TY - CHAP M1 - Book, Section TI - Structure and Composition of Neutrophils, Eosinophils, and Basophils A1 - Smith, C. Wayne A2 - Kaushansky, Kenneth A2 - Lichtman, Marshall A. A2 - Prchal, Josef T. A2 - Levi, Marcel M. A2 - Press, Oliver W. A2 - Burns, Linda J. A2 - Caligiuri, Michael PY - 2015 T2 - Williams Hematology, 9e AB - SUMMARYEarly in precursor development in the marrow, cells destined to be leukocytes of the granulocytic series—neutrophils, eosinophils, and basophils—synthesize proteins and store them as cytoplasmic granules. The synthesis of primary or azurophilic granules defines the conversion of the myeloblast, a virtually agranular, primitive cell that is the earliest granulocyte precursor identifiable by light microscopy, into the promyelocyte, which is rich in azurophilic granules. Synthesis and accumulation of secondary or specific granules follows. The appearance of specific granules marks the progression of the promyelocyte to neutrophilic, eosinophilic, or basophilic myelocytes. Thereafter, the cell continues maturation into an amitotic cell with a segmented nucleus, capable of chemotaxis, phagocytosis and microbial killing. The mature granulocytes also develop cytoplasmic and surface structures that permit them to attach to and penetrate the wall of venules. The mature granulocytes enter the blood from the marrow, circulate briefly, and move to the tissues to carry out their major function of host defense. Blood neutrophils exhibit the capacity for changes in phenotypic characteristics and life span depending on the stimulating milieu of cytokines and chemokines. Gene expression profiling studies indicate the neutrophil is a transcriptionally active cell, responsive to environmental stimuli, and capable of a complex series of early and late changes in gene expression. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1121095474 ER -