Haematology

• What is the primary function of RBCs?

  Transport oxygen from lungs to tissues
• What protein in RBCs binds oxygen?

  Haemoglobin
• How does the shape of RBCs facilitate oxygen exchange?

  Maximizes surface-to-volume ratio
• What is the diameter range of RBCs?

  7–8 μm
• What is the structure of adult haemoglobin?

  Tetramer of α2β2
• What does each haemoglobin chain contain?

  Iron-containing haem group
• What happens when oxygen binds to the haem group?

  Causes conformational changes in haemoglobin
• What is cooperative binding in haemoglobin?

  Increased O2 binding at other sites after one binds
• How does cooperative binding affect oxygen loading and release?

  Maximizes O2 loaded at lungs and released at tissues
• What is oxyhaemoglobin?

  Haemoglobin bound to oxygen
• What is the shape of red blood cells in normal peripheral blood?

  Circular biconcave discs
• What is the diameter of normal red blood cells?

  7-8 µm
• What causes the pale-staining central area in normal RBCs?

  Low haemoglobin concentration
• What is the name of the pale-staining central area in normal RBCs?

  Central pallor
• How does the diameter of the central pallor compare to the RBC?

  It is approximately 1/3 the diameter of the RBC
• What is the most common blood disorder worldwide?

  Anaemia
• What causes anaemia?

  Reduction in RBC haemoglobin concentration
• How does slow onset anaemia affect symptoms?

  It has less symptoms due to adaptations
• What do the symptoms of anaemia reflect?

  Reduced oxygen delivery to tissues
• What are general symptoms of anaemia?

  Fatigue, pallor, breathlessness, and more
• What does pulling down the lower eyelid help assess?

  Conjunctiva color in anaemia
• What color does the conjunctiva appear in healthy individuals?

  Health pink
• How does the conjunctiva appear in anaemia?

  Pale pink or white
• What is a symptom of worsening heart-related pain in anaemia?

  Angina
• What compensatory mechanisms might occur in slow onset anaemia?

  Adaptations in cardiovascular system and Hb binding
• What might cause loss of appetite in anaemia?

  Reduced oxygen delivery to tissues
• What is a common symptom of anaemia related to energy levels?

  Fatigue
• What is a symptom of anaemia that involves the skin?

  Pallor
• What is a symptom of anaemia that involves the heart?

  Palpitations
• Why might symptoms of anaemia vary in severity?

  Due to compensatory mechanisms and adaptations
• What is a potential outcome of severe anaemia?

  Fainting
• How does the oxygen binding curve of Hb change in slow onset anaemia?

  It adapts to maintain oxygen delivery
• What is the basis for classification of anaemia?

  RBC size and shape
• What are RBCs with low MCV termed?

  Microcytic
• What are RBCs with high MCV termed?

  Macrocytic
• What does poikilocytosis refer to?

  Nonuniformity of cell shapes
• What does anisocytosis refer to?

  Nonuniformity of cell sizes
• What are the fundamental divisions in the classification of anaemia?

  • Excessive loss or destruction of RBCs
  • Inadequate production of RBCs by the marrow
• What are some acquired causes of anaemia?

  Iron, VitB12, folate deficiency
• What is a cause of acquired anaemia related to blood loss?

  Blood loss