n n n
atory Care 5th EditionWalsh
n n n n n
Test Bank A+
n n
, Chapter 1: Fetal Lung Development Test Bank
n n n n n n
MULTIPLEnCHOICE
1. Whichnofnthenfollowingnphasesnofnhumannlungndevelopmentnisncharacterizednbynthenf
ormationnofnancapillarynnetworknaroundnairwaynpassages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS:nD
Thencanalicularnphasenfollowsnthenpseudoglandularnphase,nlastingnfromnapproximatelyn17nweeksnto
n26nweeksnofngestation.nThisnphasenisnsonnamednbecausenofnthenappearancenofnvascularnchannels,nornc
apillaries,nwhichnbeginntongrownbynformingnancapillarynnetworknaroundnthenairnpassages.
Duringnthenpseudoglandularnstage,nwhichnbeginsnatndayn52nandnextendsntonweekn16nofngestation,nth
enairwaynsystemnsubdividesnextensivelynandnthenconductingnairwaynsystemndevelops,nendingnwithnt
henterminalnbronchioles.nThensaccularnstagenofndevelopment,nwhichntakesnplacenfromnweeksn29nton3
6nofngestation,nisncharacterizednbynthendevelopmentnofnsacsnthatnlaternbecomenalveoli.
Duringnthensaccularnphase,nantremendousnincreaseninnthenpotentialngas-
nexchangingnsurfacenareanoccurs.nThendistinctionnbetweennthensaccularnstagenandnthenalveolarnsta
genisnarbitrary.nThenalveolarnstagenstretchesnfromn39nweeksnofngestationntonterm.nThisnstagenisnrep
resentednbynthenestablishmentnofnalveoli.
REF:npp.n3-5
2. Regardingnpostnatalnlungngrowth,nbynapproximatelynwhatnagendonmostnofnthenalveolinthatn
willnbenpresentninnthenlungsnfornlifendevelop?
a. 6nmonths
,b. 1nyear
c. 1.5nyears
d. 2nyears
ANS:nC
Mostnofnthenpostnatalnformationnofnalveolininntheninfantnoccursnovernthenfirstn1.5nyearsnofnlife.nAtn2ny
earsnofnage,nthennumbernofnalveolinvariesnsubstantiallynamongnindividuals.nAftern2nyearsnofnage,nmal
esnhavenmorenalveolinthanndonfemales.nAfternalveolarnmultiplicationnends,nthenalveolincontinuentonin
creaseninnsizenuntilnthoracicngrowthnisncompleted.
REF:np.n6
3. Thenrespiratoryntherapistnisnevaluatingnannewbornnwithnmildnrespiratoryndistressnduentont
rachealnstenosis.nDuringnwhichnperiodnofnlungndevelopmentndidnthisnproblemndevelop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS:nA
Theninitialnstructuresnofnthenpulmonaryntreendevelopnduringnthenembryonalnstage.nErrorsninndevelop
mentnduringnthisntimenmaynresultninnlaryngeal,ntracheal,nornesophagealnatresianornstenosis.nPulmonar
ynhypoplasia,nannincompletendevelopmentnofnthenlungsncharacterizednbynannabnormallynlownnumber
nand/ornsizenofnbronchopulmonarynsegmentsnand/ornalveoli,ncanndevelopnduringnthenpseudoglandula
rnphase.nIfnthenfetusnisnbornnduringnthencanalicularnphasen(i.e.,nprematurely),nseverenrespiratoryndistre
ssncannbenexpectednbecausentheninadequatelyndevelopednairways,nalongnwithninsufficientnandnimmat
urensurfactantnproductionnbynalveolarntypenIIncells,ngivesnrisentonthenconstellationnofnproblemsnknow
nnasninfantnrespiratoryndistressnsyndrome.
, REF:n p.n6
4. Whichnofnthenfollowingnmechanismsnisn(are)nresponsiblenfornthenpossiblenassociationnb
etweennoligohydramniosnandnlungnhypoplasia?
I. Abnormalncarbohydratenmetabolism
II. Mechanicalnrestrictionnofnthenchestnwall
III. Interferencenwithnfetalnbreathing
IV. Failurentonproducenfetalnlungnliquid
a. InandnIIInonly
b. IInandnIIInonly
c. I,n II,nandnIVnonly
d. II,nIII,nandnIVnonly
ANS:nD
Oligohydramnios,nanreducednquantitynofnamnioticnfluidnpresentnfornannextendednperiodnofntime,nwit
hnornwithoutnrenalnanomalies,nisnassociatednwithnlungnhypoplasia.nThenmechanismsnbynwhichnamni
oticnfluidnvolumeninfluencesnlungngrowthnremainnunclear.nPossiblenexplanationsnfornreducednquanti
tynofnamnioticnfluidnincludenmechanicalnrestrictionnofnthenchestnwall,ninterferencenwithnfetalnbreathi
ng,nornfailurentonproducenfetalnlungnliquid.nThesenclinicalnandnexperimentalnobservationsnpossiblynp
ointntonancommonndenominator,nlungnstretch,nasnbeingnanmajorngrowthnstimulant.
REF:npp.n6-7
5. WhatnisnthenpurposenofnthensubstancensecretednbynthentypenIInpneumocyte?