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BIOL 2302 Human Anatomy & Physiology II - 2302_lecture11_0223
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00:05 So I apologize a little bit for slow this morning as I was leaving
00:10 building, that was when they decided fire marshal decided to actually test the
00:15 extinguisher extinguisher is the actual uh fire . So I walked down my building
00:22 there's like hoses and they're all blasting and there's no way around it.
00:26 they're kind of looking at me and looking at them and I'm like I
00:30 I have to jump over it, is not always a a fun little
00:36 when you're carrying a backpack and a old mug and you have slippery
00:40 you know, you're just gonna But I got here and I didn't
00:44 swimming. So um All right, today, what we're gonna do is
00:50 moving into something I think is a bit more intuitive. Um we're gonna
00:55 about the respiratory system and and so a lot of of structure that we're
01:00 kind of go through it first and we're gonna start moving into the physiology
01:04 how we go about breathing and um we go through it, there's gonna
01:08 parts that are gonna be really, simple like. Yeah, well
01:11 But then there's gonna be this this here about dealing with different pressures and
01:16 gradients and while you understand, I'm you already understand gradient because we've talked
01:21 them already, we talked about them a. M. P.
01:23 So gradients in and of themselves are but we're dealing with this little thing
01:27 called a uh well we'll get to when we get to it. But
01:32 it's a trans mural gradient and it's little bit weird why we have to
01:38 on it and and I'm hopefully going make that clear for you so that
01:41 don't look at it go, this is so difficult, I don't
01:43 it. And I may actually have call a couple of you up here
01:46 give a demonstration of breathing, it's . Alright. It's actually a little
01:51 more fun. Alright. So our starting point today is really let's just
01:55 the function out of the way. are we dealing with here with when
01:58 dealing with the rest of the We have a whole bunch of different
02:02 of it. And typically what we about it, we think about the
02:05 themselves. And so what we're talking is the side of gas exchange.
02:09 so this is where we're gonna spend of our time. Alright, so
02:12 this idea of we're bringing in gasses then what we're gonna do, we're
02:15 move auction into the body and remove dioxide out of the body. It's
02:19 to take place inside the lungs in very specific location called the alveoli.
02:24 so that's primarily what we're gonna be on. But the respiratory system is
02:28 than that. Alright. So the thing is the respiratory system serves as
02:32 bellows and it pulls air from the environment and it's a rare and it's
02:38 it into that place where the gas takes place and then when we squeeze
02:43 acting again as a bellows and we the air back out and then we
02:47 and squeeze, suck and squeeze over over again. So the air moves
02:50 and forth. So it's an air way. It's a side of gas
02:55 . And then there's two things we really think about. We think we
02:59 think about protecting odors. And so have olfactory receptors that are located within
03:03 respiratory system which is your navel nasal , not your navel one. Um
03:09 so that's but we left that back A. And P. One.
03:12 just be aware that the olfactory system housed within the respiratory system. And
03:18 lastly we don't think a lot about and how we communicate and produce sounds
03:23 moving air back and forth. So focus on that a little bit.
03:28 just as a function of trying to what the larynx is. Alright.
03:32 that's another function of the respiratory system communication right? We don't just smile
03:37 each other and make faces, we noises. Alright? So that's kind
03:43 our starting point and what I wanna is I want to just kind of
03:46 through how the system is organized before get into the physiology. Alright.
03:51 depending on your choice, you know different people are going to organize things
03:56 different ways. So anatomists like to things with regard to structure. And
04:00 that's what we're gonna see first is there is a structural organization. And
04:03 we do is we take the respiratory in all its parts and we
04:06 okay, there's a part that sits the larynx. And so everything above
04:10 is gonna be the upper respiratory system everything below that is going to be
04:14 lower respiratory system. And so when talk about upper, we're talking about
04:18 nose and nasal cavity in the Notice the oral cavity is left
04:23 It can play a role in breathing it's not part of the respiratory
04:27 Okay, So I can go but not part of the system.
04:34 When we're talking about lower, you your larynx and from everything below that
04:41 we're going to define what all those . All right? So that's the
04:45 . So that's how anonymous were divided physiologist on the other hand, are
04:48 , well, I don't care if up and down. I want to
04:51 what these parts do. And so we do is we look at the
04:54 system, we kind of ask what their functions? And so there's a
04:57 of the respiratory system whose sole purpose to move air from one point to
05:01 other. So that would be the zone and then the other part is
05:06 actual gas exchange is taking place. that would be the respiratory zone.
05:11 so the conducting zone is from the . So basically up here and working
05:15 way all the way down into the to what are called the terminal bronchial
05:19 . Because they all those parts between nose and that terminal bronchial, their
05:24 purpose is to move air from here to where that respiration is taking place
05:29 then vice versa from the respiration where taking place back out. And so
05:33 respiratory zone then are what are called respiratory bronchial. So there's a distinction
05:38 between what those two bronc eels And then you're going to go from
05:43 respiratory bronchial down to the al volar down to the alveoli. Now
05:47 these are all words that we haven't . We don't know what they
05:49 but it kind of gives you a perspective of how we're looking at the
05:54 system. Alright. And so our now is to look at these structures
05:59 , see what they are and then see how they play a role in
06:02 of those two things that sound You have to nod your head because
06:07 doesn't sound okay. I don't have different lecture. All right. First
06:14 some real basic stuff. What are dealing with. Well the respiratory tract
06:18 covered in a mucosa, alright. the mucosal lining. It's exposed to
06:22 external environment. And so just like skin is exposed to external external
06:26 the digestive track track is exposed to environment. The actually parts of the
06:33 track really the your air track exposed the external environment, it's gonna have
06:36 specialized epithelium that's associated with it. with regard to the respiratory system,
06:42 is a silly ated epithelium. And that means you have epithelium, you're
06:46 have your basement membrane, you're going the lamb inappropriate altogether. That creates
06:49 barrier between the outside world and the of your body. And as you
06:56 down through the respiratory tract, if going from upper to lower, you're
07:00 see that it gets, it starts very very thick and then it gets
07:04 and thinner and thinner and thinner as go along. And this kind of
07:07 sense because the likelihood of you being to something dangerous or deadly would be
07:12 here where um where you're moving things to the external environment. But as
07:17 move further in, the likelihood of getting in deep inside is a lot
07:22 . And so what you're gonna see this respiratory system as you start off
07:26 pseudo stratified columnar epithelium and it is to be affiliated and it goes to
07:31 columnar, then it becomes simple Que and then it becomes simple squamous.
07:36 you can kind of see here, starting off big and then I'm staying
07:39 and then I get smaller and then finally get really, really thin thin
07:44 now there are some exceptions to this . The fair inks. That is
07:49 passageway for your hair in your We have a special word in we
07:52 it bearings here in anatomy, in daily life, you call it your
07:57 . Okay? So when you seafaring throat. Alright, we're gonna go
08:01 all that in just a moment. right. So the pharynx is gonna
08:04 slightly different and the larynx is gonna slightly different. This includes the vocal
08:08 . These are going to have non eyes stratified squamous epithelium. Lots of
08:13 there. And for those of you A and P. One. You
08:16 what all those words mean? And you have a stratified epithelium, what
08:20 that mean? Other than it's What does it mean? Why do
08:25 need to have the stratified protection? . So let's think about it.
08:30 many of you guys like Doritos? , if you don't like Doritos.
08:34 right, you're not you're not tempted the cheese powder that they chemically engineered
08:39 that you eat more? How many you like tortilla chips with salsa?
08:45 we go. See now see and . How do you like coffee?
08:50 many of you like eating things that just roughly dangerous for you.
08:54 I mean Yeah, I mean we all do and you can imagine you
08:58 hot coffee in your mouth with your and Doritos and your chip and stuff
09:02 that. You've got little tiny knives burning things that you're putting into your
09:07 . And so you can imagine you to protect against the burning things and
09:11 little tiny sharp knives. So that's the first thing that it's going to
09:16 is right here in the pharynx, in your throat and so you want
09:21 protect that and as it moves down further away, you don't need quite
09:25 much protection. That's the idea. , so you have a stratified squamous
09:31 in the throat and on the Now we need to talk about
09:38 mucus is awesome. It's gross but awesome stuff. All right. And
09:43 is it awesome? Well this is protective material. All right. It
09:48 all sorts of parts to it that your body from all sorts of things
09:54 to get into it. Now these gonna be produced by the goblet cells
09:57 that are gonna be located within the . So here you you see a
10:00 of stratified, you can see the cells jammed in there and there's also
10:05 mucus glands glands can be found embedded into the lamb inappropriate. But really
10:10 we're asking is what is mucus and first part of mucus apart from
10:15 Water is the primary component of The first part is a protein called
10:20 . There's actually lots of musicians. of one of my friends in grad
10:24 , her lab and the lab that was in. And what she worked
10:27 were the meuse in proteins. And something like 20 of them.
10:31 But musicians are sticky proteins. Their is to trap things. All
10:37 So, if it's a sticky that means it's attracted to or attracted
10:41 with or attractive to these these So, what we're trapping are things
10:46 dust and dirt and microorganisms and pollens all sorts of stuff. All
10:51 So, you can think about like your nose when it's a dusty
10:54 I grew up in el paso. This is the time of year where
10:58 dust storms come. And so when really really dusty, your nose feels
11:02 yucky. And you go and you that nasty little booger out. You
11:05 out its dark black. Right? what did it grab everything in the
11:11 ? All right. So, I told you I picked my nose.
11:17 , like that's a secret. You pick your nose too. I know
11:20 . All right. The second thing have is we have this enzyme that
11:25 talked about already license. I'm licensed are an antibacterial enzyme. So first
11:29 I'm gonna do is I'm gonna track trap microorganisms. Second thing I'm gonna
11:33 is I'm gonna kill them. So, we have the license.
11:36 there. We also have the We've talked about them. It's another
11:39 of antimicrobial proteins you can start Okay now I'm understanding a little bit
11:44 what this mucus does. And lastly mentioned I. G. A.
11:47 the last lecture what is I. . A. It's the antibody that's
11:50 on the surface of the body and there to tag anything that's foreign which
11:55 a lot of stuff. And basically this is something that the immune system
11:59 to hunt down and it prevents that from getting into the body. So
12:04 mucus while it might be gross and might be sticky and you it is
12:11 beneficial because it lines the respiratory track prevents all these little things because you
12:18 moving air constantly. It's preventing things going into your body by keeping them
12:25 inside. That tracked. Kind of . So let's start moving through the
12:33 . All right. So the nose the nostrils or nares are going to
12:37 our starting point for the respiratory Notice we're ignoring the oral cavity.
12:43 , so this is the main conducting for inhaled air. All right now
12:47 is formed it's it's encased by or by a bone. You have highland
12:53 . You know if you can do little Samantha thing that's from Bewitched tv
12:58 you're probably too young. All Um you have some cartilage in there
13:03 it's covered with skin externally. So know what your nose is. Hopefully
13:08 the front. Right now the opening referred to as nostrils or Nair's depending
13:13 which way you want to do that what that's gonna do. It's gonna
13:16 into this nasal cavity that has a of interesting parts to help the air
13:23 conditioned before it starts moving down the tract into the lungs. All right
13:30 is it is oblong shape and it extends from the nostrils back to this
13:34 of the back of the nasal cavity is referred to as the konia
13:40 I'm not gonna say cocaina. nuck. That's the A.
13:45 At the end of plural. But kona never gonna say it.
13:51 All right. How do you remember it is? You see the back
13:55 the nose. What shape does it like to you shaped like that?
14:01 . Kuwait a means funnel. And what you're doing is you're taking the
14:05 and you're funneling it down into the Okay now the floor of the nasal
14:11 is the hard palate. Alright. would be the roof of the oral
14:15 . So you know when you go there and tap the top of your
14:18 . That is the floor. That's the nasal or for the nasal cavity
14:22 well. All right. You have whole bunch of bones when we talked
14:25 the skull in A. And One we list a whole bunch of
14:29 that helped form this. So it's nasal bone, the frontal bones and
14:33 cartilage up here at the front that form the nasal cavity, it's divided
14:38 half. So there's a septum. . Some of you believe the noises
14:42 you make at night are a result your deviated septum but it's a septum
14:47 so if you cut through a person gonna see that there's that division that
14:53 that separates the nose into two chambers and the right chamber. Now this
14:57 gonna be formed by two bones. it's gonna be the bomber and the
15:00 Boyd bone that creates that structure. you have a left and a
15:04 And if you want to you don't to investigate right now. But when
15:07 go picking your nose for those that a little bit later today you can
15:11 and feel around. Oh yeah there a wall, there doesn't I can't
15:14 my finger through my nostrils from one to the other. Right? That's
15:20 septum. Alright. The lateral walls are not smooth. Instead what they
15:25 is they have these uh ridges, of a better term that hang out
15:30 over. And these are called the concha concha. I think it's hard
15:36 sound alright or nasal concha. If want to look at how it's
15:40 Alright now what these are are terminates you hear that word it's like okay
15:45 to terminate. what it does is you breathe in air because you have
15:50 ridge hanging out there hits that and starts roiling over itself. And so
15:55 air becomes uh instead of being um laminar flow becomes a turbulent flow.
16:02 what this does is exposes more air the surface of the epithelium where the
16:06 is, so you're able to capture grab more things that happen to be
16:11 in the air. The other thing it does is that because it's pushing
16:15 new air up to that surface, have a lot of blood vessels that
16:19 up against in that epithelium or near epithelium. So you're gonna help warm
16:23 the air. And then lastly, you have these cavities in the in
16:27 nasal cavity, you're also gonna humidified air. So this is the conditioning
16:31 we're kind of talking about. So producing turbulence so that we can expose
16:37 of the air to those conditioning It's a really bad way to put
16:43 . Now between the contra there's three them, so there's a superior and
16:48 11 that sits in the middle. space between the conta are referred to
16:53 the miatas. Alright? Or and if you see here, here's the
16:58 , there's a superior, There's the one, The little space in between
17:01 , that would be the alright. it lies kind of underneath. So
17:05 you have the superior here, that be the the me a tous.
17:08 then there would be the middle one then that would be the status.
17:11 then that would be the inferior So it just refers to that that
17:15 space in between. So, I've of already mentioned these things and I'm
17:19 gonna just reiterate them. So we're up the air because of the vascular
17:24 that takes place or that's along the of the nasal cavity. We're gonna
17:29 the air because we have the mucus grab all of the stuff. All
17:33 . And then we have cilia that to kind of move the material
17:36 And then we're humidifier in the All right. This is all occurring
17:40 a result of that turbulence that we by just breathing in air and it
17:45 those con con show nasal cavity Okay. Yeah. Yeah. Me
17:59 the caffeine today. Alright. The as I said, is the fancy
18:04 for the throat. When you see , Ferencz don't think that they're trying
18:07 be fancy or confusing. It's just throat. Alright. It's posterior to
18:12 nasal cavity. It's posterior to the cavity and it continues downward towards the
18:17 . Alright. And so its job to conduct air from the nasal cavity
18:22 to or through the respiratory system. because it's also attached or behind the
18:27 cavity, it plays a role in food down into the digestive system,
18:33 kind of like to 88 59 45 over here. It's like the most
18:39 intersection in Houston right? You get that and it's just like every car
18:43 doing this trying to get to where needs to go. That's kind of
18:46 the fairing says. It's a crossroads these two things. And so what
18:51 doing is you're dealing with a structure is responsible for figuring out where things
18:55 to go. It's very flexible, distant herbal and it aids in swallowing
19:00 propelling flute food. We're gonna learn swallowing, swallowing is a function of
19:05 oral cavity in the tongue. But it wasn't for the pharynx you wouldn't
19:09 able to do the swallowing bit. needs to happen. All right.
19:13 there's three regions. We have the oral pharynx to the law. Ringo
19:18 and we've color coded them here so we can kind of look at them
19:21 kind of keep them associated to the regions. So little purple region up
19:26 that would be the nasopharynx notice next the nasal region right? So it's
19:31 superior most one. Um The thing want to point out is that it
19:35 lined with the pseudo stratified silly ated our epithelium. So again it's the
19:41 long ones. You're not pulling things your nose. So you don't need
19:45 protect quite as much as you would in the oral pharynx. Alright.
19:50 One of the things that it has you need to be be aware of
19:53 the auditory tube you can see right . That is what allows you to
19:57 pressure inside the the middle ear. like when you're like going on an
20:04 or needing beyond, you can pop liberates the air so that your tim
20:09 membrane vibrates appropriately. This is also you'll find the first group of
20:15 What was the role of the do you guys remember? It's
20:20 Right? It's the idea is I stuff. So you can imagine if
20:24 the nasal cavity I'm breathing in and a possibility of dust and microorganisms and
20:30 sorts of horrible things. What do want to have is I wanna have
20:33 guard house sitting up in that watching for things that may be coming
20:39 the nasal cavity and that's what the does. It has all the
20:43 it's part of the uh the lymphatic in terms of its lymphatic structure,
20:48 houses part of your lymphocytes and other stuff. All right. Um The
20:54 walls deals with the fringe tonsils which also known as your adenoids. So
21:00 you've had your adenoids removed, that's you've gotten rid of as those set
21:03 tonsils. All right now, when think of tonsils, you're primarily thinking
21:08 the palantine tonsils. Um And we'll there in just seconds. So,
21:12 talking about the aura pharynx. So you go to and you look down
21:16 throat or look down your own you're looking at the oro fair
21:21 Alright. That partition beyond the you know what your uvula is,
21:26 ? It's a little dangly thing in back of your mouth going right,
21:31 . And what that does is helps to keep the milk from going up
21:35 nose. It makes it go down nose. Except when you laugh,
21:37 case it goes up your nose because already put it in the pharynx,
21:42 looking like you've never seen that happen . Have you ever seen someone laugh
21:48 out there knows you guys really went some sad schools, Have you ever
21:53 it? Yeah, you had milk out. You were the one They
21:58 laugh. Okay. Yeah, it's a cruel, cruel thing. You
22:02 until someone's drinking milk and then you them a dirty joke or something like
22:06 . And then thank you. Just trying to make it fun.
22:18 , So here this is where we're to see that non stratified stratified squamous
22:23 . Alright. And again, what we trying to do? We're trying
22:26 protect because of all the things that burn or rip or tear as it
22:32 down. All right. So here that first side of protection.
22:36 we have uh tonsils, we have palantine, we have the lingual tonsils
22:40 tonsils are located further down on the . The palantine tonsils are the ones
22:45 sit on the side. So if stop your tonsils and you see that
22:48 of bulge at the back of at the sides, near the back
22:53 the throat. That's what the palantine are moving further down into the inferior
22:59 . So this is that light Um What color is that?
23:08 No, coming out. What Thank you. Okay. See I
23:16 all the guys are just sitting there purple. You have to ask a
23:20 because she knows all the colors. know seven colors. We don't even
23:24 eight. We only know seven. . Um So here what we're doing
23:28 we're down low again, it's non , squamous as we mentioned. Um
23:35 is going to be the common pathway food and air. This is where
23:41 material going into the pharynx has to divided. Is it supposed to go
23:45 the stomach or is it supposed to to the respiratory system? Alright.
23:50 so it's the larynx job to determine or not it goes one way or
23:55 other. Okay, so how does do that? Well, the larynx
24:01 two functions right first. It serves your voice box. All right,
24:06 it is a continuous structure. So here this would be where the
24:12 larynx is located. Alright. It's color coded for you. This right
24:18 is where the larynx is and all , all this structure around it.
24:22 you can imagine back here, that be where the esophagus is going.
24:26 , so you can see structurally. has cartilage, it has some
24:31 it has some other ligaments that are to help maintain shape and so that
24:36 can do some unique things. Now larynx is a passageway for air,
24:43 do not want food going into the . So what we have is we
24:47 a structure right here. It's called epiglottis. Epi means above. So
24:53 above the Gladys. So that means need to know what Gladys is.
24:56 the epiglottis is a structure that when are trying to pass air through,
25:03 up, but when we're trying to food through, it closes over the
25:08 of the larynx and covers the So basically it serves as the the
25:13 that says, okay, we're gonna you to slide down to the
25:16 Okay, that's where you go, we want you to come down through
25:19 respiratory system. It's gonna stay open right. And so it's trying to
25:24 you right here and you can kind see from the top, it looks
25:27 little bit like a tongue. But the tongue doesn't, the tongue
25:31 moves down and it moves up just this like a lid. Okay,
25:38 the epiglottis is going to cover opening law. Ringo, inlet or the
25:44 to the larynx now underlying that right here, that is where the Gladys
25:50 located. And the Gladys is the that allows you to produce speech.
25:56 , so the structures of the Gladys these two strands right here of connective
26:04 and they're stretched really really tight. so when air blows past them,
26:10 cause those things to vibrate which creates . And then what we can do
26:15 we can contract or relax that connective . So it makes different kinds of
26:21 . It makes uh like that, ? And the space in between through
26:27 the air is passing. So this space right there that is the rima
26:34 . So the remote Gladys is the through which the air passes down into
26:39 down into the trachea. The gloppy the glasses are the true vocal
26:43 The things that make the sound. then the epiglottis is the thing that
26:47 over them so that the air doesn't that direction it goes the other direction
26:51 into the esophagus so that you can where food goes because you don't want
26:55 stuck there have swallowed wrong. Is fun? Know what do you start
27:03 , coughing? Gotta get the air push the food out, Get it
27:09 the right place. All right it also can increase the pressure in
27:15 abdominal cavity, but basically, you holding air and you're basically squeezing,
27:22 also plays a role in the cities the cough reflex. So for
27:26 if you need to cough, what doing is you open it up and
27:29 you close it up and allowed to know, basically explode open. So
27:34 the idea here. So understand epi bloody, understand rheumatology, rima.
27:43 epiglottis above Gladys. Oh by the , is it just the glass that
27:51 the noises? What else makes the ? All right, here's the fun
27:58 . Hold your tongue for those who brave enough to touch your tongue.
28:02 we have immune system. So it's . All right now here's another fun
28:18 . Try to say the same thing don't move your lips. Hey,
28:25 can you see. So a lot the noise we're making. It starts
28:31 the Gladys. Right? And so can I can go change the vibrations
28:38 that I can make higher and low , lower notes. But the shape
28:43 my mouth and the movement of my is what makes the unique sounds
28:49 right? That allows me to do communication or to sing or to do
28:54 so far so good. Okay, when you pass the larynx, you're
29:05 moving into the trachea. Alright? it moves down the middle of the
29:09 so it's moving through the media steinem what you're doing is you're moving down
29:13 its first branch which are called the bronc I All right. So,
29:18 just elongated structure. Hard to do at 22. All right,
29:23 this is the trachea from the larynx to the bronc. I.
29:28 Where it splits. Alright, structurally, what you can see here
29:33 that it's basically a bunch of cartilaginous and they're partially their partial rings.
29:39 not four rings, they're kind of shaped like a letter C.
29:46 And in between that cartilage, our of ligaments. So they're pointing out
29:50 cartilage for you. But the little stuff in our little cartoon up
29:54 that's ligament. So we got cartilage ligament. And then on the backside
29:59 we can't see here is we have and it's called the trachea less
30:03 We'll see it in the next Alright, And this allows for the
30:09 trachea to have a certain degree of to it. I'm just gonna flip
30:13 over to the slide. So you see it. So here you can
30:15 here is the cartilage, right there's trachea Alice muscle, you can see
30:20 esophagus back behind it. So, esophagus sits right next to the
30:25 And so that muscle allows you to of extend and distended, but also
30:30 you have food in the esophagus, allows for the esophagus to have some
30:35 to actually move. And so the , this muscle gives so that you
30:40 swallow whatever it is that you're swallowing now, it's this muscle that expands
30:46 reduces the space in here when you or reduce space, which we're going
30:50 see here in just a moment you pressure and so by changing pressure,
30:55 can create unique movements of air. for example, when you're coughing,
30:59 you're doing is you are basically squeezing that you can create greater pressure and
31:04 you relax that air moves is the . Now the wall of the trachea
31:11 covered again in the mucosa mucosa. is again a pseudo stratified affiliated calumnies
31:16 it has a whole bunch of goblet . So what we have is a
31:20 of cilia covered in mucus being produced the goblet cells. So anything that
31:25 get caught up in the in the is going to be caught in the
31:29 and then the little silly are I don't want this here. And
31:32 what they're doing is they're pushing the upward and away from the lungs.
31:38 , we're all friends here, we can talk about gross things.
31:41 you ever had that. Have you done that? Yeah. What you're
31:46 is you're expelling the mucus with all gross stuff that is slowly being elevated
31:54 that little cilia, right? So little silly are sitting there on the
31:58 go that way and it's constantly pushing mucus upward. Alright, so we're
32:05 things towards the fairing and then you do one of two things you can
32:08 it up and spit it out, what we normally do is and push
32:13 down into the stomach and let the deal with whatever's in it because the
32:18 is pretty tough so far. So trachea pretty easy. Yeah. All
32:24 . Let's get down into the bronchi . Alright, so the bronc i
32:30 a plural for all the structures of branches of the trachea. So what
32:34 done now the trachea sits outside what would call the lungs. The bronc
32:39 go into the lungs and we refer it collect we as the bronchial tree
32:44 if you turn it upside down, look like a tree or I could
32:48 it looks like the roots of a if you want to be really
32:52 And so we start off with the bronchi and so the primary of the
32:56 bronchi is the first branch. So have the track that goes down and
32:59 get two main bronchi. Alright then gonna branch again and now you're going
33:06 the lobes of the lungs and so refer to these as the lubber bronchi
33:12 the secondary bronchitis. Now what I to point out here is something that
33:16 to do with the lobes. The side of the heart has three
33:20 And so that means you're gonna have Loberg bronc. I the left side
33:25 the heart only has two lobes and reason it has two lobes is because
33:30 have to have space for the And so during development one side gets
33:34 . The other side gets too because need the heart. Okay so you
33:38 up with two lobes on the other . And so there's gonna be two
33:42 , so two on this side, on that side and then the next
33:46 this would be the segmental because each has a certain segments to them.
33:51 gonna see here in just a moment we talk about the lungs that each
33:55 is a compartment inside the lobe it's self contained. And so here
34:02 branches again you're gonna have anywhere between and 10 depending Um and um uh
34:10 that you're gonna get a whole another of branching and even more branching and
34:15 more branching. And this goes on quite a bit. Now some books
34:19 just say oh there's 6-9. Um have a textbook that's used at the
34:23 school level. It says it has branches. So you know pick your
34:28 , there's a lot of branches But the idea is I start with
34:32 and then I have three and two then I go down to segments.
34:36 so that each side of the lung basically has nine or 10 segments.
34:43 and what we're doing is we're going becoming more, I mean we're getting
34:48 and smaller as we go as the divide and we're gonna become less and
34:53 complex as we divide. So the was cartilage and muscle and ligament.
35:03 as you're moving downward, what you're see is that we're gonna be getting
35:08 ligament, more muscle and smaller And we're gonna finally get down to
35:13 level where we get to what are the bronchi heels. Now, the
35:17 are two different types. They're very small. We see up
35:20 they're basically path. Path, what's the word? I want to
35:29 pathways. Okay. Their pathways, was trying to say passages and pathways
35:35 the same time. I don't know I was coming out. These are
35:38 than a millimeter in diameter. So these are tiny, tiny,
35:44 that. Can you see that back ? How tiny that is?
35:50 Well, maybe you should sit up . I can show you stuff.
35:55 right. They're very small. And two different types we have, what
35:57 called the terminal bronchial. The terminal are those segments um that are part
36:03 the conducting zone. They don't play role in the movement of gas from
36:09 external environment to the internal environment. next level down is what is referred
36:15 as the respiratory bronchial. Now, just like the terminal broncos and that
36:19 passes through them, but they can't they're so small and so thin they
36:25 participate in gas exchange. In other , gas can move from inside that
36:30 across their membrane into your bloodstream. , So that's the distinction. Terminal
36:37 kills. There is no gas respiratory bron kills. There are All
36:44 . So, this is another way kind of look at it in terms
36:47 structure you can see here there's a . You can see in between
36:52 That would be the annual ligaments back . That would be the muscle.
36:55 trachea. This muscle here, you the branches and you're going down
36:59 Here's the main segment ALs or lower than down to segment ALs.
37:04 as you work down, you get and smaller and notice the degree of
37:08 begins to disappear. You don't have instead. What it is, it's
37:13 be muscle and then eventually what you're with is just muscle. So,
37:17 speaking. If you look over you'd see that the muscle is thicker
37:23 to up here. All right, as you get smaller, the relative
37:28 of the muscle is more and more to the total size. All right
37:33 , the reason these structures exist is we want the bronc I to remain
37:38 to allow air to pass through. want them to be open passageways.
37:44 when we get down to the Bronx . This is where we're going to
37:47 the movement of air. Alright? what we can do is we can
37:50 heir to where the air needs to or we can cause passageways open to
37:56 air to escape or to trap it we need a traffic which we'll talk
38:01 on Tuesday next week. So what gonna do is we're gonna regulate airflow
38:06 at the levels of the Bronx kills bronchi themselves more or less. Just
38:11 open. You can open them a bit more, you can close them
38:14 little bit less. But for the part they aren't making much change
38:18 I'm not gonna ask which of you here have asthma, but the reason
38:22 asthma is is is the unregulated closing those bronchial walls there or inappropriate closing
38:30 those bronchial. And so the the inhalers that you use basically cause
38:35 dilation. So the bronchial, the out there that are squeezing shut,
38:39 it hard to breathe or move there being forced to stay open so the
38:44 can move in and out where gas is taking place. Okay, so
38:53 to move down to the last little here. So what we're doing is
38:58 switching the way that we're kind of at this and say, alright everything
39:01 to that, to those terminal bronchial are part of the conducting zone.
39:07 everything we looked at so far plays role in conducting air down to where
39:12 exchange is gonna be taking place which the respiratory zone. All right.
39:17 here these are the respiratory bronchial. so you can see our little cartoon
39:20 , This is the respiratory bronchial up are sorry, this terminal. And
39:25 we're coming down here to where we're start seeing respiratory Barong kills. So
39:29 we've got some cute boy girl They don't play a big role in
39:32 exchange, but they're capable of doing . In other words, gasses are
39:36 of moving across that smaller cell than larger cell. Then those uh respiratory
39:44 are gonna divide into ducks. And not quack. Quack. Alright.
39:50 D. U. C. Duck, like up there. That's
39:53 duct. Alright. And then those are gonna open up into these alveoli
39:59 . So if another way you can at this is to think of it
40:02 like a bunch of grapes. Right you get down to the bunch of
40:05 where those little stems are going into of the grapes. Those are the
40:10 . And then that bunch itself is Al Viola sack. All right.
40:16 , the difference between a bunch of in the alto sax, is that
40:21 the Al viola? Excuse me? , which is where all the gas
40:26 is primarily going to be taking They're interconnected with each other. They
40:29 a series of pores. And so you take a slice through it,
40:32 can see the little tiny dots. each of the individual sacks are connected
40:37 the sacks next to them. And what that does, it ensures that
40:41 particular group, that particular sac expands the same rate. So in other
40:47 , all the alveoli are participating together the reception of air and the removal
40:55 air so that the gas exchange can place more or less equally in each
41:01 the al viola. In that particular , now wrapped around each sack and
41:07 close opposition to each al viola, have a whole bunch of blood
41:12 All right. And so again, al viola sack is in close association
41:16 vasculature so that there can be exchange takes place between the alveoli and the
41:24 . So the Alveoli, when we about gas exchange, this is where
41:29 spending our time. This is the site of gas exchange. We have
41:34 really, really tiny structures. You a whole bunch of them, about
41:38 million per lung. And what this is it expands your surface area of
41:43 lungs significantly. Now again, I I've told you guys this before.
41:51 when you're dealing with textbooks, they try to give you some kind of
41:55 to kind of help you understand. , I want you to look at
41:57 lungs or my chest for a Imagine my lung on this side fills
42:02 about that much space. If it an empty area, you could measure
42:05 inside of that. You can okay, I can measure the inside
42:09 area and it's roughly about what? don't know, maybe three uh you
42:15 , square meters or square feet or like that. It's not very
42:18 But if I divide that up and dividing it up, keep dividing it
42:21 . I ultimately increase the surface area much. And this is where I
42:26 know if this is true that each is roughly the size in terms of
42:29 surface area, of the size of tennis court. So you can imagine
42:35 can exchange a lot of gas across surface of a tennis court relative to
42:39 , oh, I don't know, computer screen. Right, That makes
42:45 . So, this is why we the structure is to ensure that we
42:50 more gas exchange then if we just a big old empty balloon sack.
42:57 right, there's also some elastic fibers there. And this is gonna become
43:04 because when we expand the balloon we to be able to shrink. That
43:08 of makes sense. So the Al can expand and contract with regard to
43:14 sex. All right, so We were all with me. I
43:22 , I know I kind of jumped with all the I should have stopped
43:24 the end of that and then Okay, let's deal with their
43:27 structures were so far so good. , Alright, so let's dive a
43:31 bit deeper into this structure here and take a look. And so what
43:34 looking at this particular picture here is slice through a single Al Viola,
43:38 actually can see there's other but we're on that one in the center.
43:42 what we can see is that there's cells in this picture. If you
43:46 carefully yours actually even some epithelium as from the vasculature, but with regard
43:51 the lungs in regard to the Al , there's three cells. All
43:55 we got the little light pink right, that make up the
43:59 Alright. These are called the type cells. These are the primary cell
44:03 the Al Viola. Alright, so 95% of the population. They are
44:08 , very flat and very, very . And so they play a role
44:11 gas exchange. Alright then, we some fatter cells. And so they're
44:17 to be shown right here, those cells are the Al Viola type two
44:23 , their jobs to secrete this material fact in that helps to oppose lung
44:29 . Alright, Or really, it's Viola collapse. Now, I'm gonna
44:35 about this in a second, but want you to picture for a
44:37 have you ever tried to blow up balloon at a kid's party been tasked
44:41 before you get like you're going you're you're blowing in there's always a little
44:45 of corn starch on the inside, ? You start blowing in there,
44:48 in your mouth, when you're breathing air, there's a lot of
44:52 And so when you push all that and that moisture in there, and
44:55 say you're now trying to tie that off and let's say, we all
44:58 it up, right? At least all that air goes out. Now
45:02 balloon is flat and now you got blow it up again. All that
45:07 that's in that balloon now is acting a glue inside that balloon, isn't
45:11 ? It takes a lot more work try to get that balloon just a
45:15 inflate. That's what surfactant does. fights that. So the balloon doesn't
45:23 . Don't collapse instead what they do of the fact that when they are
45:29 , they go from around two like instead of like that, because that's
45:35 lot harder to separate out. All now, if you want to know
45:39 it's because of the polar nature of , yada yada yada science. Third
45:47 of cells found in the Al Viola's our friend the macrophage. What do
45:53 do? Just like dr wayne? do they do? They are big
46:03 . That's right. They just cruise and say you don't belong here.
46:09 do I know you don't belong here I know everything in the body,
46:13 should be here and I'm gonna come there and it eats it up and
46:17 just sits there and it gobbles up the stuff that gets into the
46:22 it's not supposed to be there and the immune system and says,
46:26 we're being attacked by dust again. when that hay fever and all the
46:31 horrible things start popping up. Have ever heard? I don't know if
46:36 is true. I just like to out these random facts that you read
46:39 the internet because everything you read on internet is true right? Over the
46:43 of your lifetime, you're supposed to in like a bucket of dust.
46:52 don't know if that's true, but sounds true, doesn't it? So
46:56 just throwing that out there just for . That's what the alveoli or the
47:00 macrophages are for now in this what we're doing is we're going and
47:05 a cross section through the type al volar cell and we're doing a
47:10 section with the cell that's in close to opposition means next to right.
47:16 so what we have is, here's Al Viola's so this purple thing right
47:21 represents The Type one cell. And over here this would be the end
47:27 thallium of a capillary that's wrapped around . So if I go here,
47:32 can see there's all your little capillaries this picture right here, you can
47:36 there's the capillaries right there. So really just kind of focusing in right
47:41 between that relations between the relationship between Alvin herself? Type one cell and
47:45 endothelial? Um And the space from to there is about a half a
47:53 and this is what allows gas exchange take place. It is so small
47:57 the distance that the gasses have to are very very small, so it's
48:02 to pass over very, very quickly . It's not just those two cells
48:06 are there, there is a basement that sits in between them.
48:11 so anything that's coming in from the has to pass first through the
48:16 Alright, so the fact is this material that's being produced, it is
48:21 layer and there's water in your lungs is not a lot of it and
48:25 and it's primarily being spread out because the surfactant. So you have to
48:30 through that little layer of water and pass through the al viola cell,
48:36 through the basement, pass through the . And then you're now in the
48:42 and similarly gasses that are leaving past opposite direction. And so this is
48:51 all the action is taking place. when we're talking about this, you
48:55 imagine 3 to 4 million cells per and we're going down to this level
49:00 understand what that gas exchange is doing if it's the size of a tennis
49:04 that is a lot of molecules moving and forth between the two areas,
49:11 guys don't know, do you know pneumonia is, you've heard of
49:14 Right, Right. So pneumonia is result of inflammation in the lungs and
49:20 of water. Right? And so you're doing is you're making that distance
49:31 . Let's just say we increase by instead of being .5 mm .75
49:39 That's a huge distance that molecule has travel. And that's why pneumonia is
49:45 a huge deal. It makes it hard to breathe. This is a
49:54 picture, especially if you don't know the weird stuff that's going on over
49:58 . And what this is describing is relationship of surface tension and pressure.
50:05 right. In the top picture on left says without what this is showing
50:14 , is to alveoli of two different . And so there's a relationship of
50:19 relationship. So that's what physics It basically says that the inward pressure
50:24 a rounded structure is equal to the . There's a relationship to that to
50:30 tension that's taking place there. So as you get bigger, you
50:35 up with less tension. And so you get smaller there's more tension.
50:39 ? And again, think of a balloon versus a small balloon. It's
50:43 . The smaller balloon basically, it's to expand. But what happens is
50:49 that the bigger balloon has more inward . So it's able to drive fluid
50:54 drive air or whatever it is in outward very, very quickly.
51:00 so what we have here is look, here's the tension, the
51:03 here is greater. And so because this little thing has so much more
51:09 , even though air should be going both of those equally, they
51:13 what happens is the tension here builds a lot faster, so it drives
51:17 into the one that has more volume it. And when that happens that
51:22 you now have space that is not in gas exchange. So instead of
51:26 tennis court, you now have a court, does that make sense?
51:31 guys know what pickleball court is? , I don't think I've ever actually
51:35 one. Yeah, it's like a of the tennis school. All
51:42 so one of the roles of surfactant to ensure that we maintain the tennis
51:50 , okay. In other words, want to keep all the alveoli open
51:54 they're not all the same size. . And part of the reason that
51:59 is drawing it in is again, has to do with water and polar
52:02 and it's basically pulling things closer. right. And so when you have
52:08 , surfactant breaks up the water so they're not all pulling on each
52:14 . And so now you reduce the of inward tension and so now both
52:19 the alveoli of different sizes behave in other words, air goes
52:25 they both expand at the same There's not one that says,
52:29 I've got too much and pushes air other direction. So that's kind of
52:33 role here. And this is what alveoli type two cells produce. All
52:38 . So the surfactant is a bunch lipids, alright. And it's breaking
52:44 surface tension, surface tension being caused the presence of water. So it
52:50 less work to inhale because you're not so hard to fight that inward
52:56 And so it becomes easier to And also it reduces the recoil.
53:01 right. So the idea is as expand, you're gonna try to re
53:06 like a rubber band, right? more you expand the rubber band,
53:08 more it wants to snap back. ? So the further it goes,
53:12 harder it snaps. You guys learned , Right? Did you ever have
53:16 band wars in high school? Junior grade school? Know what did your
53:23 make you learn or something? And just had teachers that made me spit
53:30 in their hands. And then we like slingshots in class and shot spit
53:35 . No, spit wads. I'm looking at all these women over here
53:41 they're just like uh if you were my class, I would have told
53:45 you. Yeah, Yeah, because have the spit wads in your
53:51 No, that's so the rubber That's right. You never did
53:55 You take the rubber band put it your finger like this, wrap it
53:58 now. You have your little rubber gun. Yeah. And what you
54:02 is you want if you you know the teachers would give back like really
54:06 rubber bands. I mean those were the ones you save for the people
54:09 you really liked, right? And shoot him across the room. You
54:19 gotta get out and live more. right, Same thing is happening in
54:24 lungs, right? As you the more it wants to go back
54:29 its original shape. And so what does is it reduces that that that
54:35 . It says, okay, I'm go back at a constant rate.
54:39 right. It allows us to equalize pressure, which is what we described
54:44 . So that's where we're gonna leave . I don't want to go too
54:48 . We may talk about a little more on Tuesday, I can't
54:51 to be honest. So, so all we've talked about our passageways and
54:59 we get down to this structure. is basically this empty space that is
55:03 bunch of epithelium with elastic tissue surrounding . So, what is a lung
55:10 ? Alright, well, the lung smooth muscle, it's capillaries and it's
55:18 epithelium that makes up all these structures we just described. It's a paired
55:24 . You're probably familiar with that at , right? It has a
55:29 This is what is up against the . This part, right here is
55:34 against the heart. And so we it names associated to where it's
55:40 So the outer surface up here is to the ribs. So we call
55:43 the costal surface, the part that's the heart. The heart lies within
55:47 is called the media steinem. So call that the medial spinal surface and
55:52 things like blood vessels and nerves pass through the same point, which is
56:00 the hill. Um I think I'm spell it, healing him up
56:03 All right. And then back down , that's where the abdomen is gonna
56:07 located down here. So this right is the diaphragmatic surface because the diaphragm
56:13 a muscle that separates the abdomen from thorax. So structurally those are the
56:20 . Now there are some differences. already mentioned it, we said that
56:23 right lung has three lobes. It's larger. The left lung is
56:27 it has two lobes. It creates so that the heart has some room
56:32 exist. The lobes that the heart made up of is made up of
56:38 and each segment is its own individual . That means it has its own
56:43 tissue that creates the outer barrier to . So you can think of it
56:47 my lobe and I'm gonna break that up into a little tiny segments.
56:51 segment has its own connective tissue moving each segment is going to be a
56:56 of the artery and a branch of veins supplying blood and moving blood away
57:01 the lung. And then each segment is broken up again into these logical
57:06 each of those sections, those little rules are going to have an arterial
57:13 that are passing down into it serving particular area. So what that means
57:19 is that the lung is divided up smaller units that are functionally independent of
57:26 other units. Now they all could working together but there may be times
57:30 a segment is doing something different than other segments. Okay. And that's
57:37 your benefit because if something goes you don't want all the things to
57:41 wrong everywhere. At the same you want everything to work based on
57:47 own interactions with the environment and with blood. Now the lung itself is
57:56 in a cirrhosis. To Alright, we call the pleura. All
58:02 And so when we talk about serious or cirrhosis, remember these have two
58:06 to them. We have a side nearest the wall of the cavity.
58:11 in and we have a side that's the tissue we're looking at. All
58:15 . The side nearest the tissue is the visceral side. The side that's
58:20 the wall of the cavity is called parietal side. So we have the
58:24 pleura. We have the visceral pleura sitting in between those two things is
58:30 fluid that we were for to as pleural fluid? Alright, so that
58:37 fluid sits in a cavity into space that's the pleural cavity. And why
58:41 we have that pleural fluid? Why that why is that? They're exactly
58:49 That's what I hear when I'm up . Right, it's because we want
58:55 reduce friction. Have you guys stopped today? No. Have you noticed
59:02 you've been breathing now that I said gonna start noticing like, oh
59:07 thank goodness for that. Maybe I check and see if I'm actually
59:11 I got a pulse too. So is good so far. And so
59:16 we're doing here is we're minimizing that because the fluid that serious fluid,
59:21 pleural fluid is sitting there as a . So every time I breathe in
59:26 breathe out, those two walls of pleura don't rub up against each
59:32 Yeah. So far you guys with , okay, ready to dive into
59:42 actual interesting stuff because we're gonna learn we breathe now, that's what I
59:49 to get to. And so the part of breathing deals with that pleural
59:57 because everyone puts a lot of emphasis it and I'm gonna show you why
60:02 emphasis is not as important as some the textbooks? Lay it out.
60:07 . All right, so what is this word is used all over the
60:12 in science? All right. And when we think of respiration, what
60:16 talking about here is the exchange of from the external environment. And we're
60:23 about the two respiratory gasses were really care about two of them. We
60:26 about oxygen and carbon dioxide, but isn't just carbon dioxide and oxygen also
60:33 . It's also just name about 1000 things. All right. There's a
60:39 bunch of stuff. But we're only in those two things oxygen. Carbon
60:42 . And what we're doing is removing gasses from the external environment to our
60:47 environment, to the cells and then again. And so everything that the
60:53 system is is trying to move those between those two points. Because the
60:58 is, is you have cells that in Well, I'm just gonna pick
61:02 part of the body that is always first away from the lungs, your
61:05 toe and your big toe can exchange with the external environment. Alright,
61:11 cell that makes up the muscle in pinky toe. That's the cute
61:16 Is incapable of delivering gasses to the environment or receiving it. It is
61:22 upon the respiratory system from moving that in. And then it's dependent upon
61:29 cardiovascular system for moving that gas to then allowing the laws of physics to
61:34 the exchange between the internal environment, interstitial fluid and the plasma. And
61:40 from the interstitial fluid to then make take place with that cell. That's
61:48 we talk about respiration is what we're about is all that middleman stuff.
61:52 we have pulmonary ventilation that's just the moving in and out between the lungs
61:56 the alveoli and the external environment. . Air moves in. And what
62:02 doing is I'm bringing in oxygen when moves out, I'm pushing al Viola
62:06 and really extra carbon dioxide, that's process of inspiration and expiration. So
62:11 we hear pulmonary ventilation, that's what referring to, is the exchange between
62:16 atmosphere. That's what a team atmosphere and the alveoli. Then we're
62:21 see gas exchange occurring between the alveoli the capillaries. Alright, So that's
62:26 next step. Moving it from the into the blood. So oxygen is
62:32 diffuse from the alveoli into the Carbon dioxide is going to diffuse from
62:36 blood into the Al Viola and then blood is going to move that gas
62:41 the way around the body to where needs to go. This is what
62:43 refer to as gas transport. So is being moved to the tissues.
62:48 dioxide is moving away from the tissues then it's gonna go back to the
62:54 and the last place is the systemic exchange. This is where the gas
62:59 auction from the blood that is moved the tissues is now moving from the
63:03 into that interstitial fluid. And from interstitial fluid, ultimately to the cell
63:08 needs it. And the carbon dioxide that cell is producing is gonna move
63:12 that cell into the interstitial fluid, the interstitial fluid into the blood.
63:16 it's gonna be returning back via gas . And one thing we're not mentioning
63:23 is the dreaded thing that all of guys don't want to talk about,
63:26 is cellular respiration. Right? And those of you who've who've taken enough
63:31 , you know what those words That's where you take glucose plus
63:36 Right. And what do you get of the out of the reaction?
63:40 looking and she's going through high Yes, but all the way down
63:44 the very end, What do you ? 80 P plus water plus carbon
63:53 plus heat. And that is respiration well. Alright. That's ultimately the
64:03 we're trying to create by the movement all these gasses. Okay, but
64:09 not gonna talk about that. I it's like Bruno, I think two
64:16 three people like that. All So, how do we expand the
64:20 ? What is lung inflation dependent All right. So, if
64:24 that tissue is smooth muscle, if tissue is basically a bunch of epithelium
64:32 basically a bunch of connective tissue? does it expand? Can you control
64:37 muscle? Can you make smooth muscle contract? No, but can you
64:43 yourself to breathe in and out. practice can you do that? It's
64:49 just me. I can do But Okay. But what type of
64:54 am I controlling when I forced erin skeletal muscle? That's right. So
65:00 have to have voluntary muscle control And so the dependency that the expansion
65:06 the lungs is not dependent upon the that's found in the lungs is dependent
65:11 muscle that is found outside the Alright. That are gonna be found
65:17 the thoracic cage, and it's gonna found in the floor of the thoracic
65:23 , which is the diaphragm. All , now, the other thing that
65:27 gonna do is we're gonna expand as result of the change in surface
65:32 Right? And so that's the serious does play a role. But I'm
65:36 show you it's not as big as role as the book is trying or
65:40 text or anything is trying to make . Alright, we talk about it
65:44 there's a dependency to make sure that muscles and the lungs are working
65:52 Now, when air comes out, we're going to rely on is the
65:56 tissue that's inside the lungs. In words, if I'm stretching the rubber
65:59 of the lungs, then the rubber of the lungs want to go back
66:02 their original shape. So I just to relax my muscles to make that
66:07 . And so we have this unique of the pleural cavity to the thoracic
66:14 and to the lungs themselves that allow this compression and uh rare faction?
66:20 section that takes place. So we're need to that's where we're gonna be
66:25 be going here with this. so first off we have to return
66:29 to this wonderful equation that you all and loved, right? And I
66:33 this is gonna be one of those that you're gonna see over and over
66:36 . So we have F. Is what flow, delta P.
66:42 pressure are is see you guys already this stuff. What we should just
66:47 for the rest of the day, ? I mean everyone's like yeah please
66:52 stop talking. Alright. Airflow is amount of air that's moving in and
66:57 . It depended upon changing pressure pinned . The resistance. Pressure difference is
67:02 be what you're comparing again. So gonna be really dealing with the alveoli
67:06 we're gonna be dealing with the So it's the difference in pressure in
67:09 atmosphere and the difference of pressure inside or the pressure inside the alveoli.
67:14 is a direct relationship if I drop pressure in my alveoli, air wants
67:18 go which direction in right? If increase the pressure inside my alveoli,
67:23 pressure is now going the opposite So air wants to go and this
67:29 the easy stuff. Alright. Resistance primarily by the diamond of the conducting
67:35 . So when we look at the tubes? Is the trachea. Are
67:39 able to change the diameter of the that much. No. What about
67:46 wrong guy, nope. Keep keep moving down, down to the
67:51 hills. Yes. So this is when we're talking about resistance, this
67:55 what we're primarily dealing with. It airflow. So there's a different
67:59 right? We can alternate by the of the chest. Right?
68:03 if you are a smoker, when smoke meat, we call that
68:07 When you smoke your lungs. It also barbecue. Have you ever thought
68:13 that? No, it's pretty Right? But that's what smoking
68:17 Now, the truth is you guys a generation that smokes a lot
68:21 Even though you guys have as a bought into the fruity flavor stuff,
68:27 about baby. Right. Same principle . You're just smoking tissue. When
68:33 smoke tissue, you're cooking tissue. you cook the tissue, it becomes
68:36 elastic and so it becomes harder to expansion and contraction. Alright, that's
68:43 one. All right. If I the bronchial diameter, which we mentioned
68:47 . If I increase diameter, I resistance. If I decrease diameter,
68:51 gonna increase resistance. And lastly, I change surface tension. If I
68:56 the surface tension, I showed you picture basically that causes an increase in
69:00 . So the resistance to cause it expand out becomes greater and greater and
69:07 . Do you guys remember this? boy? Good old Boyle? This
69:12 the principle this is underlying everything we to know about the lungs. Right
69:15 , Boyle's law, Boyle's law states a constant temperature, the pressure of
69:18 gas decreases. If the volume of container increases, P one V.
69:23 equals P two V. Two. ? So if I have a volume
69:28 one liter and the pressure inside there one. So that side is gonna
69:32 one. So if I decrease the by half, that means the pressure
69:36 to increased by how much? Double heard the word. Right, so
69:42 . Double. Right. One equals times one half equals one.
69:48 so there's that relationship. Right? in order to change the pressure in
69:54 lungs, I have to change the . That's what we're looking for.
70:02 picture shows this. So the difference pressure gradients or the pressure creates the
70:07 in pressure between the two. This what's gonna be represented by that delta
70:11 . So if I have more air sorry, more pressure inside the
70:15 It's gonna drive air out. If have more pressure inside the atmosphere,
70:18 going to pull air in things move areas of high pressure, low
70:23 The end all we gotta do then change pressure. How do we change
70:27 , Change volumes? So there's different . This is the one that screws
70:36 up. Alright, we have. is the atmospheric pressure? Atmospheric pressure
70:41 ? 760 millimeters of mercury. it does change. But we're just
70:44 use that as an eye static laboratory . All right, So that's the
70:48 that's out here. That's the If you are not breathing, what
70:52 the pressure inside your lungs? In words, if air is not moving
70:57 and forth, what's pressure inside inside alveoli, it would be the same
71:02 as the atmospheric pressure. If atmosphere 60 that means the inside is gonna
71:06 7 60. Alright, but when breathe in, that must mean I
71:11 the pressure from atmospheric right? So intra pulmonary pressure is gonna be the
71:19 that changes up and down relative to atmospheric pressure. So that kinda makes
71:25 . So if this is 7 60 I'm breathing in, I have dropped
71:30 pressure less than 7 60. So flows in until the pressure inside my
71:36 Viola becomes equal abraded with atmospheric. , so that makes sense. I
71:47 a glass of water. I'm putting glass of water into a tub.
71:55 , there's no water in the There is water outside the glass as
71:59 sink, the water in, water gonna flow in until it's full until
72:06 water inside is equal to the water the outside. That's the same
72:10 Alright, when I breathe out, I'm doing is I'm pushing on the
72:16 , I'm decreasing the volume. So increased the pressure relative to atmosphere.
72:22 flows out right until equilibrium. So that would be intra pulmonary pressure
72:32 . It is 760 unless I'm changing , in which case I'm going to
72:35 or decrease, it depending the last is inter plural, Interpol pressure is
72:42 pressure inside that little tiny cavity. I want to demonstrate what this
72:50 What we have here is we have that's taking place. Now I'm gonna
72:57 one of these young men to come and be my guinea pig who wants
73:03 do it? All right. All now I've got a couple ladies up
73:10 in the front who wants to rip arms out of his sockets.
73:14 alright, excellent. I need one . Come on, this is
73:21 Alright, come on, come on , come on up, we're gonna
73:24 to rip his arms out of his . Do we think we can do
73:27 ? What do you think? Come on. Alright. Since you
73:31 up here first, you get to are you the thoracic wall or you
73:35 lung cheese lung? That means your wall now during development, what happens
73:40 the lung is way over here, growing next to the heart,
73:44 Do you see that? And the cage is growing way out over here
73:49 they're all connected to each other, ? So remember we have this parietal
73:54 next to the thoracic wall and it's to the lung or not to the
74:00 to right, so right. That just you get back over there,
74:06 can see where we're going now. with this, right? And then
74:08 have our visceral layer and it's pulling . Now look at this. It
74:18 weird now. Where do you want be Are you comfortable? Where do
74:21 want to be? You wanna be there? And where do you want
74:23 be? So get over there. look what's happening, what's happening to
74:28 pleura in between the visceral and parietal . They're trying to pull him
74:35 Now pull pull pull pull pull. can you stretch him any further than
74:40 is because you're not holding? Just pulling that we want to We want
74:46 see. All right. All you can 11 step forward.
74:54 Okay. Well, we're not going try to really rip his arm but
74:57 see he can't be stretched much but he is being stretched because he
75:00 to be like, what? Make comfortable, right? So, he
75:06 be stretched much further than they Is because she wants to be way
75:09 there and she wants to be way there. So, the lungs are
75:12 over here. He's being stretched as as you can now if I want
75:16 expand the lungs. I have no over here. Where's all my muscle
75:23 there? So, when the muscle look what it does, it pulls
75:28 the wall of the pleural sac which the pleura to move. But because
75:32 can't stretch the pleura any further, can't expand any further. It pulls
75:37 the lungs. Go ahead and look lung moves out of position. And
75:43 when the muscle relaxes, the lung back and this doesn't change. All
75:50 . What's happened is is that the , the negative pressure here is pulling
75:55 so that there can be no more . And so that forces the movement
76:00 and forth. And so when we about that plural pressure, the transmittal
76:06 , we're referring to the pressure across two points. Ok? Because this
76:11 change this moves, right? That's we're trying to go for. Thank
76:17 so much. Yeah. See it's lot more fun when we do it
76:20 way. All right. Hey guys what did I just do? All
76:24 . So, what we were talking here is the trans mural pressure and
76:29 trans pleural pressure. He was the , right? The fluid he was
76:37 out as far as he could Now when he stretched him, you
76:40 a slightly negative pressure inside that All right. But it can't be
76:47 anymore negative. In other words, you if you made it negative,
76:50 would actually start pulling backwards, Because it's like trying to separate
76:56 Um Think of a ziploc bag if pull out the If it's closed,
77:01 try to stretch it, it doesn't to stretch. Everything is already the
77:05 inside, there is already negative, can't get separated and that's what's going
77:10 here. And it ensures that the of the wall directly affect the size
77:17 the stretch of the lungs. that's what that whole trans pleural pressure
77:23 . It ensures that that happens and a lot of emphasis on it like
77:27 like this big deal. But really the big deal is saying is these
77:30 things are connected to each other and no give and there's no stretch in
77:34 them. That's what it's there Okay, I'm gonna end with this
77:46 and then you guys can get out here. All right now when we
77:51 , what we're doing is we're changing volume of the thoracic cage and the
77:57 . All right. So what that is when you breathe in in the
78:01 sense, what we're gonna see is gonna see the chest expand upward and
78:07 . Alright, so that causes increase volume in this direction laterally. The
78:12 thing, we're going to see the out this way. You can test
78:15 out for yourself by basically taking your and putting them on your chest.
78:19 , when I say put them on chest, that means don't do
78:22 Ladies in front of guys because we'll paying attention all right over here.
78:27 you breathe in and out, you'll , you'll feel your your chest expand
78:32 , you'll feel your chest expand upward last way it's going to be down
78:35 the anterior region as well, that diaphragm is being pushed downward. That
78:40 the floor or the space to fall . And so now what you've done
78:44 you've increased the volume in all three directions. And in doing so when
78:47 volume gets bigger, the pressure and when the pressure drops, air
78:54 in. And when I squeeze, thing, when the, when the
78:58 goes back down and the sides go in and the bottom goes back
79:02 the volume decreases so air moves When we come back, we're gonna
79:08 with this ventilation that we're gonna deal some other sticky problems that rise as
79:13 function of all
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