neutrophilic granulocytes,
 eosinophilic granulocytes,
 basophilic granulocytes.

Together with monocytes, they make phagocytic lineage that normally originates in the bone marrow.
We know much less about granulocytopoiesis than about erythrocytopoiesis, but we know that there is a negative feedback between the number of granulocytes in the circulation and granulocytic line in the bone marrow.

 GRANULOCYTOPOIESIS

Granulocytes originate and mature in the bone marrow and then migrate to the blood. In normal conditions the number of the cells moving from the bone marrow to the blood is equivalent to the number of the cells moving from the blood to tissue.
Proliferation, differentiation, maturation, and storage in the bone marrow are well known for neutrophilic but not for basophilic granulocytes.
In the bone marrow, the proliferation happens in the mitotic compartment where the mass of granulocytes develops after 4-5 divisional cycles. Most of the divisional cycles, about 3, happen on the level of myelocytes.
Maturation period from the myelocyte to mature granulocyte of the peripheral blood is about 5-7 days.
Myeloblast, promyelocyte, and myelocyte are cells that divide and mature. The mature of granulocytes in the bone marrow are cells that do not divide any more, just mature; they are metamyelocytes. During the maturation of the cell, the color of the cytoplasm changes, granules appear in the cytoplasm, depending on the type of granulocytes, and the shape of the nucleus changes. In the end, the nucleus takes a horseshoe appearance in the metamyelocyte and a rod-like appearance in non-segmented granulocyte. Finally, the nucleus becomes segmented in the segmented granulocyte.
Granulocytes are supposed to stay in the peripheral bloodstream for about 6-8 hours. Passing into peripheral tissues, where granulocytes live for about 2-3 days, the life-span of white blood cells is over.
In physiological conditions, the exact fate of granulocytes is not known. Granulocytes migrate from the bloodstream to the lungs, gastrointestinal tract, liver and spleen; they may be lost from mucosal surfaces, "die in these tissues", i.e., they are phagocytized by tissue macrophages.
In pathological conditions it is possible to find some or all morphological stages of this lineage in the peripheral blood. Under stress and during the maturation, time may be shortened, divisions may be skipped, so immature forms of the precursors may appear in the peripheral blood.

 NEUTROPHILIC GRANULOCYTE

Neutrophilic granulocytes play important role in inflammation. They move through the capillary endothelium and come to the site of inflamation. Only stab granulocytes and mainly segmented granulocytes migrate to the peripheral blood.

 EOSINOPHILIC GRANULOCYTE

Eosinophilic granulocytes are mostly located in tissues and not in the peripheral blood.
Eosinophilia accompanies immune and allergic reactions. Eosinophilic granulocytes have antihistaminic function: by eliminating histamine they prevent its actions leading to edema and smooth muscles spasm.
They have power of phagocytosis, but in that ability they are far behind neutrophilis. Eosinophilic granulocytes are able to phagocytize antigen-antibody complexes, as well as to use their enzymes to demolish foreign proteins.

 BASOPHILIC GRANULOCYTE

Basophilic granulocytes take part in the reactions of early hypersensitive reaction by degrading lipids. In the blood smears of peripheral blood, basophilic granulocytes make up to 1% of cells.
Basophilic granules contain histamine and heparin. Under the influence of histamine releasing factors, basophilic granulocytes release histamine responsible for numerous allergic reactions.
Immunoglobulin IgE binds, by its Fc-fragment, to specific receptors located on the membranes of basophilic granulocytes, which also provides the stimulus for the release of histamine from basophilic granules. Basophilic granulocytes release all stored heparin during hyperlipemia after food intake, which enables the degradation of triglycerides into fatty acids and glycerol (heparin activates lipoproteinic lipase).

 PHAGOCYTOSIS

In order to fulfil their protective role, phagocytes must accumulate on the site of inflammation, come in contact with harmful agents, and phagocytize them, dissolving and removing them. Accumulation of granulocytes and monocytes on the inflammatory site is caused by chemotaxis.
After binding with the harmful factors, granulocyte takes these factors in its cytoplasm with the help of pinocytosis or phagocytosis. Phagocytized material is separated from the remainder of the cytoplasm with an invagination of the cell membrane. Such a vesicle is called phagosome. Subsequently, lysosomes of granulocytes bind to the phagosomes and discharge their hydrolyzing enzymes, killing and dissolving phagocytized material.
Even granulocytes collapse after releasing their enzymes and degranulation.

 DISTURBANCES IN GRANULOCYTE MORPHOLOGY

Morphological changes of granulocytes manifest as anomalies of the nucleus or the cytoplasm. They can reflect congenital anomalies or be an acquired disturbance following various diseases:

Disturbances in the features of the nucleus (Pelger-Huet anomaly, Pseudo Pelger-Huet anomaly, hypersegmentation of the nucleus)
Abnormalities of the cytoplasm (Alder's anomaly, Chediak-Higashi anomaly, May-Hegglin anomaly, Döhle bodies, "toxic" granulations, Drumstick, Auer bodies, shift to the left)
Alterations in the size (macropolycyte, micropolycyte)