Respiratory | Compliance & Elasticity

I'm an engineer in this video, we're going to talk about

compliance

, so first of all, how do we define

compliance

well? We have a mathematical definition of compliance and I'm just going to give you a simple term of compliance, let's write compliance. down here, so what is compliance? Compliance is defined as the change in volume and we're talking about the lungs or the chest wall, so compliance could be four again, it could be for the actual lungs or it could be for the chest. On the wall we'll talk about both, so compliance is equal to the change in lung volume over the change in pressure, okay, but just when we talk about compliance, compliance is a measure of stretchability or capacity. of dispensing, in other words, if I want to stretch something that stretches very easily, you know, like a rubber band or something that stretches very easily.

Well, something like that is very tame. Our lungs are very docile by nature, but at the same time they have the opposite of that, they have just the right amount. of

elasticity

, so in order for us to talk about compliance we have to compare compliance with another term that is known as

elasticity

because compliance is another way of explaining is the ease with which something stretches is how easy it is to stretch where elasticity is the stretch resistance that wants to go back, is assumed to be as small as possible, so the elasticity and again there is the elasticity of the same, the lungs and the chest wall, but this situation is the opposite, it depends on the change in pressure. about the change in volume and we'll explain what we mean by these formulas here, let's do that before we get into all these examples where compliance can vary in certain scenarios, so if we talk about compliance first, let's see how we can compare. the situation with volume is fine, agent compliance vol 2 and the change in pressure towards compliance, well, first things first, how would we say volume is affecting compliance?

It's simple, they are directly proportional, so we can save from this formula that the change in volume is directly proportional to the compliance, whether it is the compliance of the lungs or the compliance of the chest wall, whereas if we increase the pressure, what happens with a compliance decreases, so the change in pressure is inversely proportional to the compliance, in other words, if we increase the pressure, the compliance decreases, if we decrease the pressure, the compliance increases and we will talk about what this is pressure because technically, if I were to rewrite this pressure here, if we're talking about the lungs, we're actually going to do that. let's talk a little bit because if it's in the lungs of the transpulmonary, if it's through the chest wall, it's transthoracic, we'll write that down now, let's write that down here, so if it's for the lungs, your transpulmonary will actually go and show examples of this. . but if it is the chest wall it is the transthoracic pressure to remember TTT, we denote it the same for this for the lungs the preparation pressure change is the transpulmonary pressure the TP and the chest wall that is going to be t TP well, now we saw elasticity In the relationship here, any increase in pressure, any change in pressure increase over which it increases is directly proportional to the elasticity, in other words, if the change in pressure increases, the actual elasticity increases, while What if the volume changes.

If I try to stretch something, I'm increasing the volume, what does that do to the elasticity? It decreases it, so they are inversely proportional, so I really wanted to make sure to differentiate the compatible term from elasticity because they are not the same term. They are not the same, they are exactly opposites. Okay, now what I want to do is talk about what affects compliance in the lungs, what actually maintains this normal compliance within the lungs, and then what we're going to do. After that, what's the first thing I want us to do? The first thing I want us to do in this video is talk about the things that typically affect compliance.

So what affects compliance normally. That's the first thing I want to do. Okay, then the second thing. What I want to do is go ahead and relate these changes in volumes and changes and pressures to real life examples with compliance, so we're going to compare Delta V, which is the change in volume, and then Delta P, which is the change . in pressure for compliance and then we'll add some clinical correlations with that, okay, let's go ahead and start with that, so the first thing that affects compliance is usually okay, there are three main things that are affecting compliance.

I want you to remember these three main ones. things that affect compliance here look at this there are three main things that affect compliance the first is the elasticity of the lungs this is something that is actually affecting compliance the elasticity of the lungs the second thing that affects compliance is surface tension that we've talked about a couple of times is that tension that develops in the alveoli of the lungs right between the air and the water interface, which tries to shrink the avila trying to make the alveoli collapse and the third thing that affects the Compliance is the elasticity of the chest wall, okay?

Let's explain each of these things that we're actually trying to do, so first let's start with the elasticity of the lungs. Now our lungs can stretch, but they naturally want to go back, but there's just the right amount, so in our lungs, you know. There are different types of tissues within our lungs, but in general our lungs are very pliable, they are very pliable, but they also have just the right amount of elasticity, so they are very pliable, but they have just the right amount of elasticity, just the right amount . amount, so what do I mean by this?

The lungs can actually expand easily. It's okay, they can expand easily. We have to use ice and skeletal muscle to help that process, but they can easily expand but also want to move back, let's say, for example. I change the elasticity, so now the compliance with the other lung, so the compliance of the lung is more or less equal to the elasticity, okay, there is a good interaction, a nice central plane, let's say I changed the situation, Let's say I have to actually make the lung more elastic, how can I make it longer, more elastic, why prevent it from wanting to stretch, this is how we do it, I prevent it from wanting to stretch, how do we know that?, because we made the formula , we said that, what? the formula in the formula we said that if you really decrease the volume, in other words, you just don't want the ridiculous lung to stretch as much, it will actually do what if you decrease the volume, it will increase the elasticity, or vice versa. you're going to increase the elasticity, you're actually doing what decreases the volume, so you don't want to stretch in this situation, let's say I have.

You know the person unfortunately has what's called pulmonary fibrosis, so he has pulmonary fibrosis in others. words, let's say here, it's actually over here, let's say over here, but this person is long, you're right, it has just the right amount of stretchy fabric, but now I'm going to do this and I like this brown color, these brown colors to represent fibrous tissue, so we're going to They say that if someone is getting older or has a certain type of situation, they are developing a lot of fibrous tissue and a lot of fibrous tissue is developing around the lungs, as this starts to develop a large amount of fibrous tissue, what is the purpose of this?

Fibrous tissue is not expendable, it doesn't like to be stretched, so if you actually have a lot of deposits of fibrous tissue here instead of normal healthy lung tissue, then there is a lot of scar tissue, fibrous tissue is actually scar tissue, so Let's say this is a lot. scar tissue, which is pulmonary fibrosis, so we say here that a lot of scar tissue is formed, it is not distensible, so if you do not want to stretch it, which happens with distensibility, distensibility decreases but elasticity increases, it is well, so if there is a lot of pulmonary fibrosis. from scar tissue formation, okay, fibrous tissue buildup won't want to stretch, so what about elasticity?

Now the elasticity increases and the compliance decreases, so let's write that here we will deal with the color coordinates, so in this situation the compliance actually goes to what decreases and then what happens to the elasticity, the elasticity increases and a Once all the general effect of the lungs, the lungs will not want to expand or they will want to constantly move back, so it is difficult for them to be able to do so. be inflated this is an example of some type of restrictive lung disorder where they have a low strength times capacity let's take the opposite now let's say we actually make the lung super compliant okay now let's take the opposite let's say I break a There's a lot of elastic tissue there , so let's say we use the example here of uh, you know, there's a disease called emphysema, so this is a disease here called emphysema and emphysema is a disease, you know, the alveoli have a lot of this pink tissue here. many of these are very normal, you will have a large surface area, normal healthy alveoli have a large surface area, so that's a really important thing about alveoli, they have a large surface area, but with emphysema those neutrophils start to relieve a lot of last flavor enzymes and anti alpha-1 antitrypsin don't prevent it and it starts to happen that they start to break down a lot of elastic tissue as you start to break down a lot of that elastic tissue, what's going to happen? the lungs well now they are not going to have as much elasticity if they do not have as much elasticity then what does that mean well if their elasticity is decreasing what do we say elasticity well let's go back to the formula what we said that this is inversely proportional, so if the elasticity decreases, it what happens to the volume increases, well I thought if the volume increases, the compliance increases, do you see how it's not that bad if we use the formulas, they can help us really understand it, so in this situation and in reality, emphysema, disorder chronic obstructive pulmonary, the lungs are very flexible, so they are not very flexible;

In other words, you can take in a lot of air; In general, it is easy for these people to take in a lot of air, but the problem is whether the last The wheezing lungs allow expiration passively, so when the lungs collapse they help to be able to expel the air passively without having to exert much effort, but in these Individuals are not very elastic, they are very compatible and therefore their elasticity is very less, so they have very little elasticity, so the lungs will not go back as well and therefore it will be difficult for them to get air, so they have a low forced expiratory volume.

So, in this situation we take the opposite, so what happens with its fulfillment? Your compliance increases and lastity decreases, not so bad. Now that we have done the elasticity of the lung, let's do the elasticity of the chest walls, let's just continue with this. concept here, okay, and after we do the surface tension, I'm going to talk about pressure and how pressure affects these things, okay, so let's do this one and the purple one, let's do a purple one, so let's say we talk about the wall chest, okay, chest wall again, same thing. The chest wall is generally very docile and what do we say about the lungs?

The lungs usually have an inward pullback, they want to, they want to break, and we said like this, if we were to show the arrow, it always wants to fit like this, while the chest. The wall wants to push back outward, it likes to be stretched outward, that's what helps maintain this nice, negative intrapleural pressure. In this situation, see this situation, there is a good interaction between chest wall elasticity and chest wall compliance, so it's like you. We know we said again that chest wall compliance is enough so that there's not any kind of situation where one outweighs the other, it's just the right amount in normal, healthy individuals, whether there's this nice dynamic dynamic and we need to make sure .

We say this because it's not always perfect, there is this kind of Cole Cole Poole on the one hand, but he always tries to keep it on a level playing field, so there is a dynamic interaction between these two to maintain elasticity and natural compliance, but again, Let us understand this in pathological conditions. or different interesting types of physiological situations, let's say this person has his chest wall. Let's say he has ankylosing spondylitis. You know, there is a situation: it is an inflammatory arthritis and in that inflammatory arthritis they have a hunched posture. in this situation it is called ankylosing spondylitis ankylosing spondylitis or there is another one called kyphosis kyphosis when they have that hunched posture in the chest cavity as if they were leaning like that, so they have kyphosis, so an individual we can even have what is It is called kyphosis or even scoliosis - and even scoliosis ifintrapleural is equal to atmospheric pressure, what is the atmospheric pressure? 760, so even though the intrapleural pressure becomes intrapleural pressure, it will eventually have to maintain the receiving air until it equals the atmospheric pressure, which is 760 millimeters of mercury, which in these terms negative 4 will rise to 0 millimeters of mercury, which is 760 right now?

Look at this when the intrapleural pressure, the pressure inside this pleural cavity, becomes equal to the actual intrapulmonary pressure, even by chance, becomes even higher, as if plus 1 starts to push the actual pressure.lungs and when it starts pushing and push and push and push the lumps creating this real force, what are you going to try to do? It will try to collapse the lungs. What would that do to compliance? It would decrease compliance, so it is. I'm going to try to collapse one, what's that called every time you collapse the lung, what's the name of lung collapse, whatever you do, pneumothorax or hemothorax or other different types of situations, it's a pleural effusion that's building up around there disconnects , introduces what is called atelectasis, so my two.

Okay, now if this is a collapsed lung, what is the lung trying to do? If you're trying to shrink, what does that mean for elasticity? It's actually trying to go back, so in one way you can think if it's trying to be very elastic if it's trying to be very elastic it wants to go back and become very, very small, what does that do to the volume of the long well? The lung volume will begin to decrease if the lung volume begins to decrease. Does that mean for compliance if volume decreases? Compliance decreases, it's not that bad.

Okay, so in this video we talk a lot about compliance and elasticity and basically focus on what affects compliance typically. Well, we talked about elasticity, the elasticity of the lungs or the surface area of ​​the chest wall. neuromuscular tension problems, we compiled a bunch of different types of disorders, they are different types of physiological conditions that can affect them and then we even apply them, we compare all this change in volume, change in pressure with the fulfillment of all these examples, and then even Add your little pathological condition called pneumothorax and hemothorax. Is it compared to atelectasis?

Well, iron injuries. I hope this all makes sense. I hope you enjoyed it. If you did, hit the like button, comment in the comments section and subscribe. our ninja nerds as always until next time