Ciulla: Hematology UPDATED Questions
and CORRECT Answers
What is the first type of cell produced by the developing embryo?
A. Erythrocyte
B. Granulocyte
C. Lymphocyte
D. Thrombocyte - CORRECT ANSWER - A.
The need for oxygen delivery to developing tissues results in the production of erythrocytes
before other blood cells. Erythropoiesis commences in the yolk sac as early as the fourteenth day
of embryonic development. These primitive red cells produce embryonic hemoglobins that
temporarily serve oxygen needs of the fetus. Myelopoietic and lymphopoietic activities begin
when the liver and spleen become sites of production at 6-9 weeks of gestation; however,
erythropoiesis still predominates. At this time, the red cells produce hemoglobin F, which is the
chief oxygen carrier during fetal life
What percentage of tissue located in the bone marrow cavities of adults is fat?
A. 10%
B. 25%
C. 50%
D. 75% - CORRECT ANSWER - C.
In the infant, there is an increased demand for blood formation because of the rate of growth. At
birth, all bone marrow cavities are filled with hematopoietic tissue (active red marrow). As the
growth rate slows, there is less need for active marrow. Fatty infiltration of the marrow becomes
noticeable at about 4 years of age as cell production diminishes within the shafts of the long
bones and is filled with yellow inactive tissue. Fat comprises 50% of the total marrow space in
the adult. Except for lymphopoiesis, hematopoiesis is confined to the flat bones and pelvic area
by the age of 25 years.
Which of the following is not characteristic of pluripotent hematopoietic stem cells?
A. Possess self-renewal ability B. Produce progenitor cells committed to a single cell lineage
C. Express the stem cell marker CD 13
,D. Are morphologically unrecognizable - CORRECT ANSWER - C.
Hematopoietic stem cells can make copies of themselves to maintain the stem cell pool and
possess the ability to generate cells of all lineages (pluripotential). These stem cells give rise to
multipotential myeloid and lymphoid progenitor cells, which ultimately produce progenitor cells
that are restricted to a specific cell lineage. With appropriate cytokine stimulus, the committed
progenitor cells undergo proliferation to recognizable precursors that produce an amplified
number of mature end-stage cells. Stem cells and progenitor cells cannot be morphologically
distinguished (look similar to small lymphocytes) but can be identified phenotypically by
markers such as the stem cell marker CD34. CD34 expression is lost as antigens for a specific
cell lineage are expressed. CD 13 is a marker expressed by myeloid precursors.
In an adult, what are the two best areas for obtaining active bone marrow by aspiration?
A. Vertebra, tibia
B. Sternum, vertebra
C. Anterior iliac crest, tibia
D. Posterior iliac crest, sternum - CORRECT ANSWER - D.
Unlike the infant, in which all bone marrow is capable of forming blood cells, the active marrow
in an adult is confined to the flat bones of the skeleton such as the sternum and posterior iliac
crest. Although the spinous processes of the vertebrae contain active marrow, these sites are
rarely used for aspiration in adults because of the danger of damage to the spinal cord. Sternal
puncture also presents a possibility of serious damage to underlying structures, but this site may
be used because of easy accessibility or if the aspirate is a "dry tap" in the iliac crest. To obtain
both a bone maiTow aspirate and core biopsy, most marrow specimens are taken from the
posterior iliac crest. The anterior iliac crest may occasionally be used in adults and sometimes
the tibia in children less than 2 years of age.
What is the normal ratio of myeloid to erythroid precursors in bone marrow (M:E ratio)?
A. 1:1
B. 1:3
C. 4:1
D. 8: - CORRECT ANSWER - C.
The ratio between all granulocytes and their precursors and all nucleated red cell precursors
represents the myeloid-to-erythroid ratio. Myeloid precursors outnumber erythroid precursors by
about 3 or 4 to 1 in the normal bone marrow. Although there are many more red blood cells in
the peripheral blood than granulocytes, red blood cells have a much longer life span in
,circulation (120 days) as compared to granulocytes (about 8 hours). Granulocytes, therefore,
require a more continual production than erythrocytes and are the most numerous marrow
precursors. Alterations in the M:E ratio, such as 1:1 or 8:1, may indicate erythroid hyperplasia or
granulocytic hyperplasia, respectively.
Which of the following does not accurately describe hematopoietic growth factors? A. Bind to
target cell receptors to express activity
B. Action of majority is lineage restricted
C. May promote or suppress cell death
D. Can stimulate or inhibit cell proliferation - CORRECT ANSWER - B.
A diverse group of growth factors (cytokines) regulate and maintain hematopoiesis in a steady
state. Most hematopoietic growth factors are not lineage restricted but can act on more than one
cell type and have multiple functions. For example, interleukins (IL-3) and colony stimulating
factors
(GM-CSF) affect multiple cell lines; whereas erythropoietin action is limited to erythroid cells.
Cytokines are glycoproteins that usually express activity by binding to specific receptors on
target cells. The action of growth factors on hematopoietic progenitor and precursor cells can
stimulate or inhibit cell proliferation and differentiation as well as promote or suppress cell
death. Growth factors may act alone or together to exert a positive or negative influence on
hematopoiesis as well as on the function of mature cells. A determining factor for controlling the
rate of cell production is cytokine stimulation in response to physiologic need.
In the third month of gestation, what is the primary site of hematopoiesis?
A. Liver
B. Marrow of long bones
C. Spleen
D. Yolk sac - CORRECT ANSWER - A.
The liver of the fetus assumes responsibility for hematopoiesis about the second month of
gestation. From 3 to 6 months of fetal development, the spleen, thymus, and lymph nodes are
also involved, but the principal site of hematopoiesis remains the liver. By the seventh
gestational month, the bone marrow becomes the primary hematopoietic site. Around birth, the
liver and spleen have ceased hematopoiesis (except for splenic lymphopoiesis) but maintain the
potential for reactivation of hematopoiesis.
, The mechanism that relays information about tissue oxygen levels to erythropoietin-producing
sites is located in the
A. Brain
B. Kidney
C. Liver
D. Spleen - CORRECT ANSWER - B.
Erythropoietin (EPO) is a hormone that stimulates red cell production in the bone marrow by its
action on the committed RBC progenitor cells. To maintain optimal erythrocyte mass for tissue
oxygenation, the body's mechanism for sensing tissue oxygen levels is located in the kidney.
Erythropoietin production increases when hypoxia is detected by renal oxygen sensors, with 90%
being synthesized in the kidney and 10% in the liver. EPO levels in the blood vary according to
the oxygen carrying capacity of the blood (e.g., EPO levels rise in anemia and fall when tissue
oxygen levels return to normal).
Antigen-independent lymphopoiesis occurs in primary lymphoid tissue located in the
A. Liver and kidney
B. Spleen and lymph nodes
C. Peyer's patches and spleen D. Thymus and bone marrow - CORRECT ANSWER - D.
The marrow-derived common lymphoid progenitor cell ultimately gives rise to lymphocytes of
T, B, or NK (presumably) cell lineages. Antigenindependent lymphopoiesis occurs in primary
lymphoid tissue located in the thymus and bone marrow. The formation of immunocompetent T
and B cells from precursor cells is influenced by environment (thymus, bone marrow) and
several interleukins. Antigen-dependent lymphopoiesis occurs in secondary lymphoid tissue
(spleen, lymph nodes, Peyer's patches of the gastrointestinal tract) and begins with antigenic
stimulation of immunocompetent cells.
Programmed cell death is called
A. Necrosis
B. Apoptosis
C. Cellular senescence
D. Terminal differentiation - CORRECT ANSWER - B.
Apoptosis is physiological cell death that can be induced by deprivation of growth factors or
prevented by growth-promoting cytokines. Apoptosis plays an important role in the regulation of
and CORRECT Answers
What is the first type of cell produced by the developing embryo?
A. Erythrocyte
B. Granulocyte
C. Lymphocyte
D. Thrombocyte - CORRECT ANSWER - A.
The need for oxygen delivery to developing tissues results in the production of erythrocytes
before other blood cells. Erythropoiesis commences in the yolk sac as early as the fourteenth day
of embryonic development. These primitive red cells produce embryonic hemoglobins that
temporarily serve oxygen needs of the fetus. Myelopoietic and lymphopoietic activities begin
when the liver and spleen become sites of production at 6-9 weeks of gestation; however,
erythropoiesis still predominates. At this time, the red cells produce hemoglobin F, which is the
chief oxygen carrier during fetal life
What percentage of tissue located in the bone marrow cavities of adults is fat?
A. 10%
B. 25%
C. 50%
D. 75% - CORRECT ANSWER - C.
In the infant, there is an increased demand for blood formation because of the rate of growth. At
birth, all bone marrow cavities are filled with hematopoietic tissue (active red marrow). As the
growth rate slows, there is less need for active marrow. Fatty infiltration of the marrow becomes
noticeable at about 4 years of age as cell production diminishes within the shafts of the long
bones and is filled with yellow inactive tissue. Fat comprises 50% of the total marrow space in
the adult. Except for lymphopoiesis, hematopoiesis is confined to the flat bones and pelvic area
by the age of 25 years.
Which of the following is not characteristic of pluripotent hematopoietic stem cells?
A. Possess self-renewal ability B. Produce progenitor cells committed to a single cell lineage
C. Express the stem cell marker CD 13
,D. Are morphologically unrecognizable - CORRECT ANSWER - C.
Hematopoietic stem cells can make copies of themselves to maintain the stem cell pool and
possess the ability to generate cells of all lineages (pluripotential). These stem cells give rise to
multipotential myeloid and lymphoid progenitor cells, which ultimately produce progenitor cells
that are restricted to a specific cell lineage. With appropriate cytokine stimulus, the committed
progenitor cells undergo proliferation to recognizable precursors that produce an amplified
number of mature end-stage cells. Stem cells and progenitor cells cannot be morphologically
distinguished (look similar to small lymphocytes) but can be identified phenotypically by
markers such as the stem cell marker CD34. CD34 expression is lost as antigens for a specific
cell lineage are expressed. CD 13 is a marker expressed by myeloid precursors.
In an adult, what are the two best areas for obtaining active bone marrow by aspiration?
A. Vertebra, tibia
B. Sternum, vertebra
C. Anterior iliac crest, tibia
D. Posterior iliac crest, sternum - CORRECT ANSWER - D.
Unlike the infant, in which all bone marrow is capable of forming blood cells, the active marrow
in an adult is confined to the flat bones of the skeleton such as the sternum and posterior iliac
crest. Although the spinous processes of the vertebrae contain active marrow, these sites are
rarely used for aspiration in adults because of the danger of damage to the spinal cord. Sternal
puncture also presents a possibility of serious damage to underlying structures, but this site may
be used because of easy accessibility or if the aspirate is a "dry tap" in the iliac crest. To obtain
both a bone maiTow aspirate and core biopsy, most marrow specimens are taken from the
posterior iliac crest. The anterior iliac crest may occasionally be used in adults and sometimes
the tibia in children less than 2 years of age.
What is the normal ratio of myeloid to erythroid precursors in bone marrow (M:E ratio)?
A. 1:1
B. 1:3
C. 4:1
D. 8: - CORRECT ANSWER - C.
The ratio between all granulocytes and their precursors and all nucleated red cell precursors
represents the myeloid-to-erythroid ratio. Myeloid precursors outnumber erythroid precursors by
about 3 or 4 to 1 in the normal bone marrow. Although there are many more red blood cells in
the peripheral blood than granulocytes, red blood cells have a much longer life span in
,circulation (120 days) as compared to granulocytes (about 8 hours). Granulocytes, therefore,
require a more continual production than erythrocytes and are the most numerous marrow
precursors. Alterations in the M:E ratio, such as 1:1 or 8:1, may indicate erythroid hyperplasia or
granulocytic hyperplasia, respectively.
Which of the following does not accurately describe hematopoietic growth factors? A. Bind to
target cell receptors to express activity
B. Action of majority is lineage restricted
C. May promote or suppress cell death
D. Can stimulate or inhibit cell proliferation - CORRECT ANSWER - B.
A diverse group of growth factors (cytokines) regulate and maintain hematopoiesis in a steady
state. Most hematopoietic growth factors are not lineage restricted but can act on more than one
cell type and have multiple functions. For example, interleukins (IL-3) and colony stimulating
factors
(GM-CSF) affect multiple cell lines; whereas erythropoietin action is limited to erythroid cells.
Cytokines are glycoproteins that usually express activity by binding to specific receptors on
target cells. The action of growth factors on hematopoietic progenitor and precursor cells can
stimulate or inhibit cell proliferation and differentiation as well as promote or suppress cell
death. Growth factors may act alone or together to exert a positive or negative influence on
hematopoiesis as well as on the function of mature cells. A determining factor for controlling the
rate of cell production is cytokine stimulation in response to physiologic need.
In the third month of gestation, what is the primary site of hematopoiesis?
A. Liver
B. Marrow of long bones
C. Spleen
D. Yolk sac - CORRECT ANSWER - A.
The liver of the fetus assumes responsibility for hematopoiesis about the second month of
gestation. From 3 to 6 months of fetal development, the spleen, thymus, and lymph nodes are
also involved, but the principal site of hematopoiesis remains the liver. By the seventh
gestational month, the bone marrow becomes the primary hematopoietic site. Around birth, the
liver and spleen have ceased hematopoiesis (except for splenic lymphopoiesis) but maintain the
potential for reactivation of hematopoiesis.
, The mechanism that relays information about tissue oxygen levels to erythropoietin-producing
sites is located in the
A. Brain
B. Kidney
C. Liver
D. Spleen - CORRECT ANSWER - B.
Erythropoietin (EPO) is a hormone that stimulates red cell production in the bone marrow by its
action on the committed RBC progenitor cells. To maintain optimal erythrocyte mass for tissue
oxygenation, the body's mechanism for sensing tissue oxygen levels is located in the kidney.
Erythropoietin production increases when hypoxia is detected by renal oxygen sensors, with 90%
being synthesized in the kidney and 10% in the liver. EPO levels in the blood vary according to
the oxygen carrying capacity of the blood (e.g., EPO levels rise in anemia and fall when tissue
oxygen levels return to normal).
Antigen-independent lymphopoiesis occurs in primary lymphoid tissue located in the
A. Liver and kidney
B. Spleen and lymph nodes
C. Peyer's patches and spleen D. Thymus and bone marrow - CORRECT ANSWER - D.
The marrow-derived common lymphoid progenitor cell ultimately gives rise to lymphocytes of
T, B, or NK (presumably) cell lineages. Antigenindependent lymphopoiesis occurs in primary
lymphoid tissue located in the thymus and bone marrow. The formation of immunocompetent T
and B cells from precursor cells is influenced by environment (thymus, bone marrow) and
several interleukins. Antigen-dependent lymphopoiesis occurs in secondary lymphoid tissue
(spleen, lymph nodes, Peyer's patches of the gastrointestinal tract) and begins with antigenic
stimulation of immunocompetent cells.
Programmed cell death is called
A. Necrosis
B. Apoptosis
C. Cellular senescence
D. Terminal differentiation - CORRECT ANSWER - B.
Apoptosis is physiological cell death that can be induced by deprivation of growth factors or
prevented by growth-promoting cytokines. Apoptosis plays an important role in the regulation of
