Care, 6th Edition
by Brian K. Walsh
,Chaptero1:oFetaloLungoDevelopmen
toTestoBank
MULTIPLEoCHOICE
1. Whichoofotheofollowingophasesoofohumanolungodevelopmentoisocharacterizedobyotheoformationoo
foaocapillaryonetworkoaroundoairwayopassages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS:o D
Theocanalicularophaseofollowsotheopseudoglandularophase,olastingofromoapproximatelyo17oweek
sotoo26oweeksoofogestation.oThisophaseoisosoonamedobecauseoofotheoappearanceoofovascularochannel
s,oorocapillaries,owhichobeginotoogrowobyoformingoaocapillaryonetworkoaroundotheoairopassages.o
Duringotheopseudoglandularostage,owhichobeginsoatodayo52oandoextendsotooweeko16oofogestation
,otheoairwayosystemosubdividesoextensivelyoandotheoconductingoairwayosystemodevelops,oending
owithotheoterminalobronchioles.oTheosaccularostageoofodevelopment,owhichotakesoplaceofromowee
kso29otoo36oofogestation,oisocharacterizedobyotheodevelopmentoofosacsothatolaterobecomeoalveoli.oD
uringotheosaccularophase,oaotremendousoincreaseoinotheopotential
gas-
exchangingosurfaceoareaooccurs.oTheodistinctionobetweenotheosaccularostageoandotheoalveola
rostageoisoarbitrary.oTheoalveolarostageostretchesofromo39oweeksoofogestationotooterm.oThisost
ageoisorepresentedobyotheoestablishmentoofoalveoli.
REF:o pp.ooo 3-5
2. Regardingopostnatalolungogrowth,obyoapproximatelyowhatoageodoomostoofotheoalveoliothatowillo
beopresentoinotheolungsoforolifeodevelop?
a. 6omonths
b. 1oyear
c. 1.5oyears
d. 2oyears
ANS:o C
Mostoofotheopostnataloformationoofoalveolioinotheoinfantooccursooverotheofirsto1.5oyearsoofolife.oAt
o2oyearsoofoage,otheonumberoofoalveoliovariesosubstantiallyoamongoindividuals.oAftero2oyearsoofoa
ge,omalesohaveomoreoalveoliothanodoofemales.oAfteroalveolaromultiplicationoends,otheoalveolioco
ntinueotooincreaseoinosizeountilothoracicogrowthoisocompleted.
REF:o p.o6
3. Theorespiratoryotherapistoisoevaluatingoaonewbornowithomildorespiratoryodistressodueotootrachea
lostenosis.oDuringowhichoperiodoofolungodevelopmentodidothisoproblemodevelop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS:o A
, Theoinitialostructuresoofotheopulmonaryotreeodevelopoduringotheoembryonalostage.oErrorsoinode
velopmentoduringothisotimeomayoresultoinolaryngeal,otracheal,ooroesophagealoatresiaoorostenosi
s.oPulmonaryohypoplasia,oanoincompleteodevelopmentoofotheolungsocharacterizedobyoanoabnorm
allyolowonumberoand/orosizeoofobronchopulmonaryosegmentsoand/oroalveoli,ocanodevelopoduri
ngotheopseudoglandularophase.oIfotheofetusoisobornoduringotheocanalicularophaseo(i.e.,opremature
ly),osevereorespiratoryodistressocanobeoexpectedobecauseotheoinadequatelyodevelopedoairways,oa
longowithoinsufficientoandoimmatureosurfactantoproductionobyoalveolarotypeoIIocells,ogivesoriseo
tootheoconstellationoofoproblemsoknownoasoinfantorespiratoryodistressosyndrome.
REF:ooo p.o6
4. Whichoofotheofollowingomechanismsoiso(are)oresponsibleoforotheopossibleoassociationobetweenool
igohydramniosoandolungohypoplasia?
I. Abnormalocarbohydrateometabolism
II. Mechanicalorestrictionoofotheochestowall
III. Interferenceowithofetalobreathing
IV. Failureotooproduceofetalolungoliquid
a. IoandoIIIoonly
b. IIoandoIIIoonly
c. I,oII,oandoIVoonly
d. II,oIII,oandoIVoonly
ANS:o D
Oligohydramnios,oaoreducedoquantityoofoamnioticofluidopresentoforoanoextendedoperiodoofotime,
withoorowithoutorenaloanomTaE lieSsT
,oiB
soA
asNsoKcS
iaE
teLdLwEitR
holu
. CnO
goM
hypoplasia.oTheomechanismsobyoowhi
choamnioticofluidovolumeoinfluencesolungogrowthoremainounclear.oPossibleoexplanationsofor
reducedoquantityoofoamnioticofluidoincludeomechanicalorestrictionoofotheochestowall,ointerferen
ceowithofetalobreathing,oorofailureotooproduceofetalolungoliquid.oTheseoclinicaloandoexperimenta
loobservationsopossiblyopointotooaocommonodenominator,olungostretch,oasobeingoaomajorogrowt
hostimulant.
REF:o pp.o6-7
5. WhatoisotheopurposeoofotheosubstanceosecretedobyotheotypeoIIopneumocyte?
a. Tooincreaseotheogasoexchangeosurfaceoarea
b. Tooreduceosurfaceotension
c. Toomaintainolungoelasticity
d. Toopreserveotheovolumeoofotheoamnioticofluid
ANS:o B
Theoprimaryoroleoofomammalianosurfactantoisotoolowerotheosurfaceotensionowithinotheoalveolus,os
pecificallyoatotheoair–
liquidointerface.oThisoallowsotheodelicateostructureoofotheoalveolusotooexpandowhenofilledowithoair
.oWithoutosurfactant,otheoalveolusoremainsocollapsedobecauseoofotheohighosurfaceotensionoofotheo
moistoalveolarosurface.oSurfactantoisocomposedopredominantlyoofoanointricateoblendoofophosphol
ipids,oneutralolipids,oandoproteins.
REF:o p.o8
, 6. Whichoofotheofollowingotestsoofotheoamnioticofluidohaveobeenoshownotoobeosensitiveoindicatorsoof
lungomaturity?
o
a. Levelsoofoprednisone
b. Levelsoofoepidermalogrowthofactor
c. Levelsoofoprostaglandins
d. Levelsoofophosphatidylglyceroloandophosphatidylcholine
ANS:o D
Ofoclinicalorelevanceoduringolateogestation,oanalysisoofoamnioticofluidoforotheoconcentrationoofop
hosphatidylglyceroloandophosphatidylcholineohasobeenoshownotoobeoaosensitiveoindicatoroofoth
eostateoofofetalolungomaturity.
REF:o p.o8
7.oApproximatelyohowomuchofetalolungofluidoisosecretedodaily?
a.oAbouto150otoo200oml
b.oAbouto250otoo300oml
c.oAbouto350otoo400oml
d.oAbouto450otoo500oml
ANS:oB
Fetalolungsoareosecretoryoorgansothatomakeobreathing-
likeomovementsobutoserveonoorespiratoryofunctionobeforeobirth.oTheyosecreteo
abouto250otoo300omloofoliquidoperoday.
8.oTheolungobudoemergesofromowhichoofotheofollowingostructures?
o
a.oTheopharynx
b.oTheoforegut
c.oTheomesenchyme
d.oTheotubularoepithelium
ANS:oA
Theoembryonalophaseoincludesoprimitiveolungodevelopmentoandoisogenerallyoregardedotooencompassotheofirsto2omont
hsoofogestation.o
Theolungobeginsotooemergeoasoaobudofromotheopharynxo26odaysoafteroconception.