Embryology

Question 1

Where does the lung bud originate from?

Answer 1

Upper part of gut tube

Question 2

Respiratory congenital defects

Answer 2

Oesophageal atresia (blind-ending)
Tracheoesophageal fistula (communication)

Question 3

What gives the lining of the respiratory tree?

Answer 3

Endoderm

Question 4

Where does the lung tissue come from?

Answer 4

Mesoderm

Question 5

What events in regards the maturation of the lungs occur during the embryonic stage (26 days-6 weeks)

Answer 5

Respiratory diverticulum forms

Initial branching to give lungs, lobes and segments

Question 6

What events in regards the maturation of the lungs occur during the pseudoglandular stage (6-16 weeks)

Answer 6

14 more generations of branching: Terminal Bronchioles

Question 7

What events in regards the maturation of the lungs occur during the canalicular stage (16-28 weeks)

Answer 7

Terminal Bronchioles → ≥2 Respiratory bronchioles → 3 – 6 alveolar ducts

Question 8

What events in regards the maturation of the lungs occur during the saccular stage (28-36 weeks)

Answer 8

Terminal sacs form; Capillaries establish close contact

Question 9

What events in regards the maturation of the lungs occur during the alveolar stage (36 weeks-early childhood)

Answer 9

Alveoli mature