Types of Leucocytes (WBCs)

Granulocytes: Neutrophils (60-65%, phagocytic), Eosinophils (2-3%, allergic reactions), Basophils (0.5-1%, secrete histamine/heparin/serotonin); Agranulocytes: Lymphocytes (20-25%, B and T types for immunity), Monocytes (6-8%, phagocytic macrophages).