 4 Additional images 5 References 6 External Links

[edit] Histology

When stained with the usual dyes, the cytoplasm is distinctly basophilic and relatively more abundant than in myeloblasts or promyelocytes, even though myelocytes are smaller cells.

Numerous cytoplasmic granules are present in the more mature forms of myelocytes. Neutrophilic and eosinophilic granules are peroxidase-positive, while basophilic granules are not.

The nuclear chromatin is coarser than that observed in myeloblasts, but it is relatively faintly stained and lacks a well defined membrane.

The nucleus is fairly regular in contour (not indented), and seems to be 'buried' beneath the numerous cytoplasmic granules. (If the nucleus were indented, it would likely be a metamyelocyte.)

[edit] Precursor

Myeloblasts or blasts are new, immature blood cells developed in the bone marrow that are the precursors of myelocytes.

[edit] Measurement

There is an internationally agreed method of counting blasts, with results from M1 upwards.

[edit] Additional images

Hematopoiesis

[edit] References

1. ^ Histology at BU 01809loa
2. ^ Histology at BU 01810loa
3. ^ Histology at BU 01804loa

[edit] External Links

• Image at queensu.ca

v • d • e  Blood - Blood plasma
Pluripotential hemopoietic stem cells | Red blood cells (Reticulocyte, Normoblast) | White blood cells
Lymphoid
T cells (Cytotoxic, Helper, Regulatory T cells, Natural Killer T cells) | B cells (Plasma cells & Memory B cells) | Natural killer cells
Myeloid
Granulocytes (Neutrophil, Eosinophil, Basophil) | Mast cell precursors | Monocytes (Histiocyte, Macrophages, Dendritic cells, Langerhans cells, Microglia, Kupffer cells, Osteoclasts) | Megakaryoblast | Megakaryocyte | Platelets