JR Clinical haematology Flashcards
(124 cards)
1
Q
What is the main stimulus for red blood cell production?
A
Erythropoeitin
2
Q
What is erythropoeisis?
A
Production of RBCs
3
Q
What is an immature RBC/RBC precursor called?
A
Reticulocyte
4
Q
What type do you collect samples for haematology in?
A
EDTA
5
Q
Where are platelets most likely to be found in a blood smear?
A
Feathered edge
6
Q
Where are leukocytes more likely to be found in a blood smear?
A
On the lateral edges
7
Q
What is anisocytosis?
A
Variation in cell size
8
Q
What is polychromasia?
A
Variation in cell colour
9
Q
What colour are immature RBCs?
A
More purple/blue
10
Q
What size are immature RBCs?
A
Larger
11
Q
What can cause macrocytosis in RBCs?
A
Regeneration
FeLV if not changed colour
12
Q
What can cause microcytosis/hypochromasia in RBCs?
A
Iron deficiency
13
Q
When are RBCs nucleated?
A
Very immature erythroblasts - regeneration
Or birds and reptiles
14
Q
What are schistocytes?
A
RBC fragments - from shear injury
15
Q
What can cause schistocytes?
A
Splenic tumour
16
Q
What does poikilocytosis mean?
A
Abnormal RBC shape
17
Q
What are acanthocytes?
A
RBCs with large blunt ended projections
18
Q
What are keratocytes?
A
RBCs with cup shape missing
19
Q
What are blister cells?
A
RBCs with a blister on the surface
20
Q
What are echinocytes?
A
Crenated RBCs, thin projections
21
Q
What are spherocytes?
A
RBCs with no central pallor - no lighter centre where the concave shape is
22
Q
What are produced in oxidative injury of RBCs?
A
Heinz bodies
23
Q
What are codocytes?
A
RBCs that look like targets
24
Q
What are inclusion bodies?
A
Blobs in RBCs that are got from diseases
25
What does anaemia mean?
Reduction in RBC mass
26
What is erythrocytosis?
Increased concentration of erythrocytes/RBCs
27
What is relative erythrocytosis?
Erythrocytosis due to reduced blood volume
28
What is absolute erythrocytosis?
Erythrocytosis due to a genuine increase in RBC mass
29
How does the body identify anaemia?
In the kidney
30
What is the normal PCV of a dog?
35-55%
31
What is a regenerative anaemia?
Body is still making more RBCs to correct the anaemia
32
What are the two main causes of regenerative anaemias?
Haemolysis
| Haemorrhage
33
What is non-regenerative anaemia?
Body isnt producing any RBCs
34
What are the two main causes of non-regenerative anaemia?
Primary bone marrow disease
| Extra-bone marrow disease
35
What are the two type of reticulocyte?
Punctate reticulocytes
| Aggregate reticulocytes
36
What are the less mature type of reticulocyte?
Aggregate reticulocytes
37
What do aggregate reticulocytes look like?
Have large amounts of RNA in them - can be stained
38
What do punctate reticulocytes look like?
Small dots of RNA in them
39
What are punctate reticulocytes found in?
Only in cats
40
What are morphological features of regeneration?
Polychromasia
Anisocytosis
Nucleated RBCs
41
What does MCV mean in a blood test?
Size of blood cells - mean cell volume
42
What does MCH/C mean in a blood test?
Mean cell haemoglobin/concentration
| Mean volume of haemoglobin
43
What are the different levels of MCV?
Normocytic - normal
| Macro/microcytic - bigger or smaller
44
What are the different levels of MCH/C?
Hypochromic - indicates less haemoglobin
45
Where does normal extracellular haemolysis occur?
Mainly in the spleen
46
What causes normal extracellular haemolysis?
Phagocytosis of RBCs
47
What causes normal intracellular haemolysis?
RBC lysis due to membrane damage
48
What are some differentials for haemolysis?
Immune mediated haemolytic anaemia
Parasites
Oxidative damage
Neonatal isoerythrolysis
49
What parasite is most common in cats for causing haemolysis?
Mycoplasma haemofelis
50
What causes primary immune mediated haemolytic anaemia?
Autoimmune disease
51
What causes secondary immune mediated haemolytic anaemia?
Neoplastic or inflammatory disease
| Drugs
52
What is molecular mimicry?
Pathogenic protein looks similar to a protein on host RBC
53
What is a hapten?
A drug binds to surface of a RBC, immune system attacks hapten and local damage as well
54
What is a coombs test?
Evaluates for the presence of antibody or complement on the RBC surface
55
When do cats get neonatal isoerythrolysis?
When type A/AB kitted ingest colostrum from a type B (strong anti-A alloantibodies) queen
56
What are the two main causes of haemorrhage?
Coagulopathy - bleeding disorder
| Primary pathology
57
What is the most common non traumatic primary pathology for haemorrhage?
Ruptured splenic malignancy
58
What are signs of haemorrhage in GI tract?
Haematemesis
| Haematochezia
59
What is haematemesis?
Blood in vomit
60
What is haematochezia?
Fresh blood in faeces
61
What is the most common cause of primary coagulopathy?
Thrombocytopaenia - low platelet count
62
What is the most common causes of respiratory tract haemorrhage?
Angiostrongylus vasorum
| Rodenticide intoxication
63
What does a blood smear exam look like for non-regenerative anaemias?
Normocytic, normochromic
64
What is an extra bone marrow disease that causes non regenerative anaemia?
Chronic disease (eg. inflammatory) which impedes normal bone marrow function
65
What are some causes of primary bone marrow disease?
Leukaemia - infiltrates bone marrow
| Non-regen IMHA - immune system attacks bone marrow
66
What can be a normal cause of absolute erythrocytosis?
Certain breeds
Splenic contraction
Hyperthyroidism
67
How does erythrocytosis present?
Increase in blood viscosity
68
What can cause absolute erythrocytosis?
Altitude
Pulmonary disease
Right-left cardiac shunt - blood not going to lungs
Neoplastic proliferation of RBCs in the bone marrow
69
What is another word of absolute erythrocytosis?
Polycythaemia
70
How do you find the total WBC count from a blood smear?
Count all WBCs in 10 fields
| Calculate mean then x1.5
71
What is the circulating and marginating pool of neutrophils?
Circulating - in centre of vessels
| Marginating - roll along edge
72
What are immature neutrophils called?
Band cells - not segmented nuclei yet
73
What is left shift?
Neutrophils get more immature
74
What are the two types of left shift?
Regenerative
| Non-regenerative
75
What is regenerative left shift?
Left shift with neutrophilia - high neutrophils
76
What is non-regenerative left shift?
Left shift with normal or reduced neutrophil count - demand too high for body to keep up
77
What is toxic change to neutrophils?
Where the neutrophils start to look different
78
What cause toxic change to neutrophils?
Overwhelming demand for neutrophils
79
What can cause mild neutrophilia?
Stress
| Steroids
80
What can cause severe neutrophilia?
Inflammation
Pyrexia
etc.
81
What is the word for reduced neutrophils?
Neutropenia
82
What can cause neutropenia?
```
Sampling error - marginating
Overwhelming demand
Reduced production - drugs, infections etc.
Breed
Immune mediated destruction
```
83
What is a precursor of a macrophage?
Monocyte
84
What is the role of monocytes in immune response?
Antigen presentation
Cytokine production
Phagocytosis
85
What is the function of eosinophils?
Parasite defence
| Allergic responses
86
When is eosinophilia commonly seen?
As part of a stress leukogram
87
Where are lymphocytes produced?
Peripheral lymphoid tissues
88
What can cause lymphocytosis?
Age - young
Adrenaline
Mobilisation, increased demand
Leukaemia
89
What can cause lymphopenia?
Decreased production - immunodeficiency
| Redistribution - stress
90
What does a stress leukogram look like?
```
Increase WBC count
Increased neutrophils
Decreased lymphocytes
increased monocytes
decreased eosinophils
```
91
What is the dominant WBC type in cats/dogs/horses?
Neutrophils
92
What is the dominant WBC type in cattle?
Lymphocytes
93
What is haemostasis?
The process of preventing/stopping haemorrhage
94
What is primary haemostasis?
Forming the platelet plug
95
What is exposed to form the platelet plug?
Von Willebrand factor
96
What clotting factors are involved in the intrinsic pathway?
Factor 8, 9, 11, 12
97
What clotting factors are involved in the extrinsic pathway?
Tissue factor-VII complex
98
What clotting factors are involved in the common clotting pathway?
2 (thrombin), 10, fibrinogen and fibrin
99
What are the 3 pathways of the clotting cascade?
Intrinsic, extrinsic and common pathways
100
What is tertiary haemostasis?
Fibrinolysis
101
What do primary haemostatic disorders present as?
Petechial haemorrhages
| Mucosal bleeds
102
What are the 3 causes of primary haemostatic disorders?
Platelet disorders - thrombocytopenia
Von Willebrand disease
Vasculopathies - disease of blood vessels
103
What are the two different types of thrombocytopenia?
Immune mediated
| Consumptive level
104
What does immune mediated thrombocytopenia present as?
Usually absolute - no platelets as immune system is very thorough
105
What is consumptive level thrombocytopenia?
Platelets used up in lots of clots due to chronic disseminated intravascular coagulation
106
What does consumptive level thrombocytopenia present as?
Above 30x10^9 platelets - some platelets still left
107
Which breed of dog has altered platelets? What are they called?
King Charles Cavaliers - macroplatelets
108
How many platelets cause spontaneous haemorrhage?
<30x10^9/L
109
How many platelets cause induced haemorrhage?
<50x10^9/L
110
What are some causes of secondary immune mediated thrombocytopenia?
Infection eg. lepto, ehrlichia
Inflammatory/neoplastic systemic disease
Drug/toxin exposure
111
What is the most common cause of consumptive level thrombocytopenia?
Angiostrongylus vasorum
112
What can be a cause of primary coagulopathy without any thrombocytopenia?
von Willebrand disease
| ThrombocytoPATHia
113
What do secondary haemostatic disorders usually present as?
Major cavity bleeds
114
What causes secondary haemostatic disorders?
Clotting factor deficiency
115
What can cause clotting factor deficiencies?
Rodenticide intoxication
Angiostrongylus vasorum
Liver disease
Congenital - haemophilia
116
What test do you do to evaluate the extrinsic pathway of the clotting cascade?
PT - prothrombin time
117
What test do you do to evaluate the intrinsic pathway of the clotting cascade?
APTT - activated partial thromboplastin time
118
What does a prolonged PT suggest?
Extrinsic pathway problem, factor VII deficiency
| Or early combined deficiency
119
What is the main cause for extrinsic pathway problems?
Rodenticide intoxication
120
What does rodenticide intoxication cause?
Vitamin K inactivation/deficiency so cant make factors 2,7,9 or 10
121
What does a prolonged aPTT suggest?
Intrinsic pathway problem - factors 8,9,11,12 deficiency
122
What can cause intrinsic pathway problems?
Haemophilia
Liver failure
Angiostrongylus vasorum
DIC
123
What is DIC?
Disseminated intravascular coagulation - loss of clotting equilibrium, so consumes clotting factors in lots of little clots
124
What can cause both a prolonged PT and aPTT?
```
Vitamin K inactivation - rodenticide intoxication
Severe cholestasis
Liver failure
Angiostrongylus vasorum
DIC
```
