Test Bank for Neonatal and Pediatric Respiratory Care, 6th Edition by Brian K. Walsh

Test Bank for Neonatal and Pediatric Respiratory
Care, 6th Edition
by Brian K. Walsh

,Chapter 1: Fetal Lung Development
6 6 6 6 6

Test Bank
6


MULTIPLE6CHOICE

1. Which6of6the6following6phases6of6human6lung6development6is6characterized6by6the6formation6
of6a6capillary6network6around6airway6passages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS:6 D
The6canalicular6phase6follows6the6pseudoglandular6phase,6lasting6from6approximately6176wee
ks6to6266weeks6of6gestation.6This6phase6is6so6named6because6of6the6appearance6of6vascular6chan
nels,6or6capillaries,6which6begin6to6grow6by6forming6a6capillary6network6around6the6air6passag
es.6During6the6pseudoglandular6stage,6which6begins6at6day6526and6extends6to6week6166of6gesta
tion,6the6airway6system6subdivides6extensively6and6the6conducting6airway6system6develops,6e
nding6with6the6terminal6bronchioles.6The6saccular6stage6of6development,6which6takes6place6fr
om6weeks6296to6366of6gestation,6is6characterized6by6the6development6of6sacs6that6later6become6
alveoli.6During6the6saccular6phase,6a6tremendous6increase6in6the6potential
gas-
exchanging6surface6area6occurs.6The6distinction6between6the6saccular6stage6and6the6alveol
ar6stage6is6arbitrary.6The6alveolar6stage6stretches6from6396weeks6of6gestation6to6term.6This6
stage6is6represented6by6the6establishment6of6alveoli.

REF:6 pp.666 3-5

2. Regarding6postnatal6lung6growth,6by6approximately6what6age6do6most6of6the6alveoli6that6wil
l6be6present6in6the6lungs6for6life6develop?
a. 66months
b. 16year
c. 1.56years
d. 26years
ANS:6 C
Most6of6the6postnatal6formation6of6alveoli6in6the6infant6occurs6over6the6first61.56years6of6life.6
At626years6of6age,6the6number6of6alveoli6varies6substantially6among6individuals.6After626years6
of6age,6males6have6more6alveoli6than6do6females.6After6alveolar6multiplication6ends,6the6alveo
li6continue6to6increase6in6size6until6thoracic6growth6is6completed.

REF:6 p.66

3. The6respiratory6therapist6is6evaluating6a6newborn6with6mild6respiratory6distress6due6to6trache
al6stenosis.6During6which6period6of6lung6development6did6this6problem6develop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS:6 A

, The6initial6structures6of6the6pulmonary6tree6develop6during6the6embryonal6stage.6Errors6in6d
evelopment6during6this6time6may6result6in6laryngeal,6tracheal,6or6esophageal6atresia6or6steno
sis.6Pulmonary6hypoplasia,6an6incomplete6development6of6the6lungs6characterized6by6an6abno
rmally6low6number6and/or6size6of6bronchopulmonary6segments6and/or6alveoli,6can6develop6
during6the6pseudoglandular6phase.6If6the6fetus6is6born6during6the6canalicular6phase6(i.e.,6pre
maturely),6severe6respiratory6distress6can6be6expected6because6the6inadequately6developed6ai
rways,6along6with6insufficient6and6immature6surfactant6production6by6alveolar6type6II6cells,6
gives6rise6to6the6constellation6of6problems6known6as6infant6respiratory6distress6syndrome.

REF:666p.66

4. Which6of6the6following6mechanisms6is6(are)6responsible6for6the6possible6association6between6
oligohydramnios6and6lung6hypoplasia?

I. Abnormal6carbohydrate6metabolism
II. Mechanical6restriction6of6the6chest6wall
III. Interference6with6fetal6breathing
IV. Failure6to6produce6fetal6lung6liquid
a. I6and6III6only
b. II6and6III6only
c. I,6II,6and6IV6only
d. II,6III,6and6IV6only
ANS:6 D
Oligohydramnios,6a6reduced6quantity6of6amniotic6fluid6present6for6an6extended6period6of6time,
with6or6without6renal6anomTaE lieSsT
,6iB
s6A
asNsoKcS
iaE
teLdLwEitR
h6lu
. CnO
g6M
hypoplasia.6The6mechanisms6by66w
hich6amniotic6fluid6volume6influences6lung6growth6remain6unclear.6Possible6explanations6for
reduced6quantity6of6amniotic6fluid6include6mechanical6restriction6of6the6chest6wall,6interfere
nce6with6fetal6breathing,6or6failure6to6produce6fetal6lung6liquid.6These6clinical6and6experime
ntal6observations6possibly6point6to6a6common6denominator,6lung6stretch,6as6being6a6major6gr
owth6stimulant.

REF:6 pp.66-7

5. What6is6the6purpose6of6the6substance6secreted6by6the6type6II6pneumocyte?
a. To6increase6the6gas6exchange6surface6area
b. To6reduce6surface6tension
c. To6maintain6lung6elasticity
d. To6preserve6the6volume6of6the6amniotic6fluid
ANS:6 B
The6primary6role6of6mammalian6surfactant6is6to6lower6the6surface6tension6within6the6alveolus,
6specifically6at6the6air–

liquid6interface.6This6allows6the6delicate6structure6of6the6alveolus6to6expand6when6filled6with6a
ir.6Without6surfactant,6the6alveolus6remains6collapsed6because6of6the6high6surface6tension6of6th
e6moist6alveolar6surface.6Surfactant6is6composed6predominantly6of6an6intricate6blend6of6phosp
holipids,6neutral6lipids,6and6proteins.

REF:6 p.68

, 6. Which6of6the6following6tests6of6the6amniotic6fluid6have6been6shown6to6be6sensitive6indicators6
of6lung6maturity?
a. Levels6of6prednisone
b. Levels6of6epidermal6growth6factor
c. Levels6of6prostaglandins
d. Levels6of6phosphatidylglycerol6and6phosphatidylcholine
ANS:6 D
Of6clinical6relevance6during6late6gestation,6analysis6of6amniotic6fluid6for6the6concentration6of6
phosphatidylglycerol6and6phosphatidylcholine6has6been6shown6to6be6a6sensitive6indicator6of6
the6state6of6fetal6lung6maturity.

REF:6 p.68

7.6Approximately6how6much6fetal6lung6fluid6is6secreted6daily?
a.6About61506to62006ml
b.6About62506to63006ml
c.6About63506to64006ml
d.6About64506to65006ml

ANS:6B

Fetal6lungs6are6secretory6organs6that6make6breathing-
like6movements6but6serve6no6respiratory6function6before6birth.6They6secrete6
about62506to63006ml6of6liquid6per6day.


68.6The6lung6bud6emerges6from6which6of6the6following6structures?
a.6The6pharynx
b.6The6foregut
c.6The6mesenchyme
d.6The6tubular6epithelium

ANS:6A

The6embryonal6phase6includes6primitive6lung6development6and6is6generally6regarded6to6encompass6the6first626mo
nths6of6gestation.6
The6lung6begins6to6emerge6as6a6bud6from6the6pharynx6266days6after6conception.