Which air passageways do not have cartilage and can collapse: bronchi, bronchioles, alveolar ducts, alveoli?

The correct answer choices to the question: Which air passageways do not have cartilage and can collapse:___, would be: the bronchioles, alveolar ducts and alveoli.

Explanation:

From the third branching of the bronchi, onwards towards the lungs, the cartilage that covers these structures are lost, as their purpose is to allow the flawless flow of air into the lungs, and the expulsion of CO2 from them. Because air pressure, and different pressure gradients ensure that the exchange of oxygen and CO2 takes place within the lungs, this can only be ensured with expansion of the lungs, chest cavity and of course the alveoli and alveolar ducts, where most of the exchange takes place. This is why cartilage is not a part of any of these three structures.

answer:

i don't know

explanation:

sorry

i know it happens all the time :