th
h
h h
,Chapter 1: Fetal Lung DevelopmentTest B
z z z z z
ank
z
MULTIPLE CHOICE z
1. Which of the following phases of human lung development ishcharacterized by the formationof a ca
z z z z z z z z z z z z z z
z pillarynetworkharoundairwaypassages? z
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS: D z
The canalicular phase follows the pseudoglandular phase, lasting from approximately 17 weeks t
z z z z z z z z z z z z
zo 26 weeks of gestation. This phase is so named because of the appearance of vascularchannels, or
z z z z z z z z z z z z z z z z
capillaries, which begin to grow by forming a capillary network around the air passages. Durin g the
z z z z z z z z z z z z z z z z z
pseudoglandular stage, which begins at day 52 and extends to week 16 of gestation, the ai rway syst
z z z z z z z z z z z z z z z z z z
em subdivides extensively and the conducting airway system develops, ending with the therminal bro
z z z z z z z z z z z z z z
nchioles. The saccular stage of development, which takes place from weeks 29 to 36 o f gestation, is
z z z z z z z z z z z z z z z z z z
characterized by the development of sacs thatlater become alveoli. During the sacchular phase, a tre
z z z z z z z z z z z z z z z
mendous increase in the potential
z z z z z
gas-
exchanging surface area occurs. The distinction between the saccular stage and the alveolar s ta
z z z z z z z z z z z z z z
ge is arbitrary. The alveolar stage stretches from 39 weeks of gestation to term.This stage is repr
z z z z z z z z z z z z z z z z z
esented by the establishmenthof alveoli.
z z z z z
REF: pp. 3-5 z z
2. Regarding postnatal lung growth, by approximately whathage do most of the alveoli that willbe p
z z z z z z z z z z z z z z
z resenthin the lungs for lifehdevelop? z z z z
a. 6months z
b. 1year z
c. 1.5hyears
d. 2years z
ANS:v C z
Most of the postnatal formation of alveoli in the infantvoccurs over the first 1.5 years of life. Ath2 y
z z z z z z z z z z z z z z z z z z
earshof age, the number of alveoli varies substantially among individuals. After 2 yearsof age, m
z z z z z z z z z z z z z z z
ales have more alveoli than do females. After alveolar multiplication ends, the alveoli continue to in
z z z z z z z z z z z z z z z z
crease in size until thoracic growth is completed.
z z z z z z z z
REF: p.6 z z
3. The respiratory therapist is evaluating a newborn with mild respiratory distress due to trachealste no
z z z z z z z z z z z z z z
sis. During which period of lung development did this problem develop?
z z z z z z z z z z z
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
h ANS: A z
, The initial structures of the pulmonary tree develop during the embryonal stage. Errors in develo pme nt
z z z z z z z z z z z z z z z z
during this time may resulthin laryngeal, tracheal, or esophageal atresia or stenosis. Pulmo nary hy
z z z z z z z z z z z z z z z
poplasia, an incomplete development of the lungs characterized by anabnormally low n umber an
z z z z z z z z z z z z z z
d/or size of bronchopulmonary segments and/or alveoli, can develop during the pseu doglandular
z z z z z z z z z z z z z
phase. If the fetus is born during the canalicular phase (i.e., prematurely), severe re spiratory distres
z z z z z z z z z z z z z z z z
s can be expected becausehthe inadequately developed airways, along with ins ufficienthand imma
z z z z z z z z z z z z z
ture surfactant production by alveolar type II cells, gives rise to the constellati on of problems known
z z z z z z z z z z z z z z z z z
as infant respiratory distress syndrome.
z z z z z
REF: p.6 z z
4. Which of the following mechanisms is (are) responsible for the possible association betweenoligo h
z z z z z z z z z z z z z
z ydramnios and lung hypoplasia? z z z
I. Abnormal carbohydrate metabolism z z
II. Mechanical restriction of the chest wall z z z z z
III. Interference with fetal breathing z z z
IV. Failure to produce fetal lung liquid z z z z z
a. I and III only z z z
b. II and III only z z z
c. I, II, and IV only z z z z
d. II, III, and IV only z z z z
ANS:v D z
Oligohydramnios, a reduced quantity of amniotichfluid present for an extended period of time, z z z z z z z z z z z z
withhor withouthrenalh ano mTalEieSs,Tv isBv aA sNs oKciSatEeLd wLEi thR l. uCn Og M
z hypoplasia. Theh mechanismsvbyh whichh z z z z z z z
zamniotich fluhi d volume influences lung growth remain unclear. Possible explanations for
z z z z z z z z z z z
reduced quantity of amniotic fluid include mechanical restriction of the chesthwall, interference w ith
z z z z z z z z z z z z z
zfetal breathing, or failure to produce fetal lung liquid. These clinical and experimental obser vati
z z z z z z z z z z z z z z
ons possibly point to a common denominator, lung stretch, as being amajor growth stimulant.
z z z z z z z z z z z z z z
REF: pp. 6-7 z z
5. Whathis the purpose of the substance secreted by the type II pneumocyte?
z z z z z z z z z z z
a. To increase the gashexchange surface area
z z z z z
b. To reduce surface tension z z z
c. To maintain lung elasticity z z z
d. To preserve the volume of the amniotic fluid
z z z z z z z
ANS:v B z
The primary role of mammalian surfactant is tohlower the surface tension within the alveolus, specif ic
z z z z z z z z z z z z z z z
z ally aththe air– z z
liquid interface. This allows the delicate structure of the alveolus to expand when filled with air. W itho ut
z z z z z z z z z z z z z z z z z z
zsurfactant, the alveolus remains collapsed because of thehigh surface tension of the moist al veola r
z z z z z z z z z z z z z z z
surface. Surfactant isvcomposed predominantly of an intricate blend of phospholipids, neut ral lipid
z z z z z z z z z z z z z
zs,andproteins.
z z
REF: p.8 z z
, 6. Which of the following tests of the amniotic fluid have been shown to be sensitive indicatorsof lun g
z z z z z z z z z z z z z z z z z
maturity?
z
a. Levels of prednisone z z
b. Levels of epidermal growth factor z z z z
c. Levels of prostaglandins z z
d. Levels of phosphatidylglycerol and phosphatidylcholine z z z z
ANS:v D z
Ofclinical relevance during late gestation, analysis of amniotic fluid for the concentration ofphos pha
z z z z z z z z z z z z z
tidylglycerol and phosphatidylcholine has been shown to be a sensitive indicator of the state of fet
z z z z z z z z z z z z z z z z
al lung maturity.
z z z
REF: p.8 z z
7. Approximately how much fetal lung fluid is secreted daily? z z z z z z z z
a. About 150 to 200 ml z z z z
b. About 250 to 300 ml z z z z
c. About 350 to 400 ml z z z z
d. About 450 to 500 ml z z z z
z ANS:hB
Fetal lungs are secretory organs that make breathing-
z z z z z z z
like movements but serve no respiratory function before birth. They secrete abo ut
z z z z z z z z z z z z
250 to 300 ml of liquid per day.
z z z z z z z z
8. The lung bud emerges from which of the following structures?
z z z z z z z z z
a. The pharynx z
b. The foregut z
c. The mesenchyme z
d. The tubular epithelium z z
z ANS:hA
The embryonal phase includes primitive lung developmenthand is generally regarded to encompass the first 2
z z z z z z z z z z z z z z
monthsofgestation.
z z z
The lung begins to emerge as a bud from the pharynx 26 days after conception.
z z z z z z z z z z z z z z
h
h h
,Chapter 1: Fetal Lung DevelopmentTest B
z z z z z
ank
z
MULTIPLE CHOICE z
1. Which of the following phases of human lung development ishcharacterized by the formationof a ca
z z z z z z z z z z z z z z
z pillarynetworkharoundairwaypassages? z
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS: D z
The canalicular phase follows the pseudoglandular phase, lasting from approximately 17 weeks t
z z z z z z z z z z z z
zo 26 weeks of gestation. This phase is so named because of the appearance of vascularchannels, or
z z z z z z z z z z z z z z z z
capillaries, which begin to grow by forming a capillary network around the air passages. Durin g the
z z z z z z z z z z z z z z z z z
pseudoglandular stage, which begins at day 52 and extends to week 16 of gestation, the ai rway syst
z z z z z z z z z z z z z z z z z z
em subdivides extensively and the conducting airway system develops, ending with the therminal bro
z z z z z z z z z z z z z z
nchioles. The saccular stage of development, which takes place from weeks 29 to 36 o f gestation, is
z z z z z z z z z z z z z z z z z z
characterized by the development of sacs thatlater become alveoli. During the sacchular phase, a tre
z z z z z z z z z z z z z z z
mendous increase in the potential
z z z z z
gas-
exchanging surface area occurs. The distinction between the saccular stage and the alveolar s ta
z z z z z z z z z z z z z z
ge is arbitrary. The alveolar stage stretches from 39 weeks of gestation to term.This stage is repr
z z z z z z z z z z z z z z z z z
esented by the establishmenthof alveoli.
z z z z z
REF: pp. 3-5 z z
2. Regarding postnatal lung growth, by approximately whathage do most of the alveoli that willbe p
z z z z z z z z z z z z z z
z resenthin the lungs for lifehdevelop? z z z z
a. 6months z
b. 1year z
c. 1.5hyears
d. 2years z
ANS:v C z
Most of the postnatal formation of alveoli in the infantvoccurs over the first 1.5 years of life. Ath2 y
z z z z z z z z z z z z z z z z z z
earshof age, the number of alveoli varies substantially among individuals. After 2 yearsof age, m
z z z z z z z z z z z z z z z
ales have more alveoli than do females. After alveolar multiplication ends, the alveoli continue to in
z z z z z z z z z z z z z z z z
crease in size until thoracic growth is completed.
z z z z z z z z
REF: p.6 z z
3. The respiratory therapist is evaluating a newborn with mild respiratory distress due to trachealste no
z z z z z z z z z z z z z z
sis. During which period of lung development did this problem develop?
z z z z z z z z z z z
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
h ANS: A z
, The initial structures of the pulmonary tree develop during the embryonal stage. Errors in develo pme nt
z z z z z z z z z z z z z z z z
during this time may resulthin laryngeal, tracheal, or esophageal atresia or stenosis. Pulmo nary hy
z z z z z z z z z z z z z z z
poplasia, an incomplete development of the lungs characterized by anabnormally low n umber an
z z z z z z z z z z z z z z
d/or size of bronchopulmonary segments and/or alveoli, can develop during the pseu doglandular
z z z z z z z z z z z z z
phase. If the fetus is born during the canalicular phase (i.e., prematurely), severe re spiratory distres
z z z z z z z z z z z z z z z z
s can be expected becausehthe inadequately developed airways, along with ins ufficienthand imma
z z z z z z z z z z z z z
ture surfactant production by alveolar type II cells, gives rise to the constellati on of problems known
z z z z z z z z z z z z z z z z z
as infant respiratory distress syndrome.
z z z z z
REF: p.6 z z
4. Which of the following mechanisms is (are) responsible for the possible association betweenoligo h
z z z z z z z z z z z z z
z ydramnios and lung hypoplasia? z z z
I. Abnormal carbohydrate metabolism z z
II. Mechanical restriction of the chest wall z z z z z
III. Interference with fetal breathing z z z
IV. Failure to produce fetal lung liquid z z z z z
a. I and III only z z z
b. II and III only z z z
c. I, II, and IV only z z z z
d. II, III, and IV only z z z z
ANS:v D z
Oligohydramnios, a reduced quantity of amniotichfluid present for an extended period of time, z z z z z z z z z z z z
withhor withouthrenalh ano mTalEieSs,Tv isBv aA sNs oKciSatEeLd wLEi thR l. uCn Og M
z hypoplasia. Theh mechanismsvbyh whichh z z z z z z z
zamniotich fluhi d volume influences lung growth remain unclear. Possible explanations for
z z z z z z z z z z z
reduced quantity of amniotic fluid include mechanical restriction of the chesthwall, interference w ith
z z z z z z z z z z z z z
zfetal breathing, or failure to produce fetal lung liquid. These clinical and experimental obser vati
z z z z z z z z z z z z z z
ons possibly point to a common denominator, lung stretch, as being amajor growth stimulant.
z z z z z z z z z z z z z z
REF: pp. 6-7 z z
5. Whathis the purpose of the substance secreted by the type II pneumocyte?
z z z z z z z z z z z
a. To increase the gashexchange surface area
z z z z z
b. To reduce surface tension z z z
c. To maintain lung elasticity z z z
d. To preserve the volume of the amniotic fluid
z z z z z z z
ANS:v B z
The primary role of mammalian surfactant is tohlower the surface tension within the alveolus, specif ic
z z z z z z z z z z z z z z z
z ally aththe air– z z
liquid interface. This allows the delicate structure of the alveolus to expand when filled with air. W itho ut
z z z z z z z z z z z z z z z z z z
zsurfactant, the alveolus remains collapsed because of thehigh surface tension of the moist al veola r
z z z z z z z z z z z z z z z
surface. Surfactant isvcomposed predominantly of an intricate blend of phospholipids, neut ral lipid
z z z z z z z z z z z z z
zs,andproteins.
z z
REF: p.8 z z
, 6. Which of the following tests of the amniotic fluid have been shown to be sensitive indicatorsof lun g
z z z z z z z z z z z z z z z z z
maturity?
z
a. Levels of prednisone z z
b. Levels of epidermal growth factor z z z z
c. Levels of prostaglandins z z
d. Levels of phosphatidylglycerol and phosphatidylcholine z z z z
ANS:v D z
Ofclinical relevance during late gestation, analysis of amniotic fluid for the concentration ofphos pha
z z z z z z z z z z z z z
tidylglycerol and phosphatidylcholine has been shown to be a sensitive indicator of the state of fet
z z z z z z z z z z z z z z z z
al lung maturity.
z z z
REF: p.8 z z
7. Approximately how much fetal lung fluid is secreted daily? z z z z z z z z
a. About 150 to 200 ml z z z z
b. About 250 to 300 ml z z z z
c. About 350 to 400 ml z z z z
d. About 450 to 500 ml z z z z
z ANS:hB
Fetal lungs are secretory organs that make breathing-
z z z z z z z
like movements but serve no respiratory function before birth. They secrete abo ut
z z z z z z z z z z z z
250 to 300 ml of liquid per day.
z z z z z z z z
8. The lung bud emerges from which of the following structures?
z z z z z z z z z
a. The pharynx z
b. The foregut z
c. The mesenchyme z
d. The tubular epithelium z z
z ANS:hA
The embryonal phase includes primitive lung developmenthand is generally regarded to encompass the first 2
z z z z z z z z z z z z z z
monthsofgestation.
z z z
The lung begins to emerge as a bud from the pharynx 26 days after conception.
z z z z z z z z z z z z z z
