Neonatal and Pediatric Respiratory Care 4th Edition Walsh Test Bank Chapter 1 - 36 Updated Guide 2022

,Chapter1:Fetal Lung Development
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Test Bank
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MULTIPLE CHOICE v




1. Which of the following phases of human lung development is characterized by the formation of
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a capillary network around airway passages?
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a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS: D v



The canalicular phase follows the pseudoglandular phase, lasting from approximately 17 wee ks
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to 26 weeks of gestation. This phase is so named because of the appearance of vascularchan nels,
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or capillaries, which begin to grow by forming a capillary network around the air passag es.
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During the pseudoglandular stage, which begins at day 52 and extends to week 16 of gesta tion,
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the airway system subdivides extensively and the conducting airway system develops, e nding
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with the terminal bronchioles. The saccular stage of development, which takes place fr om
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weeks 29 to 36 of gestation, is characterized by the development of sacs thatlater become
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alveoli. During the saccular phase, a tremendous increase in the potential
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gas-
exchanging surface area occurs. The distinction between the saccular stage and the alveol ar
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stage is arbitrary. The alveolar stage stretches from 39 weeks of gestation to term.This
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stage is represented by the establishment of alveoli.
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REF: pp. 3-5 v v v v




2. Regarding postnatal lung growth, by approximately what age do most of the alveoli that wil
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l be present in the lungs for life develop?
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a. 6 months v



b. 1 year v



c. 1.5 years v



d. 2 years v




ANS: C v



Most of the postnatal formation of alveoli in the infant occurs over the first 1.5 years of life. At
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2 years of age, the number of alveoli varies substantially among individuals. After 2 yearso f age,
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males have more alveoli than do females. After alveolar multiplication ends, the alveoli continue
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to increase in size until thoracic growth is completed.
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REF: p. 6 v v




3. The respiratory therapist is evaluating a newborn with mild respiratory distress due to trache
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alstenosis. During which period of lung development did this problem develop?
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a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS: A v

, The initial structures of the pulmonary tree develop during the embryonal stage. Errors in d
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evelopment during this time may result in laryngeal, tracheal, or esophageal atresia or steno
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sis. Pulmonary hypoplasia, an incomplete development of the lungs characterized by anabnor
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mally low number and/or size of bronchopulmonary segments and/or alveoli, can develop d
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uring the pseudoglandular phase. If the fetus is born during the canalicular phase (i.e., prema
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turely), severe respiratory distress can be expected because the inadequately developed airw
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ays, along with insufficient and immature surfactant production by alveolar type II cells, giv es
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rise to the constellation of problems known as infant respiratory distress syndrome.
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REF: p. 6 v v v




4. Which ofthe following mechanisms is (are) responsible for the possible association betweeno
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v ligohydramnios and lung hypoplasia? v v v




I. Abnormal carbohydrate metabolism v v



II. Mechanical restriction of the chest wall v v v v v



III. Interference with fetal breathing v v v



IV. Failure to produce fetal lung liquid v v v v v



a. I and III only v v v



b. II and III only v v v



c. I, II, and IV only v v v v



d. II, III, and IV only v v v v




ANS: D v



Oligohydramnios, a reduced quantity of amniotic fluid present for an extended period of time, v v v v v v v v v v v v v



withorwithoutrenal an o mTaE
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, iBs AasNsoKcSiaEteLd LwEitR
h .luCnO
gMhypoplasia. Themechanismsby wh
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ich 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, interfere nce
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with fetal breathing, or failure to produce fetal lung liquid. These clinical and experimen tal
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observations possibly point to a common denominator, lung stretch, as being a m ajor gro wth
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stimulant.
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REF: pp. 6-7 v v




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
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b. To reduce surface tension v v v



c. To maintain lung elasticity v v v



d. To preserve the volume of the amniotic fluid
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ANS: B v



The primary role of mammalian surfactant is to lower the surface tension within the alveolus,
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specifically at the air–
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liquid interface. This allows the delicate structure of the alveolus to expand when filled with a ir.
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Without surfactant, the alveolus remains collapsed because of thehigh surface tension of th e
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moist alveolar surface. Surfactant is composed predominantly of an intricate blend of phosp
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holipids, neutral lipids, and proteins.
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REF: p. 8 v v

, 6. Which of the following tests of the amniotic fluid have been shown to be sensitive indicators of
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lung maturity?
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a. Levels of prednisone v v



b. Levels of epidermal growth factor v v v v



c. Levels of prostaglandins v v



d. Levels of phosphatidylglycerol and phosphatidylcholine v v v v




ANS: D v



Of clinical relevance during late gestation, analysis of amniotic fluid for the concentration of
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phosphatidylglycerol and phosphatidylcholine has been shown to be a sensitive indicator of
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the state of fetal lung maturity.
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REF: p. 8 v v




7. Approximately how much fetal lung fluid is secreted daily? v v v v v v v v



a. About 150 to 200 ml v v v v



b. About 250 to 300 ml v v v v



c. About 350 to 400 ml v v v v



d. About 450 to 500 ml v es v v




ANS: B
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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 v



b. The foregut v



c. The mesenchyme
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d. The tubular epithelium
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ANS: A
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The embryonal phase includes primitive lung development and is generally regarded to encompass the first 2 mo nths
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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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