Post on 07-May-2015
transcript
ERYTHROPOIESISERYTHROPOIESIS
DR. LAXMIKANTA SAYDR. LAXMIKANTA SAY
HAEMOPOIESISHAEMOPOIESIS
A process of origin, development and maturation of erythrocytes.
CHANGES DURING ERYTHROPOIESIS Reduction in size of cell From diameter 25 to
7.5µm Disappearance of Nucleoli & nucleus Appearance of Hemoglobin Change in staining properties of cytoplasm
DEFINITIONDEFINITION
AGE SITESEarly weeks of Embryonic life
Yolk Sac
Middle of trimester gestation
Liver & spleen and lympnodes
Last trimester of gestation Bone marrow
After Birth to 5 Years of life
All bones
5 to 20 years of life All bones except proximal portion of Humerus & Tibia
More than 20 years Marrow of membranous bones as Vertebrae , sternum, ribs& iliac
Production sites Production sites
Production sites Production sites
GENESIS OF GENESIS OF ERYTHROPOIESISERYTHROPOIESIS
Haemocytoblast (stem Cell)Haemocytoblast (stem Cell)
Cell size – 19-23 µmCell size – 19-23 µm NucleusNucleus - Very big- Very big - occupies almost whole of cell with open - occupies almost whole of cell with open
chromatinchromatin - 4-5 nucleoli- 4-5 nucleoli CytoplasmCytoplasm - Rim all around the nucleus; deep basophilic- Rim all around the nucleus; deep basophilic
Mitosis – (++)Mitosis – (++)
PRO-ERYTHROBLAST(NORMOBLAST)PRO-ERYTHROBLAST(NORMOBLAST)
Cell size - 14-19 µmCell size - 14-19 µm
Nucleus Nucleus
- very big, - very big,
- occupies ¾ of cell volume - occupies ¾ of cell volume
- 2-3 nucleoli; chromatin - 2-3 nucleoli; chromatin open open
Cytoplasm Cytoplasm
- scanty , only a rim around - scanty , only a rim around the nucleus; deep basophilicthe nucleus; deep basophilic
EARLY -NORMOBLASTEARLY -NORMOBLAST
Cell size 10-14µmCell size 10-14µm Nucleus Nucleus
- size decreases than its - size decreases than its precursor; precursor;
- chromatin further - chromatin further condensescondenses
Cytoplasm Cytoplasm
- amount increases, less - amount increases, less basophilicbasophilic
INTERMEDIATE INTERMEDIATE NORMOBLASTNORMOBLAST
Cell size - 10-14µmCell size - 10-14µm Nucleus Nucleus
-size further decrease; -size further decrease; chromatin further chromatin further condensescondenses
Cytoplasm Cytoplasm
- marked,- marked,
- polychromatophilic - polychromatophilic staining due to appearance staining due to appearance
of of haemoglobinhaemoglobin
LATE NORMOBLASTLATE NORMOBLASTEarly NormoblastEarly Normoblast
Cell size 7-10µmCell size 7-10µm Nucleus sizeNucleus size
- very small with - very small with chromatin dot chromatin dot cart cart wheel appearancewheel appearance
CytoplasmCytoplasm
- markedly increase- markedly increase HaemoglobinHaemoglobin
– – further increases in further increases in amountamount
Late NormoblastLate Normoblast
Cell size 7 – 8 µmCell size 7 – 8 µm Nucleus Nucleus
- degenerates, becomes - degenerates, becomes uniformly stained pyknoticuniformly stained pyknotic
CytoplasmCytoplasm
- further increase; more - further increase; more acidic, less basophilicacidic, less basophilic
HaemoglobinHaemoglobin
– – further increases in further increases in amountamount
RETICULOCYTESRETICULOCYTES Immature RBC slightly larger Immature RBC slightly larger
than mature RBC.than mature RBC. Cell sizeCell size - 7-8 µm, No nucleus- 7-8 µm, No nucleus - Named due to presence of - Named due to presence of
reticular network or reticular network or reticulum of disintegrated reticulum of disintegrated organelle.organelle.
CytoplasmCytoplasm - Acidophilic- Acidophilic Newborn counts 2-6%,less Newborn counts 2-6%,less
than 1% in normal adults.than 1% in normal adults.
MATURE ERYTHROCYTEMATURE ERYTHROCYTE Reticular network Reticular network
disappears & cell become disappears & cell become matures RBC & attains matures RBC & attains shape biconcave shape.shape biconcave shape.
Mature RBC is with Mature RBC is with hemoglobin & with out hemoglobin & with out nucleus.nucleus.
Requires 9 days for Requires 9 days for development & maturation development & maturation of RBC .of RBC .
Requires 7 days to the Requires 7 days to the stage of reticlocyte and 2 stage of reticlocyte and 2 days for maturation to RBC.days for maturation to RBC.
Tissue oxygenationTissue oxygenation-blood flow-blood flow
-blood hemoglobin concentration-blood hemoglobin concentration
-hemoglobin oxygen saturation-hemoglobin oxygen saturation EPO(Erythropoietin)EPO(Erythropoietin) Hematopoietic CytokinesHematopoietic Cytokines Colony stimulating factorsColony stimulating factors GM-CSF(Granulocyte macrophage colony GM-CSF(Granulocyte macrophage colony
stimulating factor)stimulating factor) Thrombopoietin and stem cell factorThrombopoietin and stem cell factor IL-1,IL-3,IL-IL-6IL-1,IL-3,IL-IL-6
CONTROL OF ERYTHROPISISCONTROL OF ERYTHROPISIS
BIO-SYNTHESIS OF HEMOGLOBINBIO-SYNTHESIS OF HEMOGLOBIN GENERAL FACTORSGENERAL FACTORS
-Erythropoietin-Erythropoietin
-Thyroxine-Thyroxine
-Hemopoietic growth factors-Hemopoietic growth factors
-Vitamins.-Vitamins.
MATURATION FACTORSMATURATION FACTORS
-Vit.B12-Vit.B12
-Intrinsic factor -Intrinsic factor
-Folic acid-Folic acid
FOR HEMOGLOBIN FOR HEMOGLOBIN FORMATIONFORMATION
- First class protein & amino - First class protein & amino acidsacids
- Iron, Copper, - Iron, Copper,
- Cobalt & Nickel- Cobalt & Nickel
VITAMINSVITAMINS
-Vit-C-Vit-C
-Riboflavin-Riboflavin
-Nicotinic acid-Nicotinic acid
-Pyridoxin-Pyridoxin
ErythropoietinErythropoietin Haemopoietin Haemopoietin or Erythrocyte stimulating factor or Erythrocyte stimulating factor Chemistry Chemistry
- glycoprotein ( 74% protein & 26% carbohydrate)- glycoprotein ( 74% protein & 26% carbohydrate)
- contains 165 aminoacids- contains 165 aminoacids
- MW. 46,000- MW. 46,000 Source of secretionSource of secretion
- interstial cells of peritubular capillaries of - interstial cells of peritubular capillaries of kidneykidney, , also in also in LiverLiver & & BrainBrain
StimulantStimulant - Hypoxia - Hypoxia ActionsActions of Erythropoietin of Erythropoietin
- production, development & release of mature RBCs.- production, development & release of mature RBCs.
EFFECT OF HYPOXIAEFFECT OF HYPOXIA
THANK YOUTHANK YOU