Severson Respiratory System Vignettes

Question 1

1.	What cells are responsible for synthesizing pulmonary surfactant?
A.	Alveolar macrophages (phagocytes)
B.	Blood cells
C.	Endothelial cells
D.	Type I alveolar epithelial cells
E.	Type II alveolar epithelial cells

Answer 1

E. Type II alveolar epithelial cells

Question 2

When does pulmonary surfactant begins to form in the human fetus?
A.	16 weeks
B.	20 weeks
C.	24 weeks
D.	28 weeks
E.	32 weeks

Answer 2

B. 20 weeks

Question 3

3. When does pulmonary surfactant levels become sufficient for a baby to survive? 
A.	16 weeks
B.	20 weeks
C.	24 weeks
D.	28 weeks
E.	32 weeks

Answer 3

D. 28

note - answer key says it’s C, but his notes say 26-28 weeks

Question 4

4.	Which of the following cells does NOT develop from the epithelial component of the lung bud (respiratory diverticulum)? 
A.	Clara cells
B.	Endothelial cells
C.	Goblet cells
D.	Type I pneumocytes
E.	Type II pneumocytes

Answer 4

B. Endothelial cells

Question 5

5.	Radiographic examination of an infant's lungs revealed areas of increased parenchymal density.  A diagnosis of congenital lung cysts was made.  What is the embryological basis of this defect?
A.	Deficiency of surfactant
B.	Defective tracheoesophageal septum
C.	Dilation of the terminal bronchi
D.	Hypoplasia of the lungs
E.	Tracheal atresia

Answer 5

C. Dilation of the terminal bronchi

Question 6

6.	The lungs at birth are about half inflated with liquid.  What gives rise to the liquid in the lung tissue?
A.	Lung tissues
B.	Maternal blood
C.	Nasal mucus
D.	Pleura 
E.	Tracheal glands

Answer 6

A. lung tissues

Question 7

7. Which of the following best describes the respiratory or laryngotracheal diverticulum?
   A. The respiratory or laryngotracheal diverticulum consists primarily of splanchnic mesoderm.
   B. The respiratory or laryngotracheal diverticulum develops as an outgrowth of the pleuroperitoneal membranes.
   C. The respiratory or laryngotracheal diverticulum is an ectodermal outgrowth in the roof of the pharynx.
   D. The respiratory or laryngotracheal diverticulum is an endodermal outgrowth in the floor of the foregut.
   E. The respiratory or laryngotracheal diverticulum is indicated in the adult by the foramen cecum.

Answer 7

D. The respiratory or laryngotracheal diverticulum is an endodermal outgrowth in the floor of the foregut.

Question 8

8. Which of the following is CORRECT regarding the primitive pleural cavities?
   A. The primitive pleural cavities are separated from one another by the pleuropericardial membranes.
   B. The primitive pleural cavities are formed from the original extraembryonic coelom.
   C. The primitive pleural cavities are separated from the pericardial cavity by the transverse septum.
   D. The primitive pleural cavities originate from the pericardioperitoneal canals.
   E. The primitive pleural cavities originate from pleura derived from endoderm.

Answer 8

D. The primitive pleural cavities originate from the pericardioperitoneal canals.

Question 9

9. Hyaline membrane disease was suspected in a premature infant who showed signs of labored breathing and tachypnea at birth. What developmental abnormality is responsible for this clinical condition?
   A. Abnormal differentiation of type I alveolar cells
   B. Atelectasis
   C. Deficiency of pulmonary surfactant
   D. Excess pulmonary surfactant
   E. Intrauterine asphyxia

Answer 9

C. Deficiency of pulmonary surfactant

Question 10

10. What cells or tissue gives rise to the cartilages of the larynx?
    A. Endoderm
    B. Neural crest mesenchyme of the branchial arches
    C. Somatic mesoderm
    D. Somites
    E. Splanchnic mesoderm

Answer 10

B. Neural crest mesenchyme of the branchial arches

Question 11

11.	In the development of the lower respiratory tract, which of the following does NOT arise from splanchnic mesenchyme?
A.	Bronchial smooth musculature
B.	Cartilage in the bronchi
C.	Parietal pleura
D.	Pulmonary capillaries
E.	Pulmonary connective tissue

Answer 11

C. Parietal pleura

Question 12

12. Which of the following give rise to the connective tissue, cartilage and smooth muscle of the trachea?
    A. Endodermal lining of the laryngotracheal tube
    B. Mesenchyme of the fourth to sixth branchial arches
    C. Neural crest mesenchyme
    D. Somatic mesoderm of the lateral plates
    E. Splanchnic mesoderm around the laryngotracheal tube

Answer 12

E. Splanchnic mesoderm around the laryngotracheal tube

Question 13

13.	Which of the following malformations of the lower respiratory tract is the MOST common?
A.	Congenital emphysema
B.	Tracheal atresia
C.	Tracheal stenosis
D.	Tracheal diverticulum
E.	Tracheoesophageal fistula

Answer 13

E. Tracheoesophageal fistula

Question 14

14. Which of the following statements regarding alveolar collapse in respiratory distress syndrome or hyaline membrane disease is CORRECT?
    A. Collapse is due to excessive amounts of surfactant.
    B. Collapse occurs frequently in term infants.
    C. Collapse is the result of a decreased number of Type I alveolar epithelial cells.
    D. Collapse results from insufficient production of surfactant.
    E. Collapse occurs when less than 50% of the adult number of alveoli have formed prior to birth.

Answer 14

D. Collapse results from insufficient production of surfactant.

Question 15

15.	When do most of the mature alveoli of the lungs develop?
A.	Between week 6 and week 16
B.	Between week 16 and week 28
C.	Between week 28 and week 36
D.	Between week 36 and week 38
E.	Between birth and 8 years of age

Answer 15

E. Between birth and 8 years of age

Question 16

1. A premature infant has progressive difficulty in breathing and is diagnosed with respiratory distress syndrome. Which of the following is (are) deficient in synthesizing surfactant in this infant?
   A. Alveolar capillary endothelial cells
   B. Clara cells
   C. Mucous-serous glands, bronchial glands
   D. Type I alveolar cells
   E. Type II alveolar cells

Answer 16

E. Type II alveolar cells

Question 17

3.	After a 2-day-old newborn male swallows milk he becomes cyanotic.  After 3 days he develops pneumonia.  A tracheoesophageal fistula is suspected.  Which of the following conditions is most likely to be seen with a tracheoesophageal fistula?
A.	Oligohydramnios
B.	Patent ductus arteriosus
C.	Polyhydramnios
D.	Potter’s syndrome
E.	Toxoplasmosis

Answer 17

C. Polyhydramnios

Question 18

4.	A 2-day-old infant is diagnosed with incomplete division of the foregut into respiratory and digestive portions.  Which of the following conditions would likely be present in this infant?
A.	Congenital diaphragmatic hernia
B.	Esophageal atresia
C.	Eventration of the diaphragm
D.	Hyaline membrane disease
E.	Lung hypoplasia

Answer 18

B. Esophageal atresia

Question 19

5. A newborn baby was diagnosed with eventration of the diaphragm. What is the cause of the condition?
   A. Absence of a pleuropericardial fold
   B. Absence of a pleuroperitoneal fold
   C. Failure of cervical myotomes to migrate into the transverse septum
   D. Failure of migration of the diaphragm (cephalocaudal folding)
   E. Failure of the transverse septum to develop

Answer 19

C. Failure of cervical myotomes to migrate into the transverse septum

Question 20

6. A 3-day-old newborn was born with ectopic cordis. Despite efforts by the doctors at the newborn intensive care unit, the infant died from cardiac failure and hypoxemia. Which of the following embryologic events is most likely responsible for the development of such conditions?
   A. Faulty development of the sinus venosus
   B. Faulty development of the sternum and pericardium, secondary to incomplete fusion of the lateral folds
   C. Interruption of the third pharyngeal arch
   D. Interruption of the fourth pharyngeal arch
   E. Interruption of the fifth pharyngeal arch

Answer 20

B. Faulty development of the sternum and pericardium, secondary to incomplete fusion of the lateral folds

Question 21

7. A newborn infant with esophageal atresia experienced respiratory distress with cyanosis shortly after birth. Radiographs demonstrated air in the infant’s stomach. How did the air enter the stomach?
   A. Through a congenital diaphragmatic hernia
   B. Through an opening in the tendinous portion of the diaphragm
   C. Through a pleuropericardial fistula
   D. Through a pleuroperitoneal fistula
   E. Through a tracheoesophageal fistula

Answer 21

E. Through a tracheoesophageal fistula

Question 22

8.	A 3-day-old newborn has difficulties breathing.  A CT scan of the thorax and abdomen revealed the absence of the central tendon of the diaphragm.  Which of the following structures failed to develop normally?
A.	Cervical myotomes
B.	Dorsal mesentery of the esophagus
C.	Pleuropericardial folds
D.	Pleuroperitoneal folds
E.	Transverse septum

Answer 22

E. Transverse septum

Question 23

9.	A 4-day-old infant was admitted to the neonatal unit suffering from dyspnea and cyanosis.  Radiographic examination revealed a left hypoplastic lung and herniation of abdominal intestines into the left thoracic cavity.  Which of the following embryologic structures most likely failed to develop properly?
A.	Laryngotracheal groove
B.	Pleuropericardial membrane
C.	Pleuroperitoneal membrane
D.	Tracheoesophageal septum
E.	Transverse septum

Answer 23

C. Pleuroperitoneal membrane

Question 24

10.	A 2-day-old infant is diagnosed with failure of the division of the foregut into respiratory and digestive portions.  Which of the following is the most common congenital condition characteristic of this description?
A.	Congenital diaphragmatic hernia
B.	Esophageal achalasia
C.	Esophageal fistula
D.	Esophageal atresia
E.	Tracheoesophageal fistula

Answer 24

E. Tracheoesophageal fistula

note - answer key says it’s D. esophageal atresia, but his notes say it’s tracheoesophageal fistula

Question 25

2.	After a 2-day-old newborn female swallows milk she became cyanotic.  After 3 days she develops pneumonia.  A tracheoesophageal fistula is suspected.  Which of the following structures failed to form during embryological development in this child?
A.	Esophagus
B.	Pharynx
C.	Tongue
D.	Trachea
E.	Tracheoesophageal septum

Answer 25

E. Tracheoesophageal septum