Return to Video

Meet the lungs

  • 0:01 - 0:04
    Let's say that this is you. You're enjoying a nice sunny day
  • 0:04 - 0:09
    and you decided to take a nice long deep breath of air.
  • 0:09 - 0:15
    And of course when I say air the part that you probably care the most about is just the oxygen,
  • 0:15 - 0:21
    part of that air, that's the part that we as humans need to survive.
  • 0:21 - 0:24
    So you take a deep breath.
    Let's say you take it through your mouth,
  • 0:24 - 0:26
    you take a deep breath through your mouth.
  • 0:26 - 0:30
    And then lets say you take one more deep breath,
    a second deep breath,
  • 0:30 - 0:31
    and then you take that one through your nose.
  • 0:31 - 0:36
    And you might think, well, these are two totally different ways of getting in air,
  • 0:36 - 0:40
    that's certainly how it looks when you look at the mouth and nose,
  • 0:40 - 0:42
    they don't look like they have much in common.
  • 0:42 - 0:45
    But the truth is that actually if you follow the air,
  • 0:45 - 0:50
    it almost follows an identical path.
  • 0:50 - 0:56
    The air is going into the back of the throat really regardless of how you took it in.
  • 0:56 - 0:59
    So here we have air coming in from the nose,
  • 0:59 - 1:03
    in here yet air coming in from the mouth and they meet up in the back of throat.
  • 1:03 - 1:10
    And then they go down down down,
    they go towards this thing that we call the Adam's apple.
  • 1:10 - 1:14
    I'm gonna bring it up a little bit, you can see it more easily.
  • 1:14 - 1:19
    But basically you bring up this, you see this Adam's apple right there.
  • 1:19 - 1:22
    And actually you can go ahead and take a feel of you own Adam's apple.
  • 1:22 - 1:27
    It's a pretty cool structure in the middle of your throat
  • 1:27 - 1:30
    and everybody has it, that's the first thing I want to tell you,
  • 1:30 - 1:34
    that everybody has it, not just in men, women have it too.
  • 1:34 - 1:41
    And the reason it's called an Adam's apple is because Adam is generally a boy's name.
  • 1:41 - 1:49
    And so it's to remind us that usually men or boys have larger Adam's apples than girls.
  • 1:49 - 1:54
    And if youre trying to find it, I also want to point that its a notch here.
  • 1:54 - 1:57
    And you if you can feel the notch with your fingers,
  • 1:57 - 2:00
    in that case you have a nice clue as to where it is located.
  • 2:00 - 2:06
    This is Adam's apple and what it does is, it helps you control your voice.
  • 2:06 - 2:08
    And actually theres another name for Adam's apple.
  • 2:08 - 2:13
    Another name for it, sometimes people call it the voice box. The voice box.
  • 2:13 - 2:21
    And of course air passing through the voice box in this kind of the entry way into the trachea.
  • 2:21 - 2:28
    And so it actually allows me to make my voice very high or make my voice very low,
  • 2:28 - 2:34
    depending on how you change the muscles around in that Adam's apple.
  • 2:34 - 2:39
    So that's actually kind of a first cool thing I want to point out to you, that you can actually control your voice.
  • 2:39 - 2:44
    I'm sure you knew this already but what youre using is the Adam's apple, your voice box.
  • 2:44 - 2:49
    Now air keeps going, air is just gonna keeps making its journey down and
  • 2:49 - 2:54
    specifically of course the part of air I said, you know, we care about is the oxygen.
  • 2:54 - 2:58
    Its gonna keep making its journey down into the lung areas,
  • 2:58 - 3:05
    now the lung areas, it's gone down the trachea and it goes into the two lungs, the right and left lungs.
  • 3:05 - 3:11
    This is the left lung, I'm gonna put L for left and this is the right lung, I'll put R for right.
  • 3:11 - 3:14
    And immediately you'll think, "Wait a second, aren't they switched?"
  • 3:14 - 3:19
    Now I want you to remember that this is from the perspective of the person who owns the lungs.
  • 3:19 - 3:23
    So that's why I put it in left where I put it, in right where I put it.
  • 3:23 - 3:26
    Now we should probably go ahead and start labeling some of these.
  • 3:26 - 3:30
    You can see that the lungs actually don't look identical, right?
  • 3:30 - 3:34
    They look slightly different, for example, this one has three lobes.
  • 3:34 - 3:40
    The right side has three lobes called the upper lobe, middle lobe and lower lobe.
  • 3:40 - 3:45
    And the left one only has two lobes, that's the first kind of a big difference.
  • 3:45 - 3:53
    And the other difference is that you actually have this thing in the middle that we call a cardiac notch.
  • 3:53 - 3:57
    This thing right here, this is called the cardiac notch.
  • 3:57 - 4:03
    And the reason we call it that is that it's a little spot that gets formed
  • 4:03 - 4:07
    because the heart is literally kind of peeking out here.
  • 4:07 - 4:11
    And as a result it's kind of makes a notch in the lung where it develops.
  • 4:11 - 4:15
    So the heart takes a little space here, this is the heart.
  • 4:15 - 4:22
    And as a result, it takes or makes that notch. So this is our heart space there.
  • 4:22 - 4:27
    So on the other side you've got of course your two lobes, your upper and lower lobes.
  • 4:27 - 4:31
    And these are exclusive, you see a lung just kind of sitting by itself.
  • 4:31 - 4:36
    And you want to figure out whether its the left lung or the right lung,
  • 4:36 - 4:40
    you can look for the lobes, the number of lobes, or you can look for that cardiac notch.
  • 4:40 - 4:45
    Now around here, around these lungs, you've got ribs.
  • 4:45 - 4:52
    You've got ribs here and between the ribs you've got rib muscles and of course on both sides.
  • 4:52 - 4:59
    And below the lungs and below the heart, you've got a muscle, a big muscle.
  • 4:59 - 5:05
    Actually it's gonna come through here, I'm just gonna kind of go through the word heart,
  • 5:05 - 5:08
    and it basically becomes the floor.
  • 5:08 - 5:14
    So the heart and the two lungs sit on this floor that made up of this muscle
  • 5:14 - 5:21
    and this muscle is the diaphragm muscle, so this diaphragm muscle makes up the floor.
  • 5:21 - 5:26
    The ribs make up the walls, so what do we have?
  • 5:26 - 5:32
    We have basically a room, we have a giant room with walls and the floor.
  • 5:32 - 5:36
    And this entire room we actually call the thorax.
  • 5:36 - 5:40
    So within this room then you have your two lungs and your heart.
  • 5:40 - 5:46
    So, so far so good, but I haven't done a very nice job of actually showing you where the air goes.
  • 5:46 - 5:51
    I just kind of pointed that it goes to the two lungs, we don't have to get to see where it goes after that.
  • 5:51 - 5:53
    So let me actually, I'm gonna erase a lot of these.
  • 5:53 - 5:59
    I'm gonna reveal to you what it would look like if you could slip on some X-ray glasses
  • 5:59 - 6:03
    and look into your two lungs, this is kind of what it would look like.
  • 6:03 - 6:11
    You've got all these interesting architecture and the easiest way to kind of think about this,
  • 6:11 - 6:14
    probably the simplest way to think about this, is to imagine a tree,
  • 6:14 - 6:19
    to imagine a tree, and that tree has been flipped upside down,
  • 6:19 - 6:24
    so you've got all these branches of that tree and they are branching and branching.
  • 6:24 - 6:31
    And if you flip this tree upside down, you start seeing that it looks a lot like what we have in our lungs.
  • 6:31 - 6:37
    Our lungs basically look like a flipped up or a flipped upside down tree and we even call that,
  • 6:37 - 6:42
    we even call this entire structure, we call it a bronchial tree.
  • 6:42 - 6:47
    So when you look at the lungs and they look kind of messier and complicated.
  • 6:47 - 6:52
    Just think of them as an upside down bronchial tree and all of a sudden
  • 6:52 - 6:57
    it'll look much simpler with basically in the middle you've got this nice trunk,
  • 6:57 - 7:01
    this is our trunk, and then it's kind of branching from there.
  • 7:01 - 7:06
    So air goes down this main trunk, this trachea, and they kind of start splitting up.
  • 7:06 - 7:12
    And each of this kind of colored regions, the green region and the purple region serve a different lobe.
  • 7:12 - 7:18
    So this green region serves the lower lobe down here, the purple serves the upper lobe.
  • 7:18 - 7:23
    And on this side, you've got an upper, a middle and a lower lobe.
  • 7:23 - 7:25
    Now I know it looks a little bit strange because
  • 7:25 - 7:30
    you've got some green branches in what should be the middle lobe like right here.
  • 7:30 - 7:34
    You've got some orange branches in what looks like the upper lobe like right there.
  • 7:34 - 7:39
    But what you have to remember, this is kind of tricky, just try to play it in you head,
  • 7:39 - 7:45
    what you have to remember is that, what you have is basically a three dimensional lung.
  • 7:45 - 7:48
    So you have to imagine that we are literally looking at the front side
  • 7:48 - 7:52
    but of course that middle lobe does go back.
  • 7:52 - 7:57
    And if you went back then youd make perfect sense
    why the orange branches are where they are at.
  • 7:57 - 8:01
    Now let me continue the air journey because I wanna make sure we finish it off.
  • 8:01 - 8:05
    So let's say we take a little branch like that, we expand it.
  • 8:05 - 8:09
    We keep zooming into it, zooming into it, zooming into it,
  • 8:09 - 8:12
    until its microscopic, you cant see it with your eyes anymore.
  • 8:12 - 8:16
    But you could see it under a microscope. It would look like this.
  • 8:16 - 8:21
    It would basically in a microscope, it would look like a bunch of little sacs like these.
  • 8:21 - 8:27
    And these sacs, we call these alveoli. Alveoli.
  • 8:27 - 8:30
    And the air, it actually kind of runs into the alveoli.
  • 8:30 - 8:34
    It has a dead end and then it comes back around.
  • 8:34 - 8:37
    And then you breathe it out. So that's how breathing works.
  • 8:37 - 8:42
    The air goes all the way from the mouth down to the alveoli, takes a U-turn and it goes back out.
  • 8:42 - 8:49
    But before it does that, before it leaves, very close to the alveoli is blood.
  • 8:49 - 8:55
    Let's say blood is coming this way and going that way, and what will happen is that,
  • 8:55 - 8:58
    actually out of the or into the blood, let's do that first.
  • 8:58 - 9:05
    We've got oxygen, oxygen will actually go into the blood, and out of the blood will be waste.
  • 9:05 - 9:09
    So you'll have some carbon dioxide waste that your cells have been making.
  • 9:09 - 9:14
    And that waste actually then gets thrown back into the alveoli.
  • 9:14 - 9:18
    So now you can see how the oxygen gets from the outside world,
  • 9:18 - 9:21
    gets breathed into the lungs when you inhale,
  • 9:21 - 9:25
    gets down into the alveoli, exchanges with the blood.
  • 9:25 - 9:28
    And then you exhale and let all that carbon dioxide out.
Název
Meet the lungs
Popisek:

Every time you take a breath, oxygen makes it way into your lungs. Follow along on that journey! Rishi is a pediatric infectious disease physician and works at Khan Academy.

more » « less
Video Language:
English
Duration:
09:36

English subtitles

Revize Compare revisions