Haemopoiesis, anaemia + haemolysis Flashcards
Where does haematopoeisis occur in a fetus?
yolk sac then liver and spleen
Where does haematopoeisis occur in an adult?
bone marrow of the axial skeleton (skull, ribs, sternum, pelvis, prox femur)
Which cells develop from the lymphoid lineage?
- lymphocytes: B cells, T cells, NK cells - dendrites
Which cells develop from the myeloid lineage?
- granulocytes: neutrophils, basophils, eosinophils - platelets - erythrocytes - macrophages - dendritic cells - mast cells
Which myeloid cells target tissues?
macrophages mast cells dendritic cells
give the pathway for erythropoiesis
haemocytoblast proerythroblast early erythroblast late erythroblast reticulocyte mature erythrocyte
At what stage of erythropoeisis is/are a) the nucleus lost? b) ribosomes lost?
a) when reticulocyte is formed b) when mature erythrocyte is formed
How is erythopoeitin produced?
in kidneys cells have a signalling molecule called hypoxia-inducible factor which needs oxygen to be broken down in hypoxia this doesn’t happen so the signal is sent to increase production of erythopoeitin
Where are erythrocytes destroyed?
in the spleen by macrophages
What are the specialised antigens on rbc called?
agglutinatagens
In microcytic anaemia where is the problem?
the cytoplasm - impaired haemoglobin
In macrocytic anaemia where is the problem?
the nucleus - impaired cell division
Causes of microcytic anaemia
iron deficiency anaemia of chronic disease thalassaemia lead poisoning
How does lead poising affect blood results?
microcytic microchromic due to its effect on porphyrin ring synthesis
Causes of macrocytic anaemia
b12/folate deficiency drug-induced alcohol hypothyroid pregnancy
What is the most common cause of macrocytosis?
alcohol
Where does platelet production occur?
platelets bud off from megakaryocytes in the bone marrow
What do neutrophils do?
immediate line of defence
What do eosinophils do?
fight parasitic infections, involved in hypersensitiviy
What does a monocyte become in tissues?
macrophage
name the a) oxidised version b) reduced version of iron
a) Fe3+ = ferric (more positive because it has lost an electron and oxidation is loss) b) Fe2+ = ferrous
In red cell destruction what does a) globin b) heme become?
a) amino acids b) iron recycled, porphyrin becomes unconjugated bilirubin
Which pathway generates ATP and NADH? why?
Ebden-Meyerhof ATP needed for Na-K pump to maintain osmotic pressure NADH prevents Fe2+ oxidation
How do we prevent free radicals from damaging the erythrocyte?
hexose monophosphate shunt generates NADPH that maintains glutathione (an antioxidant capable of donating electrons)