BLOOD CELLSBLOOD CELLS

LEC 2 Nov. 2015LEC 2 Nov. 2015

ObjectivesObjectives Types of blood cellsTypes of blood cells 2.Hemopoiesis(Hematopoiesis) 2.Hemopoiesis(Hematopoiesis) 3.Red Blood Cells(RBC)3.Red Blood Cells(RBC)

BLOOD CELLSBLOOD CELLS Blood cells makes about Blood cells makes about 45 %45 % of the total blood of the total blood

volume( volume( 5600mL5600mL)) i.e. i.e. 2500 mL2500 mL..

Blood cells are the solid phase plasma. Types:Blood cells are the solid phase plasma. Types: a- a- Red Blood Cells ( RBC’s ) or erythrocytesRed Blood Cells ( RBC’s ) or erythrocytes.. b-b- White Blood Cells ( WBC’s ) or leukocytes.White Blood Cells ( WBC’s ) or leukocytes. c.Cell Fragments called platelets or thrombocytesc.Cell Fragments called platelets or thrombocytes

Hemopoiesis or HematopoiesisHemopoiesis or Hematopoiesis

is the process of blood cells production.is the process of blood cells production.

1.1.ErthropoiesisErthropoiesis:: is the proliferation & is the proliferation & differentiation of RBC’s or erythrocytes.differentiation of RBC’s or erythrocytes.

2.2.Leukopoiesis:Leukopoiesis: is the development of WBC’s is the development of WBC’s or leukocytes.or leukocytes.

3.3.ThrombopoiesisThrombopoiesis:: is the development of is the development of platelets or thrombocytesplatelets or thrombocytes..

The bone marrow ---- multipotent The bone marrow ---- multipotent uncommitted stem cells uncommitted stem cells ((pluripotential stem cellspluripotential stem cells ) ---- ) ---- differentiate ------committed stem differentiate ------committed stem cells ( cells ( progenitor cells )progenitor cells ) ----- ----- differentiated into various differentiated into various differentiated types of blood cellsdifferentiated types of blood cells

1.Proerythroblasts ( pronormoblast ):1.Proerythroblasts ( pronormoblast ): erythrocytes develop.erythrocytes develop.

2.Myeloblasts: from which granulocytes ( Neutrophil, 2.Myeloblasts: from which granulocytes ( Neutrophil, eosinophils & basophile ) develop.eosinophils & basophile ) develop.

3.Lymphoblasts: From which lymphocytes ( T & 3.Lymphoblasts: From which lymphocytes ( T & B-lymphocytes ) develop.B-lymphocytes ) develop.

4.Monoblast:4.Monoblast: from which monocytes develop. from which monocytes develop.

5.Megakaryoblasts:5.Megakaryoblasts: from which platelets or from which platelets or thombocytes develop.thombocytes develop.

Red Blood Cells (RBC’ Red Blood Cells (RBC’ ss( ( Or Erythrocytes Or Erythrocytes

Red blood cells or erythrocytesRed blood cells or erythrocytesAbout 95 % of the volume of the About 95 % of the volume of the blood cells consists of blood cells consists of erythrocytes. erythrocytes. No nuclei in RBC.No nuclei in RBC.Erythropoiesis:Erythropoiesis:is the process of RBC’s is the process of RBC’s productionproduction. . ..

Regulation of red blood cell production: Role of Regulation of red blood cell production: Role of erythropoietin.erythropoietin.

The rate of erythropoiesis is regulated by a The rate of erythropoiesis is regulated by a humoral agent known as erythropoietin. humoral agent known as erythropoietin. 90% of the erythropoietin is formed in the kidneys & 90% of the erythropoietin is formed in the kidneys & 10% in the liver. 10% in the liver. The function of this hormone is to stimulate The function of this hormone is to stimulate committed stem cells to differentiate into committed stem cells to differentiate into proerythroblasts i.e. stimulate the synthesis of proerythroblasts i.e. stimulate the synthesis of messenger RNA. messenger RNA. The main factor that cause the release of erythropoietin The main factor that cause the release of erythropoietin is is hypoxiahypoxia therapy. therapy.

Maturation of ErythrocytesMaturation of Erythrocytes

Cell division requires two vitamins :Cell division requires two vitamins :1.1.Vitamin B12Vitamin B122.2.Folic acid Folic acid ..

The type of anemia due to lack of folic acidThe type of anemia due to lack of folic acid

& vit. B12 is called & vit. B12 is called megaloblastic anemiamegaloblastic anemia

MorphologyMorphology

SizeSize : :diameter of 7.2 to 7.9 diameter of 7.2 to 7.9 micrometers -- edges 2.5 micrometers -- edges 2.5 micrometers thicker than the center micrometers thicker than the center --about 1 micrometers.--about 1 micrometers.

shapeshape----biconcave discs biconcave discs Content—Content—hemoglobin,hemoglobin, ATPase, & ATPase, &

enzyme carbonic anhydrase,water enzyme carbonic anhydrase,water

Red blood cell CountRed blood cell Count——5400000 in male 5400000 in male &4700000 in female&4700000 in female

AnemiaAnemia--RBC’s counts are less than --RBC’s counts are less than normal value normal value

PolycythemiaPolycythemia------ RBC’s count is more RBC’s count is more than normal than normal

Life span of the RBCLife span of the RBC:: average of 120 average of 120 days in males & 110 days in femalesdays in males & 110 days in females

Packed Cell Volume (PVC) or Packed Cell Volume (PVC) or hematochrit (hcr)---hematochrit (hcr)---volume of volume of RBC’s in 100ml (dl) of blood.RBC’s in 100ml (dl) of blood.

in male is 47%female is 42%.in male is 47%female is 42%. anemia PCV is less than normal while anemia PCV is less than normal while

in Polycythemia RCB is greater than in Polycythemia RCB is greater than normal valuenormal value

Hemolysis of RBCHemolysis of RBC

Total blood Volume (TBV)Total blood Volume (TBV)

TBV = plasma volume + red cell TBV = plasma volume + red cell volumevolume

About 55% of this volume is plasma About 55% of this volume is plasma (3080 ml), and about 45% of this (3080 ml), and about 45% of this volume is packed cell volume (2520 volume is packed cell volume (2520 ml).ml).

TBV in the average adult is 4-5 L TBV in the average adult is 4-5 L in female & 5-6 L in adult males.in female & 5-6 L in adult males.

Practical physiologyPractical physiology

Experiment(expt) no 1:RBC COUNTExperiment(expt) no 1:RBC COUNT

expt no 2: estimation of PCVexpt no 2: estimation of PCV