TESTBANKSELLER.COM
1. Chapter 01-01
Hematology is the study of:
*a. blood cells.
b. serum electrolytes.
c. plasma hormone levels.
d. bacteria in the blood.
General Feedback:
Hematology is the study of blood cells—red blood cells, white
blood cells, and platelets. Plasma and serum electrolytes and hormone
levels are evaluated in various subdivisions of clinical chemistry, and
bacteria are evaluated in clinical microbiology.
2. Chapter 01-02
The morphology of blood cells is important to evaluate:
a. every time a complete blood count (CBC) is requested on a
patient.
b. 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 is
TESmorphology.
necessary to evaluate cell TBANKSELLMany
ER.instrument-generated
COM 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.
3. Chapter 01-03
Who is ultimately responsible for determining the specimen integrity
before analysis?
*a. Medical laboratory professional
b. Nursing staff
c. Phlebotomist
d. 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.
TESTBANKSELLER.COM
, TESTBANKSELLER.COM
4. Chapter 01-04
Hematocrit is also called:
a. white cell count.
b. bone marrow examination.
c. red blood cell (RBC) count.
*d. packed red cell volume.
General Feedback:
Historically the hematocrit was determined by centrifuging an
aliquot 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.
5. Chapter 01-05
The primary function of platelets is to:
a. defend the body against bacterial invasion.
b. carry oxygen to tissues.
*c. facilitate blood clotting.
d. regulate acid-base balance.
General Feedback:
Whenever disruption occurs to a blood vessel so that bleeding
TESinitially
results, platelets respond TBANKSEtoLLstop
ER.Cthe
OM bleeding in small
vessels; they also play an integral role in facilitating the formation
of 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.
6. Chapter 01-06
Which of the following can be evaluated only through the microscopic
examination of a stained blood film?
a. White blood cell (WBC) count
b. Reticulocyte count
c. 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 absence
of 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.
TESTBANKSELLER.COM
, TESTBANKSELLER.COM
7. Chapter 01-07
Upon centrifugation of a blood specimen, the layer between the red
blood 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 and
plasma 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.
8. Chapter 01-08
Select the term that describes a low white blood cell count.
*a. Leukopenia
b. Leukocytosis
c. Neutropenia
d. Leukemia
General Feedback: TESTBANKSELLER.COM
The term leukopenia refers to a low total white blood cell
count. Leukocytosis is a term that describes an increase in white blood
cell 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.
TESTBANKSELLER.COM
, TESTBANKSELLER.COM
2. Chapter 02-02
A patient’s white blood cells (WBCs) are counted on an automated cell
counter 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%.
3. Chapter 02-03
What does the CV calculated in Question 2 describe about the white cell
counts?
a. Accuracy
b. Reliability
c. Proper calibration
*d. Precision
General Feedback:
The CV is a measure of precision, or how well a result can be
reproduced. It allows comparisons of assays with different means and is
a unitless number, although usually expressed as a percentage. Accuracy
is how close a result is to the true value; proper calibration is
TESTB
required to obtain accuracy. ANKSELLEis
Reliability R.how
COMwell a method holds
both accuracy and precision over time.
4. Chapter 02-04
A patient specimen is analyzed on an instrument known to be in control
from previous assays performed on a calibrated instrument and gives a
hemoglobin result of 13.2 g/dL. Two hours later it is evaluated on
another instrument that is being evaluated for purchase by the
laboratory. The result is 11.8 g/dL. This result, when compared with
the first, is:
a. acceptable agreement.
b. reportable.
c. precise agreement.
*d. inaccurate.
General Feedback:
This result is inaccurate compared with the first because it
is significantly different. Precision is not known, because multiple
results are needed to determine precision; in addition, precision must
be determined using the same instrument, not between instruments.
Because it is not accurate, it cannot be reported.
5. Chapter 02-05
Which is true regarding reference ranges?
TESTBANKSELLER.COM
1. Chapter 01-01
Hematology is the study of:
*a. blood cells.
b. serum electrolytes.
c. plasma hormone levels.
d. bacteria in the blood.
General Feedback:
Hematology is the study of blood cells—red blood cells, white
blood cells, and platelets. Plasma and serum electrolytes and hormone
levels are evaluated in various subdivisions of clinical chemistry, and
bacteria are evaluated in clinical microbiology.
2. Chapter 01-02
The morphology of blood cells is important to evaluate:
a. every time a complete blood count (CBC) is requested on a
patient.
b. 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 is
TESmorphology.
necessary to evaluate cell TBANKSELLMany
ER.instrument-generated
COM 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.
3. Chapter 01-03
Who is ultimately responsible for determining the specimen integrity
before analysis?
*a. Medical laboratory professional
b. Nursing staff
c. Phlebotomist
d. 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.
TESTBANKSELLER.COM
, TESTBANKSELLER.COM
4. Chapter 01-04
Hematocrit is also called:
a. white cell count.
b. bone marrow examination.
c. red blood cell (RBC) count.
*d. packed red cell volume.
General Feedback:
Historically the hematocrit was determined by centrifuging an
aliquot 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.
5. Chapter 01-05
The primary function of platelets is to:
a. defend the body against bacterial invasion.
b. carry oxygen to tissues.
*c. facilitate blood clotting.
d. regulate acid-base balance.
General Feedback:
Whenever disruption occurs to a blood vessel so that bleeding
TESinitially
results, platelets respond TBANKSEtoLLstop
ER.Cthe
OM bleeding in small
vessels; they also play an integral role in facilitating the formation
of 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.
6. Chapter 01-06
Which of the following can be evaluated only through the microscopic
examination of a stained blood film?
a. White blood cell (WBC) count
b. Reticulocyte count
c. 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 absence
of 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.
TESTBANKSELLER.COM
, TESTBANKSELLER.COM
7. Chapter 01-07
Upon centrifugation of a blood specimen, the layer between the red
blood 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 and
plasma 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.
8. Chapter 01-08
Select the term that describes a low white blood cell count.
*a. Leukopenia
b. Leukocytosis
c. Neutropenia
d. Leukemia
General Feedback: TESTBANKSELLER.COM
The term leukopenia refers to a low total white blood cell
count. Leukocytosis is a term that describes an increase in white blood
cell 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.
TESTBANKSELLER.COM
, TESTBANKSELLER.COM
2. Chapter 02-02
A patient’s white blood cells (WBCs) are counted on an automated cell
counter 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%.
3. Chapter 02-03
What does the CV calculated in Question 2 describe about the white cell
counts?
a. Accuracy
b. Reliability
c. Proper calibration
*d. Precision
General Feedback:
The CV is a measure of precision, or how well a result can be
reproduced. It allows comparisons of assays with different means and is
a unitless number, although usually expressed as a percentage. Accuracy
is how close a result is to the true value; proper calibration is
TESTB
required to obtain accuracy. ANKSELLEis
Reliability R.how
COMwell a method holds
both accuracy and precision over time.
4. Chapter 02-04
A patient specimen is analyzed on an instrument known to be in control
from previous assays performed on a calibrated instrument and gives a
hemoglobin result of 13.2 g/dL. Two hours later it is evaluated on
another instrument that is being evaluated for purchase by the
laboratory. The result is 11.8 g/dL. This result, when compared with
the first, is:
a. acceptable agreement.
b. reportable.
c. precise agreement.
*d. inaccurate.
General Feedback:
This result is inaccurate compared with the first because it
is significantly different. Precision is not known, because multiple
results are needed to determine precision; in addition, precision must
be determined using the same instrument, not between instruments.
Because it is not accurate, it cannot be reported.
5. Chapter 02-05
Which is true regarding reference ranges?
TESTBANKSELLER.COM
