Brainscape's Knowledge GenomeTM

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


See full index

notes to flashcards year 2 - MCD > anaemia > Flashcards

anaemia Flashcards

1
Q

what is anaemia?

A
  • reduction in amount of Hb in a given volume of blood
  • Hb reduced
  • often RBC and PCV/Hct reduced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the 4 mechanisms of anaemia?

A
  1. reduced proportion of RBCs/Hb in bone marrow
  2. loss of blood from body
  3. reduced survival of RBCs in body
  4. pooling of RBCs in spleen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is it called when there is a reduced synthesis of haem?

A

iron def

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

what is it called when there is a reduced synthesis of globin?

A

beta-thalassaemia

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

what is microcytic anaemia usually?

A

hypochromic

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

what are the common causes of microcytic anaemia?

A
  • defect in haem synthesis (iron def, anaemia of CD)

- defect in globin synthesis (thalassaemia)

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

what is normocytic anaemia normally?

A

usually often normochromic

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

what is macrocytic anaemia usually?

A

normochromic

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

what is macrocytic anaemia usually a result of?

A

abnormal haemopoiesis –> RBC precursors continue to synthesise Hb and other cellular proteins but don’t divide properly –> end up larger than normal

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

what are the causes of macrocytic anaemia?

A
  • megablastic erythopoiesis (delay in maturation of nucleus while cytoplasm continues to mature and cell continues to grow)
  • premature release of cells from bone marrow (young red cells are 20% larger)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define megaloblast

A

abnormal bone marrow erythroblast –> larger than normal, shows nucleocytoplasmic dissociation

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

what are the common causes of macrocytic anaemia?

A
  • megaloblastic anaemia (lack of Vit B12, folic acid)
  • DNA synthesis interfering drugs
  • liver disease, ethanol toxicity
  • recent major blood loss (body pumps out more reticulocytes)
  • HA (RBCs lyse in blood stream, reticulocyte numbers inc)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the mechanisms of normocytic normochromic anaemia?

A
  • recent blood loss (peptic ulcer, trauma)
  • failure of production of red of red cells (beginning of iron def, renal failure, bone marrow failure)
  • pooling of RBC in spleen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is haemolytic anaemia?

A

shortened survival of RBCs in circulation

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

what can haemolysis occur from?

A
  • intrinsic abnormality of red cells

- extrinsic factors acting on normal red cells

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

what 2 things can haemolytic anaemia be classed as?

A
  • inherited: abnormalities in cell membrane, Hb, enzymes of RBC
  • acquired: extrinsic factors e.g. microorganisms, drugs, chemicals
17
Q

in what other way can HA be classed?

A
  • intravascular: due to acute damage to RBC

- extravascular: defective RBCs removed by spleen

18
Q

when do you suspect HA?

A
  • otherwise unexplainable anaemia which is normochromic
  • morphologically abnormal cells
  • inc. RBC breakdown
  • inc. bone marrow activity
  • irregularly contracted cells, SC disease
19
Q

what do people with HA potentially have?

A
  • gall stones: high excretion of bilirubin
  • jaundice: sickle cell, RBCs breaking down quickly
  • polychromic anaemia (antibodies remove membrane of spherocytes, lyse cells)
20
Q

name a disease where the defect lies in the RBC membrane

A

hereditary spherocytosis

21
Q

name a disease where the defect lies in the Hb

A

sickle cell anaemia

22
Q

name a disease where the defect lies in glycolytic pathway

A

pyruvate kinase def

23
Q

name a disease where the defect lies in the pentose shunt

A

glucose-6-phosphate dehydrogenase def

24
Q

name a disease that is caused by immune damage to the RBC membrane

A

AI Heamolytic anaemia

25
Q

name a disease that is caused by mechanical damage to the whole red cell

A

microangiopathic haemolytic anaemia

26
Q

name a disease that is caused by oxidant damage to the whole red cell

A

drugs and chemicals

27
Q

name a disease that is caused by microbiological damage to the whole red cell

A

malaria

28
Q

how does hereditary sphericytosis cause HA?

A
  • intrinsic defect in RBC membrane
  • red cells become less flexible
  • removed by spleen prematurely
  • causes extravascular (in spleen) haemolysis
  • bone marrow responds –> inc. output of reticulocytes
  • get polychromasia
29
Q

what is the treatment of hereditary spherocytosis?

A
  • splenectomy

- good diet/folic acid tablets (so don’t get folic acid def)

30
Q

how does G6P dehydrogenase def cause HA?

A
  • G6PD is important enzyme in pentos-phosphate shunt
  • essential for protection of RBCs from oxidant damage
  • oxidants may be generated in blood stream
    G6PDD intrinsically affects RBCs –> HA
  • extrinsic oxidants = food, chemicals, drugs
31
Q

what does G6PDD cause?

A

intermittent severe intravascular haemolysis

32
Q

what are Heinz bodies?

A
  • G6PDD intravascular haemolysis –> lots of irregularly contracted cells
  • Hb becomes denatured –> forms round balls = heinz bodies
33
Q

what causes autoimmune HA?

A
  • production of autoantibodies directed at directed at RBC anitgens
  • splenic macrophage recognised antibody and removes parts of RBC membrane –> spherocytosis
  • spherocytes are less flexibke
  • dec. flexibility and antigen recognition –> removal of RBCs from circulation
34
Q

how do you diagnose autoimmune HA?

A
  • spherocytes and inc. reticulocyte count on film
  • detecting immunoglobulin of red cell surface
  • detecting antibodies to RBC antigens
35
Q

how do you treat autoimmune HA?

A
  • corticosteroids

- splenectomy for severe cases

notes to flashcards year 2 - MCD (24 decks)

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