LeukocytesWhite Blood CellsBiology Three19-3

WBCsFive Types Classified according to the presence or absence of granules and the staining characteristics of their cytoplasm.Leukocytes appear brightly colored in stained preparations, they have a nuclei and are generally larger in size than RBCs.

Type of WBCsGranulocyteshave large granules in their cytoplasm

NeutrophilsEosinophilsBasophils

Types of WBCsAgranulocytesdo not have granules in their cytoplasm

LymphocytesMonocytes

GranuloctyesNeutrophilsStain light purple with neutral dyesGranules are small and numerouscourse appearanceSeveral lobes in nucleus65% of WBC countHighly mobile/very activeDiapedesisCan leave blood vessels and enter tissue spacePhagocytosis (eater), contain several lysosomes (janitor)

GranulocytesEosinophilsLarge, numerous granulesNuclei with two lobes2-5% of WBC countFound in lining of respiratory and digestive tractsImportant functions involve protections against infections caused by parasitic worms and involvement in allergic reactionsSecrete anti-inflammatory substances in allergic reactions

GranulocytesBasophilsLeast numerous--.5-1%DiapedesisCan leave blood vessels and enter tissue spaceContain histamineinflammatory chemical

AgranulocytesLymphocytesSmallest WBCLarge nuclei/small amount of cytoplasmAccount for 25% of WBC countTwo typesT lymphocytesattack an infect or cancerous cell, B lymphocytesproduce antibodies against specific antigens (foreign body)

AgranulocytesMonocytesLargest of WBCsDark kidney bean shaped nucleiHighly phagocytic

WBC NumbersDoctors look at WBC numbers.If number goes up there is some kind of infection and surgery might be needed.Clinics will count the number of WBCs in a blood sample, this is called differential count.A decrease in the number of white blood cells is leukopeniaAn increase in the number of white blood cells is leukocytosis.

Formation of WBCsLeukocytes are formed in the red marrow of many bones.They can also be formed in lymphatic tissue.They live for about 13-20 days.