Respiratory System Normal and Abnormal Development

Question 1

What are the germ layers that contribute to the development of the larynx and the bronchial tree?

Answer 1

endoderm

The respiratory epithelium and the glands that are derived from the epithelium are endodermal in origin.

The surrounding tissues (connective tissue, smooth muscle, cartilage, etc) are derived from the splanchnic mesenchyme.

Question 2

What is the role of the tracheoesophageal septum in development of the respiratory system?

Answer 2

The laryngotracheal tube is divided into the trachea and the esophagus by the tracheoesophageal septum

Question 3

What develops from the splanchnic mesenchyme?

Answer 3

connective tissue, cartilage, and smooth muscle

Question 4

What develops from the neural crest mesenchyme?

Answer 4

laryngeal cartilage

Question 5

What are laryngeal cartilages derived from?

Answer 5

the fourth and sixth pharyngeal arches…that developed from the mesenchyme…that derived from neural crest cells

Question 6

What are laryngeal cartilages derived from?

Answer 6

the fourth and sixth pharyngeal arches…that developed from the mesenchyme…that derived from neural crest cells.

Question 7

What do laryngeal muscles develop from?

Answer 7

the myoblasts of the fourth and sixth pairs of laryngeal arches.

Question 8

What are the laryngeal muscles innervated by?

Answer 8

the superior laryngeal and recurrent laryngeal nerves of the vagus

Question 9

What are the tracheal epithelium and glandular elements derived from?

Answer 9

endoderm

Question 10

What are the tracheal cartilage, connective tissue, and muscles derived from?

Answer 10

splanchnic mesoderm

Question 11

What causes a tracheoesophageal fistula?

Answer 11

abnormal development of the tracheoesophageal fold and septum

Question 12

What is a tracheoesophageal fistula?

Answer 12

Results from abnormal partitioning of the laryngotracheal tube by the tracheoesophageal septum, producing an abnormal communication between the trachea and esophagus

Question 13

What does tracheoesophageal fistula cause?

Answer 13

Food or gastric contents may enter lungs and result in pneumonia or pneumonitis

Question 14

What danger does a tracheoesophageal fistula pose to a fetus?

Answer 14

Amniotic fluid accumulates (polyhydramnios) because amniotic fluid cannot pass to the stomach and intestines for absorption and subsequent transfer via the placenta to the mother’s blood

Question 15

What is lung hypoplasia generally associated with>

Answer 15

congential diaphragmatic hernia

Question 16

What are type 1 alveolar cells called? What are they?

Answer 16

pneumocytes; squamous epithelium of endodermal origin form

Question 17

what do type II alveolar cells do

Answer 17

secrecrete surfactant

Question 18

What is hyaline membrane disease?

Answer 18

a deficiency of surfactant and injury to the alveolar wall resulting in a protein-rich, fibrin-rich exudation into the alveolar spaces and formation of hyaline membranes (result is respiratory distress syndrome).

20% of infant deaths

Question 19

What drug accelerates fetal lung development?

Answer 19

Glucocorticoids

Question 20

What is typical therapy for newborn with Respiratory Distress Syndrome?

Answer 20

Administration of exogenous surfactant