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
A correction is necessary for WBC counts when nucleated RBCs are seen on the peripheral smear because:
A. The WBC count would be falsely lower
B. The RBC count is too low
C. Nucleated RBCs are counted as leukocytes
D. Nucleated RBCs are confused with giant platelets
Nucleated RBCs are counted as leukocytes
Using an electronic cell counter analyzer, an increased RDW should correlate with:
A. Spherocytosis
B. Anisocytosis
C. Leukocytosis
D. Presence of NRBCs
Anisocytosis
Given the following values, which set of red blood cell indices suggests spherocytosis?
A. MCV 76 μm3 MCH 19.9 pg MCHC 28.5%
B. MCV 90 μm3 MCH 30.5 pg MCHC 32.5%
C. MCV 80 μm3 MCH 36.5 pg MCHC 39.0%
D. MCV 81 μm3 MCH 29.0 pg MCHC 34.8%
MCV 80 μm3 MCH 36.5 pg MCHC 39.0%
Which of the following results on an automated differential suggests that a peripheral smear should be reviewed manually?
A. Segs = 70%
B. Band = 6%
C. Mono = 15%
D. Eos = 2%
Mono = 15%
Which of the following Hgb configurations is characteristic of Hgb H?
A. 4 Beta
B. 4 gamma
C. A 2 – y 2
D. A 2 – B 2
4 Beta
Autoagglutination of red cells at room temperature can cause which of the following abnormal test results?
A. Low RBC count
B. High MCV
C. Low hematocrit
D. All of these options
All of these options
Which of the following is not associated with hereditary spherocytosis?
A. Increased osmotic fragility
B. An MCHC greater than 36%
C. Intravascular hemolysis
D. Extravascular hemolysis
Intravascular hemolysis
The anemia seen in sickle cell disease is usually:
A. Microcytic, normochromic
B. Microcytic, hypochromic
C. Normocytic, normochromic
D. Normocytic, hypochromic
Normocytic, normochromic
Select the amino acid substitution that is responsible for sickle cell anemia.
*
1/1
A. Lysine is substituted for glutamic acid at the sixth position of the a-chain
B. Valine is substituted for glutamic acid at the sixth position of the b-chain
C. Valine is substituted for glutamic acid at the sixth position of the a-chain
D. Glutamine is substituted for glutamic acid at the sixth position of the B-chain
Valine is substituted for glutamic acid at the sixth position of the b-chain
All of the following are usually found in Hgb C disease except:
A. bar of gold morphology
B. Target cells
C. Lysine substituted for glutamic acid at the sixth position of the B-chain
D. Fast mobility of Hgb C at pH 8.6
Fast mobility of Hgb C at pH 8.6
Which of the following hemoglobins migrates to the same position as Hgb A2 at pH 8.6?
A. Hgb H
B. Hgb F
C. Hgb C
D. Hgb S
Hgb C
Which of the following electrophoretic results is consistent with a diagnosis of sickle cell trait?
A. Hgb A: 40% Hgb S: 35% Hgb F: 5%
B. Hgb A: 60% Hgb S: 40% Hgb A2: 2%
C. Hgb A: 0% Hgb A2: 5% Hgb F: 95%
D. Hgb A: 80% Hgb S: 10% Hgb A2: 10%
Hgb A: 60% Hgb S: 40% Hgb A2: 2%
Which of the following is most true of paroxysmal nocturnal hemoglobinuria (PNH)?
A. It is a rare acquired stem cell disorder that results in hemolysis
B. It is inherited as a sex-linked trait
C. It is inherited as an autosomal dominant trait
D. It is inherited as an autosomal recessive trait
It is a rare acquired stem cell disorder that results in hemolysis
An autohemolysis test is positive in all the following conditions except:
A. Glucose-6-phosphate dehydrogenase (G6PD)deficiency
B. Hereditary spherocytosis (HS)
C. Pyruvate kinase (PK) deficiency
D. Paroxysmal nocturnal hemoglobinuria (PNH)
Paroxysmal nocturnal hemoglobinuria (PNH)
Which antibody is associated with paroxysmal cold hemoglobinuria (PCH)?
A. Anti-I
B. Anti-i
C. Anti-M
D. Anti-P
Anti-P
