Haematology Flashcards
1
Q
How much blood does an average adult have?
A
- Females = 4-5 L.
- Males = 5-6 L.
- 8% of adult weight.
2
Q
Loss of how much blood is life threatening? And what may be some causes of blood loss?
A
- Loss of 1L is life threatening. Some causes: - rapid/chronic loss. - decreased production. - increased destruction.
3
Q
What is blood composed of?
A
- 55% plasma.
- 45% blood cells (these are split into white blood cells, platelets and red blood cells).
4
Q
What is the blood plasma composed of?
A
- Plasma is the liquid portion of blood. It helps maintain pH at 7.3-7.4.
- Comprised of water 92%, protein 7% and other solutes (such as waste products/respiration gases) 1%.
5
Q
What are the white cells and platelets in blood?
A
- Platelets: fragments of cells involved in clotting.
- White cells: leukocytes (made up of neutrophils, basophils, monocytes, lymphocytes and eosinophils).
6
Q
What are the red cells in blood?
A
- There is 1 white cell for every 1-2 thousand red cells so lots.
- They make up the biggest proportion of blood after plasma.
7
Q
What are the functions of blood?
A
- transport: nutrients such as CO2, O2 and waste.
- regulates: water, temp, pH.
- communication: hormones.
- protects: antibodies, defensive cells/clots.
8
Q
What is haematopoiesis?
A
- Formation of blood.
9
Q
Where are the mature and immature elements of blood found?
A
- Mature: circulate.
- Immature: remain in bone marrow.
10
Q
How many new blood cells are produced daily?
A
10(11) - 10(12).
11
Q
Where do blood cells originate from?
A
- Haeomatopoetic stem cells (these cells are self renewing).
12
Q
What do we say about cells at the top of the differentiation tree? (I.e. The photo which starts with haeomatopoetic stem cell at top).
A
- Immature but huge potential for division.
13
Q
What do we say about cells at the bottom of the differentiation tree? (I.e. The photo which starts with haeomatopoetic stem cell at top).
A
- Mature but can’t divide.
14
Q
Where is the site of haematopoesis?
A
- first few months gestation: yolk sac.
- liver and spleen take over until 7 months.
- at 7 months bone marrow key in blood cell formation.
- during childhood and adulthood bone marrow only source of new blood cells in healthy individuals.
15
Q
Where does medullary haematopoesis take place?
A
- In bone marrow.
16
Q
Where does extramedullary haematopoesis take place?
A
- Outside bone marrow in liver and spleen.
- This only seems to happen when haeomatopoetic health is compromised.
- Memory and ability from when younger.
17
Q
What are the three types of blood vessels?
A
- Arteries.
- Capillaries.
- Veins.
18
Q
What do arteries do?
A
- Tend to carry blood away from the heart.
- They have thick walls and narrow lumen.
- They work under high pressure and have a steady flow of blood.
19
Q
What is the function of veins?
A
- They carry blood back to the heart.
- They have valves present to stop backflow.
- They therefore have a pulse flow.
20
Q
What is the function of capillaries?
A
- Connect arteries to veins.
- They are one cell thick allowing material to pass through.
- Smallest of the blood vessels.
21
Q
What is the largest filter of blood?
A
- The spleen: it has an important role in red cell integrity and also has immune roles.
22
Q
What do the kidneys do?
A
- Filter blood, remove waste and extra water.
23
Q
What does the liver do?
A
- Produces many proteins found in blood including clotting factors.
- It regulates levels of fats/amino acids/glucose and cleans blood of particles.
24
Q
What does the lymphatic system do?
A
- Circulates lymph around tissues which carries nutrients and removes waste.
- This plays a vital role in immune system.
25
What is an erythrocyte?
- A mature red blood cell.
26
What is a reticulocyte?
- Immature blood cell.
27
How many reticulocytes are found in blood?
- 1% in adults.
| - 3-6% neonates.
28
How can a reticulocyte count be carried out?
- They are identified by using a stain to identify ribosomal RNA.
29
Do RBCs have a nucleus?
- No, neither immature nor mature RBCs have one.
30
When will reticulocyte count increase?
- When erythropoiesis (production of RBCs) increases e.g. When someone heavily bleeding.
31
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.
32
What do mature RBCs do?
- Transfer CO2 and O2.
33
What is lifespan of mature RBCs?
- 120 days in circulation.
| - The spleen removes RBCs, about 1% broken down each day.
34
How much of a RBCs is filled with haemoglobin?
1/3.
35
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.
36
What is the main function of RBCs?
- To carry O2 to tissues and return CO2 from tissues to lungs.
37
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.
38
Which hormone regulates erythropoiesis and where is it produced?
- Erythropoietin and its produced in kidney.
39
What is the stimulant to release erythropoietin in the tissues of the kidney?
- Low oxygen tension in these tissues.
40
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.
41
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.
42
What is a neutrophil?
- 60-70% of leukocyte pop.
- Polymorphous nucleus (2-5 lobes).
- Phagocytose bacteria.
-
43
What is an eosinophil?
- 0.5-3% of leukocyte pop.
- Polymorphous nucleus (2 lobes).
- Bright red granules.
- Release toxins to defend against parasites.
-
44
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.
45
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.
46
What are the two primary organs where lymphocytes develop?
- Bone marrow and thymus.
47
Where do lymphocytes develop from?
- Haeomatopoetic stem cells which produce lymphoid stem cell.
48
Where are B cells and NK cells produced?
- In bone marrow.
49
What are the roles of B cells and NK cells?
- B cells: antibody mediated immunity.
| - NK cells: immunological surveillance.
50
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).
51
Where are T cells produced?
- Thymus.
52
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.
53
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.
54
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.
55
What is average white cell count in normal indiv
4-11x10(9).
56
Why would red cell count be increased or decreased?
- Increased: maybe because dehydration.
| - Decreased: someone with anaemia.
57
What does full blood count include?
- WCC.
- RBC count.
- Hb count.
- Platelet count.
58
Normal ranges for Hb ?
- Male: 13.5-17.5g/dl.
- Female: 11.5-15.5g/dl.
- Decrease indicates anaemia.
59
What is normal platelet count
- 150-400x10(9).
- Increase could be because myeloproliferative disorder affecting bone marrow, inflammation or infection.
- Decrease could be thrombocytopenia or leukaemia.
60
Which blood components can be transfused?
- RBCs - anaemic patients/bleeding patients.
- fresh frozen plasma - replace clotting factor.
- platelets - patients with low/dysfunctional platelets to prevent haemorrhage.
- white cells - rare. Usually given growth factor to stimulate production of own.
61
When blood transfused why is it usually leukodepleted?
- To protect the recipient as this will reduce the risk of some infections and transfusion reactions.
62
Where is ABO gene found?
- It's an autosomal gene found on chromosome 9.
| - A + B are dominant over O and A + B are co-dominant.
63
Which antibodies do people with blood groups A, B, AB and O produce?
- A produce anti B antibodies.
- B produce anti A antibodies.
- AB produce neither anti A or anti B antibodies.
- O produce both anti A and anti B antibodies.
64
Which blood type is the universal recipient and which is the universal donor?
- Universal donor: O.
| - Universal recipient: AB.
65
What is blood?
- it's a multifunctional tissue.
- it's considered a form of fluid connective tissue as has the same embryonic origin as other connective tissues (mesodermal).
- it connects the body systems together (O2, nutrients, waste disposal etc.).
66
What is erythropoiesis?
- process which produces red blood cells.
67
How do platelets stop bleeding?
- at site of injury there will be damage and bleeding.
- vasoconstriction occurs.
- platelet adhesion and aggregate and form a plug.
- this activates a clotting cascade.
- regeneration of fibrin strands form a mesh amount platelets.
68
What is bone marrow?
- it's a flexible tissue in the anterior of bones.
- in humans red blood cells are produced by cores of bone marrow in the heads of long bones in a process known as haematopoesis.
- bone marrow is also a key component of the lymphatic system, producing the lymphocytes that support the bodies immune system.
69
What is the thymus?
- primary lymphoid organ of the immune system.
- with the thymus t lymphocytes (t-cells) mature.
- located in front of the heart and behind the sternum.
- composed of two identical lobes.
- thymus provides an inductive environment for development of T cells from hematopoetic progenitor cells.
- largest and most active during neonatal and pre-adolescent periods.
70
What is the normal RBC count?
- males: 4.5-6.5x10(12)/L.
| - females: 3.9-5.6x10 (12)/L.
