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Year 2 Semester 2 > Pathology > Flashcards

Flashcards in Pathology Deck (311)
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61

Do juvenile RBCs contain a nucleus?

No, but they do contain residual RNA and organelles

62

Where do reticulocytes migrate to?

Through transient apertures in endothelial cells into venous sinuses
Mature after 24 hours in blood

63

What morphological changes would we see with accelerated erythropoiesis?

Polychromasia, reticulocytosis

64

How is thrombopoietin production and clearance controlled?

Produced constantly, mainly by liver
Cleared by receptor-mediated uptake and destruction by platelets and megakaryocytes
However, interleukin 6 can increase TPO synthesis, independent of PLT numbers. Iron deficiency increases thrombopoiesis independently of TPO

65

What is MCV?

Mean corpuscular volume
Average erythrocyte size

66

What is MCHC?

Mean corpuscular Hb concentration
Average erythrocyte Hb concentration

67

What is MCH?

Mean corpuscular Hb
Average erythrocyte Hb per cell
Hb/RBC

68

What kind of anaemia is present if there is raised MCV?
What about reduced MCV?

Macrocytic anaemia (presence of larger cells which are usually juvenile RBCs-regenerative anaemia)
Microcytic anaemia (production of small erythrocytes, likely due to less haemoglobin available for erythropoiesis caused by iron deficiency)

69

What kind of anaemia is seen with reduced MCHC?

Hypochromic anaemia
Seen with regeneration (juvenile RBCS have lower Hb concentration) or iron deficiency

70

Which stains could you use to identify reticulocytes?

Routine Wright's
New Methylene Blue (stains RNA in ribosomes)

71

How do you calculate an absolute reticular count?

% retic x RBC (10^12/L) x 10

72

Which values for absolute reticular count in dogs and cats are a sign of non-regenerative anaemia?

Dog

73

What is the general term for abnormal RBC shape?

Poikilocytosis

74

What are the causes of regenerative anaemia?

Blood loss
Haemolysis (destruction of RBCs)

75

What are the causes of non-regenerative anaemia?

Decreased production
Lack of erythropoietin
Chronic inflammation

76

What is blood loss anaemia?

Proportional loss of all blood components (plasma and cells)
Can be acute or chronic
1. Initial decrease of blood volume, while proportion of plasma and cells is maintained. Hct and TP are unchanged
2. Within a few hours, activation of mechanisms to maintain volaemia -> influx of H2O from extracellular space -> dilution -> reduction of Hct and total protein
(Hct-ratio of volume of RBCs to a given volume of blood)

77

What are 2 causes of blood loss anaemia?

Haemorrhage
Blood-sucking parasites

78

Presence of spherocytes is strongly supportive of what?

Immune-mediated haemolytic anaemia
Macrophages partially phagocytise RBCs at the part of the membrane where the antigen-antibody complex is, causing loss of the discoid shape

79

What is agglutination?

Antibody-mediated clumping of RBCs
Stongly supportive of immune-mediated haemolytic anaemia

80

What is rouleaux formation?
What is it caused by?
In which species is it normal?

Stacking of RBCs due to increased plasma proteins coating RBCs
Caused by inflammation, cancer
Horses and cats

81

How can you differentiate between agglutination and rouleaux formation?

Saline agglutination test
Add 9 drops of saline to 1 drop of blood. Rouleaux formation will disappear, whereas agglutination persists

82

Which values for WBC in a single field are indicative of leucopenia and leucocytosis?

If 50 WBC in a single LPF10x field then likely leucocytosis

83

What do we look for at the tail end of a blood smear?

Platelets
Erythrocytes will be ruptured here

84

Give some causes of neutropenia

Severe inflammation
Bone marrow disease eg neoplasia, immune-mediated destruction of precursors
Overwhelming tissue demand
Reduced bone marrow production
Increased destruction of neutrophils

85

What is left shift?
What causes it?

Increased number of juvenile neutrophils (band or earlier stages) released from bone marrow
Due to severe acute inflammation
(Also bacterial infection, immune-mediated disease (e.g. IMHA))

86

What causes monocytosis? (monocyte count above upper reference limit)

Chronic inflammation / tissue damage / necrosis (usually combined with neutrophilia)
‘Stress leucogram’ or steroid administration (combined with neutrophilia, lymphopenia and eosinopenia)
Leukaemia

87

What causes lymphocytosis? (Lymphocyte count above upper reference limit)

Chronic inflammation
Adrenaline release in cats
Leukaemia

88

What causes lymphopenia? (lymphocyte count below upper reference limit)

Chronic inflammation (seen with neutrophilia)
Stress leucogram (effect of prolonged steroid in blood)
Viral disease eg FIV, FIP

89

What causes eosinophilia? (eosinophil count above upper reference limit)

Parasitic disease
Allergy

90

What is toxic change?
What is it due to?

Increased basophilia (blue colour) of the cytoplasm, blue granules (Dohle bodies), vacuoles (foamy appearance)
Due to reduced maturation time because of intense stimulation of myelopoiesis. Seen in overwhelming inflammation