Test Bank for Neonatal and Pediatric Respiratory
Care, 6th Edition
by Brian K. Walsh
,Chapter 1: Fetal Lung Development
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Test Bank
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MULTIPLE CHOICE AK
1. Which of the following phases of human lung development is characterized by the formationof a
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capillary network around airway passages? AK AK AK AK
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS: D A K
The canalicular phase follows the pseudoglandular phase, lasting from approximately 17 weeks
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to 26 weeks of gestation. This phase is so named because of the appearance of vascularchannels, or
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capillaries, which begin to grow by forming a capillary network around the air passages. During
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the pseudoglandular stage, which begins at day 52 and extends to week 16 of gestation, the airwa
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y system subdivides extensively and the conducting airway system develops, ending with the ter
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minal bronchioles. The saccular stage of development, which takes place from weeks 29 to 36 of g
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estation, is characterized by the development of sacs thatlater become alveoli. During the saccula
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r phase, a tremendous increase in the potential
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gas-
exchanging surface area occurs. The distinction between the saccular stage and the alveolar s AK AK AK AK AK AK AK AK AK AK AK AK AK
tage is arbitrary. The alveolar stage stretches from 39 weeks of gestation to term.This stage is
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represented by the establishment of alveoli.
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REF: pp. 3-5 A K AKAKA K
2. Regarding postnatal lung growth, by approximately what age do most of the alveoli that willbe AK AK AK AK AK AK AK AK AK AK AK AK AK AK A
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present in the lungs for life develop? AK AK AK AK AK AK
a. 6 months AK
b. 1 year AK
c. 1.5 years AK
d. 2 years AK
ANS: C A K
Most of the postnatal formation of alveoli in the infant occurs over the first 1.5 years of life. At 2
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years of age, the number of alveoli varies substantially among individuals. After 2 yearsof age, m
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ales have more alveoli than do females. After alveolar multiplication ends, the alveoli continue t
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o increase in size until thoracic growth is completed.
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REF: p. 6 AK AK
3. The respiratory therapist is evaluating a newborn with mild respiratory distress due to tracheals
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tenosis. During which period of lung development did this problem develop?
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a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS: A A K
, The initial structures of the pulmonary tree develop during the embryonal stage. Errors in deve
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lopment during this time may result in laryngeal, tracheal, or esophageal atresia or stenosis. Pu
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lmonary hypoplasia, an incomplete development of the lungs characterized by anabnormally lo
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w number and/or size of bronchopulmonary segments and/or alveoli, can develop during the p
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seudoglandular phase. If the fetus is born during the canalicular phase (i.e., prematurely), sever AK AK AK AK AK AK AK AK AK AK AK AK AK
e respiratory distress can be expected because the inadequately developed airways, along with i
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nsufficient and immature surfactant production by alveolar type II cells, gives rise to the conste AK AK AK AK AK AK AK AK AK AK AK AK AK AK
llation of problems known as infant respiratory distress syndrome.
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REF: p. 6 AKAKA K AK
4. Which of the following mechanisms is (are) responsible for the possible association betweenolig
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ohydramnios and lung hypoplasia? AK AK AK
I. Abnormal carbohydrate metabolism AK AK
II. Mechanical restriction of the chest wall AK AK AK AK AK
III. Interference with fetal breathing AK AK AK
IV. Failure to produce fetal lung liquid AK AK AK AK AK
a. I and III only AK AK AK
b. II and III only AK AK AK
c. I, II, and IV only AK AK AK AK
d. II, III, and IV only AK AK AK AK
ANS: D A K
Oligohydramnios, a reduced quantity of amniotic fluid present for an extended period of time, AK AK AK AK AK AK AK AK AK AK AK AK AK
with or without renal anomTaE
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, iB
sAasNsoKcS
iaE
teLdLwEitR
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gMhypoplasia. The mechanisms by whic A K A K AK A
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h amniotic fluid volume influences lung growth remain unclear. Possible explanations for
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reduced quantity of amniotic fluid include mechanical restriction of the chest wall, interference
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with fetal breathing, or failure to produce fetal lung liquid. These clinical and experimental obs
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ervations possibly point to a common denominator, lung stretch, as being amajor growth stim
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ulant.
REF: pp. 6-7 AK AK
5. What is the purpose of the substance secreted by the type II pneumocyte?
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a. To increase the gas exchange surface area AK AK AK AK AK AK
b. To reduce surface tension AK AK AK
c. To maintain lung elasticity AK AK AK
d. To preserve the volume of the amniotic fluid AK AK AK AK AK AK AK
ANS: B A K
The primary role of mammalian surfactant is to lower the surface tension within the alveolus, spe
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cifically at the air– AK AK AK
liquid interface. This allows the delicate structure of the alveolus to expand when filled with air.
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Without surfactant, the alveolus remains collapsed because of thehigh surface tension of the mois
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t alveolar surface. Surfactant is composed predominantly of an intricate blend of phospholipids, n
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eutral lipids, and proteins. AK AK AK
REF: p. 8 AK AK
, 6. Which of the following tests of the amniotic fluid have been shown to be sensitive indicatorsof lu
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ng maturity? AK
a. Levels of prednisone AK AK
b. Levels of epidermal growth factor AK AK AK AK
c. Levels of prostaglandins AK AK
d. Levels of phosphatidylglycerol and phosphatidylcholine AK AK AK AK
ANS: D A K
Of clinical relevance during late gestation, analysis of amniotic fluid for the concentration ofpho
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sphatidylglycerol and phosphatidylcholine has been shown to be a sensitive indicator of the sta AK AK AK AK AK AK AK AK AK AK AK AK AK
te of fetal lung maturity.
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REF: p. 8 AK AK
7. Approximately how much fetal lung fluid is secreted daily?
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a. About 150 to 200 ml
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b. About 250 to 300 ml
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c. About 350 to 400 ml
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d. About 450 to 500 ml
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ANS: B AK
Fetal lungs are secretory organs that make breathing-
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like movements but serve no respiratory function before birth. They secrete
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about 250 to 300 ml of liquid per day.
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8. The lung bud emerges from which of the following structures?
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a. The pharynx
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b. The foregut
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c. The mesenchyme
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d. The tubular epithelium
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ANS: A AK
The embryonal phase includes primitive lung development and is generally regarded to encompass the first 2 months
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of gestation.
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The lung begins to emerge as a bud from the pharynx 26 days after conception.
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