 In this video, we are going to learn about a pulmonary disorder called emphysema. Now emphysema comes from a Greek word which means to puff up. And it is called so because in emphysema the lungs puffs up. I want you to carefully look at the lungs and the dome shaped diaphragm here and in emphysema it would look somewhat like this. Now you might think what's big deal in that? Every time we inhale our lungs puffs up. So how can it be a disease? Well, in case of emphysema this condition is permanent. It's not like this person will exhale and the lungs will reduce its shape. It's a permanent condition. And because of the swelling the chest protrudes out. So it is said that in emphysema the patient gets protruded barrel shaped chest. And again this happens because their lungs swell up. Okay, now what do you think and probably cause such a situation? Swelling of lungs and protruded barrel shaped chest. Well, in normal human beings like you and me who are not infected with emphysema our lungs swell only when we inhale. When the air goes inside our air sacks, right? So maybe in emphysema the air went in but it never came out. Maybe the air got trapped. Now is that even possible? Because our lungs are quite efficient at what they do, right? Whatever amount of air we inhale the same amount of air we exhale out. So how can it just let air sit inside it? Well sadly this happens because our lungs loses their capacity their strength to push air out from their air sacks. And this poor condition of our lungs is caused by tobacco smoking. 80% of emphysema is caused by tobacco smoke and the rest by very high air pollution or chemical fumes. Now let's see what this fumes and smoke does to cause emphysema. Okay, for that we will enlarge a part of the lungs. Let's say this part we enlarged, okay? Now let's just consider this to be the regular shape of alveoli, okay? And as soon as a person inhales the air rushes into this alveoli and it increases in size, right? And when he exhales the size reduces. Inhalation, exhalation. Inhalation, exhalation, okay? Now what do you observe here? The membranes of these alveoli's they can stretch and they can snap back or recoil just like elastic, right? So they have the power of elasticity. And this property of elasticity is possible because they have a special protein called elastin on the alveolar membrane. Now when a person smokes, the smoke contains a lot of toxins that gradually gets inside these alveolus, okay? Slowly they move into the alveolus. Now our alveoli, they have their own protective mechanism. They have these tiny little immune cells to fight with anything bad that might enter our airways, okay? Now when those bad harmful toxins get in, they trigger these immune cells. And when our immune cells are triggered, they release certain mediators or let's just say chemicals into their periphery, okay? So these are the chemicals that our immune cells are releasing. Now these chemicals that are released, they will invite more immune cells. Let's just write IC for immune cells into the war zone, into the area to fight with the toxins, okay? Now there is one immune cell which releases a special kind of protein in that war zone which is called elastase. It's an enzyme and from the name you can guess elastase will work on elastin protein. It will break down elastin and our alveolus will gradually lose their elasticity. So with regular smoking, the toxins keep coming into these alveolar sex. They stimulate these immune cells way too much. They make them hyperactive. And as a result, we just saw that elastase is produced in the area and it reduces the elasticity of the alveolar walls. And this war goes on as long as the toxins keep coming into the airways. Now the elasticity is not just in these alveolar walls but also in these bronchial endings, okay? Which do not have these cartilaginous rings to hold them wide open. Now all these parts, they lose their elasticity. Now the elasticity worked differently in the alveolar walls and the bronchial endings, okay? In the alveolar walls, it helped the walls to snap back after it was inflated. But for the bronchial endings, it pulled them apart. It helped them to stay wide open so that the air can rush out from the alveolar sex. But now when they don't have the elasticity, these bronchial endings won't stay wide open. So after a proper inhalation, when the air sacs are all filled up and now the air needs to go out, these bronchial tubes won't stay wide open. They will collapse because they don't have elasticity in them. So the amount of air that was supposed to rush out of the lungs while exhaling, that didn't happen because the passage was obstructed. These bronchials became narrow. So some amount of air got trapped in these alveolar sacs. Now the next time this person inhales, a good blow of air will move into these air sacs, which already had a good amount of air filled in it, causing them to forcefully inflate and thereby destroying the alveolar membranes. And now I need not tell you how important these alveolar membranes are, right? This is where the exchange of gases takes place. There is a very close association of the alveolar membrane with the blood capillaries. And if the alveolar membranes are disrupted, it obstructs the effective exchange of gases between the blood and the lungs. And that is how the size of the air sacs becomes bigger and bigger, thereby swelling up the lungs. But even though they become big, they cannot retain their shape because of the loss of elasticity. So the alveolas would look somewhat like this. And this is emphysema. Okay, if a person has emphysema now, what are the treatment options? Is it curable? Well, sadly, just like hasma, emphysema is not curable. There are medications or therapy for emphysema which can provide temporary relief to the symptoms. You know, it can prevent complications and maybe slow down the progression of the disease, but it is not completely curable. And according to me, the first advice from any doctor to an emphysema patient would be to quit smoking. Only then can they stop further damage to their lungs. And apart from that, there are options like bronchial dilators that can provide temporary relief to those constricted airways. It will dilate the airways so that the person can breathe normally for some time. And apart from that, there are oxygen therapies. Now emphysema patients are highly oxygen deficient because the membrane through which oxygen and carbon dioxide exchange take place, that membrane gets destroyed. And as a result, there comes a situation when the person is kept alive only by giving repeated oxygen therapies. And apart from this, if the condition is detected early, okay, let's say only a small part of the lung has emphysema. I mean, only this part has lost their elasticity and lost their normal function. Then that part can be removed through surgery. We also call this as lung volume reduction. Or if all these options are not working, then the last one is lung transplantation. A new lung from another human being is transplanted to an emphysema patient. So this is the story of emphysema. Now I want you to carry something for life from this video. And not just read this chapter or this topic for the sake of exams. Because you know emphysema is a chronic disease. It's not like your lungs are perfectly fine today and tomorrow you will wake up with emphysema. It's not like common cough and cold, you know. If you're exposed to tobacco smoke for years and polluted conditions, then you may end up causing this big damage to your lungs. And do you understand what this means? You may block the passage of oxygen entry into your body. So always, whenever you are out into polluted environment, wear a mask, stay away from tobacco smoke, take care of your lungs and stay healthy.