[RS] Q.2) Zone of Lungs:

Ans. 

i) Conductive zone.
ii) Respiratory zone.

Conductive zone: (From nose, Oropharynx, Pharynx, Larynx, trachea, bronchi up to terminal bronchioles)
It is the area of air ways where no gas exchange takes place due to thickness of the wall of muscle &
cartilage. About 150 ml of air in this zone.
Importance:

• Conduction of gases/air.
• Humidification of inspired air.
• Removal of foreign particles by mucocilliary action.

Respiratory zone: (From Respiratory bronchioles, alveolar ducts, sacs, alveoli)
It is the area of air ways where gas exchange take place between blood and alveoli through alveolo-capillary membrane (Respiratory membrane).