Prac 2: Haematology Flashcards
Where do the platelets end up in the haematocrit tube?
At the top of the buffy coat
Is it plasma or serum in a haematocrit tube?
Plasma
How much does 1% buffy coat equal in terms of white cell count?
First 1% is 10 x 10^9, and every percent after is 20 x 10^9
When do you need a conversion chart for plasma protein?
If scale only shows refractive index
After haemorrhage, by what time does PCV reach its lowest point?
24 hours
Is PCV and protein are both low, how long ago was the haemorrhage?
Ongoing or less than 4 hours
Which conditions cause hyperglobulinaemia?
Myeloma, some B cell lymphomas, some infectious diseases
What blood should you use to make a smear?
Whole blood or EDTA
Why should you not use heparinised blood for a smear?
Different staining
How long should you mix the sample before making a smear?
60 seconds
When should you hold the spreader slide at a greater angle?
If anaemic
How much of the slide should the blood film take up?
2/3
Where will leucocytes end up in a poor slide?
Ends and sides of the spread
Which species has no central pallor on RBCs?
Cats
What is platelet size like in cats compared to dogs?
Variable
Which species has no polychromatophils?
Horses and cows
How common are Rouleaux in horses?
Very
In which species can Dohle bodies be normal?
Cats
In which species can acanthocytes be normal?
Cows, dogs
What are RBCs like in goats?
Small, poikilocytosis common
What shape are red cells in Alpaca?
Oval
In which species are echinocytes common?
Pigs
Which species has high numbers of polychromatophils?
Mouse
What do rabbit neutrophils look like?
Contain red granules (heterophils)
Which stain for reticulocytes?
Methylene blue
Which kind of reticulocytes in dogs and large animals?
Aggregate
Which kind of reticulocytes in cats?
Aggregate and punctate
What usually causes crenation?
Excess EDTA or uraemia
What condition can Rouleax be associated with?
Hyperglobulinaemia
In which species can low numbers of Howell-Jolly bodies be normal?
Cats (and dogs and horses)
In what conditions do Howell-Jolly bodies increase?
Regenerative anaemias and splenectomy
In what conditions are target cells seen?
Regenerative anaemias, iron deficiency, liver dysfunction
Why do target cells have increased membrane:Hb ratio?
Low Hb content
What causes basophilic stippling of cells?
Ribosomes
Which species and condition usually causes basophilic stippling?
Regenerative anaemias in ruminants
What conditions should you consider if basophilic stippling but no polychromasia/reticulocytosis in ruminants?
Lead poisoning
Where are RBC clumps sequestered?
Liver and spleen
Why does Heinz bodies form?
Oxidation of SH groups in the globin chain so Hb precipitate attached to inside of membrane
What % of Heinz bodies is normal in cats?
5-10%
What conditions can cause Heinz bodies in cats?
Diabetes, hyperthyroidism, hepatic lipidosis
WHat causes a spherocyte?
BC membrane partially phagocytosed by macrophage so can’t maintain biconcave shape
WHich are the only species where you can see spherocytes?
Dogs (due to central pallor)
Where in the smear are spherocytes found?
At the tail
Which four conditions can be assocaited with spherocytosis?
IMHA, PFK deficiency, zinc toxicity, envenomation
Which disorders can cause acanthocytes?
Those causing erythrocyte fragmentation and liver disease
Which disorders cause schistocytes?
Those causing RBC fragmentation
What does Babesia look like on a blood smear?
Paired intracellular
What is sensitivity like for Babesia on a blood smear?
Low
What does mycoplasma look like on a blood smear?
Small coccoid on edge of or within cells, sometimes in chains
In which conditions do you see right shift?
Chronic inflamm or steroids
Why do steroids cause right shift?
Prevent adhesions and migration of neutrophils into tissue
How old are right shifted cells?
Old
What proportion of the maximal diameter of the nucleus is the indentation of the nucleus of band neutrophils?
1/3
What are Dohle bodies made of?
Blue aggregates of RNA
WHich are the only neutrophils to undergo toxic changes?
Those in the peripheral blood
What kind of diseases usually cause toxic change?
Infectious disease associated with accelerated granulopoiesis
What are some examples of toxic changes?
Dohle bodies, vacuolation, granulation, giant neutrophils, doughnut nuclei
What does Ehrlichia look like on blood smear?
Morulae within neutrophil cytoplasm
Which species has rod shaped cytoplasmic granules in eosinophils?
Cats
How big are reactive lymphocytes?
Same size or larger than neutrophils
How do you differentiated acute lymphoid and myeloid leukaemias?
Flow cytometry as cells look similar
What do lymphocytes in acute leukaemias look like?
Large (larger than a neutrophil), and large prominent nucleoli
What do eosinophils look like in horses?
Large blobs in the cytoplasm
