Practical 1: Exam Notes Flashcards
What is the principle behind the Drabkin’s Method
(3)
- Drabkin’s fluid contains potassium cyanide and potassium ferricyanide
- Potassium ferricyanide converts haemoglobin to methaemoglobin
- Potassium cyanide converts methaemoglobin to red coloured cyanmethemoglobin
Define anaemia
A lower than normal haemoglobin level
Define haematocrit
A measurement of the proportion of blood that is made up of red cells
The fraction of blood that is rbcs
What are the red cell indices
MCV = Mean Corpuscular Volume
MCH = Mean Corpuscular Haemoglobin
MCHC = Mean Corpuscular Haemoglobin Concentration
What is the mean corpuscular volume
The average volume of a red blood cell expressed in femtolitres
What is the equation for the mean corpuscular volume?
-> How do you work out the volume in an rbc
(Hct% x10)/ RBC
What is the mean corpuscular haemoglobin?
The average weight of the heamoglobin in a rbc, expressed in picograms
What is the equation for mean corpuscular haemoglobin?
How do you determine the weight of the haemoglobin in a single rbc
Haemoglobin/ RBC
What is Mean corpuscular haemoglobin Concentration
The average concentration of Hb in a given volume of blood, expressed in grams per litre
What does a low MCV and MCH indicate and what might cause this
Indicates microcytic and hypochromic rbcs
Due to iron deficiency anaemia or thalassaemia
What might a normal MCV, normal MCH but low RBCC indicate and what might be the cause
Normochromic, normocytic rbcs
Blood loss, haemolysis, bone marrow infiltration or chronic disease
What does a high MCV indicate and what might be the cause
Macrocytic rbcs
=> Megaloblastic anaemias
What is a megaloblastic anaemia and what are the causes?
Rbcs are large but they are low in numbers
Vitamin 12 deficiency or folic acid deficiency
