Flashcards in Haemopoiesis & Blood Deck (12):
What are the 3 main components of blood?
1. Plasma - 55%
2. Erythrocytes - 45%
3. Buffy coat (leukocytes and platelets) - <1%
What is blood plasma made up of?
Mostly water but also contains:
- proteins, e.g. Serum albumins, immunoglobulins and fibrinogen
- clotting factors
What is the role of erythrocytes and how is their structure adapted to their function?
Transport of oxygen via haemoglobin - requires iron (without this - anaemia).
- No nucleus or organelles - maximises space for transport of Hb/O2/CO2.
- Biconcave shape with a flexible lipid bilayer - allows passage through thin capillaries.
What are leukocytes?
1. Cells of the innate immune system:
- Detect organisms via chemotaxis and kill pathogens by engulfing them and using cytotoxic contents of granules.
- Monocytes/macrophages act as APCs to lymphocytes to stimulate the adaptive IS.
2. Cells of the adaptive immune system - lymphocytes:
~ B cells: produce antibodies once activated by foreign antigen
~ T cells: recognise foreign antigen and activate other cells (e.g. Neutrophils, monocytes and B cells) /and/ directly kill infected/cancer cells /and/ can inhibit the immune response.
~ NK cells: stimulate infected/cancer cells to apoptose.
What does the cellular theory suggest?
Cells originate from other cells.
Which cell type are blood cells derived from?
- Haematopoietic stem cells
- Divide to replace themselves and produce progenitor cells giving rise to 3 cell lineages
Which 3 cell lineages do HCS give rise to?
1. Erythroid: produces RBCs and megakaryocytes (shed fragments that form platelets)
2. Myeloid: produces phagocytic and inflammatory cells of innate immunity
3. Lymphoid: produces B and T cells and NK cells
Give examples of hormones that stimulate the formation of specific blood cells.
- Thrombopoietin: stimulates megakaryocyte and thus platelet production.
- Erythropoietin: stimulates erythrocyte production.
- Interleukin: stimulate lymphocyte ( B and T cell) production.
What can be used to alter haematopoiesis in patients?
- Recombinant growth hormones
- E.g. Promacta increases platelet production in ITP
What are the different types of cell and plasma transfusions?
- Blood units
- Platelets only
- FFP (frozen)
- Cryoprecipitate (frozen)
- Stem cells via bone marrow/stem cell transplantation
Which names are used to designate high blood cell counts?
- Polycythemia = high erythrocytes
- Leukaemia = high leukocytes
- Thrombocythemia = high platelets