W1-L3-red cells Flashcards
blood cell origin
bone marrow
blood cell derived from
multipotent HSC haemapoietic steam cell
differentiate into the myeloid and lymphoid stem cell
process of ,making blood
haematopoiesis
haemopoiesis
process of making blood
HSC characteristics
part of the daughter cells do not differentiate and remain as HSC
stem cells differentiate into a specific function
erythrocytes biconcave shape
allows cells to manoeuvre within small openings
erythropoiesis
occurs in response to hypoxia or anaemia
release of erythropoietin from the kidney to the bone marrow to stimulate the production of more red blood cells
another source of erythropoietin is the interstitial cells
haemoglobin in adults
2 alpha and 2 beta chain globin chains
haemoglobin in foetus
2 alpha and 2 gamma globulin chains
structure of haem group
consist of a porphyrin ring with a Fe2+ ion in the middle which binds to 1 oxygen molecule
where is iron absorbed?
in the duodenum
how is Fe3+ absorbed?
requires the use of ascorbic acid or vitamin C
amount iron absorbed per day from diet
1-2mg
hepcidin
blocks the absorption of iron in the SI and release of iron stores
ferroportin
stimulates absorption of iron in the duodenum and breakdown of iron stores
increased hepcidin at inflammation site cause anaemia
reduce amount of iron present within the red cells and therefore impair on the development of red blood cells
dTTP synthesis
dependent on folic acid and vitamin B12
required for the synthesis of thymidine and therefore DNA
vitamin B12 absorption
stomach: combines with IF-intrinsic factor made in gastric parietal cells
SI: B12-IF binds to receptors in the illeum
life cycle of a red cell
formation in bone marrow
breakdown by reticuloendothelial macrophages in spleen
iron released from haem group and bound to transferrin, returned to bone marrow which haem group catabolism produce bilirubin excreted as bile
globin group hydrolysed to amino acids and excreted
microcytic
RBC smaller size than normal
normocytic
RBC normal size
macrocytic
RBC larger size than normal
macrocytes types
round oval and polychromasia
hypochromia
larger area of central pallor
polychromasia
increased blue tinge present in the RBC
reticulocytosis
presence of young RBC seen as a blue colour of the cell and larger size, present as a result of bleeding or anaemia
stained with methylene blue
anisocytosis
variation in size of the RBC
poikilocytosis
variation in shape of the RBC
target cell
presence of accumulation of haemoglobin in the area of central pallor
sickle cells
presence of a sickle shape RBC, results from HBS presence in the genes
replace glutamic acid with valine and therefore less soluble than HBA
reference range
carefully defined from a reference population
3 step process : particular characteristics in volunteer, analyse using instruments and techniques and statistical tests
deficiency in the B12
results of inadequate intake or inadequate secretion or malabsorption
vitamin B12 function
co-factor for CoA to succinyl CoA conversion to break down aa to enter Krebs cycle
co-factor to regenerate tetrahydrofolate-needed to convert dUMP to dTTP
