6. Red cell structure
• Red cells lack nuclei and
cytoplasmic structures such as
ER and mitochondria.
• Exist as biconcave discs, but
able to change the shape.
• Membrane and cytoskeleton
was referred to as stroma.
Membrane has proteins (band
3 protein) and
glycophorins.Cytoskeleton has
proteins called spectrin, Band
4.1 protein and ankyrin
• Over 90% of cytoplasm is
haemoglobin
7.
8.
9. Metabolism of red cell
• Survival of red cells is dependent on ATP supply by glycolysis
(90%)
• A constant supply of ATP is necessary for cation pump
• Large amounts of 2-3DPG is present in cytosol and it regulates
oxygen affinity to Hb A.
• Remaining 10% glucose enters HMP shunt and produces
NADPH necessary to keep the oxidised proteins in reduced
state.
11. Function of red cell
•Main function is oxygen and carbon dioxide
transport.
•The affinity of oxygen binding to
haemoglobin depends on the: nature of
globin chain,
pH
2-3 DPG level.
12.
13. Red cell values Red cell indices
• Haemoglobin level(Hb)
• Red cell count (RCC)
• Haematocrit (PCV)
• Mean corpuscular volume (MCV)
• Mean corpuscular haemoglobin (MCH)
• Mean corpuscular haemoglobin
concentration (MCHC)
14. Anaemia
• Anaemia is present when the haemoglobin level in the blood is below the
lower extreme of the normal range for the age and the sex of the
individual.
• Anaemia causes tissue hypoxia and body has some adaptations for it these
are increase in 2-3DPG concentration, increased cardiac output, increase
in plasma volume to maintain blood volume and by redistribution of blood
flow (low skin blood flow and increased cerebral and muscle blood flow)
16. Clinical features of anaemia
(General)
•Fatigue and weakness
•Pallor
•CVS
Dyspnoea on exertion
Angina
murmurs and CCF
*CNS
*Optic fundi pale/haemorhages
17. Specific signs /symptoms
• Koilonychia-Iron deficiency
• Jaundice- Haemolytic/megaloblastic
• Leg ulcers –sickel cell anaemia
• Bone deformities – thalassaemia major
• Excess infections- neutropenia
• Bruising- thrombocytopenia
24. Mechanism of anaemia
•Blood loss
•Decreased red cell lifespan (haemolysis)
• Congenital defects ( Hb SS, Spherocytosis)
• Acquired defect (malaria)
•Impaired red cell formation
• Insufficient erythropoiesis due to lack of necessary nutrients
• Ineffective erythropoiesis
•Pooling and destruction of red cells in an
enlarged spleen (hypersplenism)
•Increased plasma volume (pregnancy)
25. Blood film examination
• Red cells
size
shape
pattern of staining
inclusions
association
• White cell
number
morphology
• Platelets
number
morphology
32. 2.1 Which ONE of these statements is TRUE
about haemoglobin?
A. One molecule contains 1 atom of iron
B. It is broken down in macrophages
C. It is different in children and adults
D . It has a low level in blood at birth compared with adult life
E. Synthesis continues in red cells in circulation
33. 2.2 Which ONE of these statements is TRUE about
reticulocytes?
A. They contain DNA not RNA
B. They are raised in megaloblastic anaemia
C. They are raised in bone marrow hypoplasia.
D.They are raised after haemorrhage
E.They contain reticulin fibres
34. 2.3 Which ONE of these statements is
NOT TRUE concerning erythropoietin?
A. 90% of the hormone is made in the liver
B. It contains a hypoxia response gene
C. One stimulus to production is a low atmospheric oxygen level
D. Levels in blood are high if a tumour secreting erythropoietin is causing
polycythaemia but are low in severe renal disease.
E. Levels are low in polycythaemia vera
35. 2.4 Which ONE of these statements is
TRUE concerning the therapeutic use of
erythropoietin?
A. Side effects include hypotension and bleeding disorders
B. The main indication is in patients with leukaemia
C. Oral or parenteral iron is often needed to optimise the response
D. Oral administration reduces the frequency of treatment
E. Serum Epo level not useful in predicting the response