TEST BANK FOR RODAK'S
HEMATOLOGY 6TH EDITION
WALENGA QUESTIONS &
ANSWERS WITH
RATIONALES (CHAPTERS 1-
43)
Chapter 01-01
Hematology is the study of:
*a. blood cells.
• serum electrolytes.
• plasma hormone levels.
• bacteria in the blood.
General Feedback:
Hematology is the study of blood cells—red blood cells, whiteblood cells,
and platelets. Plasma and serum electrolytes and hormone levels are evaluated in
various subdivisions of clinical chemistry, andbacteria are evaluated in clinical
microbiology.
• Chapter 01-02
The morphology of blood cells is important to evaluate:
• every time a complete blood count (CBC) is requested on aclient.
• when an instrument-generated flag is obtained.
*c. when a profiling instrument result is abnormal.
d. when the white count is elevated.
, General Feedback:
Every laboratory must determine—based on its instrumentation,needs of
the clinician and other parameter flags that alert the medical laboratory scientist to the
necessity for further evaluation—when it isnecessary to evaluate cell morphology.
Many instrument-generated flags,although useful, may not require review. If an
automated CBC does not suggest the need, no reason exists to evaluate the blood
film, even if the white count is elevated.
• Chapter 01-03
Who is ultimately responsible for determining the specimen integritybefore analysis?
*a. Medical laboratory professional
• Nursing staff
• Phlebotomist
• Specimen-processing personnel
General Feedback:
The medical laboratory scientist is responsible for ensuring the integrity of
a specimen before analysis. Only he or she can judge whether the specimen is
acceptable so that valid results can be obtained. Acceptable criteria include such
things as type of specimen for the test ordered (e.g., blood, serum, urine);
appropriate additive present (if needed) and amount of specimen relative to the
additive; time interval since obtained; and presence or absence of hemolysis, lipemia,
and other similar conditions. None of the other personnel named have the education
and understanding to fully make that judgment.
• Chapter 01-04 Hematocrit is
also called:
• white cell count.
• bone marrow examination.
• red blood cell (RBC) count.
*d. packed red cell volume.
General Feedback:
Historically the hematocrit was determined by centrifuging analiquot of
anticoagulated whole blood under specified conditions (e.g.,centrifugal force, capillary
tube length, and bore diameter) and then determining the ratio of the space occupied
by the packed red cells compared with that of the entire blood volume in the capillary
tube, often expressed as a percentage. Hence, it is also called the packed red cell
volume.
• Chapter 01-05
The primary function of platelets is to:
, • defend the body against bacterial invasion.
• carry oxygen to tissues.
*c. facilitate blood clotting.
d. regulate acid-base balance.
General Feedback:
Whenever disruption occurs to a blood vessel so that bleedingresults,
platelets respond initially to stop the bleeding in small vessels; they also play an
integral role in facilitating the formationof a blood clot. White cells defend against
bacterial invasion; red cells (i.e., hemoglobin) carry oxygen to tissues; and a complex
interaction of plasma electrolytes, proteins, and carbon dioxide participates in acid-
base balance.
• Chapter 01-06
Which of the following can be evaluated only through the microscopicexamination of a
stained blood film?
• White blood cell (WBC) count
• Reticulocyte count
• Hemoglobin concentration
*d. Presence or absence of cytoplasmic inclusions
General Feedback:
Making and staining a blood film and then placing it under a microscope
allow the medical laboratory scientist to evaluate the morphology of blood cells and
examine them for the presence or absenceof blood cell inclusions. These inclusions
are important for cell identification and, when abnormal inclusions are present,
sometimes provide “clues” as to the cause of disease. All the other parameters
mentioned are or can be performed using an automated hematology instrument,
including reticulocyte counting.
• Chapter 01-07
Upon centrifugation of a blood specimen, the layer between the redblood cells and
plasma is called the:
a. hematocrit.
*b. buffy coat.
c. serum.
d. platelet pellet.
General Feedback:
When blood is centrifuged, the layer between the red cells andplasma is
called the buffy coat. This layer consists of both white blood cells and platelets. The
hematocrit is the packed cell volume that reflects the number of red blood cells. The
, serum is the liquid portion of the blood formed from a clotted blood sample. The
platelet pellet is a special layer of platelets that is required for platelet function studies.
This layer of platelets is prepared from a whole blood specimen using specific
centrifugation time and speed.
• Chapter 01-08
Select the term that describes a low white blood cell count.
*a. Leukopenia
• Leukocytosis
• Neutropenia
• Leukemia
General Feedback:
The term leukopenia refers to a low total white blood cell count.
Leukocytosis is a term that describes an increase in white bloodcell count.
Neutropenia is a low cell count that is specific to the neutrophils. Leukemia is cancer
of the blood cells, most often white blood cells.
• Chapter 02-02
A client’s white blood cells (WBCs) are counted on an automated cellcounter 10 times.
The mean white count is 8000/mL, and the standard deviation (SD) is 300. What is the
coefficient of variation (CV)?
a. 0.04%
b. 2.6%
*c. 3.8%
d. 26%
General Feedback:
% CV = (SD/mean) × 100 = (300/8000) × 100 = 3.8%.
• Chapter 02-03
What does the CV calculated in Question 2 describe about the white cellcounts?
• Accuracy
• Reliability
• Proper calibration
*d. Precision
General Feedback:
The CV is a measure of precision, or how well a result can bereproduced.
It allows comparisons of assays with different means and isa unitless number,
although usually expressed as a percentage. Accuracyis how close a result is to the
HEMATOLOGY 6TH EDITION
WALENGA QUESTIONS &
ANSWERS WITH
RATIONALES (CHAPTERS 1-
43)
Chapter 01-01
Hematology is the study of:
*a. blood cells.
• serum electrolytes.
• plasma hormone levels.
• bacteria in the blood.
General Feedback:
Hematology is the study of blood cells—red blood cells, whiteblood cells,
and platelets. Plasma and serum electrolytes and hormone levels are evaluated in
various subdivisions of clinical chemistry, andbacteria are evaluated in clinical
microbiology.
• Chapter 01-02
The morphology of blood cells is important to evaluate:
• every time a complete blood count (CBC) is requested on aclient.
• when an instrument-generated flag is obtained.
*c. when a profiling instrument result is abnormal.
d. when the white count is elevated.
, General Feedback:
Every laboratory must determine—based on its instrumentation,needs of
the clinician and other parameter flags that alert the medical laboratory scientist to the
necessity for further evaluation—when it isnecessary to evaluate cell morphology.
Many instrument-generated flags,although useful, may not require review. If an
automated CBC does not suggest the need, no reason exists to evaluate the blood
film, even if the white count is elevated.
• Chapter 01-03
Who is ultimately responsible for determining the specimen integritybefore analysis?
*a. Medical laboratory professional
• Nursing staff
• Phlebotomist
• Specimen-processing personnel
General Feedback:
The medical laboratory scientist is responsible for ensuring the integrity of
a specimen before analysis. Only he or she can judge whether the specimen is
acceptable so that valid results can be obtained. Acceptable criteria include such
things as type of specimen for the test ordered (e.g., blood, serum, urine);
appropriate additive present (if needed) and amount of specimen relative to the
additive; time interval since obtained; and presence or absence of hemolysis, lipemia,
and other similar conditions. None of the other personnel named have the education
and understanding to fully make that judgment.
• Chapter 01-04 Hematocrit is
also called:
• white cell count.
• bone marrow examination.
• red blood cell (RBC) count.
*d. packed red cell volume.
General Feedback:
Historically the hematocrit was determined by centrifuging analiquot of
anticoagulated whole blood under specified conditions (e.g.,centrifugal force, capillary
tube length, and bore diameter) and then determining the ratio of the space occupied
by the packed red cells compared with that of the entire blood volume in the capillary
tube, often expressed as a percentage. Hence, it is also called the packed red cell
volume.
• Chapter 01-05
The primary function of platelets is to:
, • defend the body against bacterial invasion.
• carry oxygen to tissues.
*c. facilitate blood clotting.
d. regulate acid-base balance.
General Feedback:
Whenever disruption occurs to a blood vessel so that bleedingresults,
platelets respond initially to stop the bleeding in small vessels; they also play an
integral role in facilitating the formationof a blood clot. White cells defend against
bacterial invasion; red cells (i.e., hemoglobin) carry oxygen to tissues; and a complex
interaction of plasma electrolytes, proteins, and carbon dioxide participates in acid-
base balance.
• Chapter 01-06
Which of the following can be evaluated only through the microscopicexamination of a
stained blood film?
• White blood cell (WBC) count
• Reticulocyte count
• Hemoglobin concentration
*d. Presence or absence of cytoplasmic inclusions
General Feedback:
Making and staining a blood film and then placing it under a microscope
allow the medical laboratory scientist to evaluate the morphology of blood cells and
examine them for the presence or absenceof blood cell inclusions. These inclusions
are important for cell identification and, when abnormal inclusions are present,
sometimes provide “clues” as to the cause of disease. All the other parameters
mentioned are or can be performed using an automated hematology instrument,
including reticulocyte counting.
• Chapter 01-07
Upon centrifugation of a blood specimen, the layer between the redblood cells and
plasma is called the:
a. hematocrit.
*b. buffy coat.
c. serum.
d. platelet pellet.
General Feedback:
When blood is centrifuged, the layer between the red cells andplasma is
called the buffy coat. This layer consists of both white blood cells and platelets. The
hematocrit is the packed cell volume that reflects the number of red blood cells. The
, serum is the liquid portion of the blood formed from a clotted blood sample. The
platelet pellet is a special layer of platelets that is required for platelet function studies.
This layer of platelets is prepared from a whole blood specimen using specific
centrifugation time and speed.
• Chapter 01-08
Select the term that describes a low white blood cell count.
*a. Leukopenia
• Leukocytosis
• Neutropenia
• Leukemia
General Feedback:
The term leukopenia refers to a low total white blood cell count.
Leukocytosis is a term that describes an increase in white bloodcell count.
Neutropenia is a low cell count that is specific to the neutrophils. Leukemia is cancer
of the blood cells, most often white blood cells.
• Chapter 02-02
A client’s white blood cells (WBCs) are counted on an automated cellcounter 10 times.
The mean white count is 8000/mL, and the standard deviation (SD) is 300. What is the
coefficient of variation (CV)?
a. 0.04%
b. 2.6%
*c. 3.8%
d. 26%
General Feedback:
% CV = (SD/mean) × 100 = (300/8000) × 100 = 3.8%.
• Chapter 02-03
What does the CV calculated in Question 2 describe about the white cellcounts?
• Accuracy
• Reliability
• Proper calibration
*d. Precision
General Feedback:
The CV is a measure of precision, or how well a result can bereproduced.
It allows comparisons of assays with different means and isa unitless number,
although usually expressed as a percentage. Accuracyis how close a result is to the
