Hematology

Question 1

Insufficient centrifugation will result in:
a. a false increase in hematocrit value
b. a flalse decrease in Hct value
c. no effect on Hct value
d. all of the above depending on the patient

Answer 1

a false increase in hematocrit value

Question 2

Erythrocytes that vary in size from the normal 6-8 um are described as exhibiting
a. anisocytosis
b. hypochromia
c. poikilocytosis
d. pleocytosis

Answer 2

anisocytosis

Question 3

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

Answer 3

Iliac crest

Question 4

Mean cell volume (MCV) is calculated using what formula?

Answer 4

(Hct/RBC)x10

Question 5

What term describes the change in shape of erythrocytes seen on a wright’s stained peripheral blood smear?

Answer 5

poikilocytosis

Question 6

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

Answer 6

Siderocytes

Question 7

a 7.0 mL etheylenediaminetetraacetic 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

Answer 7

Hct [excessive anticoagulant causes shrinkage of cells thus the Hct will be affected. RBC and WBC counts remain the same as does the Hgb content.]

Question 8

What phagocytic cells produce lysozyme that are bacteriocidal?
a. Eosinophils
b. lymphocytes
c. platelets
d. Neutrophils

Answer 8

Neutrophils

Question 9

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

Answer 9

Sickle cell anemia

[test is increased in the presence of spherocytes and decreased with sickle cells, target cells and poikilocytes]

Question 10

What effect would using a buffer at pH 6.0 have on a wright’s stained smear?
a. red cells would be stained to 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

Answer 10

red cells would be stained too pink

Question 11

Which of the following erythrocyte inclusions can be visualized with supra vital 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

Answer 11

Heinz bodies

Question 12

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)

Answer 12

MCH

Question 13

A miller disk is an ocular device used to facilitate counting of:
a. platelets
b. reticulocytes
c. sickle cells
d. nucleated red blood cells

Answer 13

Reticulocytes

Question 14

RBC indices obtained on a patient are as follows: MCV 88 um (fl); MCH 30 pg; MCHC 34%. The RBCs on the peripheral smear would appear:
a. microcytic, hypochromic
b. microcytic, normochromic
c. normocytic, normochromic
d. normocytic, hypochromic

Answer 14

Normocytic, normochromic
[because the MCV< MCH, and MCHC are all within the normal reference range

Question 15

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 15

a. blood drawn into a sodium citrate tube

Question 16

Which staining method is used most frequently to stain and count reticulocytes?
a. immunofluorescence
b. supra vital staining
c. romanowsky staining
d. cytochemical staining

Answer 16

b. supra vital staining

Question 17

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 number of cells
c. cells conduct electricity better than saline does
d. isotonic solutions cannot conduct electricity

Answer 17

Isotonic solutions conduct electricity better than cells do

Question 18

A correction is necessary for WBC counts when nucleated RBCs are seen on the peripherential smear because:
a. The WBC count would be falsely lower
b. The RBC count is to low
c. Nucleated RBCs are counted as leukocytes
d. Nucleated RBCs are confused with giant platelets

Answer 18

c. nucleated RBCs are counted as leukocytes

Question 19

Using a Coulter counter analyzer, an increased RDW should correlate with:
a. spherocytosis
b. anisocytosis
c. leukocytosis
d. presence of NRBCs

Answer 19

B. Anisocytosis

Question 20

Which of the following statistical terms reflects the best index of precision?
a. Mean
b. Median
c. coefficient of variation
d. standard deviation

Answer 20

C. Coefficient of variation

Question 21

Which of the following is considered a normal hemoglobin?
a. carboxyhemoglobin
b. methemoglobin
c. sulfahemoglobin
d. deoxyhemoglonin

Answer 21

d. deoxyhemoglobin
a physiological Hgb that results from the unloading of oxygen by Hgb. This is accompanied by the widening of the space between B chains and the binding of 2,3 DPG.

Question 22

Which condition will shift the oxyhemoglobin dissociated curve to the right?
a. acidosis
b. alkalosis
c. multiple blood transfusions
d. increased quantities of hemoglobin S or C

Answer 22

a. acidosis
acidosis is associated with a shift to the right of the oxyhemoglobin dissociation curve and therefore increased oxygen release (decreased affinity of Hgb for oxygen). Alkalosis does the opposite. Multiple blood transfusions shift the curve to the left because transfused blood is low in 2,3 DPG. Hgb S and Hgb C do not change the affinity of oxygen for hemoglobin. However man hemoglobinopathies do.

Question 23

What is the major type of leukocyte seen in the peripheral smear of a patient with aplastic anemia?
a. segmented neutrophil
b. lymphocyte
c. monocyte
d. eosinophil

Answer 23

b. lymphocyte…constitute the majority of the nucleated cells seen. The bone marrow in aplastic anemia is spotty with patches of normal cellularity. Absolute granulocytopenia is usually present; however, lymphocyte production is less affected

Question 24

What is the normal WBC differential lymphocyte percentage (range) in the adult population?
a. 20-50%
b. 10-20%
c. 5-10%
d. 50-70%

Answer 24

a. 20-50%. This range is higher in the pediatric population

Question 25

In which age group would 60% Lymphocytes be a normal finding? a. 40-60 years b. 11-15 years c. 6 months - 2 years d. 4-6 years

Answer 25

c. 6 months to 2 years there is a relative neutropenia in children from ages 4 months to 4 years of age. Because of this, the percentage of lymphocytes is increased in this population. This is commonly referred to as a reversal in the normal differential percentage ( or inverted differential).

Question 26

Which of the following results on a automated differential suggests that a peripheral smear should be reviewed manually? a. segs=70% b. band=6% c. Mono=15% d. Eos=2%

Answer 26

c. Mono=15% A relative monocyte count of 15% is abnormal, given that the baseline monocyte count in a normal differential is between 1-8%. An increased monocyte count may signal a myeloproliferative process such chronic myelomonocytic leukemia, an inflammatory response, or abnormal lymphocytes that may have been counted as monocytes by an automated cell counter.

Question 27

In which stage of erythrocytic maturation does Hgb formation begin? a. reticulocyte b. pronormoblast c. basophilic normoblast d. polychromatic normoblast

Answer 27

d. polychromatic normoblast in normal erythrocyte maturation, Hgb formation begins in the polychromatic normoblast and is seen as a pink coloration of the cytoplasm. The red cell continues to produce Hgb through the reticulocyte stage of development

Question 28

Which of the following can shift the hemoglobin oxygen dissociation curve to the right? a. increases in 2,3 DPG b. Acidosis c. hypoxia d. all of the above1`

Answer 28

d. all of the above increases in 2,3 DPG, acidosis, hypoxia and a rise in body temperature all shift the hemoglobin oxygen dissociation curve to the right. In anemia, although the number of RBCs is reduced, the cells are more efficient at oxygen delivery because there is an increase in red cell 2,3 DPG. This causes the oxyhemoglobin dissociation curve to shift to the right, allowing more oxygen to be released to the tissues

Question 29

Which of the following Hg configurations is characteristic of Hgb H? a. gamma 4 b. alpha 2-gamma 2 c. Beta 4 d. alpha 2-beta 2

Answer 29

c. beta 4 the structure of Hgb H is beta 4. Hgb H disease is a severe clinical expression of alpha thalassemia in which only one alpha gene out of four is functioning

Question 30

Autoagglutination of red cells at room temperature can result in which of the following? a. low RBC count b. High MCV c. Low hematocrit d. All of the above

Answer 30

d. All of the above autoagglutination at room temp may cause low RBC count and high Mcv from an electronic counter. The Hct will be low because it is calculated from the RBC count. Low RBC count and low Hct cause falsely high calculations of MCH and MCHC