Blood Flashcards
What is the normal concentration of Red Blood cells?
3-5 x 10^12/litre
What is the normal concentration of White blood cells?
2-5 x 10^9/litre
What is the normal concentration of Platelets?
150-400 x 10^9/litre
How often are RBCs replaced?
Every 120 days
How often are WBCs replaced?
Every 3-5 days
How often are Platelets replaced?
Every 10 days
Where is the most reliable place to get bone marrow from?
Posterior Superior Iliac Spine
How does the location of haemopoiesis change throughout development?
First few weeks -> Yolk sac
6 weeks - 7 months -> Liver and Spleen
7 months - throughout life -> Bone marrow
Later in life -> axial skeleton, after bone marrow of long bones has turned to yellow (fat) marrow.
What percentage of marrow consists of fat spaces, even in haemopoietic areas?
50%
Why, in bone marrow transplants, are a variety of cell-types transplanted, despite the fact that the only cells that are really useful for transplantation are the Pluripotent stem cells?
Because no-one knows what they look like. Can’t differentiate them from other immature cells - just have to hope that there are some PPSCs in with the cells that you transplant.
Anything above the CFUs in haemopoiesis are indistinguishable from each other.
What components make up the bone marrow stroma?
Cells
Extracellular matrix
What determines when cells are released into the circulation?
Stromal regulation of Adhesion molecules that anchor stem cells to the ECM.
What are three broad factors that influence Haemopoiesis?
Bone marrow stroma
Haemopoeitic growth factors
Haematinics
What are 4 examples of Haematinics?
Red Cells, Iron, B12, Folate
What are Haematinics?
Chemical agents or substances that are required for erythropoiesis.
Is there Folate in goat’s milk?
No, fucker!
What is a drug that interferes with the folate metabolic pathway?
Methotrexate.
What is polycythaemia?
Too many RBCs
What is Thrombocytosis?
Too many platelets
How is Anaemia measured?
Measured by haemoglobin levels, rather than RBC count.
What is the Tissue oxygen delivery equation?
CO x Hb x %Saturation x 1.34 = Tissue oxygen delivery
What is %saturation?
The percentage of RBCs that are saturated with oxygen
What are the units used for Tissue oxygen delivery?
ml/min = l/min x g/l x % x ml/g
What is the main factor that is taken into consideration when deciding whether or not to give a patient a blood transfusion?
How long the patient can maintain the compensatory heart rate.
What is implied by an increasing heart rate in an anaemic patient without fever?
That their haemoglobin has decreased.
What is MCV?
Mean corpuscular volume. Size of RBC.
What are two signs of increased production of erythrocytes?
Reticulocytes
Polychromasia
What are three signs of increased destruction of red blood cells?
Jaundice (increased serum bilirubin)
Haptoglobins
LDH = Lactate dehydrogenase
What are haptoglobins?
Found in plasma, bind free haemoglobin that has been released by erythrocyte breakdown, and carries it back to the liver.
What are two signs of increased production of Red blood cells?
Reticulocytes: immature RBCs
Polychromasia: abnormally high numbers of red blood cells
What is microcytic anaemia?
Anaemia characterised by red blood cells with reduced Mean Corpuscular volume
What are two causes of microcytic anaemia?
blood loss and dietary insufficiency
What is macrocytic anaemia?
Anaemia characterised by red blood cells with increased Mean Corpuscular volume.
What are two causes of macrocytic anaemia?
Vitamin 12 and Folate
On which chromosome will you find ABO genes?
Chromosome 9
On which chromosome will you find the H gene?
Chromosome 19
What does A gene code for? and What does the product do?
A transferase. Converts H antigen to A antigen.
What does B gene code for? and what does the product do?
B transferase. Converts H antigen into B antigen.
What are the two most common blood groups?
A and O
Where is the Rh gene located?
Chromosome 1
What antigens are involved in the Rhesus blood group system? Which is the most important?
Antigens C, c, D, E, e.
D is the most important antigen.
What genotype will make someone Rhesus positive?
DD, Dd
What does ‘A+’ mean?
Means a person has Blood Type A and is Rhesus positive.
