What is emphysema?

this is your mouthful to say chronic obstructive pulmonary disease so since there's an acronym for everything which is call it COPD now chronic means it develops and happens over a long long period of time in pulmonary disease means it happens in the lungs but obstructive is really the key word here and we'll come back to this in just a second to describe exactly what's obstructed here but first let's draw some Airways so you have your trachea so our air enters the airway and to me the whole thing looks kind of like an upside-down tree where you have these branches that keep branching off and there's only 20 or 30 branches I can't draw them all you can imagine that just keeps getting smaller and smaller just like branches on a real tree and as they get to the end of the unit here let me draw it where there's more space we encounter something that's it kind of looks like this it's kind of like a cluster of little bubbles we call this the alveoli cluster so alveoli is plural for alveolus it's a Latin thing to make the plural into an eye at the end so all of these are alveoli and in fact aside from the cluster at the end they happen around on the stem near at the end of the cluster as well kind of on the tree branch and to get into the nitty-gritty this is where emphysema happens now let's just blow up that end unit there and get a better look so you have your terminal branch here and the way I'm drawing this kind of looks like little clusters of tents you'll see in just a second while I'm drawing it in particular like this trying to get across the idea that there are walls separating each LVO list from each other so you have the walls have alveoli and then the end you have your cluster and this is what the whole thing looks like at the top of a breath when it's filled with air then I'm really tempted to compare this to a balloon that's blown up but we have to keep in mind that the comparison between lungs and balloons only exists during expiration so in a second we'll see what happens during expiration but first - just to be clear let me explain why it's only an expiration that it's like a balloon because when you first we have a balloon this is your regular balloon you have air going in usually there's positive pressure out here putting air in either you're blowing into it or hooked up to a machine or something that's how air gets in but in the lungs during inspiration there's no nothing's blowing into your mouth forcing the air in and the air comes in by a negative pressure inside and the way that happens is because our chest wall it's kind of like a box outside the balloon it expands with muscles and as they expands it takes the walls of the balloons with it and that negative pressure is how air goes in but we really not concerned with inspiration right now because obstructive diseases are expert Ori so regardless of how the air got in there we can start thinking of it exactly like a balloon at the top of a breath now because when you light a balloon go the air just rushes right out into same thing your lungs so as soon as you relax the walls of this airway pushes the air out because the wonderful protein that we call elastin that makes up the structure of these walls now whoever named this really thought it through because it elastin describes the fact that it's elastic like a rubber band so soon as you as soon as the lungs relax these walls snap back snap back to their regular size kind of like this not very much area inside at all because the recoil strength of these walls pushes the air out now in COPD what happens is this elastin gets destroyed I just said that elastin gives the elastic quality of a lot of the walls so when that's gone they last a quality of these partitioning 's the holder structure that give the recoil strength that's all gone as well so instead of looking like a perky balloon animal with all these shapes I think of a long that has COPD or this same structure same unit of the lung that has COPD kind of looks like this amorphous blob because the walls have lost their structure they've lost their recoil strength and so they don't hold their original shape it's kind of floppy kind of like a class big bag instead of a balloon and we have a plastic bag and you let it go air does not rush out right there's nothing there's no recoil strength making the wall snap back so it kind of just stays here and nothing happens so that's the first step and to make matters worse in emphysema what happens is here in the stem of the airway this area actually collapses and forms a physical obstruction to the air coming out and the reason that happens I kind of like to think of it as what happens when you have an open door in your house and it's a windy day or its breezy and as the wind goes through this open airway sometimes the door just shuts with it right and here this loud it suddenly pulls the door shut it's kind of the same thing that as air is trying to get out here it pulls the walls with it and usually there's elastin as structure to the walls so it remains open but here without all that the air the walls kind of just want to go with the air such that it collapses here and now you have all this air behind it that cannot get out not only as are the walls not pushing it out but now you have a closed door and these things combined together is what gives you obstructive disease now COPD technically refers to two different diseases there's emphysema which is what we're talking about today with elastin destruction and then there's chronic chronic bronchitis anything aidez just means inflammation or irritation to an area so the airway is irritated depending on how this person got the disease a lot of times these two variations of COPD can exist together in one person but today we're just talking about emphysema in terms of it elastin destruction okay so where were we we we talked about how there's all this extra area in here I cannot escape your lung so you might think so what I working all day to get air into my lungs that's the whole point and you will be half correct so if we imagine that there's a blood supply here I mean the blood supply and the Airways go together they because they need to form an exchange system so oxygen is usually in the lungs that we pulled from the air so oxygen goes into our bloodstream making your red and the other half of the deal is that we have carbon dioxide that the blood brings to the lungs to get rid of these are made by our tissues after they've used up the oxygen it's kind of like a waste product so this needs to go back into the lungs and out through our mouth and this exchange is really the complete job of our lungs and with obstructive disease you can do half of it you can put oxygen in but if you can't get carbon dioxide out it's just as big of a problem it's not getting oxygen because half of our exchange is not working and there's the root of all the problems in emphysema so we have about 2.5 million of these alveoli in our lungs so let's imagine that all of them have lost our last in and they look like floppy bags so what what emphysema actually look like if you have your regular lungs I usually look like this which I hope the your lungs don't look like this but I sorry I can't draw any better right now so that's what they usually look like and if they're filled all the way up and air can get out reminds me of big pillow cases in day in and day out they're overinflated and they can't go back down so as this person has emphysema for a long long time remember it's chronic the rib cage and the tissue out of the chest actually changes shape because the lungs are pushing on it all the time I don't know if you can tell what I'm drawing at all here but what I'm trying to draw is a barrel these people who have COPD are often described as having a barrel chest which means they're almost as far from front to back as they are from left to right with the shape changing this person is very uncomfortable to have to carry around such a huge round chest and have air not be able to get out I need to give him some hair I feel like that's the only way my stick people can look like real people so he's unhappy because his chest is like a barrel sitting there he can't deflate it and there's a special way that people with emphysema often breathe that have earned them the infamous nickname of being a pink puffer now there are two things that this name is trying to describe pink is because they don't lack oxygen so pink instead of blue remember I said that the oxygen getting into the lungs is not a problem our problem is an exhaling so they're pink because they don't really lack oxygen in their blood now puffers describes the fact that they have pursed lips pursed lips kind of like if you imagine putting your mouth around a straw and they breathe through this smaller opening and the reason for this goes back to is mechanical obstruction we talked about earlier with a door slamming shut so let's draw the door again so if it's like this and usually when we breathe out it's like the door is hinged on something it's not going to close and the air rushing out it's pretty fast there's a lot of air because the walls are pushing it out it's imagine this is the amount of air that goes through now in emphysema with the door unhinged and just flopping around in the wind it is less likely to snap close like that if there's a are going less air going through and it's going slower and that's why people have figured out that we have COPD if you purse your lips and you breathe slower it keeps this airway open for just a little longer and every second you can keep that door open is a tiny bit more air out okay let's just put that down and writing here so we have the pursed lips that's the first thing now we have a slowing down of the speed of the air going through because the pursed lips are trying to control it but the rate of their breathing actually goes up just because since they're breathing that so efficiently they compensate by breathing more times per minute this also contributes to the fact that they look like they're puffing and huffing to other people so in a nutshell if I were to describe what I think of emphysema as being in my head it would be these dilated lungs a big barrel chest and this person breathing with pursed lips and they're puffing