Neonatal and Pediatric Respir
v v v
atory Care 5th EditionWalsh
v v v v v
Test Bank A+
v v
, Chapter 1: Fetal Lung Development Test Bank
v v v v v v
MULTIPLEvCHOICE
1. Whichvofvthevfollowingvphasesvofvhumanvlungvdevelopmentvisvcharacterizedvbyvthevf
ormationvofvavcapillaryvnetworkvaroundvairwayvpassages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS:vD
Thevcanalicularvphasevfollowsvthevpseudoglandularvphase,vlastingvfromvapproximatelyv17vweeksvto
v26vweeksvofvgestation.vThisvphasevisvsovnamedvbecausevofvthevappearancevofvvascularvchannels,vorvc
apillaries,vwhichvbeginvtovgrowvbyvformingvavcapillaryvnetworkvaroundvthevairvpassages.
Duringvthevpseudoglandularvstage,vwhichvbeginsvatvdayv52vandvextendsvtovweekv16vofvgestation,vth
evairwayvsystemvsubdividesvextensivelyvandvthevconductingvairwayvsystemvdevelops,vendingvwithvt
hevterminalvbronchioles.vThevsaccularvstagevofvdevelopment,vwhichvtakesvplacevfromvweeksv29vtov3
6vofvgestation,visvcharacterizedvbyvthevdevelopmentvofvsacsvthatvlatervbecomevalveoli.
Duringvthevsaccularvphase,vavtremendousvincreasevinvthevpotentialvgas-
vexchangingvsurfacevareavoccurs.vThevdistinctionvbetweenvthevsaccularvstagevandvthevalveolarvsta
gevisvarbitrary.vThevalveolarvstagevstretchesvfromv39vweeksvofvgestationvtovterm.vThisvstagevisvrep
resentedvbyvthevestablishmentvofvalveoli.
REF:vpp.v3-5
2. Regardingvpostnatalvlungvgrowth,vbyvapproximatelyvwhatvagevdovmostvofvthevalveolivthatv
willvbevpresentvinvthevlungsvforvlifevdevelop?
a. 6vmonths
,b. 1vyear
c. 1.5vyears
d. 2vyears
ANS:vC
Mostvofvthevpostnatalvformationvofvalveolivinvthevinfantvoccursvovervthevfirstv1.5vyearsvofvlife.vAtv2vy
earsvofvage,vthevnumbervofvalveolivvariesvsubstantiallyvamongvindividuals.vAfterv2vyearsvofvage,vmal
esvhavevmorevalveolivthanvdovfemales.vAftervalveolarvmultiplicationvends,vthevalveolivcontinuevtovin
creasevinvsizevuntilvthoracicvgrowthvisvcompleted.
REF:vp.v6
3. Thevrespiratoryvtherapistvisvevaluatingvavnewbornvwithvmildvrespiratoryvdistressvduevtovt
rachealvstenosis.vDuringvwhichvperiodvofvlungvdevelopmentvdidvthisvproblemvdevelop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS:vA
Thevinitialvstructuresvofvthevpulmonaryvtreevdevelopvduringvthevembryonalvstage.vErrorsvinvdevelop
mentvduringvthisvtimevmayvresultvinvlaryngeal,vtracheal,vorvesophagealvatresiavorvstenosis.vPulmonar
yvhypoplasia,vanvincompletevdevelopmentvofvthevlungsvcharacterizedvbyvanvabnormallyvlowvnumber
vand/orvsizevofvbronchopulmonaryvsegmentsvand/orvalveoli,vcanvdevelopvduringvthevpseudoglandula
rvphase.vIfvthevfetusvisvbornvduringvthevcanalicularvphasev(i.e.,vprematurely),vseverevrespiratoryvdistre
ssvcanvbevexpectedvbecausevthevinadequatelyvdevelopedvairways,valongvwithvinsufficientvandvimmat
urevsurfactantvproductionvbyvalveolarvtypevIIvcells,vgivesvrisevtovthevconstellationvofvproblemsvknow
nvasvinfantvrespiratoryvdistressvsyndrome.
, REF:v p.v6
4. Whichvofvthevfollowingvmechanismsvisv(are)vresponsiblevforvthevpossiblevassociationvb
etweenvoligohydramniosvandvlungvhypoplasia?
I. Abnormalvcarbohydratevmetabolism
II. Mechanicalvrestrictionvofvthevchestvwall
III. Interferencevwithvfetalvbreathing
IV. Failurevtovproducevfetalvlungvliquid
a. IvandvIIIvonly
b. IIvandvIIIvonly
c. I,vII,vandvIVvonly
d. II,vIII,vandvIVvonly
ANS:vD
Oligohydramnios,vavreducedvquantityvofvamnioticvfluidvpresentvforvanvextendedvperiodvofvtime,vwit
hvorvwithoutvrenalvanomalies,visvassociatedvwithvlungvhypoplasia.vThevmechanismsvbyvwhichvamni
oticvfluidvvolumevinfluencesvlungvgrowthvremainvunclear.vPossiblevexplanationsvforvreducedvquanti
tyvofvamnioticvfluidvincludevmechanicalvrestrictionvofvthevchestvwall,vinterferencevwithvfetalvbreathi
ng,vorvfailurevtovproducevfetalvlungvliquid.vThesevclinicalvandvexperimentalvobservationsvpossiblyvp
ointvtovavcommonvdenominator,vlungvstretch,vasvbeingvavmajorvgrowthvstimulant.
REF:vpp.v6-7
5. WhatvisvthevpurposevofvthevsubstancevsecretedvbyvthevtypevIIvpneumocyte?
v v v
atory Care 5th EditionWalsh
v v v v v
Test Bank A+
v v
, Chapter 1: Fetal Lung Development Test Bank
v v v v v v
MULTIPLEvCHOICE
1. Whichvofvthevfollowingvphasesvofvhumanvlungvdevelopmentvisvcharacterizedvbyvthevf
ormationvofvavcapillaryvnetworkvaroundvairwayvpassages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS:vD
Thevcanalicularvphasevfollowsvthevpseudoglandularvphase,vlastingvfromvapproximatelyv17vweeksvto
v26vweeksvofvgestation.vThisvphasevisvsovnamedvbecausevofvthevappearancevofvvascularvchannels,vorvc
apillaries,vwhichvbeginvtovgrowvbyvformingvavcapillaryvnetworkvaroundvthevairvpassages.
Duringvthevpseudoglandularvstage,vwhichvbeginsvatvdayv52vandvextendsvtovweekv16vofvgestation,vth
evairwayvsystemvsubdividesvextensivelyvandvthevconductingvairwayvsystemvdevelops,vendingvwithvt
hevterminalvbronchioles.vThevsaccularvstagevofvdevelopment,vwhichvtakesvplacevfromvweeksv29vtov3
6vofvgestation,visvcharacterizedvbyvthevdevelopmentvofvsacsvthatvlatervbecomevalveoli.
Duringvthevsaccularvphase,vavtremendousvincreasevinvthevpotentialvgas-
vexchangingvsurfacevareavoccurs.vThevdistinctionvbetweenvthevsaccularvstagevandvthevalveolarvsta
gevisvarbitrary.vThevalveolarvstagevstretchesvfromv39vweeksvofvgestationvtovterm.vThisvstagevisvrep
resentedvbyvthevestablishmentvofvalveoli.
REF:vpp.v3-5
2. Regardingvpostnatalvlungvgrowth,vbyvapproximatelyvwhatvagevdovmostvofvthevalveolivthatv
willvbevpresentvinvthevlungsvforvlifevdevelop?
a. 6vmonths
,b. 1vyear
c. 1.5vyears
d. 2vyears
ANS:vC
Mostvofvthevpostnatalvformationvofvalveolivinvthevinfantvoccursvovervthevfirstv1.5vyearsvofvlife.vAtv2vy
earsvofvage,vthevnumbervofvalveolivvariesvsubstantiallyvamongvindividuals.vAfterv2vyearsvofvage,vmal
esvhavevmorevalveolivthanvdovfemales.vAftervalveolarvmultiplicationvends,vthevalveolivcontinuevtovin
creasevinvsizevuntilvthoracicvgrowthvisvcompleted.
REF:vp.v6
3. Thevrespiratoryvtherapistvisvevaluatingvavnewbornvwithvmildvrespiratoryvdistressvduevtovt
rachealvstenosis.vDuringvwhichvperiodvofvlungvdevelopmentvdidvthisvproblemvdevelop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS:vA
Thevinitialvstructuresvofvthevpulmonaryvtreevdevelopvduringvthevembryonalvstage.vErrorsvinvdevelop
mentvduringvthisvtimevmayvresultvinvlaryngeal,vtracheal,vorvesophagealvatresiavorvstenosis.vPulmonar
yvhypoplasia,vanvincompletevdevelopmentvofvthevlungsvcharacterizedvbyvanvabnormallyvlowvnumber
vand/orvsizevofvbronchopulmonaryvsegmentsvand/orvalveoli,vcanvdevelopvduringvthevpseudoglandula
rvphase.vIfvthevfetusvisvbornvduringvthevcanalicularvphasev(i.e.,vprematurely),vseverevrespiratoryvdistre
ssvcanvbevexpectedvbecausevthevinadequatelyvdevelopedvairways,valongvwithvinsufficientvandvimmat
urevsurfactantvproductionvbyvalveolarvtypevIIvcells,vgivesvrisevtovthevconstellationvofvproblemsvknow
nvasvinfantvrespiratoryvdistressvsyndrome.
, REF:v p.v6
4. Whichvofvthevfollowingvmechanismsvisv(are)vresponsiblevforvthevpossiblevassociationvb
etweenvoligohydramniosvandvlungvhypoplasia?
I. Abnormalvcarbohydratevmetabolism
II. Mechanicalvrestrictionvofvthevchestvwall
III. Interferencevwithvfetalvbreathing
IV. Failurevtovproducevfetalvlungvliquid
a. IvandvIIIvonly
b. IIvandvIIIvonly
c. I,vII,vandvIVvonly
d. II,vIII,vandvIVvonly
ANS:vD
Oligohydramnios,vavreducedvquantityvofvamnioticvfluidvpresentvforvanvextendedvperiodvofvtime,vwit
hvorvwithoutvrenalvanomalies,visvassociatedvwithvlungvhypoplasia.vThevmechanismsvbyvwhichvamni
oticvfluidvvolumevinfluencesvlungvgrowthvremainvunclear.vPossiblevexplanationsvforvreducedvquanti
tyvofvamnioticvfluidvincludevmechanicalvrestrictionvofvthevchestvwall,vinterferencevwithvfetalvbreathi
ng,vorvfailurevtovproducevfetalvlungvliquid.vThesevclinicalvandvexperimentalvobservationsvpossiblyvp
ointvtovavcommonvdenominator,vlungvstretch,vasvbeingvavmajorvgrowthvstimulant.
REF:vpp.v6-7
5. WhatvisvthevpurposevofvthevsubstancevsecretedvbyvthevtypevIIvpneumocyte?
