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Current time:0:00Total duration:6:27

Video transcript

so first let us get familiar with the image that I have drawn here and you'll see that we have an image of our lungs and if you look you see we have our right in our left lung and if we start from the top you can see that we have our large airway here also known as our trachea and that trachea or that airway is going to break off into two larger Airways so one going to the right and one going to the left and those Airways are going to branch off to even smaller Airways and at the end of these we have these very tiny sacs and we call these alveoli I'm going to draw those in in just little blue dots that way we can see and these tiny sacs that we have are really our air sacs and this is where the gas exchange occurs so this is where oxygen and carbon dioxide is swapped back and forth now if we're able to step outside of our lungs let's talk about the anatomy there so for this let's just focus on our right lung now covering our right lung and pretty snugly covering it we have this thin membrane called the visceral pleura and this visceral pleura is really like a tightly fitting sac that our lungs sit in both our right and our left lungs now on the outside of our visceral pleura we have a second membrane and that membrane is called the parietal pleura and this parietal pleura is a membrane that covers both the visceral pleura and the lung so think of it like this imagine that this lung represents your hand and you slip on a latex glove over your hand well that first latex glove that you put on would represent the visceral pleura if you slipped on a second glove that second glove that's covering the first and your hand that would represent the parietal pleura now when you can deter mistral just think of Oregon and in this case the organ that we're referring to is the lung now I'm going to zoom in just a little bit here so we can see this space that we have and we call this the pleural space this is really more of a potential space that we have in between the membranes now when we use a term potential what that really means is that there is an opportunity for something to occur here and we're going to talk about that in a little bit more detail in this space we actually have about one to two teaspoons of fluid we call that pleural fluid and this is completely normal this really acts as a lubricant to help these two membranes glide smoothly across each other as the lungs expand because remember this when we take a deep breath in the lungs are going to expand these two membranes are going to touch each other without a lubricant there's really no smooth barrier and these two membranes would stick to each other and they would rub and cause a lot of friction that would be definitely very uncomfortable so this little bit of fluid that we have in the pleural space really just acts as a lubricant now let's shift over and look at the left lung and we're going to draw the same membranes that we have so we're going to draw the visceral pleura going around the lung and we're going to draw the parietal pleura going around that now what happens if the fluid that we have in the pleural space builds up we have an excess of fluid what's going to occur well let's create that scenario so I'm going to take away our membranes and I'm just going to add in a lot of fluid right here at the base of the lungs and then let's put these membranes back and see what happens so you'll see that the area that I've drawn in with all this excess fluid has actually caused our lung to shift inward a little bit and if you compare it to our right lung you can see that the shape of the lung on our left has actually changed and that's as a result of this excess fluid that's sitting in the pleural space now remember our outermost layer is the parietal pleura but the parietal pleura lies right against our chest wall so as we have this increase of fluid building up in the pleural space the pressure is not going to push outward towards our chest because it really doesn't have anywhere to go it's covered by ribs and muscles instead the pressure this excess buildup is going to push inward against our lung and this can cause our lungs to shift a little so I want you to think about what could possibly happen as a result of this how would this person manifest certainly we would see things like difficulty breathing and we call that dis mia chest pain could be expected as well as we have this shift of the lungs as we have this buildup and pressure in our pleural space we do have pain receptors in this area so we would feel that this person may actually have a cough as well and the type of cloth that we can expect to see would be a dry cough versus a wet cough and why that's important is because when there's a decrease of air space in this case the lungs have shifted inward our body is able to recognize that and as a mechanism you're going to elicit a cough and that cough is really an effort of the lungs to try to clear the air space it feels like there's not enough so it's going to try to cough to clear it out but in this case the problem exists on the outside of the lung not the inside so nothing's going to come out now you might be thinking how does this happen how do we have a buildup of fluid in this space if normally we have such a small amount well our lymph system really helps to filter and regulate the fluid that we have in this area so something happens with our lymphatic system that it's not able to filter out fluid as rapidly as it should be we could have a buildup of fluid in the event that somebody has a medical problem like justif heart failure or liver failure that backup that occurs in our vessels can actually cause fluid to leak out into the space somebody that has pneumonia which is an inflammatory disorder that inflammation in the lung tissue can actually cause fluid to seep out as well and all of that will end up in our pleural space and cause an excess buildup of fluid and we call that a pleural effusion