Blood cells and hematopoesis
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Transcript of Blood cells and hematopoesis
BLOOD CELLS AND HEMATOPOESIS
I WAYAN SUGIRITAMAhttp://sugiritama.blogspot.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
.
NORMOBLAST
.
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