Why do the brochioles collapse?

[Cheman]

I have read the following in a textbook: "In emphysema, phagocytes release the enzyme elastase, which causes the alveoli to lose their elasticity. This interferes with their ability to relax and thus your ability to exhale. This also causes the bronchioles to collapse, which further prevents exhalation, and causes many alveoli to burst."

My question is why do the brochioles collapse?

Thanks in advance.

 

[DocToxyn]

My question is why do the brochioles collapse?

The collapse is said to come about by the increase in pressure that is required to exhale. The excessive pressure is required due to compromised alveolar function, initiated by the degradation of elastin as you mention, and this overcomes the ability of the bronchioles to remain open. Check out http://rtmagazine.com/Articles.ASP?articleid=R0110A04 under "pathophysiology".