How does asthma cause less oxygen to diffuse in the blood from the alveoli?

Are my reasons valid:
- Muscle lining bronchioles contract producing thick mucus.
-Airways become inflamed and irritated making the diffusion pathway to increase in distance.

Please can someone modify my answers and tell me if it is correct or not.

Thanks.

Reply 1

Awesomnia

I don't think there is a larger diffusion distance because the air doesn't diffuse through the inflamed airways, and the alveoli don't become inflamed. I would think it would be because the narrower airways mean that simply less fresh air can get to the alveoli so less oxygen in diffused..

Reply 2

JMonkey

I can give you a blow by blow account of what happens when I have an attack, but mostly I'm just here to get an account of the biology. Sorry.

Salbutomol acts as a dilator on inflamed areas (it is a steroid), thus opening up the airways, in series episodes this is not enough and the patient may have to go on a nebuliser for an extended period. Or in extreme cases be intubated and have a machine breath for them, or may even die due to asphyxiation.

As awesome said generally the breathing is inhibited by closing of airways rather than inflammation deep in the lungs. Although because it can often leave the airways inflamed, they become more susceptible to infection which could lead to more serious implications. There are several causes of inflammation, allergic reaction, stress and exercise can all cause an attack as can cold and damp climates.

Reply 3

raspberryice

yeh your answers are right, the reason less oxygen can be diffused is because of the contraction and mucus in the bronchioles meaning less air can get into the lungs and to the alveoli-thus less diffusion of oxygen takes place into the blood stream.