Types of pulmonary diseases | Respiratory system diseases | NCLEX-RN | Khan Academy

By Adem Lewis / in , , , , , , , , , , , , , /

Voiceover: So the job of our lungs on a pretty general level is to take blood, that’s without oxygen that our bodies have used up. So I’m going to use blue
here to represent that. To take that blood and
to put oxygen in it, and it comes out as oxygenated, which is red blood. I mean blood without oxygen
gets a little darker, that’s why conventionally we think of it as blue versus red. And from there the heart pumps this blood to the rest of the body. So in a nutshell, that’s
what the lungs do. And to do that, they grab oxygen from the atmosphere and take the carbon dioxide from the blood and blow it out. Co2, carbon dioxide. And this exchange really is a full picture of what you do with every breath. Now in terms of how the lungs do this, let’s talk about the
structure first for a bit. I think it looks kind of
like an upside down tree, just because all these
branches keep getting smaller and smaller as we reached the terminal branches. I mean there’s 20 or 30 levels here, I can’t draw them all, but you get the idea,
they keep branching off. And at the end, we’ve reached this units called alveoli. Let me write that word for you, alveoli. Which is plural for alveolus. And what that is essentially an air sac. Let’s blow that up down here. So the alveolus looks kind of like a bulb, is an air sac, it has very thin walls, and laying along the walls, almost, almost in contact but not quite, is the blood supply. This is how things get from our blood to the lungs and back and forth. So I’m going to draw a
blue here to begin with because there’s no oxygen to begin with. As it travels and that the
air goes back and forth between the blood supply and the alveolus, it becomes red as it leaves, because there’s oxygen. You can think of it as inhale, oxygen goes in, from here it goes to the blood supply. It makes you exhale, the carbon dioxide is
going the opposite way. When we exhale it can
just leave the lungs. And now the reason this
exchange takes place is just a simple loss of
air pressure in physics. So if there’s more oxygen in here, relatively more compare
to the blood supply, then the oxygen wants to
escape to the blood supply. And if there’s relatively more carbon dioxide in the blood, then it also wants to escape to where there’s less of it, which is into the air sac. So conveniently this allows
us to take what we want and get rid of or it don’t want anymore. Okay, so there’s your bird eye view of how the lungs work in a nutshell. And there’s a lot of
problems that can arise in this whole system. But I think a better way to understand it is to break it down by
the different players, the different areas that can go wrong. So again we think of lung
problems as categories. Now, the first one, the first problem I can think of is oxygen not coming in. And so on the flip side of that, number two would be carbon
dioxide not escaping. All right to keep going, let’s
go further into the lungs. Here at the alveolus, I would say number three is something going on
with this exchange process where between the air
sac and the blood supply, something is not working there, so that’s number three,
that’s the exchange. And lastly, if something is
wrong with the blood supply, blood cannot get to
the lungs and come out, that would be number four. So I think these are the four big categories of lung diseases. And let’s go through them one by one. Now problems number one and two here, we actually think of them
as a pair of diseases, there’s restrictive and obstructive. Let’s start with restrictive. And this just describes
the fact that the lungs which are suppose to
expand when you take air in to make room for the air, for some reason it’s
not expanding properly. So this is an intake
in respiration problem. And since oxygen is the
main point of taking air in, in restrictive diseases we lack oxygen. So what happens is, the lungs for a variety of reasons becomes stiff and hard
to blow up like a balloon that’s been dipped in paper mache and it can’t blow up properly. So if you look at, if
this is suppose to be the size of the lung when it’s blown up, this smaller lung her
in restrictive disease gives us a lot of wasted space, other space that could have had oxygen but is now not usable. That just makes the whole system less efficient, right? So there’s something wrong with the actual structure of the lungs that’s
making it hard to expand. So let’s think of some examples. So there’s fibrosis. Fibrosis just means, laying down too much scar tissue. So if the lungs are chronically injured or sometimes there’s a
genetic factor to it, the tissue gets stiff. Just like the scar you
would have on your hand, except you have all over your lungs. So it’s not, no longer expandable. There’s also things that
can affect the chest wall. Say if there’s a muscular
diseases that make it hard for the chest to expand, that also limits how
big the lungs can get. Or sometimes there
could be things that are deposited in the actual
tissue of the lungs, I can think of amyloidosis, which is these protein particles that get studded into the lungs, making it harder to expand. So those are our examples
of restrictive disease, oxygen cannot get in. Now it’s evil twin, or I
guess they are both evil, but it’s counterpart would
be obstructive disease. Obstructive. So if we said before that, the restrictive is about
not getting air in, then the opposite will
not be getting air out. In restrictive diseases we’re having trouble with expiration. So instead of letting the
lungs collapse back to it’s normal size at the end of an exhale. It stays expanded like this. Let me just draw some of the branches here just to show you. There’s different reasons that obstructive diseases can occur. Sometimes, let’s say
there’s a mucous plug. An air can’t get out or sometimes these airways collapse because the walls have loss it’s elastic quality structure. So the air is essentially stuck in there. Let’s think of all these extra air. Can you imagine how difficult it would be if you cannot exhale, that’s very uncomfortable. So obstructive disease describes large, over-inflated lungs. And some examples would be something you probably heard of as COPD, which is actually a group
of two different diseases. One is emphysema, which have to do with the lungs losing their elastic quality, and the other one is chronic bronchitis, which is just a lot of
irritation day in and day out, that makes a lot of mucous. Both of these result in
this large inflated lungs. Something more common that a lot of people have is asthma, which is when the air ways
spasm and they close up, blocking the air from getting out. So restrictive and obstructive diseases going have to do with a
global picture of the lung. Not to get into too much of the detail, just think of restrictive
as having trouble getting air in, oxygen in, and obstructive, having trouble getting carbon dioxide out with the exhale. So now let’s zoom back in to the alveoli. What’s going on down here that could give us lung disease. So number three I said there’s something wrong with exchange. So let me just redraw this here. We have our air sac, so air has finally made it here to where it can make contact with the blood supply. And one thing that will
really mess up this process is let’s say if this air
sac is filled with fluid. Like that. Let’s fill that in to make it, yeah, like that. Okay, so what would happen to your oxygen, so it’s coming in here, it wants to get to the blood and uh-oh, it’s stuck. As you know it’s much
harder for air to diffuse through liquid than it
is when it’s empty space. And then on the other hand, carbon dioxide is here trying to get out and uh-oh it’s stuck in the fluid too. So as you this makes the whole exchange much less efficient. So you have less oxygen going in and less carbon dioxide going out. So that when, I would say that this blue, let’s extend this a little further, instead of turning red
where it’s suppose to, since it’s so inefficient, it eventually becomes as kind of weak red when it leaves. So you have less oxygen in your blood and more to carbon dioxide than you would in a healthy lung. So what could cause this
to happen with the fluid. One thing that’s very common is an infection such as pneumonia. See when our lungs are not doing well, there’s a lot of secretions, mucous, which is fluid trying to flush out, wash out what’s there. So pneumonia, if it’s bacteria or virus this fluid happens. There’s also edema. Edema kind of is just a general word for a fluid being where it’s not suppose to, being pushed out. So, if for some reason
if there’s too much blood in the blood supply. Let’s say if your heart
is not working well, and all this blood is backed up, then it will flow into the air sac where it does not belong and give us this picture
of wet inefficient lung. And usually the lungs works
best when they are dry, because we’re talking
about air exchange here. I forgot to write a
name for this category, let’s call this ventilation. We’re talking about the exchange here, but ventilation technically means getting carbon dioxide out of here. But I want to use this
word to just describe the process of exchanging
one gas for the other. Which is not working well here. And talking about wet
versus dry lungs here, it kind of goes nicely
into our fourth point. So our fourth problem, let’s call it a problem with perfusion. So it’s funny, it’s kind of
like the lungs are too dry. So perfusion is the ability to get blood where it’s suppose to go. Again let’s draw our alveolus, singular, it’s alveolus. So we have our blood
supply coming in as usual and uh-oh, sometimes there can be a clot. So our body can make clot
and they can break off and float in the blood
stream when they get to a place that’s small
enough to get stuck, they get stuck here. And stops the blood from
flowing pass this point. So for the rest of the
path, there’s no blood. And the branches of blood supply, the branches of past
this point are also gone. So as you can see in this scenario, no matter how much oxygen we have in here, we only have, we don’t have any blood
supply to put it into. So not having enough
perfusion is a huge problem, and we call it a pulmonary embolus. So pulmonary means it’s in the lungs. Embolus describes a clot that formed somewhere else and it’s travelled. And if it gets lodged in the lungs and it’s a pulmonary embolus, now the severity of this
really has to do with where in the blood supply get stuck. So let me just go back here, up here and draw some blood vessels along these trees. So if this embolus is all the way up here in a major branch and it shuts off this whole part of the lung. They have a huge problem,
people can die from this. Now if it’s a very small branch, like down here, then it’s still uncomfortable
and you’ll lose a portion of the lungs but it’s not relatively not as a big of a problem. But of course it will still compromise how well your lungs are working, how much oxygen is getting in, so on and so forth. So here you have four
very general categories of lung disease that I think provides a nice structure for, okay, what are the
different players involved, and what can go wrong
to give us lung disease?

64 thoughts on “Types of pulmonary diseases | Respiratory system diseases | NCLEX-RN | Khan Academy

  1. scientific, fun, easy to understand and a must watch as long as you are breathing. Afterall, we need to know what's going on. Thanks a milion

  2. International Conference and Exhibition on Lung Disorders & Therapeutics held on July 13-15, 2015 Baltimore, Maryland, USA for more details please visit: https://www.facebook.com/events/1544337265814485/?fref=ts

  3. Such a helpful video! Huge thanks, geting to grips with the basics makes the hard stuff so much easier

  4. Could you please explain why in obstructive disorders air has difficulty escaping, while there is a blockage, but air can easily be inhaled. If some factor prevents exhalation, how come it doesn’t prevent inhalation? Is this because inhalation is active but exhalation is a passive act? Thank You!

  5. Thank you so much for this overview of the various kinds of resp diseases, I understand it SO much better now! I love Khan academy! You have a way of explaining/drawing things in simple and easy to understand terms!

  6. Thank you very much! That's help me a lot!
    I have few questions. I read some articles said COPD should have low flow Oxygen supply. However, there is a patient who has CHF and COPD. He also got peripheral oedema. His SaO2 is 88%. We have already gave him 3L Oxygen via nasal tube.
    What we should do in this situation? Should we prescribe medication to improve fluid retention and increase cardiac output? Can we increase the flow of oxygen or change it to mask? Could you explain it to me? Thank you very much!

  7. Hi. I have a question and i am terrified 🙂
    I visited alergopulmo clinic. I was sent cause i suffer from chronic throat inflammation, more specific-lingual tonsilitis and adenoid hypertrophy.
    I was told lung rentgen was ok, spirometry was also ok, but i have too much nitrate oxide in exhale. Is this a sign of lung respiratory conditions? I have troubles breathing,concentrating, eating..every single are of my life is effected. It feels i cant get enough air.
    These arent attacks, it feels like it from morning to night and it's agonising.
    I only hope i 'only' suffer from upper respiratory problems.

  8. Small correction: at 2:15 you say the gases at the alveoli are exchanged by "laws of air pressure". That's how the air moves into and out of the lungs, but the gas exchange across membranes at the alveoli occurs by simple diffusion, from the area of higher to lower concentration (this can happen in situations where there is no "air pressure").

  9. Khan Academy always does a good job at explaining various topics in a way that anyone can understand. Great Job with this one too!

  10. i have a question here

    the obstructive disease meaning the problem of exhalation of the air right ? in asthma patient there is chronic inflammation in the airways , so isn't will affect the inhalation of the air too or not ? i mean in that case the problem will be in getting the air out and in not out only ,, or i am understand the concept wrong here ?

    sorry for my bad English

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  12. There are more than two etiologies that are considered COPD 1 CF Cystic Fibrosis 2 Bronchiectasis 3 Asthma 4 Chronic Bronchitis 5 Emphysema. I was going through some videos as a quick review (I've loved your videos for years) but there are quit a few discrepancies throughout the video. I truly hope this is the ONLY one.

  13. I think there's a little error at (5:44)…..it's obstructive diseases not restrictive diseases that cause problems with expiration

  14. We are not bothered if she miss spelled something … we are watching these types of vids mainly because we all are either coughing .. coughing up white phlegm ? Hard to breath day to day tasks and we are all trying to find answers!

  15. I have an edit to suggest: I think by classifying 1 and 2 under ventilation (defined as air flow to and from the lungs), 3 under gas exchange (diffusion, affected by factors such as thickening of gas exchange barrier), and 4 as perfusion (as stated in video) would be a more precise explanation:) Do upvote me if you think the same way! :))

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