BLOOD CELLS AND HEMATOPOESIS

I WAYAN SUGIRITAMAhttp://sugiritama.blogspot.com

sugiritama@gmail.com

COMPONENT OF THE BLOODBlood is specialized connective tissueComposed by :•Formed elements•Fluid component , Plasma (the extracellular(matrix)

FORMED ELEMENTS OF BLOODFormed elements : cells and cell fragments (platelets)The cells of blood :•red blood cells (RBC) •white blood cells (WBCs, leukocytes).

NEUTROPHILS •60-70% of total leucocytes•9-12 µm in diameter•Multilobe nucleus •Female : drum stick/Barr Body• Granules :•Small spesific granules•Azurophilic granules (Lysosomes)•Tertiary granules (gelatine and cathepsins)

•Function :•Phagocytes

EOSINOPHILS4% of total leucocyte10 - 14 µm in diameterBilobed nucleusMany large spesific granules stained by eosinFunction :•Eliminate antibody-antigen complexes•Destroy parasitic worms

BASOPHILS <1% of total leucocyte8-10 µm in diameterS-shape nucleus (irregular lobes) Large spesific granules obscured the nucleusGranules (dark blue) contain heparin & histaminSurface receptor (Ig E receptors)Function :As initiator of inflamatory process

LYMPHOCYTES

20%-25% of total leucocyte 8-10 µm in diameterRound nucleus with slight indented, occupies most of the cellContain few azurophilic granules

MONOCYTES Largest circulating blood cells3-8% ot total leucocyte Large, acentric, kidney- shape nucleusnumerous azurophlic granulesMigrate to the connective tissue MACROPHAGES (phagocytose antigens and as APC)

PLATELETS

250.000-400.000 platelets/mm32 to 4 µm in diameterDisplay peripheral clear region (hyalomere ) and central darker region (granulomere) receptor molecules (glycocalyx) on plasmalemmaFunction : Blood clott

HEMATOPOIESIS

• Mature blood cells have a relatively short life span

• Must be continusly replaced by stem cells• Stem cells produce in HEMATOPOIETIC ORGAN

PRENATAL HEMOPOIESIS

• Subdivide into four phases :– Mesoblastic :

• begin after 2 weeks after conception at yolk sac• Mesenchymal cells aggregate into blood islands

– Hepatic• Begins at 6 weeks until end of gestation• Nucleated erythrocyte• Appear of leucocyte (8th week)

– Splenic• Begin at second trimester until end of gestation

– Myeloid• Begin at the end of second trimester• Hemopoiesis at bone marrow

POSTNATAL HEMOPOIESIS

• Hemopoiesis almost exclusively in BONE MARROW

• Stem cells undergo – multiple cells divisions– and differentiation

• Replace the cells that leave the blood stream, die or destroy

BONE MARROWA gelatinous, vascular connective tissue located in medulary cavity of long bones Responsible for hemopoiesisStructure :

Vascular compartmentExtensive network of sinusoids , arteries and veins form the

Hemopoietic compartmentIslands of hematopoietic cells Hemopoietic cells in various stage of maturation

HEMOPOIETIC GROWTH FACTORS Table 10-6 Gartner colour text histology

• Regulated the hemopoiesis• Produce by spesific cells• Acts on spesific stem cells, progenitor cells, and

precursor cells• The route to deliver growth factor :– Via blood stream– Secrete near the hemopoietic cells– Direct cell-cell contact

• Induced rapid mitosis or and differentiation• Most ot them are glycoproteins

HEMATOPOIESIS

ERYTHROPOIESIS

• Formation of red blood cells• Generates 2.5 x 10 11 erythrocytes /day• By two types of unipotential progenitor cell– BFU-E– CFU-E

• Regulate by : erythropoietin

PROERYTHROBLAST

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NORMOBLAST

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RETICULOCYTE

ERYTHROCYTE Biconcave-shape diskWithout nuclei and organellesHave soluble enzymes Filled with Hemoglobin (Hb)Average life span of erythrocyte : 120 days

GRANULOCYTOPOIESIS

• Formation of the granulocytes (neuthrophil, eosinophil, and basophil– CFU-Eo : eosinophil lineage– CFU-Ba : Basophil lineage– CFU-GM• CFH-G : Neutrophil line• CFU-M : monocyte line

– Influence by G-CSF, GM-CSF

GRANULOCYTOPOIESIS

EOSINOPHYL STAB

NEUTROPHYL STAB

BASOPHIL (BONE MARROW)

MONOCYTOPOIESIS

CFU-GM

CFU-G

PROMONOCYTE

PLATELET FORMATION

• CFU-Meg, gives rise the Megakaryoblast• Megakaryoblast differentiate

Megakaryocytes (single lobulated nucleus)• Megakaryocytes protrude clusters of

proplatelets platelets

MEGAKARYOCYTE

LYMPHOPOIESIS

• CFU-Ly divides form the CFU-LyB and CFU-LyT• CFU-LyB migrate to “bursa-equivalent

location”, divided B lymphocytes • CFU-LyT undergo mitosis migrate to the

Thymus T lymphocytes

LYMPHOBLAST

LEARNING TASKS• Expain the composition of the blood!• Explain the structure of formed elements of blood!• How to differentiate the blood cells from a blood-smear? • Explain the classification and function of leucocyte !• Explain the maturation of lymphocyte!• What blood cell would be in abundance during an active parasitic

infection? Explain your answer!• Eplain the structure and function of platelets!• What blood cell in bone marrow is the earliest recognizable stage of

the red blood cell line?• Describe the structure of erythrocyte if lack of this nutrient: vitamin

B12 and iron during the erythrocytopoiesis

• I WAYAN SUGIRITAMA• http://sugiritama.blogspot.com

• sugiritama@gmail.com