Red Cells and Haemolysis

Question 1

what is haemopoesis?

Answer 1

ther production of blood cells

Question 2

what are the sites of haematopoiesis from embryo to adulthood?

Answer 2

embryo- yolksac

birth- mostly bone marrow, liver

adult- bone marrow of axial skeleton

Question 3

what is an erythrocyte?

Answer 3

mature red cell (doesn’nt have a nucleus)

Question 4

what are mature red cells first called?

Answer 4

reticulocytes

(due to rRNA meshwork that can be seen under microscopy)

Question 5

what cells are described as polymorph (segmented nucleus)?

Answer 5

neutrophils

Question 6

what can cause an increase in neutrophils?

Answer 6

body stress- infection, trauma, infarction

Question 7

what blasts are often elevated in people with allergies i.e. asthma/dermatitis?

Answer 7

eosinophils

Question 8

how do eosinophils appear under microscope?

Answer 8

bi-lobed

bright red/orange granules

Question 9

how do basophils stain under microscope?

Answer 9

large deep purple granules

Question 10

what do basophil granules contain?

Answer 10

histamine

Question 11

what is the production of red blood cells called?

Answer 11

erythropoesis

Question 12

what regulates the poduction of red blood cells?

Answer 12

erythropoietin

Question 13

where is erythropoietin released?

Answer 13

kidneys

Question 14

what role do the kidneys play n eryhtropoeisis?

Answer 14

hypoxia sensed by kidney which then releases erythropoetin stimulating erythropoeisis

Question 15

haemoglobin is what kind of protein?

Answer 15

tetrameric globular protein

• 2 alpha
• 2 beta

Question 16

what is the haen group in haemoglobin?

Answer 16

porphyrin ring

Question 17

where does red cell desrtuction usually take place?

Answer 17

in the spleen- red cells taken up by macrophages and contents recycled

Question 18

what are the contents of red blood cells recycled to?

Answer 18

globin → amino acids

heam group → iron and bilirubin

Question 19

what happens to the bilirubin formed from the breakdown of red cells?

Answer 19

binds to serum albumin and trasnferred to liver to become conjugated and is then excreted in urine and faeces

Question 20

how is carbon dioxde transported in the blood?

Answer 20

10% dissolved in soln

30% bound directly to Hb

60% as bicarbonate

Question 21

what is the shape of the oxygen dissociation curve?

Answer 21

sigmoidal

Question 22

as one oxygen binds, on eunit changes its shape and the ability of oxygen to bind to the next unit. what is this called?

Answer 22

allosteric effect

Question 23

what happens to oxygen delivery if the curve is shifted to the right?

Answer 23

more oxygen delivered to the tissues

Question 24

what is the structure of fetal haemoglobin?

Answer 24

2 alpha chains and 2 gamma chains- HbF

Question 25

can feotal hameoglobin take oxygen from maternal curculation?

Answer 25

yes- diff shape means diff curve: if mums blood in placenta is 80% saturation foetal will be 90%

Question 26

why are red cells more susceptible ot damage?

Answer 26

biconcave shape no mitochondria no nucleus

Question 27

why is the lack of mitochondria and nucleus significant in red cells with regards to damage?

Answer 27

they have a limited metabolic reserve can't generate new proteins

Question 28

what is compensated hameolysis?

Answer 28

inc in red cell production to compensate for inc in red cell destruction

Question 29

what is decompensated haemolysis?

Answer 29

inc rate of red cell destruction exceeding bone marrow capacity for red cell production Hb falls

Question 30

what is another name for decompnesated hameolysis?

Answer 30

haemolytic anaemia

Question 31

what is the bone marrow response to haemolysis?

Answer 31

reticulocytosis erythroid hyperplasia

Question 32

which is more common extravascular or intravascular red cell desruction?

Answer 32

extravascular- at site of destruciton

Question 33

what happens in extravascular hameolysis?

Answer 33

release of protoporphyrin leading to escess unconjugated bilirubin

Question 34

what happens in intravascular haemolysis?

Answer 34

red cells destroyed in circulation spilling contents

Question 35

what are some causes of intravascular haemolysis?

Answer 35

ABO incompatible blood transfusion G6PD deficiency severe falciparum malaria (blackwater fever)

Question 36

ho wdo you investigate haemolysis?

Answer 36

FBC/film reticulocyte count serum unconjugated bilirubin coombs test

Question 37

what is the purpose of coombs test?

Answer 37

tests for antibodies againt RBC

Question 38

what does membrane damage indicate on blood film?

Answer 38

spherocytes

Question 39

how is mechanical damage indicated on blood film?

Answer 39

red cell fragments

Question 40

how is oxidative damage indicated on blood film?

Answer 40

heinz bodies

Question 41

what immunoglobulin is seen in warm autoimmune haemolysis?

Answer 41

IgG

Question 42

what are causes of warm (igG) autoimmune haemolysis?

Answer 42

idiopathic autoimmune disorders (SLE) drugs (peniclllins) infections

Question 43

what immunoglobulin is seen in cold autoimmune haemolysis?

Answer 43

IgM

Question 44

what are some causes of cold (IgM) autoimmune haemolysis?

Answer 44

idiopathic infections (EBV, mycoplasma) lymphoproliferative disorders

Question 45

other than autoimmune haemolyisis what other form of immune haemolysis is there?

Answer 45

Alloimmune haemolysis

Question 46

what can cause alloimmune haemolysis?

Answer 46

immune response passive transfer of antibody- Haemolytic disease of newborn

Question 47

what are some mechanical causes of haemolysis?

Answer 47

Disseminated Intravascular Coagulation (DIC) HUS (E.Coli 0157) Leakign heart valve infections i.e malaria

Question 48

what is the only type of haemolysis to show microspherocytes on blood film?

Answer 48

burns related haemolysis- red cells sheared as they pass through damaged capillaries