1.1 Basic Hematology Concepts and Laboratory Procedures

Question 1

Insufficient centrifugation will result in:

Answer 1

A false increase in hematocrit (Hct) value

Question 2

Variation in red blood cell (RBC) size observed on the peripheral blood smear is described as:

Answer 2

Anisocytosis

Question 3

Which of the following is the preferred site for bone marrow aspiration and biopsy in an adult?

A. Iliac crest
B. Sternum
C. Tibia
D. Spinous processes of a vertebra

Answer 3

Iliac crest

Question 4

Mean cell volume (MCV) is calculated by using the following formula:

Answer 4

(Hct ÷ RBC) × 10

Question 5

What term describes the change in shape of erythrocytes seen on a Wright-stained peripheral blood smear?

Answer 5

Poikilocytosis

Question 6

Calculate the mean cell hemoglobin concentration (MCHC) by using the following values:

Hgb: 15 g/dL (150 g/L)
Hct: 47 mL/dL (0.47)
RBC: 4.50 × 10^6/µL (4.50 × 10^12/L)

Answer 6

31.9% (0.319)

Question 7

A manual white blood cell (WBC) count was performed. In total 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?

Answer 7

0.4 × 10^9/L

Question 8

When an erythrocyte containing iron granules is stained with Prussian blue, the cell is called a:

Answer 8

Siderocyte

Question 9

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. Hgb
C. Hct
D. WBC count

Answer 9

Hct

Question 10

A 1:200 dilution of a patient’s sample was made, and 336 RBCs were counted in an area of 0.2 mm2. What is the RBC count?

Answer 10

3.36 × 10^12/L

Question 11

What phagocytic cells produce lysozymes that are bacteriocidal?

Answer 11

Neutrophils

Question 12

If a patient has a reticulocyte count of 7% and Hct of 20%, what is the corrected reticulocyte count?

Answer 12

3.1%

Question 13

A decreased osmotic fragility test would be associated with which of the following conditions?

Answer 13

Sickle cell anemia

Question 14

What effect would using a buffer at pH 6.0 have on a Wright-stained smear?

Answer 14

RBCs would be stained too pink

Question 15

Which of the following erythrocyte inclusions can be visualized with supravital stain but cannot be detected on a Wright-stained blood smear?

Answer 15

Heinz bodies

Question 16

A falsely elevated Hct is obtained. Which of the following calculated values will not be affected?

Answer 16

Mean corpuscular hemoglobin (MCH)

Question 17

A Miller disk is an ocular device used to facilitate counting of:

Answer 17

Reticulocytes

Question 18

SITUATION: RBC indices obtained on an anemic patient are as follows: MCV 88 μm3 (fL); MCH 30 pg; MCHC 34% (0.340). The RBCs on the peripheral blood smear would appear:

Answer 18

Normocytic, normochromic

Question 19

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

Answer 19

Blood drawn into a sodium citrate tube

Question 20

What staining method is used most frequently to stain and manually count reticulocytes?

Answer 20

Supravital staining

Question 21

The Coulter principle for counting of cells is based on the fact that:

Answer 21

Isotonic solutions conduct electricity better than cells do

Question 22

A correction is necessary for WBC counts when NRBCs are seen on the peripheral blood smear because:

Answer 22

NRBCs are counted as leukocytes

Question 23

Using an electronic cell counter analyzer, an increased RDW should correlate with:

Answer 23

Anisocytosis

Question 24

Given the following values, which set of RBC 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%

Answer 24

MCV 80 μm^3
MCH 36.5 pg
MCHC 39.0%

Question 25

Which of the following statistical terms reflects the best index of precision when comparing two complete blood count (CBC) parameters?

A. Mean
B. Median
C. Coefficient of variation
D. Standard deviation

Answer 25

Coefficient of variation

Question 26

Which of the following is considered a normal Hgb?

A. Carboxyhemoglobin
B. Methemoglobin
C. Sulfhemoglobin
D. Deoxyhemoglobin

Answer 26

Deoxyhemoglobin

Question 27

Which condition will shift the oxyhemoglobin dissociation curve to the right?

A. Acidosis
B. Alkalosis
C. Multiple blood transfusions
D. Increased quantities of Hgb S or C

Answer 27

Acidosis

Question 28

What is the major type of leukocyte seen in the peripheral blood smear from a patient with aplastic anemia?

Answer 28

Lymphocyte

Question 29

What is the normal WBC differential lymphocyte percentage (range) in the adult population?

Answer 29

20%–44%

Question 30

In which age group would 60% lymphocytes be a normal finding?

Answer 30

6 months–2 years

Question 31

Which of the following results on an automated differential suggests that a peripheral blood smear should be reviewed manually?

A. Segs = 70%
B. Band = 6%
C. Mono = 15%
D. Eos = 2%

Answer 31

Mono = 15%

Question 32

Which is the first stage of erythrocytic maturation in which the cytoplasm is pink because of the formation of Hgb?

A. Reticulocyte
B. Pronormoblast
C. Basophilic normoblast
D. Polychromatic normoblast

Answer 32

Polychromatic normoblast

Question 33

Which of the following can shift the Hgb oxygen (O2) dissociation curve to the right?

A. Increases in 2,3 DPG
B. Acidosis
C. Hypoxia
D. All of these options

Answer 33

All of these options

Question 34

Which of the following Hgb configurations is characteristic of Hgb H?

A. γ4
B. α2-γ2
C. β4
D. α2-β2

Answer 34

β4

Question 35

Autoagglutination of RBCs at room temperature can cause which of the following abnormal test results?

A. Low RBC count
B. High MCV
C. Low Hct
D. All of these options

Answer 35

All of these options