Constituents of Blood and Haemopoiesis Flashcards
Blood is a specialised fluid - what is it composed of?
Cells suspended in a liquid known as plasma
What are the three main groups of cells found in blood? What are their rough functions?
Red blood cells to transport oxygen / white blood cells to fight infection / platelets to prevent bleeding
Blood cells are derived from what?
Haemopoietic stem cells
Where is blood produced in an embryo? Then where from 3rd-7th months?
Yolk sac, then liver and spleen, then bone marrow / spleen
Where is most blood produced at birth?
Bone marrow
What happens to the number of active sites of bone marrow from birth - maturity? By adult life, where is blood produced?
The number of active sites decreases / the axial skeleton only
What do stem cells have to do in order to continue producing blood cells?
Self-renew
Long term and short term haemopoietic stem cells differentiate into what?
Multipotent progenitors (MPP cells)
MPP cells can differentiate into what? What can determine this?
Myeloid and lymphoid progenitors / can be determined based on what the demand for each type is
What mature blood cell can come from both myeloid and lymphoid progenitors?
Dendritic cells
What mature cells differentiate from a myeloid progenitor?
Erythrocytes, platelets, granulocytes and macrophages
What mature cells differentiate from a lymphoid progenitor?
B, T and NK cells (i.e. lymphocytes)
What is erythropoiesis?
The development of red blood cells
What are the 4 main stages of erythropoiesis?
Pronormoblast, early/intermediate/late normoblast, reticulocyte, erythrocyte
What happens in erythropoiesis between the normoblast and reticulocyte stages?
Change from being within bone marrow to within the circulation / the nucleus is left behind
What is special about granulocytes? What are the 3 examples?
They contain granules which are easily visible on light microscopy / neutrophils, eosinophils and basophils
Which cell structure is this describing: segmented nucleus, neutral staining granules?
Neutrophils
Which cell structure is this describing: usually bi-lobed, bright orange/red granules?
Eosinophils
Which cell structure is this describing: infrequent in the circulation, large deep purple granules obscuring the nucleus?
Basophils
Which cell structure is this describing: large single nucleus, faintly staining granules, often vacuolated?
Monocytes
What is the function of neutrophils?
Phagocytose invaders and kill with granule contents
When are neutrophils increased?
By body stress e.g. infection, trauma, infarction
What are the functions of eosinophils?
Fight parasitic infections, involved in hypersensitivity
When are eosinophils increased?
In patients with allergic conditions
What are the functions of basophils?
Circulating version of mast cells, mediate hypersensitivity reactions
Granules found in basophils contain what?
Histamine
Monocytes circulate in the blood for how long? They then become what?
1 week / macrophages
What is the function of macrophages?
Phagocytose invaders, kill them and then present the antigen to lymphocytes
What are some examples of lymphocytes?
NK cells, T and B cells
What is the role of lymphocytes?
Cognate the response to infection
What are the main ways of recognising primitive precursors?
Immunophenotyping and bio-assays
How do we examine the peripheral blood?
Peripheral blood film and microscopic appearance
