WBC And Platelets Flashcards
When should differential cell count be done?
Always even if automated system is used
What abnormalities can be missed and not reported by automated systems for differential cell count
Nucleated RBC’s, toxic granulation, platelet clumps, target cells, hemo parasites
What does systemic evaluation avoid
Counting errors are missing important observations
Where should you observe a slide?
Feathered edge
True or false, you should scan entire slide for platelet clumps, large abnormal cells, microfilaria
True
How many cells should you count for a relative blood count?
A minimum of 100 RBC’s
Should you record the number of each WBC found on a relative blood count
Yes
What is an absolute value?
Relative percentages of cell type for account maybe misleading, especially if the WBC count is outside of normal range
How do you calculate an absolute value?
Multiply the total WBC count by the percentage of each type
What are the types of white blood cell cells?
Neutrophils, lymphocytes, monocytes, eosinophils, basophils
What is the most abundant WBC in mammals?
Neutrophils
What are the characteristics of neutrophils?
Nucleus is irregular and elongated, and true filaments between lobes are rare
What is the primary function of a neutral fill?
Phagocytosis – increased numbers indicate infection or inflammation
What are heterophils
Similar to neutrophils, but found in birds, reptiles, and some fish
What are band neutrophils?
Nucleus is horseshoe shaped with large round ends
Are band neutrophils common
No, rare
What’s the general rule of thumb for band neutrophils
If constriction makes up more than 1/3 the width of the nucleus, it is called a segmented neutrophil
What are the characteristics of eosinophils?
Container nucleus similar to neutrophils, but the chromatin is not usually clump as coarsely – shape and size very among species and within species, such as dogs
What are eosinophil characteristic specific to cats?
Eosinophilic granules are small, elongated, and numerous
What are eosinophil characteristic specific to equine?
Granules are large and round two oval and stain orange – red in color
What is the main function of eosinophils?
Modulation of immune system – capable of phagocytosis
When will you see an increased number of eosinophils?
Patient with allergies and parasitic infections
What are characteristics of basophils
Nuclei similar to monocytes, granules at same purple to blue black
Arebasophils common?
No, rare
Who are basophils more common in
Horses and cattle
What are characteristics of basophils specific to cats
Round granules and stain a bright lavender color
What is the main function of basophils
Mediation of the immune system
What are characteristics of lymphocytes?
Variety of sizes, slightly indented nuclei, coarsely clumped chromatin, bluish cytoplasm, medium to large, may have pink – purple granule in the cytoplasm
Where are lymphocytes most abundant?
Ruminants
True or false bovine lymphocytes have nuclear rings
True
What is a major function of lymphocytes?
Production of antibodies
What do increased numbers of lymphocytes indicate?
Viral infection
What are characteristics of monocytes?
Largest WBC, variability shape, nuclei, kidney being shaped or elongated and loaded, diffuse chromatin, cytoplasm is blue – gray color and may have vases and small fine pink granules
What is the main function of a monocyte?
Phagocytosis
What is an increased number of monocytes indicate
Chronic infection
What is Pelger-huet anomaly
Nuclear hyper, segmentation, congenital defect
Is nuclear hyper segmentation common?
Yes
What is the character characteristic of nuclear hyper segmentation?
Nuclei with five or more lobes
What can be a cause of nuclear hyper segmentation
Because of aging neutrophils or common in poodles with macrocytosis
What is toxic change?
Cytoplasmic basophilia, döhle bodies, toxic, granulation, gigantism
What causes toxic change?
Common disease – induce cytoplasm changes in neutrophils
What is toxic change associated with?
Inflammation, infection, drug toxicity
What can cause intracytoplasmic inclusions
Erlichia morulae
What is atypical lymphocytes?
Have basophilic cytoplasm and Cleaved nuclei
What are platelets?
Small cytoplasmic fragments shed from megakaryocytes in bow marrow
What are the methods for evaluation for platelets?
Platelet counts, platelet, indices, platelet function
What is the word for decreased platelets?
Thrombocytopenia
What is the word for increased platelets?
Thrombocytosis
What are the two options for platelet counts?
Automated hematology analyzer, manual
What can cause automated hematology analyzer to be inaccurate?
Clumping and overlap
What can be used for manual plate count?
Hemacytometer, chamber or tube containing pre-measured volume of diluting to blood
What kind of morphological change should you observe on a blood smear?
Aggregation, giant platelets
What are reticulated platelets?
Newly released platelets with high levels of RNA
What is a platelet estimate?
Indirect measurement of platelet numbers using the differential blood film, evaluated in the mono layer
How many microscopic fields should you count on a plate estimate?
At least 10
What is the normal number of platelets per field?
8 to 10
How do you calculate a platelet estimate?
Multiply the average number in 10 fields by 15,000 to 20,000
What is an alternate method for a platelet estimate?
Count the number of platelets per 100 WBC’s on a film then calculate the playlist estimate
What is the equation for the alternate method for platelet estimates?
Reticulocytes times WBC count divided by 100 leukocytes
What is MPV stand for?
Mean platelet volume
What is an MPV?
Mathematical average of the size of the individual platelets counted by the analyzer
What increases can you expect on an MPV?
Increase loss, cats have larger platelets, breed specific, exposure to EDTA
What does high MPV indicate?
Adequate bone marrow response
Does a low or normal MPV predict a low bone marrow response
No
What is a plateletcrit/thrombocrit
Measure of the percentage of the total blood volume compromised of platelets
How is plateletcrit determined?
multiplying the total platelet count by the mean, platelet volume, normally less than one percent of mammals
What is platelet distribution width?
Assesses the variation in the size of platelets
What are larger platelets seen with?
Thrombocytopenia
True or false platelet distribution width is always correlated with bone marrow response
False
What is a platelet function test test for?
Thrombopathia, alteration of platelet function
What is hemostasis?
The ability of the body systems to maintain the integrity of the blood and blood vessels
What does hemostasis involve
A number of complex pathways, platelets, coagulation factors
What is the mechanical phase?
Initiated when blood vessel is ruptured or torn, exposed sub, endothelium of vessel is charged, platelets attract to this charge surface
What does the mechanical phase require?
Von Willebrand factor
What is the chemical phase?
Coagulation, cascade, involves the number of factors, intrinsic and extrinsic pathways, results in a fibrin mesh or clot
What are the 12 clotting factors?
1 fibrinogen
2 prothrombin
3 tissue factor
4 calcium
5proaccelerin
6 none
7 proconvertin
8 anti-hemophilic factor
9 Christmas factor,plasma thromboplastin
10 Stuart factor
11 plasma thromboplastin antecedent
What factors are part of the intrinsic pathway
12, 11, 9, 8
What factors are apart of the extrinsic pathway
3,7
What factors are apart of the common pathway
10, 5, 2
What do coagulation test evaluate?
Specific phases of the coagulation process
True or false some coagulation test requires specialized instruments are preferred over manual because of variability of manual test
True
True or false coagulation test may be altered if platelet count is low
True
What does BMBT stand for?
Buccal mucosa bleeding time
What is BMBT?
Primary essay for detection of abnormalities in platelet function
What is the procedure for BMBT?
Tie upper lip back make a 1 mm deep incision black incision every five seconds until bleeding is stopped
What is a normal BMBT?
One to five minutes
What does prolonged bleeding indicate for BMBT
Deficiencies in Von Willebrand, factor, thrombocytopenia
What clotting factors can activated clotting time evaluate
All but seven
What is the method used for whole blood clotting time?
Lee – white method
What is more sensitive whole blood clotting time or activating clotting test
Activated clotting test
What does APTT stand for?
Activated partial thromboplastin time
What does aPTT evaluate?
Intrinsic and common clotting mechanisms
What is used for a PTT?
Coag dx analyzer
What can the coag dx analyzer test for
A variety of disorders in addition of heparin can effect results
What is a prothrombin time test
Evaluates intrinsic and common coagulation pathways
Is the prothrombin time test usually performed mechanically or on automated analyzer?
Automated analyzer
What is another name for prothrombin time test
One stage prothrombin time
What does OSPT stand for?
One stage prothrombin time
What is normal for an OSPT?
7 to 10 seconds
What does a prolonged OSPT indicate?
Severe liver disease, DIC, hereditary, or acquired deficiencies of any factor, vitamin K
What is a clot retraction test?
Evaluates platelet number and function in the intrinsic and extrinsic pathways
What is the procedure for a clot retraction test?
Examine blood tube every 60 minutes over 24 hour. Period class should be evident in 60 minutes and retracted in approximately four hours with marked retraction at 24 hours.
What is the von Willebrand factor?
Required for platelet adhesion
Who is prone to von Willebrand factor
Dobermans
What are coagulation factor essays due to?
Hereditary conditions, acquired conditions
What can bleeding disorders caused by?
Congenital defects, acquired defects
What are primary coagulation disorders of a result of?
Congenital defects
What are congenital or acquired defects?
Superficial petechia, ecchymotic hemorrhage, epistasis, melana, prolonged bleeding
Hemophilia a is most commonly caused by a deficiency of
Factor eight
Hemophilia D is most commonly caused by a deficiency of
Factor Nine
What is the most common inherited coagulation disorder of domestic animals?
Von Willebrand disease
What is von Willebrand’s disease?
Decrease in von Willebrand factor
How many types of von Willebrand disease are there?
Three
What types of von Willebrand disease are most severe?
Two and three
What can be a cause for thrombocytopenia?
Unknown or result from infectious disease or administration of certain medications, such as aspirin or acetaminophen
What is vitamin K deficiency?
Can be dietary or bile obstruction, and justice of rodenticides, or moldy, sweet clover
Vitamin K is required for
Synthesis an activation of factors 279 and 10
