[W1] RBC + anaemia Flashcards
(25 cards)
What is the shape, size + volume of a red blood cell (RBC)?
Biconcave disc, ~7μm in diameter, 78–101 fl in volume.
What organelles are absent in mature RBCs?
Nucleus and cytoplasmic organelles.
What are the main functions of RBCs?
Transport O₂ and CO₂, maintain plasma pH, and optimize Hb content and deformability.
What is the RBC membrane composed of?
40% lipids, 52% protein, 8% carbohydrates.
What is the function of Band 3 protein?
Anion transport, especially chloride and bicarbonate.
What cytoskeletal protein maintains the biconcave shape of RBCs?
Spectrin.
What metabolic pathway do RBCs use for energy?
Anaerobic glycolysis.
Why is 2,3-DPG important in RBCs?
It regulates haemoglobin’s oxygen affinity.
What is erythropoiesis?
Production of RBCs in the bone marrow.
What hormone stimulates RBC production?
Erythropoietin (Epo), produced in response to renal hypoxia.
What is the lifespan of an RBC?
~120 days.
How does the spleen remove old or damaged RBCs?
Through macrophages that identify and phagocytose senescent or abnormal RBCs.
What are Howell-Jolly and Heinz bodies?
Nuclear remnants and oxidised haemoglobin inclusions, respectively.
What is the structure of adult haemoglobin (HbA)?
Tetramer of α₂β₂ globin chains, each with a haem group.
What is the Bohr effect?
Acidosis lowers O₂ affinity, enhancing oxygen delivery.
Why can’t free haemoglobin be transfused?
It is toxic to kidneys and has a fixed, unfavourable O₂ affinity.
What is Hemopure?
A polymerised bovine Hb product used in South Africa.
What is anaemia?
Reduced haemoglobin concentration in blood.
What are the three main types of anaemia based on MCV?
Microcytic, normocytic, and macrocytic.
What causes microcytic, hypochromic anaemia?
Iron deficiency, thalassemia.
What causes macrocytic, normochromic anaemia?
B12 or folate deficiency.
What are examples of normocytic, normochromic anaemia?
Acute bleeding, haemolysis, bone marrow failure.
What is the difference between structural Hb variants and thalassemias?
Structural variants alter Hb structure; thalassemias reduce globin synthesis.
What mutation causes sickle cell disease?
HbS: Glu → Val on β6.
