Red Blood Cells Flashcards
What is anaerobic glycolysis
Metabolic activity- to maintain Haem Fe in reduced state by NADPH.
What is erythropoesis
A part of the process of haemopoeisis
Where does erythropoesis occur
In adults mainly in the narrow spaces of the sternum, pelvis and long bones
What does erythropoietin do
Act on committed erythroid precursors to increase cell division and therefore rbc numbers
What is a rbc lifespan
Around 120 days
What is haemolysis
A shortening of the rbc lifespan
Where are rbc destroyed
In the spleen by macrophages if defective
What is the function of hb
To transport o2 from the lungs to respiratory tissues
What is 02 affinity
The relationship between hb 02 saturation and p02
What is anaemia
Reduced hb in blood
What is anaemia
Low hb in blood
What are physical symptoms of anaemia
- shortness of breath
- weakness
- pallor =pale skin
- lethargy =tired
- headaches
- heart failure
- palpitations
What are clinical signs of anaemia
- pallor of nail beds
- concave nails
- jaundice
- leg ulcers
- bone deformities
- recurrent infection or bruising
What rbc features show normocytic, normochromic anaemia
- Mcv is normal
- MCH is normal
- MCHB is normal
- rbc count is reduced
What rbc features show microcytic, hyperchromic anaemia
- rbc volume is reduced
- low mcv
- low mch
- low mchc
What rbc features shows macrocytic, normochromic anaemia
- rbc count is low
- rbc volume is increased
- hb have a normal concentration
- mcv is up
- mchc is normal
- mch is up
What causes microcytic, hypochromic anameia
- poor diet
- poor malabsorption
- chronic blood loss
How is IDA anaemia treated
Iron supplements
What is hereditary elliptocytosis
An inherited disorder that makes the rbc elliptical shaped
What is acquired haemolytic anaemia
Anaemia gained from drugs or autoimmune diseases
What is sickle cell
The most commonly inherited blood disease that causes sickle shaped rbcs
What is the structure of hb
2 a-globin chains, 2 b-globin chains
Fe atom
Porphyrin rings
What are the 2 categories of haemoglobinopathy
1- structural variations- where hb is made in normal amounts but the structure is abnormal.
2- thalassemia- where there is a loss of ability to produce a type of globin chain
What is a-thalassemia
The impaired ability to synthesise a globin chains
What does a-thalassemia cause
Mild microcytic hypochromic anaemia due to excess b chains
What is b-thalassemia
Impaired ability to synthesise b globin chains
What does b- thalassemia cause
Excess a chains bind to the rbc membrane reducing its survival
What is heterozygous b-thalassemia
Mild microcytic hypochromic anaemia and they are a carrier
What is homozygous b-thalassemia
Severe anaemia usually fatal in infancy or childhood without intervention
How is b-thalassemia treated
Transfusion, fe chelation therapy or in extreme cases bone marrow transplant
