anaemia

Question 1

what is anaemia

Answer 1

low hb in blood

Question 2

what are the symptoms of anaemia

Answer 2

shortness of breath, tiredness, cardiac failure, palpitations and headache

Question 3

what are signs of anaemia

Answer 3

allow, thrachycardia and hypotension

Question 4

what is the life cycle of RBC

Answer 4

bone marrow (controlled by erythropoiesis and hb synthesis) RBC (controlled by structure and function) and removal (controlled by reticuloendothelial systems)

Question 5

9 ways anaemia develops

Answer 5

1. hormonal control of erythropoiesis
2. dyserthyropoesis
3. nutrient deficiency
4. mutations in proteins encoding globin chains
5. defects in membrane structure
6. acquired defects in membrane structure
7. defects in red cell metabolism
8. removal of excess red cells by RES
9. multifactoral

Question 6

describe how it evolves by hormonal control

Answer 6

eryhtropoetin is a hormone which controls synthesis of RBC. when someone becomes anaemic its detected by kidney and more RBC produces. BUT in kidney disease erythropoietin production is reduced. if empty bone marrow after chemo then can’t respond to erythropoietin. if marrow infiltrated by cancer haemopoitic cells reduced and therefore reduced response to erythropoietin.

Question 7

describe how it evolves by dyserythropoesis

Answer 7

this is the defective development of RBC. this could be due to;
iron not being related for use in hb (happens in inflammatory diseases e.g RA which make iron stay in macrophage)
can also lead to reduced life span because don’t have proper structure and removed by spleen
example- myelodysplastie syndrome where abnormal clone of marrow stem cells are produced so don’t develop properly and can’t enter circulation OR if they do they are removed by the spleen

Question 8

describe how it evolves by nutrient deficiency

Answer 8

lack of iron means hb synthesis is deficient

Question 9

describe how it evolves by mutations in proteins encoding global chains

Answer 9

e.g thalassaemia. can’t be made properly in RBC

Question 10

describe how it evolves by defects in membrane structure (hereditary)

Answer 10

spherocytosis, eliptocytosis and pyropolikilocytosis. draw these. it means cells are flexible and break up easily or they are removed from circulation = haemolytic anaemias

Question 11

describe how it evolves by acquire defects in membrane structure

Answer 11

mechanical defects e.g heart valves put in and RBC become sheered as they move through
heat - turn them to spherocytes
drowning

Question 12

describe how it evolves by defects in red cells metabolism

Answer 12

glucose 6 phosphate dehydrogenase and pyruvate kinase deficients mean won’t be able to keep membrane in good condition and therefore RBC will be removed by spleen (upkeep of S-S bonds)

Question 13

describe how it evolves by removal of excess RBC by RES

Answer 13

antibodies bid to RBC membrane and RES removes them from circulation = AUTOIMMUNE

Question 14

describe how it evolves by multiple factors

Answer 14

example- myelofibrosis. fibrotic bone marrow= reduced response to erythropoietin. then RBC are enlarged and removed in excess by spleen

Question 15

3 factors that we can use to evaluate anaemia

Answer 15

by mechanism, by size and by presence or absence of reticulocytes

Question 16

what are microcytic cell causes in anaemia

Answer 16

TAILS - thalassaemia, aneamia of chronic disease, iron defiecney, lead poisoning and sideroblastic anaemia

Question 17

what is sideroblastic anaemia

Answer 17

sideroachrestic anemia is a form of anemia in which the bone marrow produces ringed sideroblasts rather than healthy red blood cells

Question 18

what are macrocytic cell causes in anaemia

Answer 18

vit B déficient, folate deficiency, liver disease, hypothyroidism and alcohol.

Question 19

what could be the reason for normal cell size, normal reticulocyte number in anaemia

Answer 19

primary bone marrow failure or secondary bone marrow failure which is due to disease e.g HIV

Question 20

what could be the cause of bleeding if there are reduced reticulocytes but no haemolysis

Answer 20

bleeding

Question 21

what is the cause of anaemia if there are unusual numbers of reticulocytes and haemoylsis

Answer 21

could be mechanical acquired structural defect, hereditary defect in structure, enzyme defects meaning less stable membrane , increased splencic sequestration or immune mediated response (autoimmune)

Question 22

building blocks of DNA

Answer 22

vit B12 and folate

Question 23

how is visit B12 absorbed

Answer 23

parietal cells in stomach produce HCL and Intrinsic factor . the intrinsic factor binds to fit B12 and allows it to be absorbed in the last part of the ileum

Question 24

causes of low B12

Answer 24

3-6 years worth of it stored up. if deficient occurs v slowly and causes cardiac problems because heart begins to compensate.
causes;
diet
lack of IF (intrinsic factor)
disease of ileum (e.g churns prevents absroption)
lack of Transcobalamin (congenital). This is a glycoprotein which serves to protect vit B12 from acid in stomach by forming a complex with it

Question 25

causes of low folate

Answer 25

store lasts for about 3-4 months and absorption occurs in the duodenum and the jejunum
causes;
dietary
increased use (e.g pregnancy)
disease of duodenum and jejunum e.g in coeliac disease
lack of methyTHF - some drugs may inhibit the enzyme

Question 26

what is the B12 folate link

Answer 26

if deficient of 1 then deficiency of thymidylate.
bad because uracil incorporated into DNA instead of thymine. this causes an error which is detected and then the DNA is destroyed

Question 27

how does B12 or folate deficiency result in megalobalsic anaemia

Answer 27

error in DNA due to lack of thymine means DNA is being destroyed and doesnt fully mature leading to a large nuclei with open chromatin. also asynchronous maturation between cytoplasm and nuclei meting more cytoplasm. = larger cell than normal (microcytic)

Question 28

megalobasltic cell features

Answer 28

microcytic, anidpoikilocytosis, hyper-segmented WBC and white cell precursors

Question 29

what does B12 and folate deficiency lead to

Answer 29

neurological disease and lack of folate in pregnant women also to neural tube defects

Question 30

megaloblastic anaemia signs

Answer 30

low hb,
high MCV
high bilirubin/LDH (due to hardworking bone marrow which isn’t properly producing any cells)
low B12 and folate serum levels in blood

Question 31

how to treat low folate and B12

Answer 31

low folate= oral folic acid
low B12= intramuscular hydroxycobalmine if problem with absorption OR cyanacocobalamine if dirty problem BUT must be V careful of cardiac failure because heart is already compensating