HEMA 1 QUIZ 2 Flashcards
Insufficient centrifugation will result in:
A. A false increase in hematocrit (Hct) value
B. A false decrease in Hct value
C. No effect on Hct value
D. All of these options, depending on the patient
A false increase in hematocrit (Hct) value
Variation in red cell size observed on the peripheral smear is described as
A. Anisocytosis
B. Hypochromia
C. Poikilocytosis
D. Pleocytosis
Anisocytosis
Mean cell volume (MCV) is calculated using the following formula:
A. (Hgb ÷ RBC) × 10
B. (Hct ÷ RBC) × 10
C. (Hct ÷ Hgb) × 100
D. (Hgb ÷ RBC) × 100
(Hct ÷ RBC) × 10
Calculate the mean cell hemoglobin concentration (MCHC) using the following values
Hgb: 15 g/dL (150 g/L)
RBC: 4.50 × 106/μL (4.50 × 1012/L)
Hct: 47 mL/dL (0.47)
A. 9.5% (.095)
B. 10.4% (.104)
C. 31.9% (.319)
D. 33.3% (.333)
31.9% (.319)
A manual white blood cell (WBC) count was performed. A total of 36 cells were counted in all 9-mm2 squares of a Neubauer-ruled hemacytometer. A 1:10 dilution was used. What is the WBC count?
A. 0.4 × 109/L
B. 2.5 × 109/L
C. 4.0 × 109/L
D. 8.0 × 109/L
0.4 × 109/L
A 7.0-mL ethylenediaminetetraacetic acid (EDTA) tube is received in the laboratory containing only 2.0 mL of blood. If the laboratory is using manual techniques, which of the following tests will most likely be erroneous?
A. RBC count
B. Hemoglobin (Hgb)
C. Hct
D. WBC count
Hct
A 1:200 dilution of a patient’s sample was made and 336 red cells were counted in an area of 0.2 mm2. What is the RBC count?
A. 1.68 × 1012/L
B. 3.36 × 1012/L
C. 4.47 × 1012/L
D. 6.66 × 1012/L
3.36 × 1012/L
If a patient has a reticulocyte count of 7% and an Hct of 20%, what is the corrected reticulocyte count?
A. 1.4%
B. 3.1%
C. 3.5%
D. 14%
3.1%
A decreased osmotic fragility test would be associated with which of the following conditions?
A. Sickle cell anemia
B. Hereditary spherocytosis
C. Hemolytic disease of the newborn
D. Acquired hemolytic anemia
Sickle cell anemia
What effect would using a buffer at pH 6.0 have on a Wright’s-stained smear?
A. Red cells would be stained too pink
B. White cell cytoplasm would be stained too blue
C. Red cells would be stained too blue
D. Red cells would lyse on the slide
Red cells would be stained too pink
Which of the following erythrocyte inclusions can be visualized with supravital stain but cannot be detected on a Wright’s-stained blood smear?
A. Basophilic stippling
B. Heinz bodies
C. Howell–Jolly bodies
D. Siderotic granules
Heinz bodies
A falsely elevated Hct is obtained. Which of the following calculated values will not be affected?
A. MCV
B. MCH
C. MCHC
D. Red cell distribution width (RDW)
MCH
SITUATION: RBC indices obtained on an anemic patient are as follows: MCV 88 μm3 (fL); MCH 30 pg; MCHC 34% (.340). The RBCs on the peripheral smear would appear:
A. Microcytic, hypochromic
B. Microcytic, normochromic
C. Normocytic, normochromic
D. Normocytic, hypochromic
Normocytic, normochromic
All of the following factors may influence the erythrocyte sedimentation rate (ESR) except:
A. Blood drawn into a sodium citrate tube
B. Anisocytosis, poikilocytosis
C. Plasma proteins
D. Caliber of the tube
Blood drawn into a sodium citrate tube
The Coulter principle for counting of cells is based upon the fact that:
A. Isotonic solutions conduct electricity better than cells do
B. Conductivity varies proportionally to the numberof cells
C. Cells conduct electricity better than saline does
D. Isotonic solutions cannot conduct electricity
Isotonic solutions conduct electricity better than cells do