Unit 7 Flashcards
What does a complete blood count (CBC) entail, these test make up the____
Total red blood cell count
Packed cell volume (PCV)
Plasma protein concentration (TP)
Total WBC count
Hemoglobin concentration
Erythrocyte indices
Blood film evaluation (differential count, morphology, platelets)
These tests make up the hemogram
The total WBC count and differential count make up the ___
Leukogram
What is packed cell volume
The percentage of whole blood made up of erythrocytes
Used to evaluate hydration status, detect anemia or erythrocytosis
Also called hematocrit or microhematocrit
What are some sources of error for the PCV test
Failure to mix sample
Hemolysis
Insufficient centrifugation time/speed
Where do you measure a PCV hematocrit tube on a reader card
At the intersection of the top of the RBC mass and the Buffy coat
Answer in % (convert to 0.XX L/L)
Why would plasma be yellow
Liver disease
Hemolytic disorder
Nutritional supplements
Dehydration
Normal in plant/grain eaters due to carotenoids in feed
Why might plasma be pink
Hemolysis
Usually due to poor collection/handling
May be due to intravascular disorders
With affect other tests run
Why might plasma be white
Lipemia due to the presence of fat in the blood
Seen after eating
Rarely pathological
Interferes with many chemical tests
What is the Buffy coat layer
Contains WBCs and platelets
Has a white appearance
Will appear red when there is significant numbers of nucleated RBCs
Normally the thickness of a dime (1mm)
What is the significance of the PCV values
Used as a screening test for pathological conditions
Lower values: anemia (can be gasket low due to dilution of blood)
Higher values: polychromasia or dehydration
What is the plasma protein concentration
Gives an estimate of the total proteins concentration of a sample
Requires a refractometer (read and light/dark interface)
Lipemia and hemolysis will falsely elevate values
What is hemoglobin
Functional unit of the RBC (Carrie’s oxygen to tissues and CO2 to the lungs)
Made of a heme portion containing iron and the globin portion made up of pairs of amino acid chains
What are the two test methods for hemoglobin
Measures the quantity of hemoglobin per unit of blood volume
Automated analyzers or calculated by dividing PCV by 3
What are the erythrocyte indices
Also known as mean corpuscular values
Mean corpuscular volume (MCV)
Mean corpuscular hemoglobin (MCH)
Mean corpuscular hemoglobin concentration (MCHC)
Calculated by automated machine or manually
What tests must be run to calculate erythrocyte indices
PCV
Hemoglobin
Total red blood cell count
