WBC Exam Practice Questions and Answers 2023 with
complete solution
Functionally, white blood cells are divided into
A. Granulocytes, nongranulocytes
B. Polymorphonuclears, mononuclears
C. Phagocytes, immunocytes
D. Granulocytes, lymphocytes
C. Phagocytes, immunocytes
The major function of leukocytes is defense either by phagocytosis or by immune
mechanisms. The phagocytic cells are the granulocytes and monocytes. The immune
response is mediated by lymphocytes, however, monocytes play a role in immunity as
antigen-presenting cells. Leukocytes may be classified according to granularity as
granulocytes and nongranulocytes or divided based on nuclear segmentation as
polymorphonuclears (PMNs) and mononuclears.
What is the largest WBC normally found in the peripheral blood?
A. Eosinophil
B. Neutrophil
C. Lymphocyte
D. Monocyte
D. Monocyte
Monocytes have a diameter up to 20um, making them the largest cells in the peripheral
blood under normal conditions. Eosinophils and neutrophils have diameters of about
12um. The small lymphocyte is 8-9um in diameter, similar to the RBC which has a
diameter of 6-8um. Large lymphocytes range in size from 11-16um in diameter.
What is the approximate amount of time a granulocyte spends in the circulation before
migrating into the tissues?
A. Less than 1 day
B. About 3 days
C. Up to 5 days
D. More than 10 days
A. Less than 1 day
After granulocytes are released from the BM, they remain in circulation one day or less.
Their major function takes place in tissues. They migrate through vessel walls to reach
areas of inflammation very soon after release. The life span of granulocytes is short;
however eosinophils and basophils apepar to survive longer in the tissues than
neutrophils.
What percentage of neutrophils in the peripheral blood constitutes the circulating pool?
A. 100%
B. 80%
C. 50%
D. 30%
C. 50%
Approximately 50% of the neutrophils in the PB are found in the circulating pool. This is
the pool measured when a total WBC count is done. Another 50% are found adhering to
,vessel walls (marginal pool). These pools are in constant exchange. Emotional/physical
stimuli can cause a shift of cells from the marginating to the circulating pool causing a
transient rise in the total WBC count. The total WBC count can double but return to
normal within several hours.
What is the major phagocytic cell involved in the initial defense against bacterial
pathogens?
A. Neutrophil
B. Eosinophil
C. Basophil
D. Monocyte
A. Neutrophil
Although some phagocytic activity has been attributed to the eosinophil, it is the
segmented neutrophil and monocyte that have the greatest phagocytic activity. The
neutrophil is the most important because of numbers and its ability to respond quickly,
especially against bacterial pathogens. Monocytes arrive at the site of injury after the
neutrophil to "clean up".
What is the growth factor that is primarily responsible for regulating granulocyte and
monocyte production?
A. Erythropoietin
B. Colony stimulating factor
C. Interleukin
D. Thrombopoietin
B. Colony stimulating factor
The growth factor mainly responsible for regulating the production of granulocytes and
monocytes is granulocyte/monocyte colony-stimulating factor (GM-CSF), which acts on
the committed bipotential progenitor cell CFU-GM (colony forming unit-GM). GM-CSF
stimulation of granulocyte or monocyte production increases in response to need and
can also affect the production of erythrocytic and megakaryocytic lineages. G-CSF
induces granulocyte differentiation, and M-CSF supports monocyte differentiation. EPO
is a lineage-specific growth factor responsible for stimulating erythrocyte production,
and TPO is mainly responsible for regulating platelet production. Interleukins, in
particular IL-3, influence multiple cell lines including granulocytes and monocytes.
What does the granulocyte mitotic pool in the BM contain?
A. Myeloblasts and promyelocytes
B. Band and segmented forms
C. The majority of marrow granulocytes
D. Myelocytes and metamyelocytes
A. Myeloblasts and promyelocytes
The granulocyte mitotic pool contains the cells capable of division, which are the
myeloblasts, promyelocytes, and myelocytes. The post-mitotic pool, or reserve, is the
largest BM pool and contains metamyelocytes, band, and segmented forms. This pool
is available for prompt release into the blood if needed and its early release is the cause
of a "left shift". If released, the BM mitotic pool can dramatically increase its activity to
replenish this reserve.
A "shift to the left", when used to describe a cell population, refers to
A. Increased cells in the blood due to a redistribution of blood pools
,B. An increase in immature blood cells following release of BM pools
C. A cell production "hiatus" or gap
D. A higher percentage of lymphocytes than neutrophils
B. an increase in immature blood cells following release of BM pools
A shift to the left means an increase in immature neutrophilic cells in the blood caused
by BM release of cells in response to infection or tissue damage. A redistribution of the
blood pools because of emotional or physical stimuli is characterized by an increased
WBC count without a left shift. A cell "hiatus" refers to a population of cells in which
there is a gap in the normal maturation sequence. A cell hiatus is most often seen in
acute leukemia, in which there are many blasts and a few mature cells but no
intermediate stages.
Which of the following is characteristic of agranulocytosis?
A. Neutrophils without granules
B. Decreased number of granulocytes, red cells, and platelets
C. Immature granulocytes in the peripheral blood
D. Decreased numbers of granulocytes
D. Decreased numbers of granulocytes
Agranulocytosis refers to an absence of granulocytes in both the peripheral blood and
BM. A deficiency of granulocytes is found in cases of aplastic anemia, in which
deficiencies in red cells and platelets also occur. The early release of cells from the BM
will result in immature cells in the blood but is not referred to as agranulocytosis.
Neutrophils that exhibit little or no granulation may be called hypogranular or agranular
and are a sign of abnormal growth (dyspoiesis).
Which of the following is not a characteristic of T lymphocytes?
A. Secrete cytokines
B. Synthesize antibody
C. Comprise majority of cells in the blood lymphocyte pool
D. Regulate the immune response
B. Synthesize antibody
Antibodies are synthesized by plasma cells, which are end-stage B lymphocytes that
have transformed to plasma cells following stimulation by antigen. An end product of T
cell activation is the production of cytokines such as interleukins and colony-stimulating
factors. T cells are surveillance cells that normally comprise the majority (about 80%) of
lymphocytes in the blood. T cells regulate the immune response by helping (T helper or
inducer cells) or suppressing (T suppressor cells) the synthesis of antibody by plasma
cells.
An adult has a total WBC count of 4x10^9/L. The differential count is as follows: PMNs
25%, bands 5%, lymphocytes 65%, monocytes 5%. The absolute reference range for
lymphocytes is 1-4x10^9/L. Which of the following is true?
A. The percentage of lymphocytes is normal
B. There is an absolute lymphocytosis
C. There is a relative lymphocytosis
D. There is both an absolute and a relative lymphocytosis
C. There is a relative lymphocytosis
Absolute values for cell types are obtained by multiplying the percentage of the cell type
by the total number of cells. In this case 4x.65=2.6*10^9/L which is within the normal
, absolute count for lymphocytes. Normal percentage of lymphocytes is 20-44% so there
is a relative lymphocytosis but the absolute lymphocyte value is normal.
Which of the following statements is correct?
A. Hypersegmented neutrophils have four nuclear lobes
B. Auer rods are composed of fused primary granules
C. Toxic granules are prominent secondary granules
D. Dohle bodies are agranular patches of DNA
B. Auer rods are composed of fused primary granules.
Auer rods are seen in the cytoplasm of malignant cells, most often myeloblasts, and are
composed of fused primary granules. Hypersegmented neutrophils have five lobes or
more and are associated with vitamin B12 or folate deficiency. Toxic granules are
primary granules with altered staining characteristics that stain in late-stage neutrophils
due to toxicity. Dohle bodies are agranular patches of RNA present in neutrophil
cytoplasm and associated with toxic states.
Which of the following factors is not associated with variations in the total WBC count?
A. Age
B. Exercise
C. Emotional stress
D. Sex
D. Sex
The total WBC count reference ranges for males and females are equivalent. WBC
counts do change with age, being higher in newborns and children than in adults. Any
change from basal conditions, such as exercise or emotional stress, will cause a
transient leukocytosis due to a redistribution of blood pools. WBC values are lower in
the morning and higher in the afternoon (diurnal variation).
Of the following, an absolute neutrophil count of 1.0*10^9/L would be associated with
A. Shortness of breath
B. Bleeding tendencies
C. Risk of infection
D. No clinical symptoms
C. Risk of infection
Neutropenia is associated with a risk of infection. The degree of neutropenia correlates
with the infection risk from high susceptibility (<1.010^9/L) to great risk (<0.510^9).
Infection increases with the degree and duration of the neutropenia. Shortness of breath
and bleeding tendencies are clinical symptoms associated with severe anemia and
thrombocytopenia, respectively.
Which of the following statements about basophils is false?
A. Morphologically, basophils resemble tissue mast cells
B. Membrane receptors bind IgG
C. Basophilic granules contain heparin and histamine
D. Granules are water soluble
B. Membrane receptors bind IgG
Basophils and tissue mast cells have receptors for IgE and complement components,
which trigger degranulation when appropriate antigens are present and are responsible
for severe hypersensitivity reactions (anaphylaxis). Basophils and tissue mast cells
have morphologic similarities but represent distinct cell types. Basophils possess water-
complete solution
Functionally, white blood cells are divided into
A. Granulocytes, nongranulocytes
B. Polymorphonuclears, mononuclears
C. Phagocytes, immunocytes
D. Granulocytes, lymphocytes
C. Phagocytes, immunocytes
The major function of leukocytes is defense either by phagocytosis or by immune
mechanisms. The phagocytic cells are the granulocytes and monocytes. The immune
response is mediated by lymphocytes, however, monocytes play a role in immunity as
antigen-presenting cells. Leukocytes may be classified according to granularity as
granulocytes and nongranulocytes or divided based on nuclear segmentation as
polymorphonuclears (PMNs) and mononuclears.
What is the largest WBC normally found in the peripheral blood?
A. Eosinophil
B. Neutrophil
C. Lymphocyte
D. Monocyte
D. Monocyte
Monocytes have a diameter up to 20um, making them the largest cells in the peripheral
blood under normal conditions. Eosinophils and neutrophils have diameters of about
12um. The small lymphocyte is 8-9um in diameter, similar to the RBC which has a
diameter of 6-8um. Large lymphocytes range in size from 11-16um in diameter.
What is the approximate amount of time a granulocyte spends in the circulation before
migrating into the tissues?
A. Less than 1 day
B. About 3 days
C. Up to 5 days
D. More than 10 days
A. Less than 1 day
After granulocytes are released from the BM, they remain in circulation one day or less.
Their major function takes place in tissues. They migrate through vessel walls to reach
areas of inflammation very soon after release. The life span of granulocytes is short;
however eosinophils and basophils apepar to survive longer in the tissues than
neutrophils.
What percentage of neutrophils in the peripheral blood constitutes the circulating pool?
A. 100%
B. 80%
C. 50%
D. 30%
C. 50%
Approximately 50% of the neutrophils in the PB are found in the circulating pool. This is
the pool measured when a total WBC count is done. Another 50% are found adhering to
,vessel walls (marginal pool). These pools are in constant exchange. Emotional/physical
stimuli can cause a shift of cells from the marginating to the circulating pool causing a
transient rise in the total WBC count. The total WBC count can double but return to
normal within several hours.
What is the major phagocytic cell involved in the initial defense against bacterial
pathogens?
A. Neutrophil
B. Eosinophil
C. Basophil
D. Monocyte
A. Neutrophil
Although some phagocytic activity has been attributed to the eosinophil, it is the
segmented neutrophil and monocyte that have the greatest phagocytic activity. The
neutrophil is the most important because of numbers and its ability to respond quickly,
especially against bacterial pathogens. Monocytes arrive at the site of injury after the
neutrophil to "clean up".
What is the growth factor that is primarily responsible for regulating granulocyte and
monocyte production?
A. Erythropoietin
B. Colony stimulating factor
C. Interleukin
D. Thrombopoietin
B. Colony stimulating factor
The growth factor mainly responsible for regulating the production of granulocytes and
monocytes is granulocyte/monocyte colony-stimulating factor (GM-CSF), which acts on
the committed bipotential progenitor cell CFU-GM (colony forming unit-GM). GM-CSF
stimulation of granulocyte or monocyte production increases in response to need and
can also affect the production of erythrocytic and megakaryocytic lineages. G-CSF
induces granulocyte differentiation, and M-CSF supports monocyte differentiation. EPO
is a lineage-specific growth factor responsible for stimulating erythrocyte production,
and TPO is mainly responsible for regulating platelet production. Interleukins, in
particular IL-3, influence multiple cell lines including granulocytes and monocytes.
What does the granulocyte mitotic pool in the BM contain?
A. Myeloblasts and promyelocytes
B. Band and segmented forms
C. The majority of marrow granulocytes
D. Myelocytes and metamyelocytes
A. Myeloblasts and promyelocytes
The granulocyte mitotic pool contains the cells capable of division, which are the
myeloblasts, promyelocytes, and myelocytes. The post-mitotic pool, or reserve, is the
largest BM pool and contains metamyelocytes, band, and segmented forms. This pool
is available for prompt release into the blood if needed and its early release is the cause
of a "left shift". If released, the BM mitotic pool can dramatically increase its activity to
replenish this reserve.
A "shift to the left", when used to describe a cell population, refers to
A. Increased cells in the blood due to a redistribution of blood pools
,B. An increase in immature blood cells following release of BM pools
C. A cell production "hiatus" or gap
D. A higher percentage of lymphocytes than neutrophils
B. an increase in immature blood cells following release of BM pools
A shift to the left means an increase in immature neutrophilic cells in the blood caused
by BM release of cells in response to infection or tissue damage. A redistribution of the
blood pools because of emotional or physical stimuli is characterized by an increased
WBC count without a left shift. A cell "hiatus" refers to a population of cells in which
there is a gap in the normal maturation sequence. A cell hiatus is most often seen in
acute leukemia, in which there are many blasts and a few mature cells but no
intermediate stages.
Which of the following is characteristic of agranulocytosis?
A. Neutrophils without granules
B. Decreased number of granulocytes, red cells, and platelets
C. Immature granulocytes in the peripheral blood
D. Decreased numbers of granulocytes
D. Decreased numbers of granulocytes
Agranulocytosis refers to an absence of granulocytes in both the peripheral blood and
BM. A deficiency of granulocytes is found in cases of aplastic anemia, in which
deficiencies in red cells and platelets also occur. The early release of cells from the BM
will result in immature cells in the blood but is not referred to as agranulocytosis.
Neutrophils that exhibit little or no granulation may be called hypogranular or agranular
and are a sign of abnormal growth (dyspoiesis).
Which of the following is not a characteristic of T lymphocytes?
A. Secrete cytokines
B. Synthesize antibody
C. Comprise majority of cells in the blood lymphocyte pool
D. Regulate the immune response
B. Synthesize antibody
Antibodies are synthesized by plasma cells, which are end-stage B lymphocytes that
have transformed to plasma cells following stimulation by antigen. An end product of T
cell activation is the production of cytokines such as interleukins and colony-stimulating
factors. T cells are surveillance cells that normally comprise the majority (about 80%) of
lymphocytes in the blood. T cells regulate the immune response by helping (T helper or
inducer cells) or suppressing (T suppressor cells) the synthesis of antibody by plasma
cells.
An adult has a total WBC count of 4x10^9/L. The differential count is as follows: PMNs
25%, bands 5%, lymphocytes 65%, monocytes 5%. The absolute reference range for
lymphocytes is 1-4x10^9/L. Which of the following is true?
A. The percentage of lymphocytes is normal
B. There is an absolute lymphocytosis
C. There is a relative lymphocytosis
D. There is both an absolute and a relative lymphocytosis
C. There is a relative lymphocytosis
Absolute values for cell types are obtained by multiplying the percentage of the cell type
by the total number of cells. In this case 4x.65=2.6*10^9/L which is within the normal
, absolute count for lymphocytes. Normal percentage of lymphocytes is 20-44% so there
is a relative lymphocytosis but the absolute lymphocyte value is normal.
Which of the following statements is correct?
A. Hypersegmented neutrophils have four nuclear lobes
B. Auer rods are composed of fused primary granules
C. Toxic granules are prominent secondary granules
D. Dohle bodies are agranular patches of DNA
B. Auer rods are composed of fused primary granules.
Auer rods are seen in the cytoplasm of malignant cells, most often myeloblasts, and are
composed of fused primary granules. Hypersegmented neutrophils have five lobes or
more and are associated with vitamin B12 or folate deficiency. Toxic granules are
primary granules with altered staining characteristics that stain in late-stage neutrophils
due to toxicity. Dohle bodies are agranular patches of RNA present in neutrophil
cytoplasm and associated with toxic states.
Which of the following factors is not associated with variations in the total WBC count?
A. Age
B. Exercise
C. Emotional stress
D. Sex
D. Sex
The total WBC count reference ranges for males and females are equivalent. WBC
counts do change with age, being higher in newborns and children than in adults. Any
change from basal conditions, such as exercise or emotional stress, will cause a
transient leukocytosis due to a redistribution of blood pools. WBC values are lower in
the morning and higher in the afternoon (diurnal variation).
Of the following, an absolute neutrophil count of 1.0*10^9/L would be associated with
A. Shortness of breath
B. Bleeding tendencies
C. Risk of infection
D. No clinical symptoms
C. Risk of infection
Neutropenia is associated with a risk of infection. The degree of neutropenia correlates
with the infection risk from high susceptibility (<1.010^9/L) to great risk (<0.510^9).
Infection increases with the degree and duration of the neutropenia. Shortness of breath
and bleeding tendencies are clinical symptoms associated with severe anemia and
thrombocytopenia, respectively.
Which of the following statements about basophils is false?
A. Morphologically, basophils resemble tissue mast cells
B. Membrane receptors bind IgG
C. Basophilic granules contain heparin and histamine
D. Granules are water soluble
B. Membrane receptors bind IgG
Basophils and tissue mast cells have receptors for IgE and complement components,
which trigger degranulation when appropriate antigens are present and are responsible
for severe hypersensitivity reactions (anaphylaxis). Basophils and tissue mast cells
have morphologic similarities but represent distinct cell types. Basophils possess water-
