lung development, structure and gas movement

Question 1

what are the 5 stages of lung development

Answer 1

1) embryonic - establishes basic lung structure as a template for further growth
2) pseudo glandular - establishes the branched network of gas conducting airway
3) canalicular - formation of the blood-gas barrier
4) saccular - formation of the respiratory acinus - the zone of gas exchange
5 alveolar - formation of the alveolus and high surface area for gas exchange. 5x increase in surface area for 2x increase in lung volume

Question 2

in the embryonic stage formation of left and right lobes take how long

Answer 2

26 days - 6 weeks

Question 3

in stage two, the formation of gas conducting the airway of the respiratory tree takes how long

Answer 3

6-16 weeks

Question 4

Irregular Dichotomous Branching

Answer 4

Achieves even dispersal of gas among terminal airway branches. Mechanical strain dispersed evenly among units