maacrocytosis and microcytic anaemia Flashcards Preview

Haemotology > maacrocytosis and microcytic anaemia > Flashcards

Flashcards in maacrocytosis and microcytic anaemia Deck (60)
Loading flashcards...
1

what is microcytic anaemia?

anaemia in which the red cells have a larger than normal volume

2

what is macrocytic anaemia?

anaemia in which the red cells have a larger than normal volume

3

what is the unit to measure MCV?

femtolitres (1 femtoliter is equal to 10^-15L)

4

how to measure MCV?

Modern analysers use the light scatter properties of red cells to measure the MCV.

5

normal size of the red cell is the same size as the

nucleus of the lymphocyte

6

what are the two causes of macrocytosis?

genuine (true) or spurious (false)

7

what are the two causes of true macrocytosis?

megaloblastic
non-megaloblastic

8

normal precurors of red cells excluding the reticulocyte are?

erythroblasts or normoblasts and have a nucleus (they are the same)

9

where are normal red cells precursors based?

marrow-based

10

what is the immediate precursor of the red blood cell?

reticulocyte (loses of nucleus) and have a small amount of RNA which is lost after about 24 hours

11

reticulocytes leave marrow to join

circulation

12

developing erythroblasts?

accumulate Hb
reduce in size and increasing nuclear maturation
stop dividing and lose nucleus

13

what triggers loss of nucleus and end of division?

critical Hb content

14

at the point the nucleus is lost and the division ends?

the erythroblast becomes a reticulocyte

15

between pronormoblaast and late normoblast cells are?

increasing in HB, becoming smaller still has nucleus

16

what is an megaloblast?

an abnormally large nucleated red cell precursor with an immature nucleus and more open chromatin and have a larger nucleus

17

what are the characteristics of megaloblastic anaemias?

lack of red cells due to predominant defects in DNA synthesis and nucleus maturation but RNA and hemoglobin synthesis are preserved

18

pro erythroblasts -------- but in --------- erythroblasts, division is ------- and apoptosis ----------

expand, reduced
increased

19

in a megaloblast what occurs normally?

cytoplasmic development and haemoglobin accumulation

20

megaloblasts are

precursors that are bigger with an immature nucleus

21

once the hemoglobin level in the cell is optimal the nucleus if extruded leaving behind ?

a bigger than normal red cell ie. microcyte

22

but overall in megaloblastic anaemia there are?

fewer macrocytes and hence anaemia

23

the end result after enucleation you go from megaloblast to

macrocyte

24

megaloblastic anaemia is?

charaacteristed by larger precursor cells with an immature nucleus leading to microcytic anaemia

25

what are the causes of megaloblastic anaemia?

B12 deficiency
folate deficiency
others such as drugs and rare inherited abnormalities

26

why are B12 and folate essential co-factors?

they are co-factors in linked biochemical reaction regulating

27

what are the functions of B12 and folate?

DNA synthesis and nuclear maturation - (e.g. blood cell effect)
DNA modification and gene activity – (e.g. nervous system)

28

B12 is rich in which foods?

meat and meat products, eggs

29

what is pernicious anaemia?

autoimmune condition with resulting destruction of gastric parietal cells

30

gastric parietal cells produce?

Intrinsic factor