, Chapter 1: Fetal Lung Development Test Bank
MULTIPLE CHOICE
1. Which of the following phases of human lung development is characterized by the
formation of a capillary network around airway passages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS: D
The canalicular phase follows the pseudoglandular phase, lasting from approximately 17 weeks
to 26 weeks of gestation. This phase is so named because of the appearance of vascular channels,
or capillaries, which begin to grow by forming a capillary network around the air passages.
During the pseudoglandular stage, which begins at day 52 and extends to week 16 of gestation,
the airway system subdivides extensively and the conducting airway system develops, ending
with the terminal bronchioles. The saccular stage of development, which takes place from weeks
29 to 36 of gestation, is characterized by the development of sacs that later become alveoli.
During the saccular phase, a tremendous increase in the potential gas- exchanging surface area
occurs. The distinction between the saccular stage and the alveolar stage is arbitrary. The
alveolar stage stretches from 39 weeks of gestation to term. This stage is represented by the
establishment of alveoli.
REF: pp. 3-5
2. Regarding postnatal lung growth, by approximately what age do most of the alveoli that
will be present in the lungs for life develop?
a. 6 months
,b. 1 year
c. 1.5 years
d. 2 years
ANS: C
Most of the postnatal formation of alveoli in the infant occurs over the first 1.5 years of life. At 2
years of age, the number of alveoli varies substantially among individuals. After 2 years of age,
males have more alveoli than do females. After alveolar multiplication ends, the alveoli continue
to increase in size until thoracic growth is completed.
REF: p. 6
3. The respiratory therapist is evaluating a newborn with mild respiratory distress due to
tracheal stenosis. During which period of lung development did this problem develop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS: A
The initial structures of the pulmonary tree develop during the embryonal stage. Errors in
development during this time may result in laryngeal, tracheal, or esophageal atresia or stenosis.
Pulmonary hypoplasia, an incomplete development of the lungs characterized by an abnormally
low number and/or size of bronchopulmonary segments and/or alveoli, can develop during the
pseudoglandular phase. If the fetus is born during the canalicular phase (i.e., prematurely), severe
respiratory distress can be expected because the inadequately developed airways, along with
insufficient and immature surfactant production by alveolar type II cells, gives rise to the
constellation of problems known as infant respiratory distress syndrome.
, REF: M p. M6
4. Which Mof Mthe Mfollowing Mmechanisms Mis M(are) Mresponsible Mfor Mthe Mpossible
Massociation Mbetween Moligohydramnios Mand Mlung Mhypoplasia?
I. Abnormal Mcarbohydrate Mmetabolism
II. Mechanical Mrestriction Mof Mthe Mchest Mwall
III. Interference Mwith Mfetal Mbreathing
IV. Failure Mto Mproduce Mfetal Mlung Mliquid
a. I Mand MIII Monly
b. II Mand MIII Monly
c. I, MII, Mand MIV Monly
d. II, MIII, Mand MIV Monly
ANS: MD
Oligohydramnios, Ma Mreduced Mquantity Mof Mamniotic Mfluid Mpresent Mfor Man Mextended Mperiod Mof
Mtime, Mwith Mor Mwithout Mrenal Manomalies, Mis Massociated Mwith Mlung Mhypoplasia. MThe
Mmechanisms Mby Mwhich Mamniotic Mfluid Mvolume Minfluences Mlung Mgrowth Mremain Munclear.
MPossible Mexplanations Mfor Mreduced Mquantity Mof Mamniotic Mfluid Minclude Mmechanical Mrestriction
Mof Mthe Mchest Mwall, Minterference Mwith Mfetal Mbreathing, Mor Mfailure Mto Mproduce Mfetal Mlung Mliquid.
MThese Mclinical Mand Mexperimental Mobservations Mpossibly Mpoint Mto Ma Mcommon Mdenominator,
Mlung Mstretch, Mas Mbeing Ma Mmajor Mgrowth Mstimulant.
REF: Mpp. M6-7
5. What Mis Mthe Mpurpose Mof Mthe Msubstance Msecreted Mby Mthe Mtype MII Mpneumocyte?
MULTIPLE CHOICE
1. Which of the following phases of human lung development is characterized by the
formation of a capillary network around airway passages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
ANS: D
The canalicular phase follows the pseudoglandular phase, lasting from approximately 17 weeks
to 26 weeks of gestation. This phase is so named because of the appearance of vascular channels,
or capillaries, which begin to grow by forming a capillary network around the air passages.
During the pseudoglandular stage, which begins at day 52 and extends to week 16 of gestation,
the airway system subdivides extensively and the conducting airway system develops, ending
with the terminal bronchioles. The saccular stage of development, which takes place from weeks
29 to 36 of gestation, is characterized by the development of sacs that later become alveoli.
During the saccular phase, a tremendous increase in the potential gas- exchanging surface area
occurs. The distinction between the saccular stage and the alveolar stage is arbitrary. The
alveolar stage stretches from 39 weeks of gestation to term. This stage is represented by the
establishment of alveoli.
REF: pp. 3-5
2. Regarding postnatal lung growth, by approximately what age do most of the alveoli that
will be present in the lungs for life develop?
a. 6 months
,b. 1 year
c. 1.5 years
d. 2 years
ANS: C
Most of the postnatal formation of alveoli in the infant occurs over the first 1.5 years of life. At 2
years of age, the number of alveoli varies substantially among individuals. After 2 years of age,
males have more alveoli than do females. After alveolar multiplication ends, the alveoli continue
to increase in size until thoracic growth is completed.
REF: p. 6
3. The respiratory therapist is evaluating a newborn with mild respiratory distress due to
tracheal stenosis. During which period of lung development did this problem develop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveolar
ANS: A
The initial structures of the pulmonary tree develop during the embryonal stage. Errors in
development during this time may result in laryngeal, tracheal, or esophageal atresia or stenosis.
Pulmonary hypoplasia, an incomplete development of the lungs characterized by an abnormally
low number and/or size of bronchopulmonary segments and/or alveoli, can develop during the
pseudoglandular phase. If the fetus is born during the canalicular phase (i.e., prematurely), severe
respiratory distress can be expected because the inadequately developed airways, along with
insufficient and immature surfactant production by alveolar type II cells, gives rise to the
constellation of problems known as infant respiratory distress syndrome.
, REF: M p. M6
4. Which Mof Mthe Mfollowing Mmechanisms Mis M(are) Mresponsible Mfor Mthe Mpossible
Massociation Mbetween Moligohydramnios Mand Mlung Mhypoplasia?
I. Abnormal Mcarbohydrate Mmetabolism
II. Mechanical Mrestriction Mof Mthe Mchest Mwall
III. Interference Mwith Mfetal Mbreathing
IV. Failure Mto Mproduce Mfetal Mlung Mliquid
a. I Mand MIII Monly
b. II Mand MIII Monly
c. I, MII, Mand MIV Monly
d. II, MIII, Mand MIV Monly
ANS: MD
Oligohydramnios, Ma Mreduced Mquantity Mof Mamniotic Mfluid Mpresent Mfor Man Mextended Mperiod Mof
Mtime, Mwith Mor Mwithout Mrenal Manomalies, Mis Massociated Mwith Mlung Mhypoplasia. MThe
Mmechanisms Mby Mwhich Mamniotic Mfluid Mvolume Minfluences Mlung Mgrowth Mremain Munclear.
MPossible Mexplanations Mfor Mreduced Mquantity Mof Mamniotic Mfluid Minclude Mmechanical Mrestriction
Mof Mthe Mchest Mwall, Minterference Mwith Mfetal Mbreathing, Mor Mfailure Mto Mproduce Mfetal Mlung Mliquid.
MThese Mclinical Mand Mexperimental Mobservations Mpossibly Mpoint Mto Ma Mcommon Mdenominator,
Mlung Mstretch, Mas Mbeing Ma Mmajor Mgrowth Mstimulant.
REF: Mpp. M6-7
5. What Mis Mthe Mpurpose Mof Mthe Msubstance Msecreted Mby Mthe Mtype MII Mpneumocyte?
