فسلجة الدم/ هيموكلوبين/كلية الرافدين

Professor Ali Altimimi

 

Types of blood cells

  1. Hemopoiesis (Hematopoiesis)
  2. Red Blood Cells (RBC)
  • Blood cells makes about 45 % of the total blood

volume (5600ml)  i.e. 2500   ml.

  • Blood cells are the solid phase of theblood. Types:
  1. Red Blood Cells ( RBC’s ) or erythrocytes.
  2. White Blood Cells ( WBC’s ) or leukocytes.

III. Cell Fragments called platelets or thrombocytes

Blood Cells

Hemopoiesis or Hematopoiesis

  • is the process of blood cells production.
  • Erthropoiesis: is the proliferation & differentiation of

RBC’s or erythrocytes.

  • Leukopoiesis: is the development of WBC’s or

leukocytes.

Thrombopoiesis: is the development of platelets or

thrombocytes.

Hemopoiesis or Hematopoiesis

  • The bone marrow —- multipotent uncommitted stem cells

(pluripotential stem cells) —- differentiate ——committed

stem cells (progenitor cells) —–differentiated into various

differentiated types of blood cells.

Proerythroblasts ( pronormoblast ): erythrocytes develop.

  1. Myeloblasts: from which granulocytes ( Neutrophil,

eosinophils & basophile ) develop.

  1. Lymphoblasts: From which lymphocytes ( T & B-

lymphocytes ) develop.

  1. Monoblast: from which monocytes develop.
  2. Megakaryoblasts: from which platelets or thombocytes

develop.

Hemopoiesis or Hematopoiesis

Red blood cells or erythrocytes

  • About 95 %  of the volume  of the blood  cells  consists  of

erythrocytes.

  • No nuclei in RBC.
  • Erythropoiesis:

is the process of RBC’s production.

erythropoietin.

  • The rate of erythropoiesis is regulated by erythropoietin.
  • 90% of the erythropoietin is formed in the kidneys &

10% in the liver.

  • The function of this hormone is to stimulate committed

stem cells to differentiate into proerythroblasts i.e.

stimulate the synthesis of messenger RNA.

  • The main factor that cause the release of erythropoietin

is hypoxia.

Maturation of Erythrocytes

  • Cell division requires two vitamins :
  1. Vitamin B

12

  1. Folic acid
  • The type of anemia due to lack of folic acid vit. B12 is

called megaloblastic anemia

Maturation of Erythrocytes

  • Size: diameter of 7.2 to 7.9 micrometers — edges 2.5

micrometers thicker than the center –about 1

micrometers.

  • Shape: biconcave discs
  • Content: hemoglobin, ATPase, & enzyme carbonic

anhydrase, water

Red blood cells

  • Red blood cell Count—5400000 in male &4700000 in

female

  • Anemia–RBC’s counts are less than normal value
  • Polycythemia– RBC’s count is more than normal
  • Life span of the RBC: average of 120 days in males &

110 days in females

Red blood cells

 

  • Hemolysis of RBC

Red blood cells

  • Total blood Volume (TBV)
  • TBV = plasma volume + red cell volume
  • About 55% of this volume is plasma (3080 ml), and

about 45% of this volume is packed cell volume (2520

ml).

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

adult males.

وزاره التعليم العالي

كلية الرافدين الجامعة