Ch 14 Testing Flashcards
What does a hemocytometer do?
counting chamber for manual cell counts.
What is the rule of 3
hematocrit count is 3 times the hgb value
What are common sources of error in manual cell counts
not cleaning hemocytometer, dust and fingerprints. could be overfilled or underfilled, not allowing cells to settle
What is hematocrit
volume of packed RBCs in a given volume of whole blood
What is microhematocrit
procedure when filling capillary tubes with EDTA blood and allowing it to seperate the RBCs from plasma and WBCs
What are the RBC indicies
mean corpuscular volume (MCV)
Mean corpuscular hemoglobin (MCH)
Mean corpuscular hemoglobin concentration (MCHC)
How long can a reticulocyte be in peripheral blood.
1 day
What is an ESR
erythrocyte sedimentation rate: distance in mm for RBCs to settle in 1 hour
When is ESR needed
if there is swelling or inflammation
What fluid is usually used for manual cell counts
body fluid
Why are reticulocyte counts done?
to know if BM is compensating for low RBC count
What does it mean if RBCs settle too fast in an ESR
there is likely inflammation because too many + charged proteins makes it settle faster
What is counted in a hemocytometer?
WBCs and RBCs
Name the layers of a microhematocrit in order
Plasma, buffy coat (WBCs and platelets), RBCs and clay
Name the layers of a microhematocrit in order
Plasma, buffy coat (WBCs and platelets), RBCs and clay
What are the three values reported for a reticulocyte count
% of reticulocytes
absolute reticulocyte count
corrected reticulocyte count
What is the formula for the % of reticulocytes
reticulocytes / 1000 RBCs x 100
What is the formula for the absolute reticulocyte count
actual reticulocyte # in 1L of whole blood
What is the formula for the corrected reticulocyte count
% reticulocytes (%hct/45)
