NeonatalandPediatric
RespiratoryCare5thEdition
WalshTest BankA+
, 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 weeks29 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 continueto 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), severerespiratory 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: p. 6
4. Which of the following mechanisms is (are) responsible for the possible
association between oligohydramnios and lung hypoplasia?
I. Abnormal carbohydrate metabolism
II. Mechanical restriction of the chest wall
III. Interference with fetal breathing
IV. Failure to produce fetal lung liquid
a. I and III only
b. II and III only
c. I, II, and IV only
d. II, III, and IV only
ANS: D
Oligohydramnios, a reduced quantity of amniotic fluid present for an extended period of
time, with or without renal anomalies, is associated with lung hypoplasia. The mechanisms
by which amniotic fluid volume influences lung growth remain unclear. Possible
explanations for reducedquantity of amniotic fluid include mechanical restriction of the
chest wall, interference with fetalbreathing, or failure to produce fetal lung liquid.
These clinical and experimental observations possibly point to a common denominator,
lung stretch, as being a major growth stimulant.
REF: pp. 6-7
5. What is the purpose of the substance secreted by the type II pneumocyte?
RespiratoryCare5thEdition
WalshTest BankA+
, 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 weeks29 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 continueto 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), severerespiratory 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: p. 6
4. Which of the following mechanisms is (are) responsible for the possible
association between oligohydramnios and lung hypoplasia?
I. Abnormal carbohydrate metabolism
II. Mechanical restriction of the chest wall
III. Interference with fetal breathing
IV. Failure to produce fetal lung liquid
a. I and III only
b. II and III only
c. I, II, and IV only
d. II, III, and IV only
ANS: D
Oligohydramnios, a reduced quantity of amniotic fluid present for an extended period of
time, with or without renal anomalies, is associated with lung hypoplasia. The mechanisms
by which amniotic fluid volume influences lung growth remain unclear. Possible
explanations for reducedquantity of amniotic fluid include mechanical restriction of the
chest wall, interference with fetalbreathing, or failure to produce fetal lung liquid.
These clinical and experimental observations possibly point to a common denominator,
lung stretch, as being a major growth stimulant.
REF: pp. 6-7
5. What is the purpose of the substance secreted by the type II pneumocyte?
