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#1
09-28-2016
 USMLE Forums Newbie Steps History: Not yet Posts: 3 Threads: 3 Thanked 0 Times in 0 Posts Reputation: 10
Lung compliance question

Hello everyone
Sorry but i have a question regarding physiology of the lung (from kaplan book edition 2013 page 179 )
The book say that if we increase lung volume the compliance will be decease how come is that??according to math they are directly proportion to each other so any increase in volume proportionally will cause increase in compliance??really confused (Compliance=change in volume\change in pressure)
Sorry if the question seems to be silly but really appreciating any help
Thank you all for your time
Regards

#2
03-07-2017
 USMLE Forums Newbie Steps History: Not yet Posts: 7 Threads: 0 Thanked 1 Time in 1 Post Reputation: 11

I think what is meant is much more simple than that.
If you breath in (increased delta V), the lung has less elasticity / compliance (left). (equation in screenshot attached)
You cannot breath in limitless.
Here, the lung could compared to a balloon: A ballon's compliance will decrease, too, when it is inflated.
Attached Thumbnails

#3
03-07-2017
 USMLE Forums Scout Steps History: Not yet Posts: 27 Threads: 2 Thanked 3 Times in 3 Posts Reputation: 13

No compliance increases as volume increases

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