Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y3 Haematology > Macrocytic Anaemia > Flashcards

Macrocytic Anaemia Flashcards

1
Q

what is macrocytic anaemia?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what cell can be used to estimate RBC size?

A

the mature lymphocytes nucleus

normocytic RBC = same size as this nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what red cell precursors have a nucleus?

A

erythroblasts and normoblasts

reticulocytes do not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a true macrocytosis?

A

one in which there is a true increase in the volume of red cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the two types of true macrocytosis?

A

megaloblastic

non-megaloblastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

name four causes of non-megaloblastic macrocytosis

A

alcohol
liver disease
hypothyroidism
marrow failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

name three causes of marrow failure that can cause non-megaloblastic macrocytosis

A

myelodysplasia
myeloma
aplastic anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a spurious macrocytosis?

A

red cell volume is normal but MCV is measured as high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a megaloblast?

A

an abnormally large nucleated red cell precursor with an immature nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what characterises a megaloblastic anaemia?

A

lack of red cells

maturation of megaloblasts in the marrow - presence of large precursor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does a megaloblast become a macrocyte?

A

once appropriate Hb levels reached in the megaloblast, nucleus is extruded leaving behind a bigger than normal RBC

bevcause cell division has occurred less = less macrocytes = anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the two main causes of megaloblastic anaemia?

A

B12 deficiency

folate deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the treatment of megaloblastic anaemia in pernicious anaemia?

A

vitamin B12 injections for life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is given for folate deficiency anaemia?

A

folic acid tablets 5mg daily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are B12 + folate needed for?

A

DNA synthesis and nuclear maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how is B12 released from food?

A

by stomach acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how is B12 protected from the stomach acid?

A

binds to rapid binder proteins from the saliva or stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is secreted by the gastric parietal cells in response to the presence of food in the stomach?

A

intrinsic factor (IF)

19
Q

what happens to B12 when it reaches the duodenum?

A

released from binder proteins and binds to IF

20
Q

where is B12 bound and in what form?

A

the distal small bowel

bound to IF

21
Q

what does B12 bind to in circulation?

A

transcobalamin (TC) receptors

22
Q

name two sources of B12 in the diet

A

meat

eggs

23
Q

what gastric conditions can cause B12 deficiency?

A

atrophic gastritis

pernicious anaemia

24
Q

what medications can lead to B12 deficiency?

A

PPIs

H2 receptor antagonists

25
Q

what small bowel conditions can result in B12 defiiency?

A

bacterial overgrowth
coeliac
crohn’s

26
Q

what surgeries can increase risk of B12 deficiency?

A

gastrectomy

resection

27
Q

what are dietary folates converted to for absorption?

A

monoglutamate

28
Q

where is monoglutamate absorbed?

A

jejunum

29
Q

name some possible causes of folate deficiency

A

inadequate intake
malabsorption
excess utilisation
drugs

30
Q

which has higher body stores - folate or B12?

A

B12 (much more)

31
Q

name four states that can lead to excess folate utilisation

A

haemolysis
exfoliating dermatitis
pregnancy
malignancy

32
Q

what group of drugs can cause folate deficiency?

A

anti-convulsants

33
Q

what foods are a source fo folate?

A

leafy veg
liver
fortified cereals

34
Q

how long to body stores of B12 and folate last?

A 
B12 = 2-4 years 
folate = 4 months
35
Q

which is higher - daily requirement of folate or B12?

A

folate (200ug/day)

B12 is 1.5ug/day

36
Q

what serious way can B12 deficiency present?

A

neurological problems - subacute combined degeneration of the cord

37
Q

what does blood film in B12/folate deficiency anaemia show?

A

macrocytes

hyper-segmented neutrophils

38
Q

what investigations are done for B12/folate deficiency?

A

measure B12 + folate
check for auto-antibodies to rule out PA
trial of therapy

39
Q

in what states can low B12 not indicate B12 deficiency?

A

pregnancy

on the COCP

40
Q

what auto-antibodies are present in pernicious anaemia (PA)?

A

anti gastric parietal cell (GPC)

anti IF

41
Q

what is pernicious anaemia?

A

an autoimmune condition resulting in destruction of gastric parietal cells = IF deficiency

42
Q

what are some risk factors for pernicious anaemia?

A

atrophic gastritis

personal or family history of other autoimmune disorders

43
Q

what causes non-megaloblastic macrocytosis?

A

red cell membrane changes

44
Q

what are two possible causes of a spurious macrocytosis?

A

reticulocytosis - bigger than RBCs

abnormal clumping of cells due to cold agglutinins

Y3 Haematology (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions