v
v
v
v
v
v
v v
v v
v
v
v
v
v v
v
v
Neonatal and Pediatric v v v
v
Respiratory Care 5th Editionv v v v
v v
v
v
Walsh Test Bank A+
v
v
v
v
v
v
Chapter 1: Fetal Lung Development Test Bank
v v v v v v v
v
MULTIPLEvCHOICEv
v
,1.v
Whichvofvthevfollowingvphasesvofvhumanvlungvdevelopmentvisvcharacterizedvbyvthevformationvofvav
capillaryvnetworkvaroundvairwayvpassages?v
a. Pseudoglandularv
b. Saccularv
c. Alveolarv
d. Canalicularv
v
ANS:vDv
Thevcanalicularvphasevfollowsvthevpseudoglandularvphase,vlastingvfromvapproximatelyv17vweeksvtov
26vweeksvofvgestation.vThisvphasevisvsovnamedvbecausevofvthevappearancevofvvascularvchannels,vorvc
apillaries,vwhichvbeginvtovgrowvbyvformingvavcapillaryvnetworkvaroundvthevairvpassages.vDuringvthe
vpseudoglandularvstage,vwhichvbeginsvatvdayv52vandvextendsvtovweekv16vofvgestation,vthevairwayvsys
temvsubdividesvextensivelyvandvthevconductingvairwayvsystemvdevelops,vendingvwithvthevterminalv
bronchioles.vThevsaccularvstagevofvdevelopment,vwhichvtakesvplacevfromvweeksv29vtov36vofvgestatio
n,visvcharacterizedvbyvthevdevelopmentvofvsacsvthatvlatervbecomevalveoli.vDuringvthevsaccularvphase,
vavtremendousvincreasevinvthevpotentialvgas-
vexchangingvsurfacevareavoccurs.vThevdistinctionvbetween vthevsaccularvstagevandvthevalveolarvstagev
isvarbitrary.vThevalveolarvstagevstretchesvfromv39vweeksvofvgestationvtovterm.vThisvstagevisvrepresent
edvbyvthevestablishmentvofvalveoli.v
v
REF:vpp.v3-5v
vv
2.v
Regardingvpostnatalvlungvgrowth,vbyvapproximatelyvwhatvagevdovmostvofvthevalveolivthatvwillvbevpr
esentvinvthevlungsvforvlifevdevelop?v
a. 6vmonthsv
b. 1vyearv
c. 1.5vyearsv
d. 2vyearsv
v
ANS:vCv
,Mostvofvthevpostnatalvformationvofvalveolivinvthevinfantvoccursvovervthevfirstv1.5vyearsvofvlife.vAtv2vy
earsvofvage,vthevnumbervofvalveolivvariesvsubstantiallyvamongvindividuals.vAfterv2vyearsvofvage,vmal
esvhavevmorevalveolivthanvdovfemales.vAftervalveolarvmultiplicationvends,vthevalveolivcontinuevtovin
creasevinvsizevuntilvthoracicvgrowthvisvcompleted.v
v
REF:vp.v6v
v
3.v
Thevrespiratoryvtherapistvisvevaluatingvavnewbornvwithvmildvrespiratoryvdistressvduevtovtrachealvsten
osis.vDuringvwhichvperiodvofvlungvdevelopmentvdidvthisvproblemvdevelop?v
a. Embryonalv
b. Saccularv
c. Canalicularv
d. Alveolarv
v
ANS:vAv
Thevinitialvstructuresvofvthevpulmonaryvtreevdevelopvduringvthevembryonalvstage.vErrorsvinvdevelop
mentvduringvthisvtimevmayvresultvinvlaryngeal,vtracheal,vorvesophagealvatresiavorvstenosis.vPulmonar
yvhypoplasia,vanvincompletevdevelopmentvofvthevlungsvcharacterizedvbyvanvabnormallyvlowvnumber
vand/orvsizevofvbronchopulmonaryvsegmentsvand/orvalveoli,vcanvdevelopvduringvthevpseudoglandula
rvphase.vIfvthevfetusvisvbornvduringvthevcanalicularvphasev(i.e.,vprematurely),vseverevrespiratoryvdistr
essvcanvbevexpectedvbecausevthevinadequatelyvdevelopedvairways,valongvwithvinsufficientvandvimm
aturevsurfactantvproductionvbyvalveolarvtypevIIvcells,vgivesvrisevtovthevconstellationvofvproblemsvkno
wnvasvinfantvrespiratoryvdistressvsyndrome.v
v
REF:vvp.v6v
vv
v
4.v
Whichvofvthevfollowingvmechanismsvisv(are)vresponsiblevforvthevpossiblevassociationvbetweenvoligo
hydramniosvandvlungvhypoplasia?v
v
I. Abnormalvcarbohydratevmetabolismv
II. Mechanicalvrestrictionvofvthevchestvwallv
, III. InterferencevwithvfetalvbreathingvIV.v Failurevtovproducevfetalvlungvliquidv
a. IvandvIIIvonlyv
b. IIvandvIIIvonlyv
c. I,vII,vandvIVvonlyv
d. II,vIII,vandvIVvonlyv
v
ANS:vDv
Oligohydramnios,vavreducedvquantityvofvamnioticvfluidvpresentvforvanvextendedvperiodvofvtime,vwit
hvorvwithoutvrenalvanomalies,visvassociatedvwithvlungvhypoplasia.vThevmechanismsvbyvwhichvamnio
ticvfluidvvolumevinfluencesvlungvgrowthvremainvunclear.vPossiblevexplanationsvforvreducedvquantit
yvofvamnioticvfluidvincludevmechanicalvrestrictionvofvthevchestvwall,vinterferencevwithvfetalvbreathin
g,vorvfailurevtovproducevfetalvlungvliquid.vThesevclinicalvandvexperimentalvobservationsvpossiblyvpoi
ntvtovavcommonvdenominator,vlungvstretch,vasvbeingvavmajorvgrowthvstimulant.v
v
REF:vpp.v6-7v
v
v
5.v WhatvisvthevpurposevofvthevsubstancevsecretedvbyvthevtypevIIvpneumocyte?v
a. Tovincreasevthevgasvexchangevsurfacevareav
b. Tovreducevsurfacevtensionv
c. Tovmaintainvlungvelasticityv
d. Tovpreservevthevvolumevofvthevamnioticvfluidv
v
ANS:vBv
Thevprimaryvrolevofvmammalianvsurfactantvisvtovlowervthevsurfacevtensionvwithinvthevalveolus,vspeci
ficallyvatvthevair–
liquidvinterface.vThisvallowsvthevdelicatevstructurevofvthevalveolusvtovexpandvwhenvfilledvwithvair.vW
ithoutvsurfactant,vthevalveolusvremainsvcollapsedvbecausevofvthev
vv
highvsurfacevtensionvofvthevmoistvalveolarvsurface.vSurfactantvisvcomposedvpredominantlyvofvanvintr
icatevblendvofvphospholipids,vneutralvlipids,vandvproteins.v
v
v
v
v
v
v v
v v
v
v
v
v
v v
v
v
Neonatal and Pediatric v v v
v
Respiratory Care 5th Editionv v v v
v v
v
v
Walsh Test Bank A+
v
v
v
v
v
v
Chapter 1: Fetal Lung Development Test Bank
v v v v v v v
v
MULTIPLEvCHOICEv
v
,1.v
Whichvofvthevfollowingvphasesvofvhumanvlungvdevelopmentvisvcharacterizedvbyvthevformationvofvav
capillaryvnetworkvaroundvairwayvpassages?v
a. Pseudoglandularv
b. Saccularv
c. Alveolarv
d. Canalicularv
v
ANS:vDv
Thevcanalicularvphasevfollowsvthevpseudoglandularvphase,vlastingvfromvapproximatelyv17vweeksvtov
26vweeksvofvgestation.vThisvphasevisvsovnamedvbecausevofvthevappearancevofvvascularvchannels,vorvc
apillaries,vwhichvbeginvtovgrowvbyvformingvavcapillaryvnetworkvaroundvthevairvpassages.vDuringvthe
vpseudoglandularvstage,vwhichvbeginsvatvdayv52vandvextendsvtovweekv16vofvgestation,vthevairwayvsys
temvsubdividesvextensivelyvandvthevconductingvairwayvsystemvdevelops,vendingvwithvthevterminalv
bronchioles.vThevsaccularvstagevofvdevelopment,vwhichvtakesvplacevfromvweeksv29vtov36vofvgestatio
n,visvcharacterizedvbyvthevdevelopmentvofvsacsvthatvlatervbecomevalveoli.vDuringvthevsaccularvphase,
vavtremendousvincreasevinvthevpotentialvgas-
vexchangingvsurfacevareavoccurs.vThevdistinctionvbetween vthevsaccularvstagevandvthevalveolarvstagev
isvarbitrary.vThevalveolarvstagevstretchesvfromv39vweeksvofvgestationvtovterm.vThisvstagevisvrepresent
edvbyvthevestablishmentvofvalveoli.v
v
REF:vpp.v3-5v
vv
2.v
Regardingvpostnatalvlungvgrowth,vbyvapproximatelyvwhatvagevdovmostvofvthevalveolivthatvwillvbevpr
esentvinvthevlungsvforvlifevdevelop?v
a. 6vmonthsv
b. 1vyearv
c. 1.5vyearsv
d. 2vyearsv
v
ANS:vCv
,Mostvofvthevpostnatalvformationvofvalveolivinvthevinfantvoccursvovervthevfirstv1.5vyearsvofvlife.vAtv2vy
earsvofvage,vthevnumbervofvalveolivvariesvsubstantiallyvamongvindividuals.vAfterv2vyearsvofvage,vmal
esvhavevmorevalveolivthanvdovfemales.vAftervalveolarvmultiplicationvends,vthevalveolivcontinuevtovin
creasevinvsizevuntilvthoracicvgrowthvisvcompleted.v
v
REF:vp.v6v
v
3.v
Thevrespiratoryvtherapistvisvevaluatingvavnewbornvwithvmildvrespiratoryvdistressvduevtovtrachealvsten
osis.vDuringvwhichvperiodvofvlungvdevelopmentvdidvthisvproblemvdevelop?v
a. Embryonalv
b. Saccularv
c. Canalicularv
d. Alveolarv
v
ANS:vAv
Thevinitialvstructuresvofvthevpulmonaryvtreevdevelopvduringvthevembryonalvstage.vErrorsvinvdevelop
mentvduringvthisvtimevmayvresultvinvlaryngeal,vtracheal,vorvesophagealvatresiavorvstenosis.vPulmonar
yvhypoplasia,vanvincompletevdevelopmentvofvthevlungsvcharacterizedvbyvanvabnormallyvlowvnumber
vand/orvsizevofvbronchopulmonaryvsegmentsvand/orvalveoli,vcanvdevelopvduringvthevpseudoglandula
rvphase.vIfvthevfetusvisvbornvduringvthevcanalicularvphasev(i.e.,vprematurely),vseverevrespiratoryvdistr
essvcanvbevexpectedvbecausevthevinadequatelyvdevelopedvairways,valongvwithvinsufficientvandvimm
aturevsurfactantvproductionvbyvalveolarvtypevIIvcells,vgivesvrisevtovthevconstellationvofvproblemsvkno
wnvasvinfantvrespiratoryvdistressvsyndrome.v
v
REF:vvp.v6v
vv
v
4.v
Whichvofvthevfollowingvmechanismsvisv(are)vresponsiblevforvthevpossiblevassociationvbetweenvoligo
hydramniosvandvlungvhypoplasia?v
v
I. Abnormalvcarbohydratevmetabolismv
II. Mechanicalvrestrictionvofvthevchestvwallv
, III. InterferencevwithvfetalvbreathingvIV.v Failurevtovproducevfetalvlungvliquidv
a. IvandvIIIvonlyv
b. IIvandvIIIvonlyv
c. I,vII,vandvIVvonlyv
d. II,vIII,vandvIVvonlyv
v
ANS:vDv
Oligohydramnios,vavreducedvquantityvofvamnioticvfluidvpresentvforvanvextendedvperiodvofvtime,vwit
hvorvwithoutvrenalvanomalies,visvassociatedvwithvlungvhypoplasia.vThevmechanismsvbyvwhichvamnio
ticvfluidvvolumevinfluencesvlungvgrowthvremainvunclear.vPossiblevexplanationsvforvreducedvquantit
yvofvamnioticvfluidvincludevmechanicalvrestrictionvofvthevchestvwall,vinterferencevwithvfetalvbreathin
g,vorvfailurevtovproducevfetalvlungvliquid.vThesevclinicalvandvexperimentalvobservationsvpossiblyvpoi
ntvtovavcommonvdenominator,vlungvstretch,vasvbeingvavmajorvgrowthvstimulant.v
v
REF:vpp.v6-7v
v
v
5.v WhatvisvthevpurposevofvthevsubstancevsecretedvbyvthevtypevIIvpneumocyte?v
a. Tovincreasevthevgasvexchangevsurfacevareav
b. Tovreducevsurfacevtensionv
c. Tovmaintainvlungvelasticityv
d. Tovpreservevthevvolumevofvthevamnioticvfluidv
v
ANS:vBv
Thevprimaryvrolevofvmammalianvsurfactantvisvtovlowervthevsurfacevtensionvwithinvthevalveolus,vspeci
ficallyvatvthevair–
liquidvinterface.vThisvallowsvthevdelicatevstructurevofvthevalveolusvtovexpandvwhenvfilledvwithvair.vW
ithoutvsurfactant,vthevalveolusvremainsvcollapsedvbecausevofvthev
vv
highvsurfacevtensionvofvthevmoistvalveolarvsurface.vSurfactantvisvcomposedvpredominantlyvofvanvintr
icatevblendvofvphospholipids,vneutralvlipids,vandvproteins.v
