,Neonatal and pediatric respiratory care 6th
edition by brian
Chapter 1: Fetal Lung Development Test
B ank
MULTIPLE CHOICE
1. Which of the following phases of human lung development is characterized by the
formationof a capillary network around airwaypassages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
Answer: 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
vascularchannels, or capillaries, which begin to grow by forming a capillary network around the air
passages. Durin g the pseudoglandular stage, which begins at day 52 and extends to week 16 of
gestation, the ai rway system subdivides extensively and the conducting airway system develops,
ending with the t erminal bronchioles. The saccular stage of development, which takes place from
weeks 29 to 36 o f gestation, is characterized by the development of sacsvthatlater become alveoli.
During the sacc ular phase, a tremendous increase in the potential
gas-
exchanging surface area occurs. The distinction between the saccular stage and the alveolar s
tage 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 willbe
present in the lungs for life develop?
a. 6 months
b. 1 year
c. 1.5 years
d. 2 years
, Answer: 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 yearsof 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 trachealste
nosis. During which period of lung development did this problem develop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveola
Answer: A
The initial structures of the pulmonary tree develop during the embryonal stage. Errors in develo
pment during thisvtime may result in laryngeal, tracheal, or esophageal atresia or stenosis. Pulmo
nary hypoplasia, an incomplete development of the lungs characterized by anabnormally low n
umber and/or size of bronchopulmonary segments and/or alveoli, can develop during the pseu
doglandular phase. If the fetus is born during the canalicular phase (i.e., prematurely), severe re
spiratory distress can be expected because the inadequately developed airways, along with ins
ufficient and immature surfactant production by alveolar type II cells, gives rise to the constellati
on of problems known as infantrespiratorydistress syndrome.
REF: p. 6
4. Which of the following mechanisms is (are) responsible for the possible association
betweenoligo hydramnios 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
Answer: D
, Oligohydramnios, a reduced quantity of amniotic fluid present for an extended period of time, with or
without renal anomTalEieSs,TisBv aA sNs oKciSatEeLd wL Ei thR l. uCn Og M
hypoplasia. The mechanismsvby which amniotic flu id
volume influences lung growth remain unclear. Possible explanations for
reduced quantity of amniotic fluid include mechanical restriction of the chest wall,
interference w ith fetal breathing, or failure to produce fetal lung liquid. These clinical and
experimental obser vations possibly point to a common denominator, lung stretch, as being amajor
growth stimulant.
REF: pp. 6-7
5. What is the purpose of the substance secreted by the type II pneumocyte?
a. To increase the gas exchange surface area
b. To reduce surface tension
c. To maintain lung elasticity
d. To preserve the volume of the amniotic fluid
Answer: B
The primary role of mammalian surfactant is to lower the surface tension within the alveolus, specif
ically at the air–
liquid interface. This allows the delicate structure of the alveolus to expand when filled with air. W
ithout surfactant, the alveolus remains collapsed because of thehigh surface tension of the moist al
veolar surface. Surfactant is composed predominantly of an intricate blend of phospholipids, neut
ral lipids, and proteins.
REF: p. 8
edition by brian
Chapter 1: Fetal Lung Development Test
B ank
MULTIPLE CHOICE
1. Which of the following phases of human lung development is characterized by the
formationof a capillary network around airwaypassages?
a. Pseudoglandular
b. Saccular
c. Alveolar
d. Canalicular
Answer: 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
vascularchannels, or capillaries, which begin to grow by forming a capillary network around the air
passages. Durin g the pseudoglandular stage, which begins at day 52 and extends to week 16 of
gestation, the ai rway system subdivides extensively and the conducting airway system develops,
ending with the t erminal bronchioles. The saccular stage of development, which takes place from
weeks 29 to 36 o f gestation, is characterized by the development of sacsvthatlater become alveoli.
During the sacc ular phase, a tremendous increase in the potential
gas-
exchanging surface area occurs. The distinction between the saccular stage and the alveolar s
tage 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 willbe
present in the lungs for life develop?
a. 6 months
b. 1 year
c. 1.5 years
d. 2 years
, Answer: 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 yearsof 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 trachealste
nosis. During which period of lung development did this problem develop?
a. Embryonal
b. Saccular
c. Canalicular
d. Alveola
Answer: A
The initial structures of the pulmonary tree develop during the embryonal stage. Errors in develo
pment during thisvtime may result in laryngeal, tracheal, or esophageal atresia or stenosis. Pulmo
nary hypoplasia, an incomplete development of the lungs characterized by anabnormally low n
umber and/or size of bronchopulmonary segments and/or alveoli, can develop during the pseu
doglandular phase. If the fetus is born during the canalicular phase (i.e., prematurely), severe re
spiratory distress can be expected because the inadequately developed airways, along with ins
ufficient and immature surfactant production by alveolar type II cells, gives rise to the constellati
on of problems known as infantrespiratorydistress syndrome.
REF: p. 6
4. Which of the following mechanisms is (are) responsible for the possible association
betweenoligo hydramnios 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
Answer: D
, Oligohydramnios, a reduced quantity of amniotic fluid present for an extended period of time, with or
without renal anomTalEieSs,TisBv aA sNs oKciSatEeLd wL Ei thR l. uCn Og M
hypoplasia. The mechanismsvby which amniotic flu id
volume influences lung growth remain unclear. Possible explanations for
reduced quantity of amniotic fluid include mechanical restriction of the chest wall,
interference w ith fetal breathing, or failure to produce fetal lung liquid. These clinical and
experimental obser vations possibly point to a common denominator, lung stretch, as being amajor
growth stimulant.
REF: pp. 6-7
5. What is the purpose of the substance secreted by the type II pneumocyte?
a. To increase the gas exchange surface area
b. To reduce surface tension
c. To maintain lung elasticity
d. To preserve the volume of the amniotic fluid
Answer: B
The primary role of mammalian surfactant is to lower the surface tension within the alveolus, specif
ically at the air–
liquid interface. This allows the delicate structure of the alveolus to expand when filled with air. W
ithout surfactant, the alveolus remains collapsed because of thehigh surface tension of the moist al
veolar surface. Surfactant is composed predominantly of an intricate blend of phospholipids, neut
ral lipids, and proteins.
REF: p. 8
