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106 Cards in this Set
- Front
- Back
What is hemoglobin composed of? |
4 heme, 4 iron, 1 globin |
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What disorder does defect in heme synthesis lead to? |
porphyria |
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What is the function of the enzyme methemoglobin-cytochrome C reductase in red blood cell?
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to keep iron in ferrous state |
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Which hemoglobin has a 200 times greater binding capacity for the hemoglobin molecule than oxygen? |
carboxyhemoglobin |
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What product is formed when ferrous iron of hemoglobin is oxidized to the ferric state? |
methemoglobin |
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Which hemoglobin derivative causes irreversible changes in the red blood cells? |
sulfhemoglobin |
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Which of the following hemoglobins is NOT normally present in a normal adult? |
Hb-S |
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Which embryonic hemoglobin is normally found in newborns? |
Hb-F |
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What is the most abundant hemoglobin in a newborn? |
Hb-F |
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What is the molecular structure of hemoglobin S? |
valine replaces gultamic acid in the 6th position of the beta chain |
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Which of the following hemoglobins is insoluble under lowered oxygen tension? |
Hb-S |
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What laboratory test is used to confirm the specific diagnosis of sickle cell anemia? |
hemoglobin electrophoresis |
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In the solubility test for hemoglobin S, what is the reagent responsible for the reduction of hemoglobin molecule? |
sodium dithionite |
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In hemoglobin C, what replaces glutamic acid? |
lysine |
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Which red blood cell inclusion is characteristic of hemoglobin C disease? |
rod-shaped crystals |
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What is hemoglobin F composed of? |
2 alpha + 2 gamma chains |
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Which hemoglobin is resistant to alkali denaturation? |
Hb-F |
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What hemoglobins are differentiated by the Kleihauer-Betke technique? |
Hb-A1 from Hb-F |
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What is the order of migration of hemoglobins, from fastest to slowest, on cellulose acetate at pH 8.4? |
A1, F, S, C |
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Why is citrate agar used when abnormal hemoglobins are identified on cellulose acetate at pH 8.6? |
It separates hemoglobin S from hemoglobin D |
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The cyanmethemoglobin method measures all hemoglobin pigments EXCEPT which one? |
sulfhemoglobin |
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What is the diluent used in the cyanmethemoglobin method for the determination of hemoglobin? |
Drabkin's solution |
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What is the normal plasma hemoglobin concentration? |
2-3 mg/dL |
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Which plasma protein binds free hemoglobin? |
haptoglobin |
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Which one of the following statements concerning hemolytic anemia is false? |
The serum haptoglobin is increased |
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Myoglobin can be separated from hemoglobin by saturating the specimen with what reagent? |
ammonium sulfate |
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The hematocrit is also known as what term? |
packed red blood cell volume |
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The degree of packing of cells during centrifugation depends on? |
bore size of the microhematocrit tube |
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During examination of a spun hematocrit, in which layer are the white blood cells found? |
Buffy coat |
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When performing a microhematocrit, where should one read the percentage of packed red blood cell column from a microhematocrit reading device? |
below the buffy coat |
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An increase in the erythrocyte sedimentation rate can be the result of an increase in the quantity of what? |
fibrinogen |
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Which test is increased in acute infections? |
erythrocyte sedimentation rate |
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Which sources of error will falsely elevate the erythrocyte sedimentation rate? |
tilted tube macrocytes vibrations from a nearby centrifuge |
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What is the Westergren ESR reference range for males? |
0-15 mm/hr |
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A cerebrospinal fluid has 285 red blood cells counted in the 5 red blood cell squares after being diluted in a Unopette (1:100). What is the calculated red blood cell count/uL? |
1,425,000 |
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Any cell that passes through the aperture will momentarily increase the resistance of the electrical flow between the electrodes, generating a pulse. This is the basic principle of what? |
electrical impedance |
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What principle utilizes laminar flow and hydrodynamic focusing to characterize cell based on granularity and reflectivity? |
laser light scatter |
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Scatterplots are created using what? |
scatter volume conductivity |
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Both nucleated red blood cells and large platelets interfere with what parameters? |
WBC |
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Lyse-resistant red blood cells detected by automated hematology analyzers are seen in which clinical condition? |
sickle cell anemia |
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ON automated hematology analyzers, what will affect both the red blood cell count and the platelet count? |
schistocytes |
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The white blood cell count is 10.5. There are 5 nucleated red blood cells seen on the 100 cell differential. what is the corrected WBC count? |
10.0 |
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On automated hematology analyzers, hemoglobin determinations may be falsely elevated due to the presence of which one of the following interfering substances? |
lipemia |
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The following CBC results are obtained: WBC 6.5 RBC 1.69 HGB 9.1 HCT 22.8 MCV 135.0 MCH 53.8 MCHC 39.9 What is the most likely cause of these results? |
cold agglutinin |
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What may cause a falsely decreased platelet count? |
giant platelets platelet clumps platelet satellitosis |
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A leukocyte count greater than the linearity of the automated analyzer will falsely elevate what other CBC parameter? |
HGB |
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Fragile white blood cells seen in leukemia patients may cause pseudoleukopenia, which in turn may cause automated WBC and WBC estimate not to match. What action should be taken if this occurs? |
perform a manual WBC hematocytometer count |
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What is the dilution factor for performing a platelet count from a sodium citrate tube? |
1.1 |
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What is the formula for correcting a WBC count for the presence of nucleated red blood cell? |
(WBC X 100)/(nRBC + 100) |
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Smudge cells can cause the automated WBC and the WBC estimate not to match. What action can be taken to prevent this occurrence? |
add 22% bovine albumin to stabilize the WBC |
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If cryoglobulin causes WBC cellular interference, then what is the most appropriate action to take to resolve this interfering substance? |
incubate the specimen at 37 degrees C for 15 minutes |
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If a cold agglutinin is suspected to be causing erroneous results, then what is the most appropriate action to take before reporting the results? |
incubate the specimen at 37 degrees C for 15 minutes |
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After centrifuging a microhematocrit, the presence of lipemia is noted. What is the most appropriate correction action? |
perform a saline replacement procedure |
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What can produce a normal MCV but hypochromic red blood cells to appear on the peripheral blood smear? |
hyperglycemia |
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If a WBC count is performed on a 1:100 dilution and the number of cells counted in a total of 8 squares is 50, then what is the WBC count? |
6,250 |
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A blood smear shows 80 nucleated red blood cells per 100 leukocytes. The total leukocyte count is 18.0 x 109/L. What is the corrected WBC count? |
10.0 |
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What reagent is the fixative incorporated in the Wright's stain? |
methanol |
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How can the color of Wright-stained red blood cells be adjusted? |
adjusting the pH of the buffer |
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Malarial parasites in red blood cells are best demonstrated by which stain? |
Giemsa |
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Which RBC inclusions is NOT visible with Wright Stain? |
Heinz bodies |
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What is a stain for iron? |
Prussian blue |
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In which special cytochemical stain are homogeneously pink cells counted as positive? |
Kleihauer-Betke stain |
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What stains both nonspecific and specific granules in myelogenous cells? |
Sudan black B |
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IN the cytochemical stain for peroxidase, which cell stains negative? |
lymphocytes |
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The results on a leukemic patient are as follows: alpha-naphthol-AS-D-acetate esterase (NASDA) 3+ NASDA with sodium fluoride (NAF) 1+ These results are suggestive of which type of leukemia? |
AMML |
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In which leukemia are the blasts periodic acid-Schiff (PAS) stain positive? |
ALL |
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What is a stain for neutral lipids? |
Oil red O |
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Which stain is used to differentiate chronic myelogenous leukemia (CML) from a leukemoid reaction? |
leukocyte alkaline phosphatase |
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What stain is positive for hairy cell leukemia? |
acid phosphatase |
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What is the most reliable criterion for the estimation of a cell's age? |
nuclear chromatin |
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What is the last red blood cell precursor to retain the nucleus before it becomes an erythrocyte? |
metarubricyte |
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Which peripheral smear finding is consistent with reticulocytosis? |
polychormatophilia |
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what is the life span of an erythrocyte? |
3 months |
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what are indications of anemia? |
decreased RBC decreased HGB decreased HCT |
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What lab results are consistent with anemia? |
neonate: HGB 17.7 g/dL adult male: HGB 13.0 g/dL adult female: HGB 10.9 g/dL |
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The following results were obtained from a CBC specimen: WBC 10.3 X 10 9/L RBC 4.19 X 10 12/l HGB 9.9 g/dL HCT 27.0% MCV 95 fl MCH 33.2 pg MCHC 33.3% What is the most probable cause of these results? |
anemia |
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To calculate the mean corpuscular volume (MCV), what parameters must be known? |
RBC and HCT |
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Given the following lab results, what is the calculated MCH? RBC 3.01 x 10 12/L HGB 9.4 g/dL HCT 27.5% |
31.2 pg |
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What is the reference range for the mean corpuscular hemoglobin concentration? |
32%-36% |
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Which CBC parameter is a numerical expression of anisocytosis? |
RDW |
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What is the abnormal variation in the size of the erythrocytes known as? |
anisocytosis |
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Which determination is considered a reliable assessment of effective erythropoiesis in the bone marrow? |
reticulocyte count |
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To calculate the reticulocyte production index, other than the reticulocyte count (%), what other hematological parameter is needed? |
HCT |
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What are the erythrocytes with a diameter of 9 to 12 microns referred to as? |
macrocytes |
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What causes the red cell color of immature erythrocytes to appear polychromatophilic? |
residual RNA |
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What is abnormal variation in the shape of the erythrocytes known as? |
poikilocytosis |
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What does the peripheral blood smear show in a patient with iron deficiency anemia? |
microcytic, hypochromic cells with poikilocytosis present |
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What is a characteristic finding in the iron deficiency anemia? |
low ferritin, low iron, high TIBC, high transferrin |
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Which red blood cell shows a peripheral rim of hemoglobin with a dark staining central area? |
leftocyte |
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Target cells are present in what conditions? |
thalassemia myelofibrosis postsplenectomy |
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Basophilic stippling refers to what? |
aggregated RNA in the red blood cells |
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Which red cell blood inclusion is described as a threadlike oval or figure-eight-shaped? |
Cabot rings |
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What inclusion represents a remnant of nuclear DNA in a red blood cell? |
Howell-Jolly body |
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RNA remnants in red blood cells are visualized by which supravital stain? |
new methylene blue |
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What are red blood cells that contain iron-stained granules termed? |
siderocytes |
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Chronic blood loss can lead to what kind of anemia? |
iron deficiency anemia |
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Increased iron in the mitochondria of normoblasts is characteristic of which type of anemia? |
sideroblastic anemia |
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A peripheral blood smear from a patient with thalassemia would exhibit what? |
target cells, basophilic stippling, teardrop cells |
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What lab results are found in iron deficiency anemia but not in thalassemia? |
low serum iron and increased total iron binding capacity |
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A macrocytic anemia characteristically accompanies what? |
fish tapeworm infection vitamin B12 deficiency folate deficiency |
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What is NOT typically seen in the peripheral smear in megaloblastic anemia? |
spherocytes |
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What is the most characteristic change seen in the white blood cells of the megaloblastic anemia bone marrow? |
giant metamyelocytes |
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What is true of hereditary elliptocytosis? |
osmotic fragility and autohemolysis are usually normal |
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an increased osmotic fragility is observed in which type of hemolytic anemia? |
hereditary spherocytosis |
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What test is associated with the diagnosis of paroxysmal nocturnal hemoglobinuria? |
sugar water test sucrose hemolysis acidified serum test |
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What is the most common thalassemia in the United States? |
beta thalassemia minor |