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BIOL 3324 Human Physiology - 3324_lecture16_1026
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00:08 just very brief announcements. First I know I thought I said in
00:12 class but I may not have um put anything past me but remember I'm
00:20 longer doing office hours on teams, doing office hours. I didn't drop
00:25 conduct. I'll find I'm doing office in my office. So if you've
00:31 going on two teams and not finding , then you need to be coming
00:37 my office to come and see I'll figure out where the other thing
00:39 a little bit. All right. being is I just got sick and
00:43 of just waiting for people to not up. That's you know, I'd
00:48 help you guys than stare at a . Does anybody love me?
00:54 Mhm. So That that so if haven't seen me, that's why.
00:59 my other class, they've been showing in in groups of 12 so they've
01:03 keeping me really busy. Um But that also second announcement, what's next
01:11 ? A test? Woo hoo ! not woo hoo. It is.
01:17 hoo. That means you're three quarters done. So um I don't know
01:21 it went. All right. Um anyway, so we have a test
01:25 . So we have two more lectures and thursday is all about respiration.
01:29 straightforward stuff. Test next Tuesday Wednesday I'm going to be working on all
01:36 peer reviews and stuff like that. I'll get the paper grades up stat
01:40 you didn't know they changed the drop . So if you're panicking about dropping
01:43 stuff, come and see me, talk you out of it. I
01:45 , I'll walk you through the steps you need to have in order to
01:50 what your grade is and so and forth. But I should have your
01:53 grades up online. Hopefully by say noon ish. That's that's my
01:57 . Okay. It's just been So, uh, we'll have that
02:02 care of and I think that was . So, yeah, test
02:07 Respiration ready. All right. Maybe teaches like a class class and everyone
02:16 breathe yoga. That's what this class kind of about today. It's about
02:26 . All right. Um, you are familiar with the respiratory system,
02:30 ? Yeah. one person. Anyone ? Okay. Does look for low
02:39 . All right. So, basically purpose of aspiration is to obtain oxygen
02:42 eliminate carbon dioxide, but it's not the function or process of breathing in
02:47 out. All right. You spend lot of time in biology. You've
02:51 this stuff right here, cellular That is part of respiration.
02:55 The whole point of breathing in and is to bring auction into and close
03:00 the cells so that they can then through the process of cellular respiration.
03:05 right. So, we're looking at half of the respiratory system and respiration
03:11 exchange of oxygen carbon dioxide with the environment and delivering it to the cells
03:16 . Okay. That's what all this . So, the good news is
03:20 we're really uh we're looking at a that is not particularly difficult. In
03:24 , I think we try to make more difficult than it really is.
03:27 right. So, well, that's I got to touch the screen to
03:31 it know that I'm here. All . But your respiratory system isn't solely
03:35 respiration. It has multi functions. . We've already talked about the nose
03:40 the organ of smell vocalization. You've noticed that different people sound differently,
03:46 ? That part of that is the within the nasal cavity and the sinuses
03:52 give you that kind of unique And if you heard someone talk,
03:56 really days early? I mean, that's a real key thing, but
04:01 helps in terms of vocalization, water heat loss. Uh This is what
04:04 going to look like tomorrow When it to 58°. Yeah. You guys never
04:10 the weather, do you? Um going to rain all day tomorrow.
04:16 get yourself ready. Bring your Right, and the front is coming
04:21 and the temperature is gonna drop 30° into the 50s. Thank goodness.
04:26 tired of sweating. And then after days of cold, it'll be warm
04:32 , I'm sure All right. so water loss. You know,
04:37 familiar with that. I know it's , but you you've seen this
04:40 People breathing. You can see that's actually that's going on right
04:44 We just can't see it because it's hot, right? Uh Really?
04:48 also plays a role in processing So, the idea here is that
04:51 we breathe in, it's not at level of humidity that it needs to
04:54 maybe in Houston. It is. don't know. But you breathe in
04:57 we humidified the air. We warm air and we bring it down into
05:00 lungs and we also filter out all nasty things. All right.
05:05 that's what the mucus in your nose for. That's what the cilia and
05:09 down the the trick is for is to trap all those nasty things.
05:14 of course, we have immunity sites are located with within the respiratory system
05:19 destroy out and seek out pathogens. foreign substance will seek out and
05:24 All right. In terms of It enhances venous return. We've talked
05:29 the respiratory pump. We've talked about blood reservoir just briefly. It also
05:34 and activates materials that pass through the circulation. We're going to spend some
05:39 in the next unit talking about Right? And so the way that
05:44 get angiotensin two is through what's going in the respiratory system through the
05:51 And we're not gonna spend any time about acid base balance. But it
05:54 plays a major role in acid base . So respiratory system complex system does
06:00 of things. We're focusing on the big thing that is named after
06:04 All right. So, we've got do some anatomy here and again,
06:08 not going to be real abusive when comes to anatomy in this class.
06:11 more like do you know where this ? And so you can think of
06:14 as being divided into upper and And so the upper is the mouth
06:18 nose. So the oral and nasal . Then the pharynx, which is
06:21 fancy word for throat. All And then the larynx. Alright.
06:26 from the larynx, what you're doing you're passing into the trachea because that's
06:30 you kind of get this division between trachea and the esophagus just below the
06:34 . And so from the trachea, go into the bronchi and then into
06:37 bronchi. There's many, many divisions through the bronchial trees. So are
06:42 point here is really the larynx. , So anything above that is considered
06:46 respiratory. Anything below that's lower All right. The larynx, if
06:50 don't know that's your voice box or where your vocal cords are located.
06:55 basically these are little uh basically connective that's attached to muscle that stretches and
07:02 and creates different vibrations as air passes . And that's what allows us to
07:07 the different sounds that we make for . Now. Obviously, if all
07:15 doing is doing that. I have have other things to look if I
07:18 used my throat. Uh right, can go up and down. But
07:22 not making sounds that are understandable. ? I don't I'm presuming I'm
07:29 I'm just the way you guys are at me. I'm like lips tongue
07:35 palate. Also make noises that you then understand. All right. Have
07:39 ever tried to talk to that You don't have fun, do
07:45 It's half an hour. So it very insistent. Oh, as long
07:52 we have fun with this cash you want to just talk about the
08:00 instead? Sorry if I talk about Astros will lose. Mm Alright,
08:08 tree, Trachea, bronchi, that's air passageway, primarily cartilage. It
08:13 bend, doesn't get much smaller. very uh fairly rigid in terms of
08:19 structure. And you move down to bronc. I there's different generations which
08:23 see down here. And then what working down as to what are called
08:26 Bronx heels. Now there are terminal heels. And so everything up to
08:31 terminal broncos which we'll see on the slide are considered part of the conducting
08:35 , which means that they're basically tubes which the air travels. They don't
08:39 any role in gas exchange. And we have the respiratory bronchial which is
08:44 first segment of the respiratory zone. these do play a role in gas
08:48 and things beyond that play a role gas exchange. So if you look
08:52 this nice little tree that your textbook you, you can see here there's
08:57 generations. In other words, multiple . And again, I don't you
09:01 need to know it's 16 or 17 however many it is. It's basically
09:05 can go down several generations and that's conducting zone. No rolling gas
09:11 And then down below that, that's you get down to the respiratory broncos
09:14 you can see little al viola that branching off that and then ultimately becomes
09:19 bunches of al viola. So, would be called valvular ducks. And
09:23 the little stuff things on the end the valvular sacks. All right.
09:28 this is kind of looking at We're now in the respiratory zone.
09:32 right. So everything up through the bronc cules conduction. Now, we're
09:38 the respiration. So, these are smallest airways that divide into valvular
09:43 So here you can see duct right? Those lead into the
09:47 And then this bundle of Al viola an Al Viola sack. And if
09:51 look at them carefully, you can that they're all interconnected with one
09:55 They're not individual bunches like grapes on the end of a bunch of
10:00 right? They're actually connected with each . What we've done here is we've
10:04 increased surface area. So, what have here is a side of gas
10:09 . Now, you can have al off the individual alveoli ducks, you
10:13 even have them off the respiratory but they're not in these bunches.
10:19 they're very, very small. You see in terms of size, a
10:22 of less than a millimeter in There's about three million of them per
10:28 . So you've got lots of them they're interconnected so that what you have
10:32 an ability as you expand one, basically expanding all of them together.
10:37 then you can see over on this what we have our series of capillaries
10:40 are wrapped around each Al Viola. what they're trying to show you this
10:43 looks like a whole bunch of other is that they also have elastic fibers
10:46 around them. Now, I'm just get you involved here for a
10:49 Why would I have a bunch of bands wrapped around each al villas.
10:54 would I have that elastic connective yep. So once I expanded,
10:59 going to happen, it's going to back to its original size.
11:05 so, what you're seeing here is basic structure of the lung.
11:12 when we get down to it, is what the lung more or less
11:15 like. All right. So, you get down to the Al
11:18 I and we look inside the Al right. What's there? Well,
11:23 have three different types of cells. have macrophages that are wandering around trying
11:27 kill things. Yeah, that's Right, okay. You know how
11:34 don't know if this is true. heard the axiom right Over the course
11:37 our lifetime, we breathe in about buckets of dirt or dust into our
11:42 . You know, Over the course our lifetime. Never heard that
11:46 I don't know if that's true. sounds true. I bet you if
11:49 saw it on the internet you believe . Right. That's a lot.
11:54 ? Something has to deal with that . What is dust made up
11:59 Yeah, you said what was Huh? Dead cells most Yeah,
12:07 dead cells. You're breathing in dead . Except for those of you wearing
12:19 . Which case you're accelerating the speed which the dead cells go around the
12:23 . Great. All right, so are there to deal with the stuff
12:28 you get in your lungs. All , so, that's our first line
12:31 defense, right? But then we two cells that make up the walls
12:35 the Al Viola. We have type and type two AL Viola cells.
12:39 . The type one cells. And we think of an Al Viola,
12:41 is what we're thinking of. These the flat cells. They make up
12:43 actual walls. They're very very And so you can see here here
12:48 the wall of the capillary. So an endothelial cell right here, this
12:52 a type one cell and you can that there's a very very short distance
12:56 this thin it sells very thin that very thin and so it's very easy
13:00 move things from here to there. , so far so good. So
13:05 the walls are made up of the one cells. The type two cells
13:10 what are responsible for producing pulmonary Which is the last thing we're going
13:14 talk about today. All right, surfactant plays an important role in preventing
13:19 opposing valvular collapse. All right. , in our little cartoon up
13:25 All right, what we have there macrophage, macrophage that's supposed to be
13:29 our cartoon. These are supposed to the L. V. Or type
13:32 cells. So, you can see not flat. They're just kind of
13:35 in the wall just kind of hanging . Right? And what they're doing
13:38 they're producing the serve active so that al violence doesn't come and collapse on
13:45 . Now, the distance across the is called the respiratory membrane basically that
13:51 the wall of type one cell and wall of the enough helium is very
13:57 , about half a millimeter. All . And this half a miller millimeter
14:01 very, very important because it allows quick exchange of gasses between those two
14:07 between the capillary and the AL Now, you can imagine what we
14:12 here with all these flat cells and these bunches of AL Viola that are
14:17 together in sex. What we've done is we've increased the surface area of
14:21 lung. Now, I don't normally a board that I can draw this
14:24 . But today I've gotta board to it on and I feel like I
14:27 be drawing on the board to wake up. All right. So,
14:30 look at a lung. Here is lung. All right, then that
14:37 like a lung. Isn't it nice pretty. If that was a
14:41 like a lung, lower lung like balloon, then your surface area is
14:44 everything inside that. Right? if I cut that in half,
14:48 actually increase that surface area. If cut that in half again, I've
14:51 the surface area again. Right? if I keep doing that and keep
14:55 this over and over again and imagine doing it and all those things all
14:58 a sudden now I've increased surface That's the purpose of the Al Viola
15:02 to take this little tiny itsy bitsy in my chest and to make it
15:07 . So I can have an increased area for gas exchange or material
15:12 Now, The calculated surface area is between 50 and 100 m squared.
15:18 don't know how big that is. textbooks. If you go and look
15:22 them say that's about the size of tennis court. I don't know if
15:25 true or not. All right. went to a conference and someone said
15:29 wasn't true. And so you who am I going to believe?
15:31 guy that wrote the book? Or person that told me at the
15:34 They're probably both liars. They probably don't know. All right. We
15:38 go and measure it out if you to write, that's huge.
15:42 So, imagine taking that surface area putting that in front of your body
15:46 saying that is the surface area in oxygen uses to penetrate into my capillary
15:52 . That's huge. Now, how error are we able to breathe in
15:56 that, in that space? And these Al viola? Somewhere between five
16:00 6 L. All right. it's a vast amount of air that
16:05 bringing in. Mhm. So, you look at the anatomy of the
16:09 and everything that we just talked what do we have? We
16:11 The bronchitis? The bronchitis, not , the bronc I the bronchial
16:15 We have the AL Viola. We about there's pulmonary blood vessels, which
16:19 can see there's a lack of elastic tissue. There's some smooth muscle as
16:24 to help uh with regard to contraction the uh the bronchi ALs. And
16:31 it. And you surround that all the series membrane. There's no skeletal
16:36 in there. I want everyone to in on my command? 1,
16:40 , 3 breathe in. Now. were you able to do that smooth
16:47 ? Is that voluntary? No. type of muscles voluntary skeletal muscle?
16:56 . But there's no skeletal muscles in lungs. So diaphragm, okay,
17:02 still doesn't explain how my chest gets . The diaphragm sits here between my
17:07 belly and my uh my thoracic Well, that's good. You're you're
17:14 pressure. Great. You're thinking of the right things. But what this
17:17 you then is if this is under control, there are skeletal muscles involved
17:23 the skeletal muscles like the diaphragm are part of the lungs. They have
17:28 be external to the lungs in order make me breathe. Okay,
17:35 our starting point is going to be understand this serious membrane and what it
17:39 called the pleura. All right, pleura. This is every book has
17:44 picture. All right. So, going to see this everywhere. You
17:47 think of the pleura if your lung your air filled balloon. A pleura
17:51 another balloon filled with fluid. And you've done is you're sinking the air
17:55 balloon into the fluid filled balloon so it presses down and at the other
18:00 stretches out. And so now you part of the pleura. So you
18:03 see there's two walls. One part the wall is touching along the other
18:06 of the wall is touching the thoracic and in between there you have
18:11 Okay, so, the pleura creates environment or a a sack that's fluid
18:20 that is attached to the lung and to the wall of the of the
18:25 . Right? The thoracic area. you're gonna see these terms later in
18:30 . So, I'm just gonna introduce now. So, it makes your
18:32 easier whenever you have a serious there's always two membranes to them.
18:36 a visceral and parietal. All And so that is not confusing to
18:40 . You refer to the guts in body as your viscera, right?
18:45 your stomach is part of your Your intestines are part of the
18:48 yada yada yada yada. All So, when you see visceral what
18:51 saying? It's touching part of your . Right. And then parietal is
18:56 other one that's touching away from the . Okay, So the parietal layer
19:01 gonna be the one that's touching the cage and then the visceral is gonna
19:04 touching the lungs. All right. , the purpose of this space which
19:11 called the pleural cavity is to minimize during breathing. All right.
19:16 this is an example that I use and over in classes and I think
19:19 an easy one to remember you are of meat. Would you agree with
19:24 on that? Write your muscle and stuff If you're a Cajun, we'd
19:29 all of you. Right. Some look at me like I don't know
19:34 you're talking about, cajuns eat everything for the for I think they make
19:39 out of that. I'm making fun today. All right. You're just
19:45 that thing that they're eating that whatever they're eating. You're just like
19:48 , they're going everything about you is . Right? So you're made of
19:53 now before you eat meat. We eat meat raw. We are
19:57 And if we're Cajun Texans, what we going to do with our
20:01 We're gonna barbecue it actually camera which I was watching the other day or
20:05 you and somebody else you in florida make sense. The big old alligator
20:10 a spit. Right. All I thought they were making that
20:15 nope. That's that's they literally put whole alligator on a spit now if
20:20 never had alligator alligators. Okay. has a it has a flavor like
20:23 . So it means it doesn't taste anything and then it's flaky, like
20:27 fish. It's really weird. You can't eat it. And they
20:34 . And I think they did, they? I mean, did
20:37 No, no, I mean it against florida. That's why they did
20:40 beat florida? Yeah, that's Did they beat florida that? I
20:45 they did, didn't they? I can't remember. Yeah, but
20:50 was kind of the cool thing. sitting there grilling a thing.
20:53 So yeah, they barbecue it. . And so you're made of meat
20:57 . Barbecuing and cooking in general with exception of certain marinades, Certain acidic
21:04 is basically the application of heat to to cause cross linking of proteins,
21:10 ? If you watch Alton Brown you'll learn this stuff. I'm just
21:14 to see who watches cooking network and of you do apparently. Alright,
21:18 hands together. Yeah, fine. let's make some heat. You feel
21:25 hands getting hot. Yeah. All . Every time you breathe, that's
21:29 your lung is doing, it's producing , Right? And you can imagine
21:35 that over a long period of what's going to happen? You're going
21:39 cook your love. All right. your heart is doing the same
21:42 You can cook your heart and your system moving around. You can cook
21:44 digestive system. So whenever you see membranes, you're dealing with an opposition
21:49 or trying to prevent friction because friction heat. Heat on meat is cooking
21:58 now. I'm glad you said You know why? Because what is
22:04 ? It's cooking with what? No and there's low temperature right?
22:11 we get to make fun of the who stick those death sticks in their
22:19 when you take that cigarette, pull in, it's not very hot,
22:27 ? And what you're doing is you're smoke in your lungs and you're slowly
22:32 yourself over time. People who smoke a long period of time, you
22:39 look at their lungs COPD. What it look like. Looks like cooked
22:44 . All right. Not the good meat that we like to eat
22:47 I'm not judging. You. Just I got trained at MD Anderson.
22:53 want don't want any of you ending there unless you're working there,
22:57 So stop doing that. Whatever you're . I don't That was my my
23:03 service announcement. All right. this serious membrane allows the lung to
23:09 and contract without producing measurable heat so the tissue itself does not cook.
23:17 , there are a bunch of respiratory then that are not found in the
23:22 . They have to be outside the because all we have is what type
23:25 muscle went for her to answer. , suppose muscle. That's right.
23:32 everyone helped you. I knew you the answer. That's why I asked
23:36 . All right. So, we We have skeletal muscle that's found external
23:41 the lungs. All right. these are going to act on the
23:45 . Right? I'm sorry. They're to act on the thoracic cavity.
23:49 going to be found in the thoracic . They're going to be pulling on
23:52 lungs in an indirect fashion. the reason they're acting are not on
23:57 lungs themselves is because you have that . All right. And so,
24:02 you have This is where I pull up. All right. You're a
24:06 guy. Come on up. I'd to find the biggest guy in the
24:10 . All right. Who wants to his arms out. I like You
24:14 come up. We're gonna rip his out. Yeah. Come up.
24:19 . You look like you're strong. look like you can rip his arms
24:22 . Yeah. This is fun. . All right. Yeah.
24:32 Don't break anything. All right. , here's our plural. All
24:36 What do you want to be a or you wanna be a thoracic
24:39 No. No. What do you to be? All right.
24:44 here's our lungs. Our lung very on in development is way over
24:47 This is gonna be hard because there's very small stage. All right.
24:50 then our thoracic cage very early The development is way over here.
24:55 looks like a right back. All , keep going. All right.
25:00 remember we have this plural and the is attached to the lung. All
25:06 . And it's attached that there is cage. All right. Now.
25:09 you see they're kind of No. you scoot it in. You gotta
25:11 back out. No, no. go back out where you were.
25:14 does Does she look comfortable? Apart being up on the stage?
25:17 She's being pulled. Does she look ? Does she look like she's being
25:21 little bit? Everything You need to one more step out. All
25:24 You see, is she uncomfortable Right now, what we have here
25:30 on the in the thoracic cage. have muscle that exists in the thoracic
25:36 when we go to a barbecue joint we order ribs. That's the muscle
25:40 we're going to be eating. All . So that's what that is.
25:44 lungs. On the other hand, is no muscle, but she's full
25:47 elastic tissue. Notice where she wants be, she wants to be way
25:51 here and so she pulls very hard the floor to get back to where
25:55 wants pulling the floor. All Now, notice he's getting stretched a
26:01 bit, a little bit and notice thoracic cage is being stretched a little
26:08 and he's being stretched in the other . So, you see what they're
26:11 is they're trying to pull the pleura . But because the pleura is full
26:15 fluid, fluid is not particularly he doesn't stretch all that much.
26:19 just, the pleura doesn't have a to it, but the pleura is
26:23 stretched right. And so when I the muscles in the thoracic cage,
26:29 pull on the pleura, pull on pleura, who pulls on the lung
26:37 makes the lung move. All When the when the thoracic cage
26:44 the pleura gets pulled on by the , which is trying to get
26:50 See it's really hard when they when don't participate. Well, no,
26:55 mean, I really picked the wrong here, you're you're doing right,
27:01 supposed to be like, but my things are not strong enough to rip
27:06 apart. No, no, I've it happen. We've seen the small
27:12 ripped the arms out of the No, I'm just here. But
27:17 you see what's going on here? hands again because we like making
27:21 Alright. So, again, what we do is the thoracic cage
27:25 pulls the pleura, which pulls the . When the threats cage relaxes,
27:31 pleura is pulled in by the And so all the movement of the
27:37 movement is not acting directly on the . It's acting on the plural,
27:42 is pulling on the lung itself. what we're trying to get across
27:46 Okay. You need to see the of it because it does get a
27:50 bit confusing a little bit later. you very much for playing my
27:56 No, no. You trust You did just fine. All
28:03 What we're dealing with here is cohesiveness the transmittal gradient and the transmittal gradient
28:09 to that pressure inside that pleural pleural . Now, what we're gonna do
28:14 we're going to pause the physical or the physical this stuff, right?
28:20 we're going to deal with some physics we need to remember stuff you've already
28:26 at least once in your life. right. So you don't need to
28:29 afraid of it. We're gonna talk gas exchange and you're sitting on.
28:34 never learned about gas exchange. You have you took Earth sciences way
28:37 in seventh grade. They just didn't it with big words. All
28:41 And basically it says, look, air is a mixture of gasses.
28:45 you guys learn that at some So, what's an air? What
28:48 the gasses in there? You can if you want to. But
28:49 Our oxygen, nitrogen and Co two a whole bunch of other stuff.
28:55 . You're right. I mean, a whole bunch of other stuff.
28:57 you can see has has percentages that very, very low actually, carbon
29:02 even less than are gone. the noble gasses actually, there's more
29:05 gasses in the air than there are carbon of carbon dioxide by a
29:09 All right. So atmosphere mr of , there's an atmospheric pressure. And
29:15 that pressure is equal to all the of each of the gasses that are
29:20 in that mixture. All right. English what that says is if I
29:24 this percentage of gas and plus this of gas plus this percentage of gas
29:29 100%. If I know what their are. And I know what the
29:33 pressure is, then I can determine the pressures of each of the gasses
29:37 that total mixed gas is equal to Dalton's law. All right.
29:42 we're gonna start with the two easy . Alright, nitrogen makes up about
29:47 of the of of the atmospheric air atmospheric air is 760, what is
29:54 partial pressure of nitrogen? 2%. , exactly. That's the type of
30:01 I like. Right. It's 0.8 7 60. All right.
30:06 you can go and do the math you want to 56 55 160
30:10 I don't know someone do it. got a phone. No 1's pulling
30:13 their phones. You get literally I phones on the desk and you're all
30:19 at me like Alright, 608. you. How far off are
30:25 Yeah, a little bit because I rounded up all right amount of oxygen
30:31 the air is 2021. So, gonna round down make it 20%.
30:36 we put nitrogen. So 20 times .2 times 7 60 would be
30:44 So, that's how you can determine pressure and then you can do the
30:47 thing for all the little smaller percentiles well. All right now again,
30:52 playing really loose with numbers right right? Because it's 79%. And
30:57 you're dealing with decimals. Right? , we can really just calculate it
31:01 out. Now. Here's another So, that was Dalton's Law.
31:05 rule gas has moved down the partial gradients. All right. That's not
31:09 new or different than we've learned Right. If everything moves down a
31:14 gradient or a chemical gradient or a pressure greater than a partial pressure gradient
31:20 be any different. Right? I've got a lot of oxygen in
31:23 air over here and I got very oxygen in the air over here.
31:26 way the oxygen going to go? going to go down until equilibrium is
31:30 . Okay? So, there's a of the gas is so that they
31:34 distributed. All right. Third, the gas is dissolved in liquid because
31:39 , despite what we've learned since the of time, you can treat it
31:42 a gas, right? It's just different form of that chemical.
31:47 when it's in its liquid form, also exerts a partial pressure.
31:51 when I put gas into a it's going to have a pressure that's
31:57 there. And if you don't believe , think about a soda when you
32:01 it up. What's the first time hear when you pop that top?
32:06 ? Because there's more carbon dioxide in can then there's out here. And
32:11 if you look at that, what you see little tiny bubbles as the
32:16 dioxide is desperately leaving? That's that's mixture. Right? So, that's
32:22 same thing. So, the more areas, the greater the pressure and
32:25 of course there's a partial pressure gradient as well and why we need to
32:28 Henry's law as well as dogs laws this is going to help us understand
32:32 those gasses are doing when they cross the Al Viola into the capillaries,
32:39 ? They're just going down there pressure . It's a partial pressure gradient and
32:43 moving from an environment that is not gas or is a gas that they're
32:47 to an environment that is liquid. they still have partial pressure in
32:53 Now your L Viola air is not same thing as atmospheric air. And
32:58 reason for that is because of what respiratory system is supposed to do.
33:02 there too humid if I it so doing is we're adding in water.
33:06 if I am breathing in air that Not 100%. But let's just pretend
33:12 a moment, nitrogen and auction plus stuff. So we're not counting all
33:16 humidity in the Houston air. But imagine if I'm breathing that in
33:21 when it comes in at 760 of when I'm breathing it in when I
33:26 breathing in air, The pressure inside lungs because 760. But I mixed
33:32 air With water right? There is is evaporated water in my respiratory
33:38 So that pressure even though it's 760 has a portion of it, that
33:43 now water. So the pressure partial gradient favors nitrogen from the outside moving
33:50 . In other words, it's higher than in oxygen is higher outside than
33:55 and yada yada yada. So there's gradient, if you can imagine that
34:01 oxygen and nitrogen. Everything trying to into my lungs, right? But
34:07 flow won't let it. Why? out here 760 when I breathed in
34:15 , we're going to get to that in just a moment. All
34:19 But Dawn's law understandable. Henry's law . I'll be a layer. Not
34:25 same. Has much lots more Second thing, Um, we don't
34:31 breathe in 100% fresh air. All . What we have and we're gonna
34:36 about this a little bit is we dead space in our lungs. And
34:40 when we breathe out, we still air that we haven't processed yet.
34:44 we're just gonna call it stale air for fun because that sounds gross and
34:48 . Right? But we have air in our bodies. And so when
34:50 breathe in that fresh air mixes in that stale air. And when you
34:54 out again, there's still about there's 15% of that air still is
34:59 And then when you breathe in you mix it in. So there's
35:02 a bit of stale air as you're in. All right, well,
35:05 that stale air has done has gone gas exchange, Right? So the
35:10 and breathing out should have more carbon then the air that I'm breathing
35:15 Would you just I kind of agree me on that, Right? And
35:19 you can imagine as I'm breathing in , I have more carbon dioxide.
35:23 that again modifies. Or just the of or the partial pressures of each
35:29 the gasses inside my lungs. Because what I've done now, in
35:34 between those two things, can you that look on your face going,
35:38 not sure I've added in water. added in some extra carbon dioxide.
35:44 so what I started off as with , oxygen and CO two, what's
35:50 is I've added more of this. even though I started off with some
35:55 simple numbers, those numbers have gone as a result of me adding these
36:00 and actually this one goes up. sorry. Yeah. Okay. So
36:07 elbow lawyer is a little bit Lastly when air goes into the alveoli
36:13 the auction in the capillaries is so oxygen is always moving out,
36:19 It's just always gonna be moving down partial pressure gradient. So if auction
36:23 always moving out, that means auction always dropping, which means I'm again
36:27 or modifying the pressures inside the Al . All right. That kind of
36:33 sense that things are always moving. I have kind of a moving
36:37 And so my values are slowly changing adjusting. What we can do though
36:41 we can actually look at a period time doesn't matter for breathing in breathing
36:44 or holding our breath. If you at the average across the street,
36:47 partial pressure of oxygen is roughly about of mercury? Think your thing up
36:52 says like 102? No, that's what I'm looking for. That's that's
36:59 in the trachea if you'll see. , So it's about 200 of mercury
37:04 of that auction always moving. It down to about 100 of mercury.
37:07 right. I think the actual calculations 102. Alright, and that's gonna
37:12 true as well as carbon dioxide is back to lung. That's actually bringing
37:15 the partial pressure of carbon dioxide. so on average, it's about 40
37:19 mercury. Now, here's where you the big giant star in your
37:24 Okay. I always ask this question the test. Everyone's gonna get it
37:27 everyone better get it right. All . It doesn't matter if you're breathing
37:31 , doesn't matter. You're breathing It doesn't matter if you're holding your
37:33 , partial pressure of oxygen doesn't Alright, now, I'm going to
37:38 that even though we just it's not true auctions always moving. So,
37:44 average doesn't change, Right? That's I'm trying to get at. Is
37:48 when you're holding your breath, gas is taking place, would you agree
37:52 me, right? If I'm breathing gas exchange is taking place. If
37:57 breathing out? Gas exchange is taking . Now, if I hold my
38:01 for five minutes, will I reach ? Maybe? Maybe. I don't
38:07 . But I mean, we sure pass out, won't we?
38:10 So, you can imagine that we're closer to equilibrium. I don't know
38:13 we actually do. But you can there's gonna be a point where equal
38:16 could be reached if if no gas is occurring from the external environment to
38:21 internal environment. But if I'm just breaths, gas exchange is occurring,
38:28 I'm breathing in, that's not gonna me from gas exchange. If I'm
38:31 out, I'm still undergoing gas We'll explain why a little bit
38:35 and I think that's actually on All right. But I want you
38:39 understand. But I do ask that . Does it matter if you're breathing
38:42 or out? You know? I the question is something that affected whether
38:46 breathing in or out or holding your ? Which one results in? You
38:50 , a change in the partial pressure oxygen, And the answer is none
38:54 them. Right. It's always the partial pressure. That's true for carbon
38:59 as well. The second thing I to point out, you do not
39:03 to memorize those numbers. All I'm not gonna ask you what is
39:06 partial pressure of oxygen in the All right. Because that number is
39:09 correct. What did I tell you about 102. All right.
39:14 it's slightly better. Right. Same for carbon dioxide, it's good to
39:19 those numbers, but not memorizing because going to use them to do
39:23 So you can see there's a big in a small number. Thanks.
39:34 . We remember fixed law of Yeah, checking their head going.
39:41 don't know. All right. I don't remember it. It's
39:45 This is why I say everything we in that first six weeks or those
39:50 six lectures comes back to haunt All right. We learned about fix
39:54 . Yes, partial pressure. This also Yeah. Yes. Well,
40:04 . So, when you breathe in goes into your lungs and it goes
40:07 the blood. But we don't care we don't do any sort of real
40:10 with it. We only care about . Carbon. That's a good
40:12 Oxygen. Carbon dioxide is the only we care about because of cellular
40:16 All right now, can we do with nitrogen? Probably I don't
40:20 I'm not familiar with anything where we break down nitrogen for it most of
40:24 night when we get from is from acids and well, not just that
40:29 acids and other places, but but . So, we don't worry about
40:33 gas. All right. Got to back. Where was I I was
40:39 you? Oh, fixed law of . Oh, yeah, Yeah.
40:44 even forget in the last like three you learn about fixed law of diffusion
40:47 first unit when we're talking about the of diffusion And thick was the guy
40:52 figured it all out. And if go look on Wikipedia to see all
40:55 things he did, I think you'll really impressed because he like figured this
40:59 out in the 1700s with equipment that just be like like glass tubes.
41:04 made work that were like 30 ft . And he was asking questions like
41:08 long does it take this to get there? Like using dyes? It
41:11 like pretty impressive stuff. Right? , basically fixed law of diffusion,
41:15 same thing you see here, Surface area matters, right? The
41:19 the surface area, the easier it to move things through that surface
41:22 right? I like to think of like in terms of a golf ball
41:26 a basketball going through a picket fence not picket fence, but a chain
41:30 fence. Right? If if my of exchange is the size of a
41:36 stamp, very little can move through , right? But if my area
41:40 exchange is the size of say a , I'm gonna have more things move
41:46 . It. Wouldn't you agree? you move through a door the size
41:48 a postage stamp? No. so size matters, right? We
41:56 this by opening up more capillaries. when we dilate capillaries, we increase
42:01 area. And we also do it stretching or increasing the title volume of
42:06 Al Viola. So as you stretch calculus that gets bigger and that means
42:10 in more contact with more capillaries. it does. So, thickness
42:16 The thicker the barrier, the less . I'm gonna go back a couple
42:20 , a lot of slides right All right. We said, the
42:23 from here to there is about .5 . Alright, imagine you accumulate a
42:28 bit of fluid in your lungs, know, pneumonia. That's right.
42:33 a little layer of fluid so we'll make it, you know, A
42:36 of a millimeter thick. Now I to diffuse across that 10th of a
42:41 fluid and then I have to do . That's going to slow down the
42:45 of diffusion. So thickness matters. thicker the membrane, the harder it
42:51 to defuse and lastly diffusion coefficients. know you guys love chemistry. I
43:02 see it in your eyes remember. old chemistry lab? Yeah. Did
43:08 ever notice the chemistry lab? They that big old book in the corner
43:11 covered in dust. It's called the . You ever seen a serious see
43:16 people are all going no, you . Okay. Next time you go
43:19 to the chemistry chemistry department store taking organic chemistry look for the CRC.
43:23 you can't see it asked for the . E. C. Do we
43:25 a CRC? They'll be able to it for you. It's a big
43:28 book and then that is all the of every chemical that everyone's ever
43:34 All right. And that's all. is a big list of the most
43:38 thing ever. Right? You just through chemical after chemical that gives you
43:42 you ever need to know about And we look at it and say
43:45 the molecular weight? So we don't to do any sort of math.
43:48 . And so one of the things has diffusion coefficients and really what it
43:51 , it tells you how fast something through fluid, Right? It's typically
43:56 they do. Uh What we do when we talk about we talk about
43:59 in uh lung tissue, right? we're talking about the lungs and every
44:04 , every chemical has its own diffusion . The diffusion coefficient from carbon dioxide
44:10 roughly 20 times greater than the diffusion of oxygen. All right.
44:14 what that means is you can imagine this if I take a molecule this
44:19 a pressure grade. If I take molecule of carbon dioxide, it's gonna
44:22 down a slope that's pretty steep. if I take a molecule of
44:27 it rolls down a hill. That's less steep. All right.
44:31 if you take a carbon dioxide and and put them in the same
44:34 they're moving in opposite directions. Carbon moves a lot faster than oxygen
44:39 Right? And so there is not fair exchange, Right? In other
44:43 , you end up with more carbon exchanging versus oxygen if they're moving in
44:47 directions. All right. So, is actually kind of important in terms
44:52 gas exchange. But the thing is in the environment we have About
44:58 oxygen in the environment. We have what did the slides say? Do
45:00 guys remember .03% carbon dioxide? So so much less carbon dioxide in the
45:09 so that the exchange between these two in the tissues is actually about
45:16 So, you can basically say the dioxide that goes out of my body
45:18 roughly equal to the amount of carbon oxygen going into my body because of
45:23 diffusion coefficient. So, that's kind important. Yes, a molecular
45:29 I should have made something up there to confuse you. All right.
45:36 why I was capitalist. I think time I wrote the slide. All
45:42 . So, the fusion coefficient, , surface, er all played a
45:47 . So, we've already learned about gradients, Right. And pressure gradients
45:51 basically just the difference in pressure between two environments. So, here you're
45:55 you pressure is about the same we have higher pressure than than
45:59 So, we're basically moving from an of high pressure air of low pressure
46:02 then here, what we're doing is doing the reverse. All right.
46:05 the reason we're able to do the here's what we're looking at here is
46:08 volumes. Yes, ma'am. You're asking a chemical question to a
46:23 . Sorry, I don't know the to that. It just is.
46:26 that's I mean that's how I'm going answer. It just is the fun
46:30 is go ask one of the chemist see if they know and they'll be
46:34 uh and then they'll give you some and make them sound really smart and
46:38 sound really dumb and you'll walk away they'll be like, I can't believe
46:41 bought that. Yeah. What is about? Rights. Okay. Just
46:47 checking. Yeah. See notice what did. I don't know. I
46:52 Right now. It doesn't have to solely with partial pressure. It has
46:56 do with the chemical makeup of that . Right? So it's a property
47:02 the molecule. Not so much. not a quantity question. So,
47:07 had to think about a little bit . That's why I see what you
47:09 see that was me distracting you over while I was thinking over here.
47:14 right, volume pressure. Does that like something you guys learned it
47:20 Volume and pressure? But what what was volume And pressure? What is
47:27 ? What there's a law I What law is it? Boyle's law
47:33 you're thinking perfect gas law which is very valuable in understanding all this stuff
47:37 temperature and all that other fun stuff in. But when I was looking
47:42 with Boyle's law, because that deals with P and V and N.
47:47 and T. Are basically constant, ? There is under constant temperature and
47:52 constant number of molecules. Think that at the end, see all the
47:56 you don't every years you just come like whatever. All right, so
48:01 what we're dealing with now is we're to introduce this idea of Boyle's
48:04 And you already understand Boyle's law. learned it a long time ago.
48:09 basically what it says is look as increase if I if I have a
48:14 right, that's a closed system, ? This it could be an open
48:18 as well I suppose. But basically I increase the volume in this
48:22 the items in there have more so there's less pressure. And so
48:26 I decrease the volume in that those those particles or whatever in that
48:32 will become close together. So you up with greater pressure and guess what
48:36 dependent upon Boyle's law. I'm not breathing. Thank you very much glad
48:44 staying awake and helping me out because don't know if I'd get all
48:48 that's good. Right? So really we're dealing with here is we're gonna
48:51 dealing with pressure grades to change volume that's gonna we're gonna change the
48:56 let me do it together. We're change volume to change pressure and that's
49:00 to drive the movement of fluid in out or not fluid but air in
49:04 out of our lungs. All So, breathing two different parts to
49:10 . Right? It's the movement of between the atmosphere and Al Viola.
49:14 what we're gonna be referring to. . Or inhalation draws air in the
49:18 . Expiration or exhalation pushes the air of the lungs. All right.
49:23 we're doing right now in this classroom what is called quiet breathing. All
49:27 . It's basically what you're doing. rhythmic breathing when you're at rest,
49:31 breathing is what I'm gonna do right . Mhm. I did it
49:40 But do you see it wasn't the tidal movement of my air. I
49:45 basically contracting and relaxing muscles to force in and out of my lungs,
49:51 breathing. Alright. Usually it's with exercise or exercise or hard exertion or
49:56 my case, you know, putting pants, that sort of stuff.
50:02 . Okay. Mhm mm. All doing is basically we're using autonomic nuclei
50:11 stimulate skeletal muscles. Alright, notice are those under control? Volunteers are
50:17 , voluntary, voluntary control. Uh , on autonomic is not voluntarily
50:25 That's involuntary but is your breathing voluntarily ? Yes. Right. But notice
50:30 title volume, right? You're quiet is basically just a pattern that you
50:35 not have to think about now. I told you hold your breath,
50:39 could stop the autonomic regulation, If you are breathing harder,
50:45 You can force yourself to breathe That's not autonomic. But the pattern
50:50 autonomy. All right. So, that's allowing you to cycle between contraction
50:55 . We're going to look at how being regulated on thursday. All
50:59 What we're doing is we're changing the or the volume of the thoracic
51:04 That's gonna change the pressure and that's we get air to move. All
51:10 . Three pressures atmospheric intra pulmonary intra . Alright, atmospheric pressure is around
51:15 60 millimeters of mercury. Yes, know it's not exactly 7 60 changes
51:20 the time. That's why we have so that we can know when the
51:23 is coming, right? Because that's the pressure, right? But we're
51:28 gonna use the nice 7 60 because a nice number to work with.
51:32 , intra pulmonary pressures. The pressure the Al Viola. Alright. You
51:36 say lungs if you want to. we're looking at the Al Viola.
51:39 is going to rise and fall When breathing in and out. But it's
51:43 always always always going to equalize with pressure. So, what we do
51:47 we say it's at 760. when I'm breathing in I've dropped the
51:51 in my lungs. Air is gonna in until it reaches 7 60.
51:56 I'm breathing out increasing the pressure inside lungs air is going to move out
52:02 it reaches 7 60. Really atmospheric since we just defined atmospheric 7 60
52:08 going to do with that. And we have the intra pleural pressure.
52:13 good buddy, inter pleural pressure, pressure is slightly below its about four
52:19 mercury less. Now, why is four of mercury less? I want
52:24 to envision our pleura up here again I want you to picture our lung
52:32 our thoracic cage up here again. what they were doing. Remember the
52:37 wanted to be way over there that asked the cage want to be way
52:40 there. And so they're pulling in direction, stretching out the pleura as
52:45 as they can stretch. Right? creates a negative pressure inside that
52:51 But that negative pressure doesn't want to there. What does the pressure wannabe
52:55 that space? Atmospheric. And so trying to pull the other direction.
52:59 because the force in both directions is than the inside pressure, they're able
53:04 stretch outward to create that negative pressure the inside, which is why it's
53:08 four of mercury less than the And why this is good is because
53:14 is now a little bit uh there's very little give right, it's already
53:19 stretched as much as possible. So I am pulling on the thoracic
53:23 I can't stretch the pleura any it's already been stretched as far as
53:27 gonna go. So when I pull it, it's gonna move,
53:31 And if it's gonna move, it's pull the lung with it. And
53:35 when I relax at Jurassic age, the pleura, I'm sorry. The
53:40 is like, no, no, , I don't have to be pulled
53:43 anymore. I can go and And because you already stretched as far
53:46 you can go, there's no And so it just pulls over this
53:50 and the plural comes with it. other words, the stretchy rope,
53:55 is the pleura is stretched as far it's going to be stretched. All
54:02 . Does that kind of makes Yeah. Yeah. Say that one
54:11 time. How does the how does , that's correct. So, you
54:21 imagine the reason you can't exert pressure you've done all the stretching you possibly
54:26 . So, In a perfect let's imagine no stretching. So the
54:30 would be 760. But now let start pulling on those two membranes.
54:34 ? So if it was 760, I start pulling on the membranes,
54:38 begin pulling them apart and I'd actually creating that negative pressure and then there's
54:42 be a point where I can't pull further. And so that's where that
54:45 pressure stops. It's basically where that . If you can't visualize this.
54:50 have some fun at home. Science at home. Right? I'll
54:54 you go watch movies here. Your ? No, go home. Get
54:57 ziploc bag. Put some water in . Get inside wet, push out
55:02 the air, seal it And then to stretch the two sides apart.
55:07 ? He didn't want to stretch. ? What's water like? What does
55:13 have? What property does water Mhm. What's that? Cohesion?
55:19 what I'm looking for. It's non . Also know it's cohesive,
55:22 So, if you put a little of water in that in that zip
55:25 bag, it doesn't want to It's like, no, I'm glue
55:29 I'm gonna hold on to these two has a whole bunch of hydrogen
55:34 That basically says I'm glue like. right. And that's why the two
55:38 don't want to separate for the who worked in the lab. One two
55:44 done Northern blots Western blots Western You have to clean glassware afterwards.
55:50 you get the water on them. get those two plates stuck together.
55:53 as well just throw them away. ? Well, what you can do
55:57 you turn them this way. And you reduce the number of hydrogen
56:00 You can separate them out, but stuck together. Just forget it.
56:04 mean, they're just you can't claw two things apart. Alright. Without
56:08 yourself. All right? So, what's going on there. Is
56:11 It's already been pre stretched for All right. So, we've already
56:17 that. They're stretched. We've already about this inter pleural fluids that have
56:21 stretched as much as possible. We the thoracic cage way over there.
56:24 put the lung way over there. it's been stretched as much as
56:27 That's what all this tells you. it's showing you a pretty picture.
56:31 right. And so what the process inspiration is then is to contract the
56:36 in the thoracic cage. And that's pull that should be over here because
56:40 is where the threat is. I'm gonna contract over here. That's
56:44 pull on the parietal layer of the . Can't stretch the fluid so that
56:50 on the visceral layer which then pulls the lung which is attached to it
56:55 you're gonna keep pulling on that and the pressure inside the lung. So
57:00 in the atmosphere now has a pressure into the lung. So air flows
57:04 its pressure gradient. All right. it's going to keep flowing until equilibrium
57:11 met. Air stops flowing when the of my lung pressure wise matches the
57:17 environment. All right. Now, do I expire? All right.
57:26 what all this stuff says has all amount of air we've moved in about
57:29 miles. This is what is called title volume. We'll get to that
57:32 . Oh we got to talk about muscles first. All right. What
57:36 do we have involved in quiet All right. We have the
57:41 right? This is a muscle that between the abdomen and the thoracic
57:45 Right? It's basically a big flat . If you've been a singer,
57:48 learned how to control your diaphragm and is used when you contract that
57:51 it pulls downward and increases the volume the thoracic cage in the vertical
57:59 All right. So that makes the drop out more volume there. But
58:02 other muscle are called the external intercostal . Alright. External meaning they're on
58:09 outside outside of what? Well, outside of the rib and then intercostal
58:15 in between the ribs. All Here's your other homework assignment. Go
58:20 ribs this week. Can't eat That's okay. Guess what? Cows
58:24 ribs. And there are certain places serve you know, cow rib.
58:31 like, well, I don't It's like it's like you get to
58:34 like fred Flintstone. It's yeah, homework. You're now required to go
58:38 that. If you're vegetarian. I'm , plants don't have ribs.
58:44 Thank God for that. That's All right. No, I
58:47 and it's why I ask you to this. This is actually one of
58:50 best assignments ever. Although it does a lot of money because ribs can
58:53 expensive when you take that bite out your yummy rib. I want you
58:57 look and you're going to see So rib you're going to see? There's
59:01 slight curve to it. This is external side. This would be the
59:04 side. You will see the fibers the muscles on the external side going
59:08 way and then on the other side another muscle. If this is the
59:13 intercostal. What's that one? Internal muscle, That's what rivets to different
59:20 . All right. But for quiet , what you're doing right now to
59:23 are important. The diaphragm which drops floor, the external intercostal muscles which
59:29 in the thoracic cage and pull it and outward. All right. That
59:33 greater volume. Expiration is just the . I relax those muscles I just
59:42 . Is said to be the external and the diaphragm get relaxed. Diaphragm
59:45 back to its original position, thoracic moves back to the original position.
59:49 pressure inside the lungs increases above the pressure. Now, I've got a
59:54 gradient that drives the air out of lungs. Air moves continues to move
59:58 until it reaches equilibrium with the atmosphere roughly 500 mils. That's what's going
60:05 here. That's what all that All the opposite pleura basically moves back
60:10 position because the thoracic muscles are relaxed and so forth. All right.
60:15 you just remember the pleura is acting the lungs and the thoracic cage and
60:20 diaphragm are acting on the pleura. right. So you're getting three different
60:25 . Alright, the thoracic cage is laterally and interior in the posterior direction
60:30 we're expanding outward and all those And then vertically. We're talking about
60:35 the diaphragm. So that's where we're volume there. Mhm. Forced
60:42 And notice when you're exhaling, notice muscles are involved. It's those two
60:48 but they're relaxing, right? the external intercostal muscles relaxing the diaphragm
60:52 relaxing when you're dealing with forced We're going to bring in a couple
60:57 other muscles. What we're doing is forcing the air out and we're forcing
61:02 air in and I want you to me carefully when I breathe in and
61:06 . Alright, when I do force ? Probably gonna start coughing because that
61:10 of year. Right. What actions you see that are different than regular
61:19 , shoulders are moving. What else am? I am moving my hips
61:24 there's a reason I'm moving my It's actually not my hips that are
61:28 . It's up here and it's this old fat muscle down there. That's
61:35 . So, we're adding a couple muscles in. All right. The
61:39 . All right, So Clyde um . These are the neck muscles.
61:42 the ones raising your shoulders. All . And why am I raising my
61:46 ? I'm trying to increase the rate which I'm expanding. So I'm adding
61:50 muscles into pulling the thoracic cage to that lateral anterior and posterior movement.
61:56 right, when I'm breathing out and also picked her Alice and other
62:00 But I really just focus on the lines. All right. When I'm
62:04 out. Doesn't have it on this , does it? No. There
62:08 go front. I'm dealing primarily with abdominal muscles. All right. And
62:13 , with regard to the thoracic It's the internal intercostal muscles. So
62:18 muscles pull on the inside of the cage to bring it in faster so
62:23 can expel air faster. The abdominal are pushing on the diaphragm to force
62:28 up faster. So that's why you're and what I'm pushing out. I'm
62:34 and driving air out faster. All . There's a lot of muscles in
62:39 . But really I want you to on these first two and then over
62:42 forced inspiration. Focus on those basically up the thoracic cage. Now,
62:53 are lung volumes and capacities you want have asthma did you get you know
62:57 you get tested that they make you into the machine? Yeah, that's
63:01 machine. That's the old version of machine now, it's all electronic,
63:06 ? But basically what they're doing, just trying to figure out what our
63:08 capacities. What are you capable of , what is going on and based
63:12 your size and age and all sorts stuff. They have expectations for what
63:17 of of of lung capacity you should capable of doing alright. So,
63:23 volume is being measured via this device here, which is called a
63:29 All right. And it can look see how much you're able to breathe
63:33 and out. And you basically mark off. And so we have these
63:36 capacities and specific volumes that we have for. All right. So,
63:42 basically we use it to see how our lungs are working. All
63:46 So, when you're breathing in and out, your lungs are not
63:51 filling up completely Northern emptying completely. right. Basically, our maximum volume
63:57 around six leaders to about 4000 depending on your size and sex.
64:01 right. And again, this is a size thing. So, when
64:04 see that sex thing, think, , that's probably has to do with
64:07 . So, um are Anyway, during quiet breathing, you're going to
64:13 from about 2700 mils Of air inside lungs to about 2200 mils of air
64:20 your lungs. So, you can there's that 500 mil difference.
64:23 you can imagine there's always air in lungs now. Why would I always
64:26 to have air in my lungs? , exactly. So, you can
64:32 gas exchange taking place. That's what said. Right? Just nod your
64:35 . Yes, of course. So, you can always have gas
64:39 because remember what we said doesn't matter you're breathing in breathing out or holding
64:42 breath. Gas exchange is always So you always have air in your
64:46 for gas exchange to occur? All , Now, I can force expire
64:52 get my volume in my lungs to 1200. This is the fun part
64:57 the demonstration. All right, We're gonna try. Yeah, see
65:16 breathing in, thank goodness. But yeah, I can push as
65:19 out. You're right, and that's still get air trapped down there about
65:23 . So, what this does as I'm forcing air out, it
65:27 collapses some of the smaller pass up the smaller uh conducting pathways,
65:33 Because you start losing those cartilage rings you move further and further and further
65:38 that bronchial tree. And so what is those collapse and now air is
65:43 behind them so that I can have exchange. So there'll never be a
65:47 where I don't have gas in my for gas exchange, even when I
65:51 the air knocked out of me. right, It ensures the second thing
65:56 it does is it ensures that the , I'd never collapsed. Alright,
66:00 here have a younger sibling or a nephew or cousin or something. Did
66:03 ever have to blow balloons for a party? Alright, You start blowing
66:07 that balloon and all of a sudden tying it off. There is down
66:12 you've been spitting into that balloon and now that balloon is really collapsing.
66:15 do you do? You can't blow thing open again, can you?
66:18 do you have to do? You to throw away the balloon and get
66:20 new one because that spit now serves glue on the inside of the
66:26 Why does the spit service glue That's right. There it is.
66:34 cohesiveness. It's the water, the bonding. All right, So,
66:39 , one of the things we do humidified the air. So, if
66:41 alb, it'll like collapse, it's be a lot of work to get
66:46 to expand out again. Right? , it's gonna be a lot of
66:50 . Might as well just throw it . You can't do that. All
66:54 . So, we're trying to avoid that. All right. So,
66:57 respiratory volumes titled Volume is the amount air entering or leaving the lung per
67:02 . That's being shown right here. your title volumes. About 500
67:06 All right. The inventory reserve volume the amount of air you can breathe
67:11 above the title volume. So, you are breathing in and out.
67:14 not gonna try doing this. I'm much mucus and other fun stuff.
67:18 breathing fun this time of year. , So, you're breathing in,
67:23 out and then how far you can that up? That would be your
67:27 . Reserve volume. Alright, the reserve volume. Is that air that
67:31 just expelled outward beyond my title All right. So, it's this
67:36 right here and then the residual volume what's left over in your lungs.
67:41 , So those four volumes then determine help us determine capacities. All
67:47 So we have the inspirational capacity. inspirational capacity is basically basically your title
67:53 plus your inventory, reserve volume. right. The functional residual capacity is
67:59 amount of your basically the amount that's your lungs. I mean during regular
68:05 . So basically it's the amount of that's already there. So it's your
68:10 reserve volume plus your uh vital capacity residual. Sorry about this residual
68:16 Alright, vital capacity is how much can push in and out of your
68:19 . So if you can imagine for moment it's everything but the residual
68:23 I was gonna see if I could , it's basically your high versus your
68:26 all the way through. And then total lung capacity is all of it
68:31 . So take all four of those . And that's your total lung
68:38 And I'm going a lot slower than wanted to today. But I'm just
68:40 fun. So if you don't have teaching this stuff, then there's no
68:45 . Right. Right. Yeah. why chemists are mad all the
68:53 No. Oh man, I just it. All right. For secretary
68:58 , basically it's a percentage of the capacity and expelled during a period of
69:02 . Typically it's usually in a So you breathe the nearest barometer that
69:06 familiar. Now there's your machine you that in and what they're doing is
69:10 trying to see how fast you can air out max maximum voluntary ventilation.
69:15 much can we exhaled in a These are just tests to help you
69:19 how well you're able to move air out. Two terms you see frequently
69:26 compliance and the last it's alright, is how much effort is required to
69:30 or to stay in the lung. right. So, in other
69:33 is it stretchable? All right. , if you've been smoking and you've
69:38 all those last elastic tissue, it's difficult to stretch the lungs.
69:42 it takes a lot of work to in. All right. And then
69:47 it's stretched. Now, what you're with is you're looking at Elastin.
69:52 well does it return back to its shape? This is the compression
69:57 Right. So, you see that , you can think about like this
70:03 ever had an old sock. You it, you put it on and
70:06 stretch it, you just feel the bands popping in it, right?
70:10 right. So, you basically there's compliance. It didn't want to stretch
70:15 you, but you made it and when you put it on, there
70:17 all like it lacked it's Elastin. So that's what compliance and elastics refer
70:25 . Yes. Yeah. I I'm sure there's some repair mechanism,
70:30 it's it's become because you're breathing all time. It's it's I'm sure it's
70:35 difficult to repair that. Now the do repair themselves, but as I
70:40 , it's just very, very difficult do that. All right. So
70:44 compliance yields greater resistance. Local essence more air remains in. It takes
70:49 work to work it out. All . So, this is uh also
70:53 by how much last in this So, if you bake the
70:56 that's why you don't get that But surface tension also plays an important
71:01 . And this is where surfactant comes . So let's just be clear what
71:06 tension is, Right? It's basically the water that's in the lungs.
71:12 hydrogen bonds are formed by water and tissue surrounding it. And so basically
71:16 as a glue and it opposes the of that tissue. Alright,
71:23 when you're breathing in and breathing you can imagine you're Alvy Ally are
71:28 and then contracting. But if they to the point where the two sides
71:31 into contact and there's water, what going to want to do is collapse
71:34 themselves and now you have something that have to overcome, right? You
71:38 to overcome all those hydrogen bonds. , what we wanted to we want
71:41 break that up and that's what the of surfactant is is to get in
71:45 the water molecules to prevent hydrogen bonding occurring. All right. So,
71:51 the role of surfactants. That's what little picture is trying to show you
71:56 . Right? It's basically I'm just to get these seems like Yeah,
71:59 , so here we see the water trying to hydrogen bond with everything and
72:04 what all that represent. What surf does. It gets in between
72:07 And so it prevents the hydrogen bonds actually occurring. Now, what surfactant
72:12 is primarily lipids and some proteins. right. And what it does is
72:18 increases pulmonary compliance. So it's easier expand the lung and then when it
72:23 it refuses to actually go to the state. And what it can do
72:28 that it actually plays an important role moving oxygen around to ensure that Al
72:36 I have different sizes are all expanding so that you're taking full advantage of
72:41 surface area in the lungs. first off, all your people are
72:46 of the same size. That makes . That makes sense to you,
72:50 everything is the same size. Great. So, you can imagine
72:53 we have a big al veel some . I'm gonna go to a different
72:56 . Big Al Viola. Small All right. What we have here
73:00 better because I have that picture right . There's an inward pressure that you
73:04 calculate. Good old physics once again the surface tension divided by the resistance
73:10 the radius gives the inward pressure. , it's two times that will give
73:14 the pressure. All right. And basically what this says is look as
73:18 breathe in both things are going to . But the inward pressure and the
73:23 Al Viola increases faster than the rate the pressure inside the bigger one.
73:30 so if I have greater pressure inside small one to the greater one,
73:33 have a pressure gradient. So what gonna do, it's going to move
73:38 an area of small to an area larger to equip liberate the pressures.
73:42 so you're losing surface area for gas . That's not helpful. We want
73:49 have as much surface area as we . So what surfactant does is it
73:53 that this uh inward pressure becomes a liberated. That's its function. It
74:00 the collapse of these Al Viola. you increase the surface area. And
74:06 the inward pressure czar become roughly the . And that's what this picture is
74:09 to show. It's like look the actions in there. So it ensures
74:12 they both grow roughly equally and it liberates those inward pressures. So basically
74:18 lungs expand so that you can enjoy that surface area equally. So what's
74:25 role of surfactant helps me breathe there ensure surface area. It prevents
74:36 It's to 16 were done early. that amazing? Yeah, you have
74:44 idea. Mhm. What's that? thought I was too But then I
74:49 the end of the light at the of the tunnel and I just got
74:51 excited and started talking fast again. , yep. Oh yes. So
74:57 you like No, sorry. Second . Yes. All right. So
75:04 question is like something like pneumonia, is pneumonia caused? Pneumonia is an
75:07 in the lungs. But what what pneumonia cause? It's natural inflammation and
75:12 overproduction of water. So, what now have is you have too much
75:16 for the surfactant to battle against and why it becomes difficult. But really
75:21 more of the distance that you're But yeah, you still have to
75:25 all that fluid. Yeah. Uh . Before speed freaks. Right?
75:35 when you have a pneumothorax, what done is you now punched a hole
75:40 that pleura So there's no negative It's actually now a pressure that's a
75:45 liberated with the external environment which allows lung to collapse on itself,
75:50 Because there's nothing pulling it right? air fills in that area. It
75:56 allows allows the player to expand because flu is not the fluids not being
76:01 , it's just in the space. it basically expands outwards. So your
76:05 collapses on itself, you get quick and then there's no way even when
76:10 breathing in and out, you're not on that tissue. Which is why
76:15 so bad. Right. Yeah. ma'am. I want to go
76:26 What do you have? a complex
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