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Flashcards in Introduction to haematology Deck (26)
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1
Q

Haemopoiesis

A

physiological development process that gives rise to the cellular components of blood

2
Q

Symmetric self-renewal

A

Resting stem cell; rely on them in the times of stress e.g. in injury

3
Q

Asymmetric self-renewal

A

giving rise to a differentiated cell and a stem cell – maintains stem cell pool

4
Q

What are the 2 blood lineages

A
  • myeloid and lymphoid
5
Q

Erythrocytes

A
  • 120 day lifespan
  • haemoglobin for oxygen
  • Low red cells = anaemia
  • High RC = polycythaemia
6
Q

Relative polycythaemia

A

plasma volume is reduced but cell number stays same. RBC are suspended in plasma = increased proportion

7
Q

Leukocytes (WBCs)

A
  • Immunity and host defence

- Granulocytes - have cytoplasmic granules

8
Q

Neutrophils

A
  • Phagocytes
  • Most common white cell -fairly short lived
  • Lobed nucleus - can be reduced in myelodysplasia and in other malignant diseases. Lobes can increase = hypersegmented – seen in b12 anaemia or folic acid deficient
  • Increased numbers = neutrophilia = seen in infection; particularly bacterial. Decreased numbers = neutropenia = seen in response to chemo/side effect of drugs
9
Q
  • Eosinophils
A
  • Nucleus is bilobed and granules are orange/red
  • Fights parasitic infections and allergies
  • Increased numbers = eosinophilia - occurs during use of aspirin
10
Q
  • Basophils
A
  • Rare cells – dark heavily granulated cells
  • Found in CML (chronic myeloid leukaemia)
  • Increased numbers = basophilia
11
Q

Monocytes

A
  • Phagocytic and antigen presenting cells
  • Can migrate to tissues and are then identified as macrophages or histiocytes
  • Increased numbers = monocytosis caused by diseases like TB
12
Q

Platelets

A
  • Derived from bone marrow megakaryocytes (have many nuclei)

- form part of the blood clotting system, Aggregate to plug holes in damaged blood vessels

13
Q

Lymphocytes

A
  • Increased numbers = lymphocytosis – e.g. atypical in glandular fever, CLL (accumulation of mature looking lymphocytes)
  • Decreased numbers = lymphopenia – e.g. in bone marrow transplant and infection
14
Q

Natural killer cells

A
  • Innate immune system – don’t rely on human leukocyte antigen system
  • Larger granular lymphocytes
  • Recognise “non-self”
15
Q

T lymphocytes

A
  • Adaptive immune system – dependent on HLA system
  • Multiple sub-types
  • Involved in cell-mediated immunity
  • Interact with B cells and macrophages- Regulate immune responses
16
Q

B lymphocytes

A
  • Adaptive immune system
  • Rearrange IG genes to enable antigen specific antibody production
  • Humoral immunity – make antibodies
  • Increase numbers of plasma cells = plasmacytosis
17
Q

Full Blood Count

A
  • taken in EDTA anticoagulated blood bottle
    Measures:
  • Haemoglobin concentration
  • Red cell parameters (MCV = mean cell volume and MCH = mean cell haemoglobin content)
  • White cell count (WCC)
  • Platelet count
18
Q

When interpreting FBC be alert of:

A
  • Technical problems e.g. thrombocytopenia
  • Abnormal results
  • Serious urgent abnormalities
19
Q

Blood film

A
  • blood on film, get a tail of blood cells that separate to look down microscope
20
Q

Coagulation screen

A
  • Measures time taken for a clot to form when plasma is mixed with specific reagents
  • PT = prothrombin time
  • APTT = activated partial thromboplastin time
  • TT = thrombin time
21
Q

Bone Marrow Aspirate and Trephine

A
  • Aspirate = liquid marrow aspirated from posterior iliac crest – looks at the cells in them
  • Trephine = core biopsy is taken to look at bone marrow architecture
22
Q

Anaemias

A
  • Defined as Hb below 130 (male) or 115 (female)
23
Q

Microcytic hypochromic anaemia

A
  • Microcytic = small red cells - MCV < 80
  • Hypochromic = low Hb per cell – MCH < 27 – cells look paler than usual
  • Causes = iron deficiency, thalassaemia, chronic disease
24
Q

Normocytic normochromic anaemia

A
  • Normal cell size and normal Hb per cell – MCV = 80-95, MCH > 27
  • Causes = haemolytic anaemia, chronic disease, acute blood loss, bone marrow failure
25
Q

Macrocytic anaemia

A
  • MCV > 95 but normal Hb per cell = MCH > 27
    2 types:
  • Megaloblastic = inadequate development of nucleus – causes = vitamin B12 deficiency or folate deficiency
  • Non-megaloblastic = big cells but no nuclear dysmorphia - causes = alcohol, myelodysplasia
26
Q

Sickle cell =

A

associated with haemolysis and thrombosis

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