Tabuk University

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Tabuk University

• Faculty of Applied Medical Sciences
• Department Of Medical Lab. Technology
• 2nd Year Level 4 AY 1433-1434

Hematology 1, MLT 205
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Erythrocyte, Haemoglobinand Introduction to
Anaemias
Mr. Waggas Elaas, M.Sc, MLT
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Objectives

• To know detailed information about erythrocytes.
• To know the synthesis, structure and function of
  Hemoglobin.
• To identify anemias and know their
  classification.

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An Erythrocyte (RBC)
Biconcave discs Non nucleated 120 days life span
Practical Values 65 of Fe in Hb 1 g Hb 3.46 mg
Fe 1 mL blood at 15 g/dL Hb 0.5 mg Fe
Normal Values RBCs, male 4.7-6.1 x
106/µL female 4.2-5.4 x 106/µL Hb, male 13.0-16.0
g/dL female 12.0-15.0 g/dL
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RBCs structure

• Three Constituents of RBCs
• RBC membrane internal metabolic apparatus
  hemoglobin
• RBC membrane
• Has lipid bilayer membrane with proteins in it.
  Below this membrane there is a cytoskeleton of
  proteins allowing rubbery elasticity with main
  protein being Spectrin Ankyrin
• Membrane antigen structure there are over 300
  RBC membrane Ags. They are Polysaccharides.
• (Blood Groups A, B, Rh, Duffy, etc).

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The red cell membrane
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Red cell metabolism

• Embden-Meyerhof Pathway - glycolysis from glucose
  to lactate. ATP is produced.
• Hexose-Monophosphate Shunt (Pentose phosphate
  Pathway) -10 of glycolysis. NADPH is generated
  and used to protect Hb and membrane from
  oxidation.
• Methemoglobin Reductase Pathway - prevents iron
  of Hb from being oxidized, makes NADH which is
  reducing power.

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How erythrocytes carry O2 CO2 ?

• The main function of red cells is to carry O2 to
  the tissues and to return carbon dioxide (CO2)
  from tissues to the lungs.
• In order to achieve this the red cells contain
  the specialized protein hemoglobin.
• Each red cell contains approximately 640 million
  Hb molecules.

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• 65 of the Hb is synthesized in the
  erythroblasts, and 35 at the reticulocyte stage.
• Although haem and globin synthesis occur
  separately within developing red cell precursors,
  their rates of synthesis are carefully
  coordinated to ensure optimal efficiency of Hb
  assembly.

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Haemoglobin

• The haemoglobins are red globular proteins,
  which have a molecular weight of about 68,000
  and comprise almost one third of the weight of a
  red cell.

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Hb structure

• Each RBC contains 640 million Hb molecule.
• Each molecule consists of 4 Polypeptide chains.
• Polypeptide amino acids
• Each polypeptide chain has a Haem group
• Haem Globin
• ??????
  ????
• How many Haem groups in each Hb molecules???

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Haem synthesis

• - In the developing erythroblasts.
• - By Mitochondria
• - Biochemical reactions
• Glycine Succinyl Coenzyme A d-ALA
  Protoporphyrin
• 
  vit. B6
• Protoporphyrin Fe 2
  Haem

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Globin synthesis

• - In the developing Erythroblasts.
• - By ribosomes.
• - Each molecule of normal adult haemoglobin
  (Hb-A) consists of four polypeptide chains a2b2,
  each with its own haem group
• - Each globin chain is a polypeptide of
  approximately 150 amino acids in length

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Hb synthesis
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Hb structure
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Haemoglobin

• Normal adult blood also contains small quantities
  of two other haemoglobins
• Hb-F
• Hb-A2
• These also contain a chains but with g and d
  chains respectively instead of b.
• The major switch from fetal to adult haemoglobin
  occurs 3-6 months after birth.
• Why the fetus has a different Hb.???

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Normal Hb in adult blood
Hb A Hb A2 Hb F
structure a2b2 a2d2 a2g2
Normal 96 - 98 1.5 - 3.2 0.5 - 0.8
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Introduction to Anaemias

• Anemia is defined as a reduction in Hb
  concentration.
• Less than 13.5 g/dl males
• Less than 11.5 g/dl female
• Less than 14.0 g/dl neonate
• Less than 11.0 g/dl from 2 yrs
  puberty

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• Plasma volume alterations affect Hb conc.
• Increase in plasma volume (splenomegally
  pregnancy) may cause anemia even with normal Hb
  conc. And red cell count.
• Decrease in plasma volume (dehydration) may mask
  anemia .

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Clinical Features

• Fatigue. ?????
• headache.????
• Faintness.?????
• Dyspnea.??? ?? ??????
• Angina. ????? ?????
• Palpitations. ?????
• Tachycardia.????? ?????
• murmur.??? ?????

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Signs

• 1- General
• Pallor of mucus membranes
• (Hb less than 10 9 g/dl)
• Tachycardia

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Signs

• 2- Specific
• Koilonychia (spoon nails in iron deficiency)
• Jaundice in Hemolytic anemias
• Leg ulcers in sickle cell disease.
• Bone deformities in Thalassemia.

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Causes

• 1. Reduced red cell production.
• 2. Increased red cell destruction.
• 3. Blood loss.

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According to MCV)) Classification of anemia

• Normocytic normochromic anemia
• Some anemias of chronic disease
• hemolytic anemias (accelerated destruction of
  RBCs)
• anemia of acute hemorrhage blood loss
• aplastic anemias Bone marrow failure
• Renal disease.
• MCV Mean Cell Volume

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• Microcytic Hypochromic, anemia
• iron deficiency anemia
• thalassemias
• anemia of chronic disease (rare cases)
• Sideroblastic anemia
• Lead poisoning

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• Macrocytic anemia
• Megaloblastic anemia (vitamin B12 or Folate
  deficiency)
• Alcohol
• Liver disease
• Myeldysplasia
• A plastic anemia

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Homework-2

• 1. What should you do to avoid having anemia?
• 2. Why is oxygen important to blood and to the
  cells?
• 3. Mature erythrocytesA) have a centrally
  located nucleus.B) are actually just cellular
  fragments.C) contain hemoglobin in their
  cytoplasm.D) mature from cells called
  megakaryocytes.E ) do not contain protein
• 4. Plasma is a) blood that has no
  red blood cells b) the liquid portion
  of blood including clotting factors
  c) the liquid portion of blood after it has
  clotted d) the proteins of blood

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