Haematopoiesis Flashcards
What 6 cell types can the multipotent haematopoietic stem cell become?
- Megakaryocyte
- Erythrocyte
- Monocyte
- Neutrophil
- Basophil
- Eosinophil
What is the function of Erythropoietetin? How is it controlled and how is it made?
- Ensure the number of RBCs is sufficient
- Act mainly of later RBCs, enhances survival of erythroid precursors and increases maturation rate.
- 90% synthesised in the kidney.
- Control: if oxygen levels drop, kidneys release Epo.
What is the function of Granulocyte colony stimulation factor (G-CSF)? How is it controlled and how is it made?
- Ensure neutrophil number is sufficient
- Must provide baseline number to protect the body, but also respond rapidly during infection. No upper limit.
- Act on late granulocyte precursors, increase granule formation.
- Released by endothelial cells during infection.
- Enhances the effects of: SCF, Flt-L, IL-3 and GM-CSF
What is the function of Thrombopoitetin (Tpo)? How is it controlled and how is it made?
- Ensure there is always enough platelets to prevent haemorrhage.
- Act mainly on megakaryocytic to enhance their precursors’ survival to increase the number and rate of maturation.
- Made mainly in the liver
- Control: mature platelets can bind to Tpo and destroy it.
Formation of:
- Red blood cells
- Granulocytes and monocytes
- Platelets
- Erythropoiesis
- Myelopoiesis
- Thrombopoiesis
What transcription factor commits cells to myeloid lineage?
PU.1
What transcription factor commits cells to erythropoietic and megakaryocytic differentiation?
GATA-1
Lineage of erythropoiesis.
Stem cell-> CFUgemm-> BFUe-> pronormoblast-> normoblast-> late normoblast
What is a pronormoblast?
A large cell with a dark blue cytoplasm, nucleus with nucleoli and chromatin.
What is a normoblast?
It contains progressively more haemoglobin and less RNA.
