Flashcards in Haematology Deck (70)
What do mature RBCs look like?
- These are known as erythrocytes.
- They are smaller than reticulocytes.
- They are found in circulating blood.
- Flexible bi-concave discs - no nucleus/organelles, uniform in size and shape.
- 8uM in diameter.
What do mature RBCs do?
- Transfer CO2 and O2.
What is lifespan of mature RBCs?
- 120 days in circulation.
- The spleen removes RBCs, about 1% broken down each day.
How much of a RBCs is filled with haemoglobin?
What is the normal range of mature RBCs in adults?
- Male: 4.5-6.5 x 10(12)/L.
- Female: 3.9-5.6 x 10(12)/L.
What is the main function of RBCs?
- To carry O2 to tissues and return CO2 from tissues to lungs.
What is haemoglobin?
- It's a tetrameric protein.
- Contains two alpha and two beta globin chains and each has its own haem molecule.
- Each haemoglobin molecule can carry up to four oxygen molecules.
Which hormone regulates erythropoiesis and where is it produced?
- Erythropoietin and its produced in kidney.
What is the stimulant to release erythropoietin in the tissues of the kidney?
- Low oxygen tension in these tissues.
What are platelets?
- Also known as thrombocytes.
- Megakaryocytes are platelet forming cells. They produce about 1000-5000 platelets each. Platelets contain granules.
- Life span can be a few days to a lifetime.
- They are 10-15x bigger than RBCs.
- They are the largest cells in bone marrow.
- They are involved in clotting. Once in blood they last about 7-10 days. - Normal range is 150-400x10(9)/L.
What are white blood cells?
- Also known as leukocytes.
- Nucleated large cells.
- Involved in defence and immunity. In health individual 4-11x10(9)/L.
- Composed of phagocytes (granulocytes such as neutrophils) and immunocytes (lymphocytes).
- Only mature cells found in blood, immature types are found in bone marrow and lymph nodes.
What is a neutrophil?
- 60-70% of leukocyte pop.
- Polymorphous nucleus (2-5 lobes).
- Phagocytose bacteria.
What is an eosinophil?
- 0.5-3% of leukocyte pop.
- Polymorphous nucleus (2 lobes).
- Bright red granules.
- Release toxins to defend against parasites.
What is a basophil?
- Rare in blood.
- 0.01-0.3% leukocyte pop.
- Polymorphous nucleus (2 lobes) -can't see once stained.
- Involved in inflammatory reactions.
- Produce heparin to prevent clotting.
- Important in parasite infections.
- Few h - few days life span.
What is a monocyte?
- 3-8% of leukocyte pop.
- Nucleus: kidney shaped.
- Can develop into macrophages or dendritic cells.
- Respond to inflammation signals.
- Life span 1-5 days.
What are the two primary organs where lymphocytes develop?
- Bone marrow and thymus.
Where do lymphocytes develop from?
- Haeomatopoetic stem cells which produce lymphoid stem cell.
Where are B cells and NK cells produced?
- In bone marrow.
What are the roles of B cells and NK cells?
- B cells: antibody mediated immunity.
- NK cells: immunological surveillance.
What is blood?
- Multifactorial tissue. Considered a form of fluid connective tissue (due to same embryonic origin as other connective tissues i.e. Mesodermal).
- Connects body systems together (CO2, nutrients, waste disposal).
Where are T cells produced?
What are lymphocytes?
- Make up 20-30% of leukocyte population.
- Round nucleus.
- Consist of b, t and NK cells.
- B: form antibodies.
- T: prepare foreign proteins for phagocytosis.
- NK: destroy infected cells and tumour cells.
- Life span few days - life time.
What can blood be used to detect?
- Used to detect haematology diseases.
- Haematological changes in other diseases.
- Monitor side effects of treatment e.g. Chemo, anti inflammatory and psychotic drug treatments.
If you have a high or low leukocyte count what can this mean?
- High: infection, inflammation, leukaemia.
- Low: medications, severe infection, autoimmune disease, BM failure.
What is average white cell count in normal indiv
Why would red cell count be increased or decreased?
- Increased: maybe because dehydration.
- Decreased: someone with anaemia.
What does full blood count include?
- RBC count.
- Hb count.
- Platelet count.
Normal ranges for Hb ?
- Male: 13.5-17.5g/dl.
- Female: 11.5-15.5g/dl.
- Decrease indicates anaemia.
What is normal platelet count
- Increase could be because myeloproliferative disorder affecting bone marrow, inflammation or infection.
- Decrease could be thrombocytopenia or leukaemia.