Chapter 30: Alterations of Hematologic Function in Children

Chapter 30: Alterations of Hematologic Function in Children

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. 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 a- and two g-chains rather than two a-and two b-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.

 

 

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.

 

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2. 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 g-chains on the hemoglobin, rather than two b-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.

 

 

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.

 

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3. Which blood cell type is elevated at birth but decreases to adult levels during the first year of life?

a.	Monocytes	c.	Neutrophils
b.	Platelets	d.	Lymphocytes

 

 

ANS:  A

Only monocyte counts are high in the first year of life and then decrease to adult levels.

 

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4. 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	c.	90 to 110; 140
b.	60 to 80; 120	d.	120 to 130; 150

 

 

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.

 

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5. What is the most common cause of insufficient erythropoiesis in children?

a.	Folic acid deficiency	c.	Hemoglobin abnormality
b.	Iron deficiency	d.	Erythrocyte abnormality

 

 

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.

 

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