Introduction to haematology Flashcards
What is the term used to describe the production of red blood cells?
Haemopoiesis/haematopoiesis
Where does haematopoiesis occur in embryos?
Yolk sac then liver then marrow 3rd to 7th month = spleen
Where does haematopoeisis occur at birth?
Mostly bone marrow liver and spleen when needed
Where does haematopoeisis occur from birth to maturity?
Number of active sites in bone marrow decreases but retain ability for haematopoiesis
Where does haematopoeisis occur in adults?
Bone marrow of skull, ribs, sternum, pelvis, proximal ends of femur
Are the majority of stem cells actively dividing or in a quiescent state?
Quiescent state
Name the primary haemaopoietic stem cell
LT-HSC = long term-haematopoietic stem cell
What can multipotent progenitor cells (MPP) divide into?
Either CMP (common myeloid progenitor) or CLP (common lymphoid progenitor)
What can common myeloid progenitor cells divide into?
Megakaryocyte-erythrocyte progenitor (MEP) or granulocyte-monocyte progenitor (GMP)
What can common lymphoid progenitor cells divide into?
Pro-T cell, Pro-NK cell (NK=natural killer) or Pro-B cell
What do pro-T, pro-B and pro-NK cells divide into respectively?
T-cells, B-cells an natural killer cells
What can MEP cells divide into/
Either erythrocytes or platelets
What can GMP cells divide into?
Granulocytes or macrophages
What cell type can both CMP and CLP cells divide into and what does this cell type differentiate into?
Pro-DC which becomes a dendritic cell
What are immature red blood cells called?
Reticulocytes
Why are granulocytes named granulocytes?
They contain granules that are easily visible on light microscopy
How are the different types of granulocyte named?
Based on their uptake of stains (eosin and basic dyes) i.e. basophils take up basic dyes, eosinophils take up eosina and neutrophils have neutral uptake
Neutrophils are polymorphs, what does this mean?
They have a segmented nucleus
What is the function of neutrophils?
Phagocytose invaders, kill with granule contents and die in the process, attract other cells, increased by body stress e.g. infection, trauma. They have a short life in circulation
Describe the structure of eosinophils
Usually bi-lobed, bright orange/red granules
What is the function of eosinophils?
Fight parasitic infections, involved in hypersensitivity (allergy), often elevated in patients with allergic conditions e.g. asthma
Describe the structure of basophils
Large deep purple granules obscuring nucleus (they are infrequent in the circulation)
What is the function of basophils?
Circulating version of tissue mast cell, mediates hypersensitivity reactions, Fc Receptors bind IgE, granules contain histamine!
Describe the structure of monocytes
Large single nucleus, faintly staining granules, often vacuolated
What is the function of monocytes?
Circulate for a week then enter the tissues to become macrophages, phagocytose invaders, attract other cells. More long lived than neutrophils
Describe the structure of lymphocytes
Mature - small with condensed nucleus and rim of cytoplasm Activated - large with plentiful blue cytoplasm extending round neighbouring red cells on the film, nucleus has more open structure
What is the function of lymphocytes?
Respond to infection - brains of the immune system
How do you identify the more primitive blood cell precursors?
Immunophenotyping and bio-assays
What is a common site for bone marrow aspiration and biopsy?
Posterior iliac crests
