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A level biology unit 3 lung disease graph help

Hey. Can someone explain why group B would be asthma. I don’t understand the markscheme answer. Thanks.
Reply 2
Hety can someone help thanks
Reply 3
Original post by Tanyme
Hety can someone help thanks

The question is about fibrosis and not asthma.
I think the markscheme means that the initial rate of expiration is just as high as A (normal) indicating that the mechanisms for ventilation have not been affected but that the graph levels off at reduced volume as time goes on. This suggests that the surface area for effective exchange has reduced and limiting the maximum capacity of the lungs. This is in line with fibrosis that leave thickened scarring in the alveoli.
(edited 10 months ago)
Reply 4
Marking point 1: FEV means forced expiratory volume, which is how much can be initially expelled in a breath out.
Marking point 3: FVC means forced vital capacity, which is how much more you can expel if you continue to try to breathe everything out of your lungs.
(edited 10 months ago)

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