pathophysiology of RBC p1 Flashcards
(25 cards)
What happens in the 5-7 days in the bone marrow?
Hb accumulation, decreased cell size, decreased mRNA
What does erythropoietin do?
EPO stimulates erythropoiesis by increasing progenitor cells
Where is erythropoietin synthesised?
90% kidney
How is EPO regulated?
By amount of oxygen in tissues
What is advantage of RBCs uncomplicated membrane?
Simple passage of O2
What is advantage of lack of nucleus, mitochondria, and many enzymes?
Flexibility to penetrate fine capillaries
What is advantage of membrane lacking HLA?
Relatively easy to transplant
What is the function of the red cell cytoplasm?
Transport O2
What does haemoglobin require?
Globin synthesis
Haem synthesis
Iron supply
Where does the RBC cytoplasm get energy?
From glycolysis
What does transferrin do?
Collect free iron
What does transferrin receptor 1 do?
Receive free iron from transferrin which then allows entrance into developing RBC
What does ferritin do?
Stores up ferric iron
What does hepcidin do?
Regulates iron export
Secreted by liver
What does haemosiderin do?
Formed by aggregation of ferritin
What is haem?
Complex molecule synthesised in cytoplasm and mitochondria of developing RBCs
What does it mean if haem is seen in tests?
Means there is problem with bone marrow
On what does haem and haemoglobin synthesis depend on?
Iron availability
Where does the synthesis of globin molecule occur?
RBC cytoplasm
What does globin do?
Moves as oxygen loaded and unloaded
How is anaemia developed?
RBC loss or destruction exceeds the max capacity of the BM RBC production
What are the mechanisms leading to anaemia?
Lack of iron, haemn and decreased protein translation
What does it mean if blood film shows hypochromic, microcytic cells with occasional target and pencil cells but the reticulocyte count is low?
Increased erythtropoiesis is expected in anaemic patients so suggests impaired BM functions
What is the cause of vitamin B12 deficiency?
Caused by pernicious anaemia
