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".

 

[ravenprp]

The bronchioles collapse in emphysema due to the loss of elasticity in the alveoli. As stated in the textbook, the enzyme elastase released by phagocytes causes the alveoli to lose their elasticity. This loss of elasticity interferes with the ability of the alveoli to relax and expand during exhalation. As a result, the bronchioles, which are the small airways that lead to the alveoli, also lose their ability to expand and contract properly. This collapse of the bronchioles further impairs the exhalation process and can also lead to the bursting of alveoli. This is why individuals with emphysema may experience difficulty breathing and have a decreased ability to exhale.