WHITE BLOOD CELLS LEUKOCYTES (WBCs)

WHITE BLOOD WHITE BLOOD CELLSCELLS

LEUKOCYTESLEUKOCYTES(WBCs)(WBCs)

Dr. Shaikh Mujeeb AhmedDr. Shaikh Mujeeb Ahmed

PLASMA

CELLS

PATHOGENS

INFECTIONS

GGrranulocytesanulocytes Polymorphonuclear leukocytes (PMNs)Polymorphonuclear leukocytes (PMNs) NeutrophilsNeutrophils EosinophilsEosinophils BasophilsBasophils

AgAgranulocytesranulocytes LymphocytesLymphocytes

T lymphocyte T lymphocyte B lymphocyteB lymphocyte

Monocytes Monocytes macrophage system macrophage system ThrombocytesThrombocytes (platelets) (platelets)

TYPES TYPES (CLASSIFICATION)(CLASSIFICATION)

CLASSIFICATIONCLASSIFICATION

GRANULOCYTES AGRANULOCYTES

Cell ApproximateNormal range(/µL)

Percentage of Total WBC

Total WBC 4000-11000 - - -Granulocytes Neutrophils Eosinophils Basophils

3000-6000150-300

0-100

50-70%1-4 %

0.25 - 0.5%Lymphocytes 1500-4000 20-40Monocytes 300-600 2-8

Concentration (Normal Counts)

Site of Formation Ultimately originate from same

undifferentiated multipotent stem cells in red bone marrow

Granulocytes and monocytes are produced only in bone marrow

Most new lymphocytes are actually produced by lymphocytes already in lymphoid tissues such as lymph nodes and tonsils

Total number of white cells and percentage of each type may vary considerably to meet changing defense needs

GENERAL CHARACTERISTICS

OF WBCSs

Granulocytes 4-8 hours

Monocytes 10-20 hours

Lymphocytes & macrophages

months & years

Life span of leukocytes:

NEUTROPHILSNEUTROPHILS

Most Abundant WBCs 60-70 Most Abundant WBCs 60-70 %%

Size: 15-20 µmSize: 15-20 µm Nucleus: Multilobed 2-5 Nucleus: Multilobed 2-5

lobeslobes Life span: 6-8 hoursLife span: 6-8 hours

1.1. DiapedesisDiapedesis2.2. ChemotaxisChemotaxis3.3. OpsonizationOpsonization4.4. DegranulationDegranulation5.5. Phagocytosis & Phagocytosis &

DigestionDigestion

DEFENSIVE PROPERTIES DEFENSIVE PROPERTIES OF MACROPHAGES OF MACROPHAGES

NEUTROPHILSNEUTROPHILS

PMNs Digestive SystemPMNs Digestive System(Antimicrobial system)(Antimicrobial system)

ENZYMATIC GranulesGranules HeparinHeparin HistamineHistamine BradykininBradykinin SerotininSerotinin DefensinsDefensins Lysosomal enzymesLysosomal enzymes Slow reacting substance of Slow reacting substance of

anaphylaxisanaphylaxis

NON ENZYMATICNON ENZYMATICrespiratory burstrespiratory burstOO22 Free Radicals (O Free Radicals (O--22, H, H22OO22, , --OH)OH)NADPH-oxidaseNADPH-oxidaseMyeloperoxidaseMyeloperoxidaseCl- Cl- HoCl HoClHypochlorous acid “very toxic”Hypochlorous acid “very toxic”

PMNs Digestive SystemPMNs Digestive System(Antimicrobial system)(Antimicrobial system)

EosinophilEosinophil Granules contain arginine rich protein, which take Granules contain arginine rich protein, which take

acid dye (eosin)acid dye (eosin) Function: PhagocytosisFunction: Phagocytosis Chemotaxis: attracted towards chronic Chemotaxis: attracted towards chronic

inflammationinflammation Neutralises allergic products such histamine, 5-HT, Ag-Neutralises allergic products such histamine, 5-HT, Ag-

Ab complex, bradykinin (allergic disease of skin &lungs)Ab complex, bradykinin (allergic disease of skin &lungs) Phagocytosis is same as neutrophil, but less Phagocytosis is same as neutrophil, but less

efficientefficient

Eosinophils cont,Eosinophils cont, High eosinophil count:High eosinophil count:

Parasitic (hook worm, ascaris, bilharzia)Parasitic (hook worm, ascaris, bilharzia) Allergic (asthma, rhinitis, drug reaction)Allergic (asthma, rhinitis, drug reaction) Dermatological diseasesDermatological diseases

BasophilsBasophils Weak phagocytic cellsWeak phagocytic cells Granules contain polysaccharide granules > Granules contain polysaccharide granules >

base methylene blue color.base methylene blue color. Similar to mast cells releases its granules Similar to mast cells releases its granules

containing heparin, histamine, 5HT. Which containing heparin, histamine, 5HT. Which causes inflammation reactioncauses inflammation reaction

MONOCYTESMONOCYTES No Granules but No Granules but

VacoulesVacoules Size: 15-20 µmSize: 15-20 µm More Efficient than More Efficient than

NeutrophilsNeutrophils Life span: 10-20 hours Life span: 10-20 hours

in bloodin blood

MACROPHAGESMACROPHAGES Two typesTwo types

FixedFixed MobileMobile

Reticuloendothelial Reticuloendothelial SystemSystem

Monocyte/Macrophage Monocyte/Macrophage SystemSystem

Consist of;Consist of; MonocytesMonocytes Mobile macrophages Mobile macrophages fixed tissue macrophages fixed tissue macrophages specialized endothelial cells in specialized endothelial cells in

bone marrow, spleen and bone marrow, spleen and lymph nodeslymph nodes

TISSUE MACROPHAGE SYSTEM

Reticuloendothelial SystemReticuloendothelial SystemMonocytes/Macrophage Monocytes/Macrophage

SystemSystemExamples are: -Examples are: -1.1. Tissue macrophages in Skin and Tissue macrophages in Skin and

Subcutaneous tissues (Histiocytes)Subcutaneous tissues (Histiocytes)2.2. Macrophages of Lymph NodesMacrophages of Lymph Nodes3. 3. Alveolar macrophagesAlveolar macrophages4.4. Tissue macrophages in Liver sinusesTissue macrophages in Liver sinuses (Kupffer Cells)(Kupffer Cells)5.5. Macrophages of Spleen & Bone Macrophages of Spleen & Bone

marrowmarrow6. Microglia in Brain6. Microglia in Brain

Tissue macrophages in Tissue macrophages in Liver sinusesLiver sinuses

Lymphocytes Provide immune defense against targets for which

they are specifically programmed Live about 100 to 300 days 2 types of lymphocytes

B lymphocytes Produce antibodies which circulate in blood Responsible for antibody-mediated or humoral immunity

T lymphocytes Do not produce antibodies Directly destroy specific target cells by releasing

chemicals that punch holes in the victim cell (cell-mediated immunity)

Target cells include body cells invaded by viruses and cancer cells

Lines of DefenseLines of DefenseResponse to InflammationResponse to Inflammation

1.1. 11stst line of defense – Tissue macrophages & Physical line of defense – Tissue macrophages & Physical BarriersBarriers2.2. 22ndnd line of defense – Neutrophil Invasionline of defense – Neutrophil Invasion

of the inflamed areaof the inflamed area

3.3. 33rdrd line of defense – Monocytes –macrophage line of defense – Monocytes –macrophage invasion of inflamed area invasion of inflamed area

4.4. 44thth line of defense – Increased production line of defense – Increased production of granulocytes and of granulocytes and

Monocytes by Bone marrowMonocytes by Bone marrow

1st1st line of defense – Tissue macrophages line of defense – Tissue macrophages

2nd2nd line of defense – Neutrophil Invasion line of defense – Neutrophil Invasion

3rd3rd line of defense – Monocytes –macrophage line of defense – Monocytes –macrophageTHIRD

4th4th line of defense – Increased line of defense – Increased production of granulocytes and production of granulocytes and

Monocytes by Bone marrowMonocytes by Bone marrow

IMPORTANT TERMSIMPORTANT TERMS LeukocytosisLeukocytosis LeukopeniaLeukopenia NeutrophiliaNeutrophilia LeukemiasLeukemias PusPus

Formation of PusFormation of Pus

Dead Neutrophils Dead Neutrophils Dead Macrophages Dead Macrophages Necrotic tissueNecrotic tissue

Thank youThank you