Haematopoiesis to Haematogram Flashcards
What is Haematopoiesis?
The production and development of different blood cell lineages
What blood cell has the highest turnover rate?
erythrocytes
Where in the foetus does haematopoesis begin?
begins in the yolk sac of the foetus
Where does haematopoiesis shift to mid-gestation?
It shifts to the liver and the spleen
then bone marrow/lymphoid organs from mid-gestation onwards
What replaces haematopoietic tissue as an animal ages?
Fat
What can bone marrow sampling assess for?
Thrombocytopenia and Neutropenia
(Lack of platelets, lack of White Blood Cells)
In what animals can you assess the sternum/ rib for haematopoiesis?
Horses/ large animals
What animals have haematopoiesis in the kidneys?
Fish
e.g what shape, where is the iron?
How are erythrocytes produced?
They are produced in islands with iron in the centre
called an called an erythroblastic island
What are rubriblasts?
The first recognisable stage of erythricyte production
deep basophillic cytoplasm with a round nucleus
What are prorubricytes?
The second stage of erythrocyte production
they have more nucleus but less cytoplasm
What are rubricytes?
The last stage with a nuclues, the chromatin becomes progressively more clumped
develops from basophillic to a mature red
What are polychromatophils?
Slightly larger than a mature erythrocyte, they contain no nucleus- more purple in appearance than a mature erythrocyte
What is the principal growth factor of erythrocytes?
erythropoietin
produced in the kidney in adults, liver in the foetus
What two stages of erythrocyte production are together called early erythoid
Rubriblasts and Prorubricytes
How many days does it take to go from a rubroblast to a metorubricyte?
3-5 days
What are some examples of inhibitors that inhibit erythropoiesis?
TGF-b, TNF-a, IFN-g, IL-6
What is a myelocyte?
Stage at where it becomes recognisable as to the lineage which the cell will finally differentiate to
has a thick bean shaped nucleus and a high N:C ratio
What is a metamyelocyte?
Where the cells become smaller in size with each division until they enter the segmented stage (nucleus narrows)
What is granulopoiesis?
The production of neutrophils, eoisinophils and basophils
What is thrombopoiesis
Production of thrombocytes/ blood platelets
What is the main driver of thrombopoiesis?
Thrombopoietin (TPO)
Where does the most production of thrombocytes occur?
The liver (endothelial cells)
The kidney and bone marrow stromal cells
What are some thrombopoiesis inhibitors?
- PF4, TGF-b, IL-4, TNF-a
What is PCV?
Packed cell content
centrifugation of a well mixed anticoagulated sample to produce layers
considered to be more reliable than blood smears
What is an impedence counter?
Use the change in electrical charge generated
by the passage of the cell to allow counting
Different sizes of cells will generate different
change
What does an impedence counter produce?
It produces an histogram of the distribution cell population
white cell count is usually the most reliable value
What is light scatter flow cytometry?
Scatters light according to the size, complexity, granularity and diameter of the cell
Produces a chart based on the results
How does haemoglobin measurement work?
lyse all the red cells and what haemoglobin is left in the sample, then look at the difference between the light put in and the light detected
What is non-regenerative anaemia?
The bone marrow is unable to produce sufficent new blood cells to replace the ones that die off naturally
What is the last stage of an erythrocyte with a nucleus
rubricyte
What are the promotors for Granulopoiesis?
IL-3, GM-CSF, G-CSF
What are the stimulants for Thrombopoiesis?
IL-6
What are the inhibitors for thrombopoiesis?
- PF4, TGF-B, IL-4, TNF- a
What does IL-7 increase proliferation of?
T cells, B cells, and NK cells
What other organs can haematopoiesis occur in mammals?
Thymus and spleen
