CH 17 WBC Morphology

Five Types of Leukocytes (WBCs)

Granular Leukocytes

Neutrophil60-70% of all WBCsAnatomy10-12 m diameter2-6 nuclear lobesFine, pale inconspicuous granulesPhysiologyRespond first to bacteria damage by chemotaxisPhagocytosisAfter engulfing pathogen releases several chemicalslysozymestrong oxidantsdefensins

Eosinophil2-4% of all WBCsAnatomy10-12 m diameter2 connected nuclear lobesred/orange large, uniform granules, do not obscure the nucleusPhysiology exit capillaries, enter tissue fluidcombat parasiteshistaminephagocytize antigen-antibody complexes

Basophil0.5-1% of all WBCsAnatomy8-10 m diameterbilobed or irregular nucleusround, blue-black granules may obscure the nucleusPhysiologyexit capillaries to enter tissue fluidmature into mast cellsrelease heparin, histamine, serotonin stimulate inflammationHypersensitivity (allergic) reactions

Agranular Leukocytes

Lymphocytes20-25% of all WBCs

Anatomy7-15mnucleus large and dark stained, round or indented cytoplasm forms a pale blue rim around the nucleus

Monocytes3-8% of all WBCsAnatomy14-19 mindented or kidney-shaped nucleus (not round)cytoplasm foamyPhysiologyslower to arrive but survive longer enlarge, differentiate into fixed and wandering macrophages remove microbes, cellular debris, following injury

End WBC MorphologyCH 17

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