Cell Type Description Function Life Span
Erythrocyte 7um in diameter; concave disk shape; entire cell stains pale pink; no nucleus Transportation of respiratory gases
(O 2 and CO 2 )
105 to 120 days
Neutrophil 12-15mm in diameter; spherical shape; multi-lobed nucleus; small, pink-purple staining cytoplasmic granules Cellular defense - phagocytosis of small pathogenic microorganisms Hours to 3 days
Basophil 11-14mm in diameter; spherical shape; generally two-lobed nucleus; large purple staining cytoplasmic granules Secretes heparin (anticoagulant) and histamine (important in inflammatory response) Hours to 3 days
Eosinophil 10-12mm in diameter; spherical shape; generally two-lobed nucleus; large orange-red staining cytoplasmic granules Cellular defense - phagocytosis of large pathogenic microorganisms such as protozoa and parasitic worms; releases antiinflammatory substances in allergic reactions 10 to 12 days
Lymphocyte 6-9mm in diameter; spherical shape; round (single-lobe) nucleus; small lymphocytes have scant cytoplasm Humoral defense - secretes antibodies; involved in immune system response and regulation Days to years
Monocyte 12-17mm in diameter; spherical shape; nucleus generally kidney- bean or "horseshoe" shaped with convoluted surface; ample cytoplasm often "steel blue" in color Capable of migrating out of the blood to enter tissue spaces as a macrophage - an aggressive phagocytic cell capable of ingesting bacteria, cellular debris, and cancerous cells Months
Platelet 2-5mm in diameter; irregularly shaped fragments; cytoplasm contains very small pink staining granules Releases clot-activating substances and helps in formation of actual blood clot by forming platelet "plugs" 7 to 10 days

White Blood Cells - Normal Values

Differential Count*
Class Normal Range (%) Typical Normal (%)
Those with granular cytoplasm and irregular nuclei
Neutrophils (neutral staining) 65 to 75 65
Eosinophils (acid staining) 2 to 5 3
Basophils (basic staining) 1/2 to 1 1
Those with nongranular cytoplasm and regular nuclei
Lymphocytes (large and small) 20 to 25 25
Monocytes 3 to 8 6
Total 100

* In any differential count the sum of the percentages of the different kinds of leukocytes must, of course, total 100%.