Chapter 31: Alterations of Hematologic
Function in Children UPDATED ACTUAL
Exam Questions and CORRECT Answers
What is the cause of polycythemia in the fetus?
a.
Fetal hemoglobin has a greater affinity for oxygen as a result of diphosphoglycerate (DPG).
b.
The fetus has a different hemoglobin structure of two α- and two γ-chains rather than two α-and
two β-chains.
c.
Increased erythropoiesis occurs in response to the hypoxic intrauterine environment.
d.
The lungs of the fetus are undeveloped and unable to diffuse oxygen adequately to the
pulmonary capillaries. - CORRECT ANSWER - ANS: C
The hypoxic intrauterine environment stimulates erythropoietin production in the fetus. This
selection is the only option that accurately explains why the fetus develops polycythemia.
Why does fetal hemoglobin have a greater affinity for oxygen than adult hemoglobin?
a.
The fetus does not have its own oxygen supply and must rely on oxygen from the maternal
vascular system.
b.
The fetus has two γ-chains on the hemoglobin, rather than two β-chains as in the adult.
c.
Fetal hemoglobin interacts less readily with diphosphoglycerate (DPG), which inhibits
hemoglobin-oxygen binding.
d.
Fetal hemoglobin production occurs in the vessels and liver rather than in the bone marrow as in
the adult - CORRECT ANSWER - ANS: C
,Fetal hemoglobin has greater affinity for oxygen than does adult hemoglobin because it interacts
less readily with the enzyme, DPG, which inhibits hemoglobin-oxygen binding. This selection is
the only option that accurately explains why fetal hemoglobin has a greater affinity for oxygen
than adult hemoglobin.
Which blood cell type is elevated at birth but decreases to adult levels during the first year of
life?
a.
Monocytes
b.
Platelets
c.
Neutrophils
d.
Lymphocytes - CORRECT ANSWER - ANS: A
Only monocyte counts are high in the first year of life and then decrease to adult levels.
In a full-term infant, the normal erythrocyte life span is _____ days, whereas the adult
erythrocyte life span is _____ days.
a.
30 to 50; 80
b.
60 to 80; 120
c.
90 to 110; 140
d.
120 to 130; 150 - CORRECT ANSWER - ANS: B
In full-term infants, normal erythrocyte life span is 60 to 80 days; in premature infants it may be
as short as 20 to 30 days; and in children and adolescents, it is 120 days, the same as that in
adults.
, What is the most common cause of insufficient erythropoiesis in children?
a.
Folic acid deficiency
b.
Iron deficiency
c.
Hemoglobin abnormality
d.
Erythrocyte abnormality - CORRECT ANSWER - ANS: B
Similar to the anemias of adulthood, ineffective erythropoiesis or premature destruction of
erythrocytes causes the anemias of childhood. The most common cause of insufficient
erythropoiesis is iron deficiency. The other options may be causes but are not common ones.
How does hemolytic disease of the newborn (HDN) cause acquired congenital hemolytic
anemia?
a.
HDN develops when hypoxia or dehydration causes the erythrocytes to change shapes, which are
then recognized as foreign and removed from circulation.
b.
HDN is an alloimmune disease in which the mother's immune system produces antibodies
against fetal erythrocytes, which are recognized as foreign and removed from circulation.
c.
HDN develops when the polycythemia present in fetal life continues after birth, causing the
excessive number of erythrocytes to be removed from circulation.
d.
HDN is an autoimmune disease in which the fetus's immune system produces antibodies against
fetal erythrocytes, which are recognized as foreign and removed from circulation. - CORRECT
ANSWER - ANS: B
HDN is an alloimmune disease in which maternal blood and fetal blood are antigenically
incompatible, causing the mother's immune system to produce antibodies against fetal
Function in Children UPDATED ACTUAL
Exam Questions and CORRECT Answers
What is the cause of polycythemia in the fetus?
a.
Fetal hemoglobin has a greater affinity for oxygen as a result of diphosphoglycerate (DPG).
b.
The fetus has a different hemoglobin structure of two α- and two γ-chains rather than two α-and
two β-chains.
c.
Increased erythropoiesis occurs in response to the hypoxic intrauterine environment.
d.
The lungs of the fetus are undeveloped and unable to diffuse oxygen adequately to the
pulmonary capillaries. - CORRECT ANSWER - ANS: C
The hypoxic intrauterine environment stimulates erythropoietin production in the fetus. This
selection is the only option that accurately explains why the fetus develops polycythemia.
Why does fetal hemoglobin have a greater affinity for oxygen than adult hemoglobin?
a.
The fetus does not have its own oxygen supply and must rely on oxygen from the maternal
vascular system.
b.
The fetus has two γ-chains on the hemoglobin, rather than two β-chains as in the adult.
c.
Fetal hemoglobin interacts less readily with diphosphoglycerate (DPG), which inhibits
hemoglobin-oxygen binding.
d.
Fetal hemoglobin production occurs in the vessels and liver rather than in the bone marrow as in
the adult - CORRECT ANSWER - ANS: C
,Fetal hemoglobin has greater affinity for oxygen than does adult hemoglobin because it interacts
less readily with the enzyme, DPG, which inhibits hemoglobin-oxygen binding. This selection is
the only option that accurately explains why fetal hemoglobin has a greater affinity for oxygen
than adult hemoglobin.
Which blood cell type is elevated at birth but decreases to adult levels during the first year of
life?
a.
Monocytes
b.
Platelets
c.
Neutrophils
d.
Lymphocytes - CORRECT ANSWER - ANS: A
Only monocyte counts are high in the first year of life and then decrease to adult levels.
In a full-term infant, the normal erythrocyte life span is _____ days, whereas the adult
erythrocyte life span is _____ days.
a.
30 to 50; 80
b.
60 to 80; 120
c.
90 to 110; 140
d.
120 to 130; 150 - CORRECT ANSWER - ANS: B
In full-term infants, normal erythrocyte life span is 60 to 80 days; in premature infants it may be
as short as 20 to 30 days; and in children and adolescents, it is 120 days, the same as that in
adults.
, What is the most common cause of insufficient erythropoiesis in children?
a.
Folic acid deficiency
b.
Iron deficiency
c.
Hemoglobin abnormality
d.
Erythrocyte abnormality - CORRECT ANSWER - ANS: B
Similar to the anemias of adulthood, ineffective erythropoiesis or premature destruction of
erythrocytes causes the anemias of childhood. The most common cause of insufficient
erythropoiesis is iron deficiency. The other options may be causes but are not common ones.
How does hemolytic disease of the newborn (HDN) cause acquired congenital hemolytic
anemia?
a.
HDN develops when hypoxia or dehydration causes the erythrocytes to change shapes, which are
then recognized as foreign and removed from circulation.
b.
HDN is an alloimmune disease in which the mother's immune system produces antibodies
against fetal erythrocytes, which are recognized as foreign and removed from circulation.
c.
HDN develops when the polycythemia present in fetal life continues after birth, causing the
excessive number of erythrocytes to be removed from circulation.
d.
HDN is an autoimmune disease in which the fetus's immune system produces antibodies against
fetal erythrocytes, which are recognized as foreign and removed from circulation. - CORRECT
ANSWER - ANS: B
HDN is an alloimmune disease in which maternal blood and fetal blood are antigenically
incompatible, causing the mother's immune system to produce antibodies against fetal
