1. neutrophils (60-70%), exhibit phagocytic behavior by engulfing and digesting bacteria and other invading particles, commonly found at the site of injury
2. Eosinophils (1.5%), defend against larger invaders such as worms and other parasites, also active during allergic reaction
3. Basophils (very rare), when activated at sight of injury, histamine is released, promoting excess blood flow to the injured area (when stained with Wright stain, large granules of basophils stain blue or violet)
1. Lymphocytes (25-35%), specialized as either B cells or T cells. Bcells possess antigen receptors that bind to a particular antigen and then signal for its destruction. T cells kill diseased cells and cancer cells
2. Monocytes (immature macrophages) are also phagocytes (5%) These specialized WBC take on amoeboid forms that engulf and destroy invading microbes. Largest blood cells, monocytes have long life spans.