Respiratory Development (embryo)

Question 1

How is the respiratory system developed?

Answer 1

Epithelium: endoderm
CT, muscle: mesenchyme

Question 2

Formation of the laryngo-tracheal groove

Answer 2

Forms a tube that extends from the 4th pharyngeal arch through the floor of the pharynx

Question 3

What does the rostral opening of the laryngo-tracheal groove become?

Answer 3

Glottis and is guarded by the epiglottis

Question 4

Caudal tube of the laryngo-tracheal groove

Answer 4

Separated by the tracheoesophageal ridge that separates the tube dorsally into esophagus and ventrally into trachea

Question 5

What does the caudal most part of the of the caudal tube form?

Answer 5

A lung bud that divides into lobar bronchi that ventilate each lobe

Question 6

What are the stages of lung development

Answer 6

1. Pseudo-glandular
2. Canalicular
3. Terminal sac
4. Alveolar

Question 7

Pseudo-glandular

Answer 7

5-16 weeks
Bronchi and termal bronchioles

Question 8

Canalicular

Answer 8

6- 26 weeks
Terminal and respiratory bronchioles, alveolar ducts (cuboidal epithelium)

Question 9

Terminal sac

Answer 9

26-32 weeks
Primitive alveoli and capillaries establish contact (cuboidal –> bronchiole surrounded by capllaries)

Question 10

Alveolar

Answer 10

32 weeks to infancy
Matur alveoli and capillaries

Question 11

Functional maturation of the lungs

Answer 11

The more active the animals is @ birth, the greater # of alveoli
Ruminants –> horses and pigs –> carnivores

Question 12

Congenitl esophageal tracheal fistula

Answer 12

Fistula between esophagus and trachea
Caused by incomplete partitioning of the tracheoesophageal septum

Question 13

Respiratory distress syndrome (atelectasis)

Answer 13

Lack of surfactant because of lack of differentiation of great alveolar cells