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00:02 There we go. I'm hoping that not bouncing around while I'm doing

00:08 So Okay, great. So here are, all 700 of us sitting

00:18 this classroom. It's just so Um, anyway, so what?

00:23 ? What? We're gonna continue on the cardiovascular system. Um, but

00:28 I do, just reminder we have do tomorrow. What's that? The

00:33 . Write your paper. Basically. make sure you get it in on

00:36 and then remember, next week you the peer reviews that you need to

00:42 . This will be, um you , you gotta make sure you do

00:45 five of them that you're assigned. you turn in your paper too

00:49 you're not able to participate. So becomes a zero. So you need

00:53 be able to that. Secondly, thing you guys did a calibration,

00:58 ? Was that the last one really ? Harder, wasn't it?

01:03 Now? Yes. No. You I wanna comment on that paper.

01:09 one wants to comment on the I just want somebody. Does I

01:12 him? You're there. It's a . Okay. Your mike is freaking

01:25 . Alright? I'll do this. we go. Thank you.

01:29 Basically, this paper was kind of middle of road paper. All

01:31 so it had some good points that bad points. You probably figured that

01:35 . Probably after the second attempt was , Okay, there's a little bit

01:39 nuance to it then this. This be a paper that would probably average

01:43 78 or so. You know, think this is what I graded it

01:47 . So if you found yourself always off the first time, maybe you

01:53 to temper yourself. Kind of think terms of All right, I'm not

01:57 to be nice. I'm not trying be mean. I'm just trying to

02:01 a proper assessment here, which is a really instructive thing to say.

02:06 the idea is that extremes are hard come by and most of this

02:10 I mean, it's real. Tell us something is garbage. It's

02:12 obvious when something is is really It's a little bit more difficult to

02:17 that middle of the road stuff. right? And so that's what's gonna

02:20 coming up. Um, I did an email from a student asking

02:24 um, sources and says the question , Is it okay if I use

02:29 source older than 2010? The answer yes. You can use a couple

02:32 sources older than 2010. You're not to 2010 and newer. But you

02:40 the majority of your sources becoming from stuff as opposed, opposed to older

02:44 . So you're not limiting yourself. idea is, I'm trying to move

02:49 what's new. All right, put in perspective. You're not going to

02:52 through your mom's closed toe where something , Because her stuff is from 1990

02:58 ? You're gonna pick out new stuff people are gonna laugh at you.

03:00 you were in your mom's clothes as dumb example, I don't know why

03:03 thought about that one. I was , maybe because listen to the spinners

03:08 , which really is from the And I'm just picturing my mom's

03:12 which is really old. All there's gonna be a lot harder

03:17 I can see you guys were not the mood to be here, are

03:21 ? You didn't want to come did you? And you online?

03:23 guys were all watching YouTube, aren't ? We're getting thumbs up now.

03:29 , they're not paying attention. All , so let's talk about the E

03:33 g. You know, TCG is seen it. You watch enough movies

03:37 TV shows about medicine. So you've what a BCG looks like,

03:42 It looks like this thing right This is a perfect BCG. By

03:45 way. Most CCGs are not this perfect when you're looking at, um

03:49 right. And so the example I to use about this is I want

03:54 to think about football. And given I'm looking here, I don't see

03:59 lot of football fans here. I'm you guys not big football fans.

04:03 . All right. You ever watch football game? You know, someone

04:07 you, made you sit down and it like maybe the Super Bowl.

04:10 . Have you ever noticed that the angles none. Okay. Everyone knows

04:19 angles. Not always the same. not always from the same side.

04:21 like they're sitting there looking at the and watching the game from one angle

04:25 the time, right? Why is ? Why can't you see different

04:29 What do they have at the stadium allows you to see different angles?

04:37 cameras is what I'm looking for We could do charades here.

04:42 That's an old camera. You just to crank it. Now you just

04:45 your phone up. Maybe I should that. All right. Camera.

04:51 . So how many cameras do they on a football field? Do you

04:55 ? Lots. That's a good That's what I'm looking for is lots

04:58 we don't know. But you notice they if there's, like, a

05:01 call, you know, they go the replay booth, right? And

05:05 you have the announcer sitting there you know? Oh, well,

05:07 can see from this angle and then this angle, but this angle is

05:10 , but this angle you can But this one you can't and they're

05:13 showing you like five or six different of the play, right? So

05:17 E C G is like the cameras a football game. That was a

05:23 way for me to get around to right. And really, what you're

05:26 is you're looking at the electrical activity the heart. So when you're talking

05:30 S E. G s, it's electrical activity of the heart. The

05:32 that those cardiac muscles are producing they have their own action potentials and

05:37 action potential spreading from cell to cell cell. And so you're looking at

05:41 of that activity at the same you're not just looking at a single

05:45 potential. Alright, so E G s do not record single action

05:49 . They record the refraction of the activity of the heart. As

05:54 you know, reflects throughout the I should say the reflection, not

05:58 refraction. All right, so when looking at this, we have to

06:02 that's what we're seeing. All Now the way that we're gonna we're

06:06 we're gonna see this in the next slides and you can kind of see

06:09 has this triangle looking thing in our cartoon. And what this represents is

06:14 the leads air actually located, all ? And so what you're not doing

06:18 you're not looking specifically at the hardened heart. What are you doing?

06:22 looking at the heart from different angles what you're doing is you're looking at

06:28 pulses from those angles, and then take a composite of all of these

06:32 angles, and it gives you this right here. All right. It

06:37 shows you what that comprehensive view of that electrical activity looks like from all

06:43 different angles. All right, so gives you a complete picture of what's

06:47 on. All right, so it's comparison, the vulture voltage detected by

06:52 of the different electrodes that air So what we call these electrodes refer

06:57 them as leads. And these leads connected in very specific locations. Good

07:01 . You don't need to know all locations, but this kind of shows

07:04 a picture of one where you can how it's like, Look up there

07:08 the top left corner. You can that I have a lead at each

07:12 . And so basically, I'm looking the heart between those two points and

07:17 electrical activity, and you could see each of these different leads give you

07:22 sorts of views in terms of what electrical activity looks like. All

07:26 so there's 12 leads and all. one of the wrist went the leg

07:30 then six across the chest. And can see this is the thing showing

07:33 with the chest how they're kind of up on there, right? So

07:37 , I'm not gonna ask you I'm gonna ask you what is V

07:39 ? Looks like what is V six like, you know, that's that's

07:42 important. For if you ever taken BCG class, then you'll have to

07:46 all that stuff. All right? not even gonna ask you what a

07:50 one looks like, What or what bad E. C G looks

07:54 All I want to understand right now that this represents the total electrical activity

07:59 the heart. And if you look this, each of these little parts

08:03 the E C G represents something as of the cardiovascular events that are

08:09 All right, so we're asking the we talked about yesterday or Tuesday.

08:14 said, Okay, the heart goes these periods of contraction and relaxation.

08:18 have two Atria. We have two . The eight year contract Together,

08:21 ventricles contract together. There's a pulse begins in the a V or

08:25 The essay No travels to the A , no doubt travels down the bundle

08:28 his up through the parking G fiber to all the contract ourselves to create

08:33 , this Siris of contractions, from atria to the ventricles to move blood

08:37 the body. So if that's all , how or what does this look

08:43 ? What does this is? How this represented electrically, All right.

08:46 that's what the BCG does. It says, Look, if I look

08:49 this, I can see I have wave forms you can see there's the

08:52 wave, the QRS wave, the wave. Then there's this period of

08:55 in the P wave. The Q s t t and just repeats over

08:59 over and over again. And if watch enough, uh, hospital TV

09:03 or hospital movies, you've seen a where someone's lying on the bed.

09:07 doctor is looking very concerned, and machine in the bad going beep people

09:12 . And that's what you're looking at E. C G. All

09:17 so what do these way forms Well, the PIF wave represents the

09:23 polarization of the muscles of the So when they begin to be polarized

09:28 that they can create a contraction, what you're watching. Is that electrical

09:31 spread over all that muscle? All , The QRS represents ventricular deep

09:38 So that's the spread of the pulse the ventricular portion of the heart.

09:44 then the T wave represents that ventricle polarizing and returning back to rest.

09:50 are we missing? Re polarization? huh. Okay. Well,

10:03 Does the atrial re polarized? What you think? Should it re

10:07 Have a deep polarizes. Should have polarized. Yeah. Yeah. So

10:11 right. So that that should be Okay, Yeah, that kind of

10:14 sense. If it's contracting at some , it has to relax. So

10:18 is it? All right, I'll tell you where it is.

10:21 up there. You just can't see . I have three Children. I

10:25 four kids. I have three All three boys look exactly like

10:29 All right. They're just small versions Dr Wayne's. Put them in a

10:32 like this and jeans right here. think I shrunk down. I got

10:35 bunch of mini Mees. All Well, the 13 year old is

10:39 to look more my size. you know, you get the just

10:44 If I brought my youngest son in , he's a little bit shy and

10:48 put him in front of this There's only eight of you, but

10:50 still freak out there. There's six you, plus ta, right?

10:55 when you could imagine this whole room , he'd be like, you

10:59 and he would zip behind me and behind me, right? And then

11:02 try to move. And what would did Move with me. If I

11:05 to turn, he'd hide behind You'd never be able to see

11:08 You might see him peek out every and then. But if I really

11:11 of like, tried to go real , you just stay right over

11:13 Just wouldn't move. Well, guess ? That's where the the atrial re

11:19 is. It's hiding behind the R s. All right, It's

11:24 there because the atrial muscle is so relative to the ventricular muscle, you

11:31 get to see its activity. The atrial muscle. Remember what I

11:36 ? is not so much about propelling through the body, so there's muscle

11:41 . But it's not really strong All it has to do is squeeze

11:44 to get the blood from the atria the ventricle. It's not even all

11:46 blood that enters into the atria that that. We're going to see more

11:49 that today, right? Instead, we have is we have this really

11:54 muscle, the ventricle, which is for squeezing the blood out of the

11:58 and into either the systemic circulation or the pulmonary circulation. It's a

12:03 strong muscle, which is what gives this very big wave. And in

12:07 , if you think about it, what we said. We said the

12:09 of hiss went down the middle of septum and then spread upward and outward

12:14 the ventricular muscles and look at what wave does. It goes down then

12:18 , then down again. And what represents is that movement of that wave

12:22 electrical impulses traveling down and back and . And that's why you're seeing going

12:27 and down all right? It's a of actual direction. All right,

12:35 , you don't see the s a firing. You see a point where

12:38 firing up there? I mean, labeled it, but do you see

12:41 actual blip or anything on there? . So the s a node is

12:45 series of action potential. They're very small and undetectable relative toe all

12:49 muscle that's there. Now, you also see that there's these periods of

12:54 where there is no current taking All right, we have names when

12:58 call the PR segment. Right? have the S T segment, and

13:02 we have the teepee interval. Sounds something that you do in the

13:09 That was funny. You're supposed to my wife. I do jokes like

13:13 . That's so soft. Mark, like, yeah, you married

13:16 E was like that. Come 20 p interval. I mean,

13:21 funny, isn't it? Yes. getting to get. See? Now

13:25 starting to do it. Okay? can laugh at stuff like that when

13:29 have kids. Then you can put the stoic face and pretend like nothing's

13:32 . But now it's OK. What? Each of these represents is

13:37 period of time where that electrical activity happening, right? So if I

13:42 eight year old deep polarization, that's that wave of activity that's causing the

13:47 to contract. And then during that before you muscle relaxes, then you're

13:54 having electrical activity, right? So polarization represents the period of contraction.

13:59 polarization represents a period of relaxation. in between, what do you you're

14:03 a state of? You're in a of contraction. There is no

14:07 right? And then between the eight contracting in the ventricle contracting, you

14:11 this period of rest, and then you have in the ventricles. You

14:16 a period of contraction. The Q s. You have the teepee,

14:19 is a period of relaxation. But those two things, you're in a

14:23 of contraction, so there's no So it's a period of electrical

14:28 and that's what those represent. The represents the rest between the period of

14:33 , when the ventricles contract and then . There's TP is relax ation,

14:40 then the P wave, remember, the period of atrial contraction in the

14:45 step. So that's a long period diacetyl that's taking place, but in

14:51 teepee period. All right, I mentioned this on, um,

15:02 about the valves. Alright, I'm reiterating it. I guess I had

15:06 in the wrong order something, or is how I used to teach

15:09 I don't know, but this is I put here. Remember, those

15:12 in the heart are one way Alright. All their opening and closing

15:17 is they are not dependent upon electrical . They're dependent upon pressure. Grady

15:23 right. So when the valves it's because the pressure on the backside

15:28 the valve becomes greater than the pressure the front side of the valve.

15:32 right. And then when the valve , it's a function of the pressure

15:36 the front side of the valve being than the pressure on the back side

15:39 the graph valve. It's not because heart decided all of a sudden time

15:43 open the gate and let the blood its solely a function of pressure.

15:48 we need to be kind of aware those pressures. Alright. Thes states

15:53 the vows being an open and closed us to see the different phases of

15:58 it's called the cardiac cycle and with majority of today's lectures on is gonna

16:03 on this cardiac cycle. I'm gonna you a graph in a couple of

16:10 , and you're all going to freak because it's a graph. All

16:13 But if you understand this graph that going to show you, you're gonna

16:20 everything you need to know about the and the truth. ISS is the

16:24 isn't that hard. Don't tell All right, let the people freak

16:31 . Who don't like graphs. The of us could go. This is

16:35 . Oh, I'm freaking out, . Okay, that's cool. All

16:41 , So what is the cardiac Simply put, the cardiac cycle is

16:46 period of sisterly versus diastolic. All , And so this is kind of

16:50 big picture right here. Forward sisterly Sicily means contraction and emptying. It's

16:55 period of time when that spread of is occurring and the muscle begins to

16:59 to propel the blood forward. What diastolic? Diastolic simply means relax

17:04 So at this point, this is muscle relaxing because the muscles relaxing that

17:08 for the flow of blood into that . And it's a period of re

17:15 . Alright? And so your heart gonna alternate between these two states and

17:19 already know this, right? You the thump? Thump, thump,

17:21 . What are you doing? You're and relaxing. Thump, thump,

17:24 , relax, Squeeze, relax, , Relax. That's what your heart

17:27 all day long from now until the you die. And that's a true

17:32 in it. When you die, heart's not gonna be doing that.

17:39 huh. All right, now, we think Assistant Lee in Diastolic,

17:44 typically think of the ventricles. because the ventricles are doing all the

17:48 of pumping the blood out into But the atria have the same cycles

17:55 sisterly and die asleep. But when talk about sisterly, that's if you

17:59 me say okay insistently, you should think ventricular sisterly. If you hear

18:04 say diocese, you immediately think ventricular . When I prefix it with

18:09 Then you know I'm specifically talking about , sisterly or atrial joyously. There's

18:15 that's just the way the nomenclature All right, But you can see

18:19 our little circle out here and the circle. We have ventricular system.

18:23 showing you a ventricular cycle and on inner circle, showing you the atrial

18:28 . All right. And you can do the two things line up with

18:31 other. Are sisterly atrial system in atrial or ventricular system where they align

18:36 or no, you can look at picture and tell me, Are they

18:41 up? No. You got atrial , occurring before ventricular Sicily. And

18:47 did I tell you yesterday, Or on Tuesday? What I say

18:51 atria have to contract. First, blood is pushed into the ventricles.

18:55 the ventricles push second. So there an order They're not lined up

18:59 Don't work together. The 28 year together, the tooth ventricles work

19:04 But the atria always precedes the ventricle terms of its contraction. All

19:10 now, depending on which textbook you to, they'll have a new inordinate

19:17 of phases for these this cycle. right. I think the freshman textbook

19:23 we used to use had, seven stages. I've seen books that

19:27 nine stages. Some have five but ultimately it boils down to four

19:33 stages. And that's what this represents the four phases. Right? So

19:38 way you can think about is we an inflow phase and we have an

19:41 phase. That's really easy, Blood comes into the heart, blood

19:44 out of heart. That's pretty right? So real simple. In

19:50 inflow phase, that means you're inlet . The valve that is on the

19:54 on the front or on the back opens up and allows blood to flow

19:58 it into that chamber, the outflow into the venture. Cole has to

20:03 closed. Otherwise the blood would just going. But there's not enough force

20:07 be able to push it forward. that valve remains closed. We're going

20:10 see how this all works in just moment. Right? So in the

20:13 phase, we have the in valve the out valve closed. All

20:18 We're looking at the ventricle here. he ate your heaven in valve?

20:23 does not. Right. There is valve on the end. On the

20:27 side, it's just an out as far as it's concerned. All

20:31 , so in the outflow phase notice skipping here. I just want you

20:34 see this. So in the outflow , the inlet valve has to be

20:38 because there was not closed and blood flow backwards into the atria.

20:43 So the only value that's gonna be is the out valve. This allows

20:46 blood to go into circulation, So in flow allows blood to go

20:51 the ventricle. Outflow allows blood to the ventricle. Between these two

20:57 we have thes isil volumetric phases. is called a contraction. Phase one

21:03 called a relaxing phase. What do think is occurring during the contraction

21:08 What's happening to the muscles? The are contracting. And in the relaxation

21:13 , What's happening? See how this really, really complex and scary?

21:18 , it's relaxing, the muscles All right, but the key word

21:22 is isil. Volumetric. All which is why I pointed out first

21:26 a volumetric contraction phase is a volumetric ation phase. During the isil volumetric

21:32 phase, the muscles of the ventricles contracting, and there's fluid surrounding

21:39 All right, since I'm not allowed touch your stuff right now because

21:43 cove in and everyone's scared of I need you. Since I don't

21:48 anyone's name, I need you to your bottle, and I want you

21:52 squeeze it is hard you can to the fluid pop out. Go.

21:57 can't do it right now. The you can't do that is because you're

22:01 with the metal bottle. All I want you to do the

22:03 The same thing with yours. All ? Can you squeeze right?

22:08 the fluid wants to come out, it? Do you think you can

22:10 a force strong enough to make that come out? You could write.

22:14 the part that would give to allow fluid to escape the top?

22:19 so your top is acting as a in this case. And so what's

22:23 here is during the contraction phase, muscle is squeezing on that chamber just

22:29 you both squeeze on your bottles, ? The differences, her body a

22:32 bit weaker. It's basically being held the plastic years. Metal,

22:36 But you can imagine on this week bottle she can squeeze, and that's

22:40 push on. The fluid is creating inward pressure on the fluid is trying

22:44 drive. The pressure is trying to the fluid outward right, but it's

22:49 gonna leave until you create a strong pressure to overcome the pressure that's keeping

22:55 fluid in all right, and so this case, it happens to be

22:59 bottle cap. But on your the pressure that's keeping the fluid in

23:04 ventricle is the pressure, either in aorta that would be on the left

23:09 or the pressure in the pulmonary arteries would be on the right side.

23:14 if you can create strong enough pressure overcome that outward pressure that that back

23:21 , then that Zatz that period of where you're contracting. So in the

23:26 phase, blood flows into the ventricles the volumetric contraction phase of ventricle,

23:33 start contracting and creating greater and greater greater tension. In the outflow

23:39 the tension overcomes the back pressure so blood flows out. And then,

23:45 the muscles stopped contracting, they That valve slam shut, the change

23:52 volume or basically the muscle, There's no change in volume, so

23:57 what's occurring when you see is a . No change in volumes during that

24:01 . There's no change in the Just like when you squeezed on that

24:04 . There's no change in the volume the bottle was there. That makes

24:10 . Where have I lost you There is no change of when you

24:19 a change in volume. Look up . When do you think that volume

24:22 be changing? We'll squeeze it. . But just like what she

24:27 she squeezed on her bottle. Did change the volume inside the chamber?

24:33 . When she squeezed on her did she change the volume inside her

24:38 ? No, but it's trying to its attempting to, but there's not

24:43 strength being produced. Excuse me. enough attention being produced yet to allow

24:49 to happen. Once she produces either produced enough tension. Then what

24:55 Valve opens. Fluid flows out. changes. Yes. All right.

25:03 the question is, is there liquid not? Is there liquid there is

25:07 . Alright, so I'm gonna go the chart here and try to try

25:11 draw a little bit. We're gonna back to all this in greater detail

25:14 just smoke, but let me just of show you here. All

25:17 So we have our pan. Here's INC right there. That's your

25:23 Okay, so in your aorta, full of blood. Where does that

25:28 want to go? What? Where all liquid wanna go down? Where

25:33 the least amount of pressure. This is trying to flow back into your

25:40 ventricle. It's also trying to leave , And there's different ways that it

25:44 leave. There's different ways or different through which that blood could go.

25:49 just trying to find a way to out. All right, But that

25:54 resulting coincide that valve, which is there is closed. It won't let

26:00 out. But because you have pressure on that valve, you need to

26:06 enough pressure that causes that valve to in the direction you wanted to

26:10 Because remember what we said. Back slides. These valves are one way

26:20 . All right, so these are four phases. Now, if you

26:30 to, you can drop that same and you can put in there.

26:35 your cardiac cycle, right? And , we're just looking at the

26:38 We're ignoring the atria right now. ? So look what's happening in Diastolic

26:45 the ventricle is relaxed, What do have? All right, I'm gonna

26:49 up here at the start, in middle of die asleep. We have

26:52 flowing in and even further in to ventricle because the ventricles relaxed. We

27:01 this valve open. So blood flows the ventricle, all right, And

27:09 isil volumetric. And that's what it's . You see, it's like the

27:11 going in. No, look, keeps going in. That's what that

27:14 arrow is showing you. And then say, All right, now the

27:17 begins to contract. That's at What happens? That valve slam

27:24 Right valve, slam shut. Fluid leave backwards. It can't leave

27:31 so the volume stays the same. tension is building up. When the

27:37 becomes great enough, Then we become enter into the outflow phase. Those

27:41 still insistently right now, the blood depending on which side of the heart

27:46 looking out through the order through the arteries. And then volume is leaving

27:52 ventricles. Squeeze on that chamber. volume of the chamber gets smaller,

27:56 then the muscle relaxes, which causes valve to slam shut again.

28:04 So there's this period of time where volume inside their stays the same.

28:10 then the fluid builds up in the . And then when that pressure inside

28:14 atria becomes large enough, boom ! opens up that valve. And now

28:18 back to the inflow phase. That of makes sense. Are you

28:27 Be ready for the big the big big picture. Yes. Here we

28:38 . This bad boy right here, even blanking on the names right

28:40 It's like the Higgs I can't And you look at this thing and

28:46 gets a little scary, all And I want you to first,

28:50 know, just kind of take it for a second, and then

28:51 Okay? This really isn't as scary I think it is. And the

28:55 it's not so scary because you already this right there. That's your E

28:59 G. This right here is your cycle. We just saw that you

29:03 even see that we've labeled down there different stages of the cycle. All

29:10 . And then the rest of it's of simple. It's like, All

29:12 , well, we're gonna look at pressures inside the different chambers. All

29:18 ? We're gonna look at volume inside ventricle, and then this little part

29:22 here in the middle is the heart all right. So that's what that

29:28 chart is. And it's basically over . So this is time in that

29:34 . All right? Now, the step that we're looking at when we

29:37 at this cardiac cycle through this graph called DIA Stasis. Now, in

29:42 of these pictures, I'm gonna show . I'm gonna ask you to look

29:45 the valves, look at the flow the fluid look at the pressure and

29:50 the pressure is, and I'm gonna atyou in terms of the ventricular

29:55 All right, So here's our Where are we when we're talking about

30:02 Stasis? We're right here at the of the chart. But remember,

30:05 chart repeats itself, so it's also . Okay, so we're basically kind

30:10 in the there were looking at it this point, but this would be

30:14 next cycle. So dia Stasis is first stage. So if we look

30:19 the valves where in mid ventricular so mid ventricular diastolic, it means

30:24 ventricles are in their relaxed state, ? And so blood is flowing into

30:30 ventricles, and that's what's showing you here. The reason blood can flow

30:35 the intervals because the A V valve to be open, right? This

30:39 that inflow state. The semi lunar has to be closed. The reason

30:44 closed is because the pressure in the is greater than the pressure inside the

30:50 . All right, now we can that if we look over here,

30:53 aortic pressure. The red line down represents the ventricular pressure. The blue

30:59 right there represents the atrial pressure. notice the eight year pressure is higher

31:06 the ventricular pressure. So the reason flows from the atria to the ventricles

31:11 because fluid flows down at pressure grading high pressure. The low pressure,

31:17 the pressure and the atria was less the ventricle than blood, would want

31:21 flow the opposite direction. So the that you have greater pressure in the

31:26 is allowing the fluid to flow in direction. Now, why is there

31:31 pressure in the atria? No one to ask me that question. You're

31:35 fading on me. I can see in your eyes. Like pressure,

31:39 pressure sleep. Oh, yeah. reason is because remember, you just

31:46 blood out of the heart, pushed the blood. Remember you all

31:48 You don't know this shit. You about five liters of blood in your

31:51 , guys. About about 5.5 Females, You're about 4.5 liters

31:55 That's basically based on an average average average Every blah, blah,

31:59 blah. All right, But if push blood from my heart, I'm

32:02 a volume of blood out of my which pushes the volume in front of

32:05 forward which pushes the volume in front it. It forward? Yeah,

32:08 , all the way back around to heart. So what you've done

32:10 you basically pushed the bullets of blood to the lowest point, which happens

32:15 be your atria. So the pressure your atria went up the moment your

32:19 pumped, okay? And so that's you're seeing this flow into the

32:25 All right. Atria has higher pressure into the ventricles. It's a very

32:30 flow. You can see here. at the look at the slope.

32:34 not very steep, is it? . All right. Now the pressure

32:42 the ventricles is going up. if I put stuff into the

32:48 Increasing volume right? Not the space , but the amount of stuff

32:53 If I increase the amount of stuff , what happens to the pressure?

32:57 goes up. You want to visualize ? Go back to the example I

33:00 at the beginning of semester of a , right? I said, Here's

33:03 smart car. Put two people in car. There's not a lot of

33:07 in there, right, But there's pressure than there was when there was

33:10 . Put a third person in their . That space is still limited.

33:15 more pressure trying to get out, mawr even more. As you added

33:19 and more people, that's the same of things going on here. More

33:22 , I add in, the greater pressure inside the chamber. So you

33:26 the slow rise in terms of the . But the pressure inside the vein

33:32 driving the fluid into the atrium is than that in the a tramp.

33:36 pressure inside the atrium is greater than of the ventricle. And so what's

33:40 to the volume while it slowly rising the fluid moves from the atria to

33:44 ventricle? This is our first All right. Now I know this

33:49 very kindergarten is when I'm walking step step. But when we start putting

33:52 of the stages together, you can what's going on. Because what's gonna

33:57 now is because of the essay. , we're gonna have the S a

34:01 fire, and that's going to create contraction of the atria. Alright,

34:07 this is late ventricular diastolic, and leading into atrial sisterly. Alright,

34:14 here again is where we are. can see there is the P wave

34:18 that deep polarization. When that what happens to the pressure when I

34:23 on the atrial? What happens to pressure inside? It increases. So

34:27 a slight rise in the pressure and pressure inside the atrium goes up.

34:31 it greater than the pressure inside the chart? says yes. And it

34:35 because the ventricle is still in So what we do is we see

34:40 blip, and you can see right . Look at how it rises

34:44 Right? And because I'm squeezing whatever happens to be inside the atria,

34:49 now squeezing it out, as opposed allowing it to trickle through. I

34:53 this slight bump of volume inside the that also is represented in an increase

35:01 pressure inside the ventricles. Well, right. And you can see that

35:07 right there. Now the A V is still open, all right,

35:13 the pressure is greater. Yes, semi lunar valve still close because the

35:19 inside the aorta is significantly greater than pressure is down there inside the

35:24 the ventricle. All right. the flow of blood is very,

35:29 quick at this point. All Think about you. Have a

35:33 You know, you dunk in the and you pull out, pull it

35:36 . Water drips out of the right? What happens when you squeeze

35:40 ? Water come out faster? it's the same principle. Okay,

35:44 what you're doing is you're squeeze getting the fluid forward. That's why it's

35:49 now the volume of blood. At point, I'm gonna race income.

35:52 slide right here reaches the maximum that's enter into the ventricle. We have

35:58 name for it. Alright. It's the in diastolic volume E T.

36:03 . So it's at the end of because the diocese referring to here is

36:07 diastolic, so e TVs in diastolic , It is the maximum volume that

36:12 gonna be found in the ventricle. we've had the atria contract. That

36:19 moves from the s. A note the A V node Thievy note now

36:23 its signal down the bundle of hiss the per Kinji fibers. Right?

36:27 so we're now entering into ventricular This is that Q r s

36:33 The signal goes down and then back and around so down the bundle of

36:37 around the back injury fibers. So why we get this really cool wave

36:41 it goes down, up, like that, Right? And so

36:46 you've got the muscle contracting. All , But when the muscle contracts,

36:51 gonna reach resistance. You're gonna or resistance, right? because there's fluid

36:55 that chamber. The chamber doesn't want collapse like a balloon. It wants

36:59 resist because there's a volume of fluid it, All right. And so

37:04 happens is the muscle begins contracting and starts building up tension. All

37:10 Just like when you are squeezing on bottle. When you squeezed on your

37:14 , you built up tension. You keep building up more and more and

37:16 attention. And that's what's happening is . Now see that tension increasing.

37:23 that red line now? Obviously the the ventricle overcomes the pressure, the

37:30 and the ventral overcomes the pressure in atria. So what happens is is

37:35 A V valve slam shut blood? don't want blood to go back to

37:39 Atria. You wanna keep it in ventricle, right? Because you want

37:42 project it out of the ventricle into arteries, right to systemic circulation.

37:46 the A V valve slams shut as result. Now you're gonna have massive

37:53 buildup. So you're going to squeeze squeeze and squeeze and squeeze and

37:58 You're gonna keep squeezing upward. But the semi lunar valve has it.

38:03 haven't overcome the pressure of the The semi lunar valve never opens or

38:09 open. At this point, I say never shouldn't say never.

38:13 the volume doesn't change. So this why it's an ISO volumetric contraction and

38:18 the pressure is building up once the reaches its apex. In other

38:25 the pressure in the ventricle overcomes the in the aorta. That's gonna be

38:32 that semi lunar valve opens right When pressure is greater inside the ventricle than

38:37 is in the aorta, blood is wanna move out, and so it

38:40 move very, very quickly out. so that's what you're seeing is that

38:44 as it drops out? Alright, valve still closed because you want to

38:50 the fluid in a specific direction and what happens once that valve opens,

38:57 ? You have the valve opening It's actually that sound is a result

39:01 this valve slamming shut the bump. the A V valve slamming shut

39:06 And then over here this will be semi lunar valve slamming shut in the

39:11 . Those air the sounds all but in essence, what you have

39:14 is Look, the valve opens the pressure still rises inside the

39:19 Why I've overcome my resistance now can squeezing to the point where the muscle

39:24 to its full contracted state. I'm all those blood out into the aorta

39:29 , if I'm on the right side the heart into the pulmonary artery.

39:32 now that artery, which is expands outward and fills up like a

39:37 . And so what's happening is you're more and more volume that can't leave

39:41 it's like a balloon. You're increasing pressure inside the aorta as well.

39:45 notice if you look very closely that black man sits underneath the little red

39:50 , doesn't it? So the pressure the ventricle is slightly above the pressure

39:55 the order. That's why blood continues flow out, and that is ventricular

40:01 . And it continues on right until muscle decides to relax, because then

40:08 you're in ventricular diastolic. So in ventricular sisterly, you still see a

40:14 contracting. The pressures are starting to a little bit because fluid is leaving

40:19 , but you're reaching the point where squeezed everything I can out of the

40:25 . So there is. Whatever is over is what is called the in

40:30 volume. Now we're going to see the slide a little bit later that

40:34 maximum volume you can have inside the about 120 mils. Alright, You

40:40 about 70 mils of that blood. mil stays inside the heart.

40:47 So for each cycle, you're not all the blood out. It's not

40:51 completely. So the in systolic volume tells you the amount of blood that's

40:57 over after a contraction. All And so what you're seeing here,

41:02 drop in pressure is a function of leaving out of the aorta. So

41:07 pressure is dropping and you don't and the muscle begins to start relaxing

41:11 ventricles as well. All right, here again, we are in ventricular

41:16 . A V valve is closed. valve is open. Blood is moving

41:21 until it reaches that low point of S V. All right and again

41:29 and it slows down. You could rapid and slows down there as

41:36 So let's kind of look, that's next slide. There it is.

41:38 , there's those numbers I just talked . Okay, so we start off

41:44 blood into the ventricle. That's the diastolic volume. That's the maximum volume

41:48 ventricle is gonna hold. We contract push the blood out. What's ever

41:53 behind is called the in systolic If you take the in diastolic volume

41:58 subtract from it the in systolic volume tells you how much blood you ejected

42:03 the heart and the word we use that is called the stroke volume.

42:07 ? So stroke volume equals E T minus E s v. And

42:12 where do we see the SV Remember, we had cardiac output equals

42:16 heart rate, times the stroke All right. Now, the ejection

42:26 should be about, um um a bit over 55%. It shows you

42:31 a healthy individual. You can calculate out. You basically take the stroke

42:34 divided by the total volume. The . T. V. And that

42:38 tell you your ejection fraction. So healthy person is ejected at least 55%

42:44 the blood out of their heart with stroke. Yeah, so far you

42:49 with me First stage was late. asleep. Dia Stasis was what we

42:55 to it. Then we had the , a volumetric contraction. Then we

42:58 a ventricular sisterly. We had a stages in there that just to distinguish

43:03 it's not always just one big And then lastly, we come back

43:07 to the isil volumetric relaxation phase. what we have going on here?

43:11 where that ventricular muscle is relaxing as relaxes the pressure inside that chamber

43:18 which is what we're seeing right Right As it comes down, it's

43:22 . The pressure inside the area is coming down. Why? Because we

43:26 the blood is leaving through the other , right? But at a certain

43:31 during that period of relaxation, the inside the aorta doesn't drop us fast

43:37 . The pressure inside the ventricle of ventricular pressure is dropping the fastest.

43:42 so eventually what will happen is the . The semi lunar valve will slam

43:47 because the blood in the order Oh, look, there's a path

43:50 least resistance backwards, and it tries go back, and that's going to

43:53 the semi lunar valve to close. right, So when the arterial pressure

43:59 greater than the ventricular pressure, that's the simulator valve closes, and then

44:05 muscle continues to relax, Right? there's your pressure dropping, and then

44:13 , in the next phase, it's drop to the point where the pressure

44:16 lower. Now, I just ejected out of the heart. That blood

44:21 on the blood in front of which pushes on the blood in front

44:23 it all the way back around to heart. So what's gonna happen to

44:26 blood on the atrial side? It's to move into the atrium,

44:30 Yeah. And then what's gonna happen the pressure As that blood flows into

44:34 atrium, it goes up right. you're starting to build up pressure inside

44:39 H here and you can see right . That's what's going on. That

44:43 is rising, so the pressure in atrium is beginning to climb. The

44:49 in the ventricle is beginning to At some point, they're gonna have

44:52 cross, all right. And when cross, that's when you're gonna open

44:55 that valve again. So we had question online. What was that?

45:01 exercise? Do you? No, gonna change. And we're gonna talk

45:10 that a little bit later. So question was, does the does the

45:14 volume stay the same? Is that essence, what you're asking? You

45:17 , the stroke volume stay the same I'm exercising or if I'm resting or

45:21 , that stuff is going to be . But because the heart is trying

45:26 maintain or the body's trying to maintain constant cardiac output, modifications and stroke

45:31 are also going to result in modifications heart rate. Alright. And what

45:35 gonna see the very last slide in lecture deals with different ways that the

45:40 manages stroke volume, um, in to different activities. So it's a

45:47 question to ask, right? you know, I mean, you

45:50 know this, right? I you go and exercise, your heart

45:53 goes up right, because you increase need. But what is your What

45:56 your heart feel like when you just sprinted really hard? It's like pounding

46:02 of your chest, right? So it's doing is it's actually increasing stroke

46:07 to get Mawr fluid out per even though, in order to meet

46:12 needs of the body also has to the heart rate as well. So

46:16 two factors air increasing. And so allows for even greater cardiac output than

46:21 would normally think. If I'm only one or the other or both of

46:25 are being adjusted. Have I answered question? Okay. All right.

46:31 the last phase is we're kind of back to where we started. This

46:35 where we're gonna start refilling the So this is a little bit before

46:39 DIA Stasis, right? So we the the pressure inside the atria was

46:47 . We said the pressure inside the was dropping and they basically cross over

46:52 other. When that happens, when pressure inside the atria becomes greater than

46:56 inside the ventricle that causes the valves open up the A V valve.

47:02 the AP valve open ups blood, has been building up inside the

47:06 You're basically opening up, you basically spill directly into the ventricle.

47:11 because the pressure inside the venture inside atria remains higher than the ventricle.

47:15 valve remains open, so we initially off with a fast flow. But

47:21 it kind of slows down. Kind like if you take a cup or

47:25 and you spill it the majority, fluid comes out at the front

47:29 and then the rest of it kind trickles out. That's kind of what's

47:32 on here is it's trickling in, so the rate of flow into the

47:37 slows down over time. But as as you have the ventricle in its

47:43 state and the atria is in, pressure inside, the tree is

47:47 That's gonna allow the flow. So , blood is basically going from the

47:51 into the atria, just kind of as it goes through and enters directly

47:55 the ventricles, so notice it's The flow of blood in the ventricle

47:59 not dependent upon the atria of It's just dependent upon the pressure,

48:04 the fluid from the circulation through the directly into the ventricle. Does that

48:11 sense a little bit now, why is a new, interesting strategy.

48:18 this works is because this allows us change our heart rate all right,

48:25 really kind of mucking up how much our heart gets. So, I

48:29 , we got these periods of Alright, so right now you guys

48:33 sitting around your slowly falling asleep to nice sound of my sweet voice.

48:38 should talk a little bit deeper and little bit more soothing so that you

48:43 feel a little bit better while we sitting here. You might want to

48:46 out your lights, guys at All right, So what happening is

48:50 heart rate slows down, right? like thumb, thumb, some thumb

48:55 , thump, thump, thump. . So the diastolic period is pretty

49:02 , but you can increase your diastolic , right? We bring shafts in

49:07 room and say everything has to go . You know, all of a

49:10 your heart rate is gonna go up quick. It's gonna thump.

49:12 thump, thump, thump, thump, thump, thump.

49:14 You just shorten your diastolic time, ? You didn't change your systolic

49:19 You change your diastolic time. Now is a slight change systolic, but

49:23 not gonna worry about that right All right, but because ventricular filling

49:29 based on that type of physics, ? Most of my feeling of the

49:34 occurs on that front end, Because it's building up inside the A

49:40 . You open up the valve. of that blood jumps in, you

49:42 , just spills over into the And so the rest of that

49:47 right? So if you if you about it, look at this point

49:51 here, all right? This is line we're looking at. How much

49:55 in my feeling during that trickle time I just kind of outlined there Very

50:01 , right? I mean, if is 100% Phil, there's your

50:06 Going from here to here is, , what, 5%? Maybe 10%

50:10 the blood is kind of trickling right? And then the remaining portion

50:17 squeezing in when the atria contract. what that blip is, right?

50:24 blip right here, that's when the contract I get that blip of I'm

50:28 you out. So very little is during those latter stages of the passive

50:36 . All right, so when I my heart rate and reduce my diastolic

50:41 really, all I'm missing out on this little bit flowing in on its

50:47 passive nature? Instead of waiting for , Thio slowly trickle in. I'm

50:54 it in. I'm using the atrial to contract to push it in so

50:58 don't lose the volume. I just the time and I don't need the

51:02 . The time is is a just period that allows for rest occur That

51:11 me to make adjustments to my heart . Okay, So fill volume is

51:19 affected because of the natural physics that of blood. Kind of accumulating in

51:24 atria during that systolic period, the systolic period. And then when you

51:30 into ventricular, die asleep, you the most of the fluid in,

51:34 the rest kind of just trickles in the last little bit of a squeeze

51:38 . Okay. So far, how doing? Are you okay? That

51:47 people too sweet. Sleep. All . Heart sounds, heart sounds represent

52:02 sounds of the valves. Clothing. right. The way I like to

52:07 this to people just so you can it, uh, your your heart

52:10 a room, you know, write rooms and your blood is an angry

52:19 , right? Do you remember being angry teachers you can't tell me or

52:23 teenage? You can't tell me what do. Slam. That's what's

52:28 Slam slam. It's just those doors . All right, So the first

52:36 y'all, if you've all heard the , right, if you haven't go

52:39 somebody on the street randomly say, still and then just put your head

52:43 their heart, they won't mind. won't think you're crazy, right?

52:49 you're here. It's loved up. up, loved up. Looked up

52:53 sound. That bump bump is slam . All right, slamming the A

52:58 valve closed ventricular contraction, right. the blood out blood wants to come

53:05 in slam again, assuming lunar valve or aortic valve. If you're looking

53:10 the left side of the heart, all this. Now some of you

53:14 lucky and have extra hearts or not hearts. That would be really

53:19 You know, you have extra heart and they're galloping rhythms. Um,

53:24 worry about them so much. I asked questions about thes. It's these

53:27 . If I'm gonna ask you gonna be What are those two?

53:29 are those two sounds? Mhm. we listen to the heart sounds.

53:37 you went to the doctor at the of the year before you started school

53:40 everyone is supposed to. All Get yourself checked out. Make sure

53:44 don't carry any sort of strange viruses anything on a campus. I don't

53:52 . What do you do? Do listen to your heart? What do

53:57 say? Breathe. Breathe. Hold your breath. Right. What

54:00 you doing there? Just listen to your heart's doing right, And they

54:03 that primarily. Just kind of determine or not your hearts in good

54:08 All right. Now, obviously, my heart pushes all that blood

54:15 it creates a pressure wave in the . And because of the way the

54:19 work directly outside the heart, their . We're gonna learn more about this

54:22 a coming lecture. When we talk the vein, what happens? Our

54:26 and the veins. What's gonna happen that the aorta expands. And so

54:30 creates this pressure, Bullis. And uses that pressure boats to drive

54:34 And so you actually can look at pressure inside the aorta, and it

54:38 like it has a systolic and diastolic , Right? It's not as large

54:44 the, uh, the, uh . Remember, we saw that on

54:49 previous lecture where literally was like, . Zero. Here's 1 20.

54:53 was going up and down like so that would be the ventricle.

54:57 ? But in the aorta, it's going between those two points at

55:00 20 and 80 right? Because there's blood inside the aorta, right?

55:06 then that pressure is really pulse a for a long period of time,

55:11 . So have you ever tried to your heart rate by putting your fingers

55:16 your wrist or on your neck? maybe over here? Have you felt

55:21 who have tried that? Alright, you have it, well, you

55:25 go home and do it now. do you do it now? I

55:27 care. Yeah? Can I have find it right? You know,

55:32 is the hard one, right? you can feel it, you

55:34 Yeah, I can feel the thump , thump thump. Right. That's

55:39 the pressure that Z being pushed through arteries by that Boulis of blood through

55:47 body. But as you move further further away from the heart and you

55:51 encountering the smaller and smaller arteries, not quite as elastic they have.

55:58 basically produced resistance, and it removes pulse little wave. So what you

56:03 up with is mawr smooth flow instead , ah, flow that's going up

56:07 down a pulse. It'll flow And so that's kind of what this

56:11 of this thing is showing you. can see here is the pulse.

56:14 is all the way, and then you get down here and it's like

56:17 no pulse. It basically it becomes smooth slope. That's just the representation

56:24 there's higher pressure here. Lower pressure , And it's there is that resistance

56:28 not allowing you to have that pulse it doesn't expand and contract, all

56:33 , it lacks the complicity or the , I guess is the correct

56:38 all right. And as you move and further away right, you get

56:42 , smaller structures which have greater which produces less flow. In other

56:48 , the pressure great. It drops more rapidly and the flow becomes more

56:54 . But again, if you look this chart, you know, here

56:57 am over in the aorta, there's mean arterial pressure. Here I am

57:03 in the Vienna Cavell. That's low . And even though that goes all

57:07 way around my body, is there pressure? Grady Int If this is

57:13 pressure over here in the order, this is my pressure down there and

57:16 Kiva is there pressure? Radiant? , that's where the blood want to

57:21 to the vena cava. That's because it's naturally flowing down its pressure

57:27 . Alright, so there is a wave that is occurring in the

57:32 It's easy to see, but it over the Kapler's in the veins.

57:36 , typically, what we say, is no pressure wave in the

57:39 But the truth is, is, you move into the more advanced

57:44 you'll see that there is not a wave of a pressure wave in the

57:50 . But we create these unique pressure on the Venus side of the

57:57 All right, so they lack a pulse. But we have factories that

58:03 them and what we have is we these air kind of cool. There's

58:05 retrograde activity of the heart, the pump and the skeletal pump. All

58:13 , so this one is the least . Do not memorize any of these

58:16 things. I'm not asking you to the primarily because look at the time

58:20 on this less than a second, . And this is basically looking specifically

58:25 the jugular vein, right? So gonna be different in different areas.

58:29 what we have here basically says, , when the heart contracts, what

58:34 gonna do, So we're meant when ventricle contracts, you have the aorta

58:37 top. When it contracts, it's pressure, which is going to cause

58:41 aorta or not the sort of the to kind of expand and contract with

58:49 . Well, that's gonna be effect the vein that's attached to it,

58:52 ? The vena cava. So if caused the order to expand outward,

58:56 creates a drop in pressure inside the , right? Which is gonna drive

59:01 fluid from the veins. Right. if I contract the atrium right,

59:06 I'm gonna do is I'm squeezing and I'm creating back pressure, and

59:10 builds up pressure inside the vein. so what I'm doing is I'm basically

59:14 and relaxing in a micro scale, basically creates these small pressure gradients that

59:20 fluid forward or allow pressure to build so fluid can drive forward once relaxation

59:26 . So when the heart contracts, not just pushing blood, it's pulling

59:33 . That's what I want you to about it. All right? That's

59:36 the retrograde action of the heart So we don't have a push pump

59:42 . We also have a pool pump for the cool one. I think

59:46 is the coolest one respiratory pump. right, now we're gonna talk about

59:53 again. So people at home, can do this without fear of looking

59:57 an idiot. People in the I want you to look like an

60:00 with me. Put your hands on on your chest. I'm not saying

60:04 your chest. I'm saying on your right where your ribs are. All

60:09 ? I want you to feel when breathe in breathe, do a deep

60:13 and then breathe out. Do you the rise and fall of your rib

60:20 . All right, you're bellows, ? And that's what we talk about

60:23 we talk about breathing, right, gonna use that example over and

60:26 When we talk about respiration, you're a bellows. Alright, So what's

60:29 is is I'm expanding the thoracic all right? And then I'm compressing

60:34 thoracic cage when I breathe in Breathe out. Compression. Alright.

60:40 if I'm expanding the thoracic cage, increasing the volume inside the thoracic

60:45 which also results in a drop in . Right? That drop in pressure

60:52 relative to the abdominal cavity. Because I breathe in and we're sorry when

60:57 breathe in, right, I'm pushing my diaphragm, which pushes down on

61:02 abdomen. Right. So I'm reducing volume in my abdominal space. And

61:07 I'm reducing the volume of my abdominal , what am I doing with the

61:10 in the increasing it? So when breathe in dropping pressure in my

61:16 increasing pressure in my stomach, what's do it's going to push blood from

61:21 belly, right? That's moving towards heart towards the heart faster,

61:27 You see that? Expanding this pressure down, pushing on this pressure goes

61:34 and so drives it that way. right, then, when I breathe

61:37 , what do I do? I greater pressure here, which is basically

61:43 upward here, which creates a volume in the abdomen, which pulls

61:48 Blood up towards the abdomen allows pressure build up as blood accumulates in the

61:55 veins. Right. But at the time, I'm pressing on my chest

62:00 I press on my chest that propels blood towards the atrium, so just

62:06 is a secondary pump. It's not strong pump, but it's a pump

62:12 . And so what you're doing is sucking to the stomach, pushing to

62:15 chest, sucking to the stomach, to the chest over and over and

62:19 again. Just a function of Trying to call. I think it's

62:24 . All right. Third, pump skeletal muscle pump. All right,

62:31 all sitting down. E want you to contract your quads and your,

62:36 , calves. All right. You propelled blood to your heart. Moving

62:44 blood to move to your heart. , Most your veins or deep

62:48 They're not superficial, superficial veins or ones on the surface. Deep veins

62:53 usually found inside, not inside the but surrounded by muscles. The word

62:58 want to kind of use here. right. Now, if you think

63:02 the way your body is alright, basically one big giant structure has the

63:08 at the top and you have a that goes right to it,

63:10 So it's basically a column of All right. Now you can imagine

63:15 the bottom of that column that blood down there. That small unit of

63:19 is holding the unit above above which is holding the unit above,

63:23 above it yada, yada, yada, yada. So, down

63:26 at the bottom, what's the pressure that high or low? It's

63:32 right? If you've ever gone scuba , right, you can You can

63:35 . And then the deeper and deeper go, the greater the pressure

63:38 Basically, you have all that water down on top of you, all

63:43 . It's buoyant, but it's still , and so you can imagine the

63:48 it takes to get your blood from little toe up to your up to

63:52 heart is gonna be a lot of . So one of the ways that

63:56 body accomplishes this is it's gonna break that column. Now, we're gonna

64:00 here in a moment that they are not in the moment. But in

64:03 lecture is that veins have valves in . That's that's one way that it

64:07 up the columns. So you have a valve every couple of centimeters.

64:11 you're really not carrying the full weight blood on that column? It's basically

64:16 that small little immune it whatever from to valve. But how do you

64:21 blood to move forward if you don't a lot of pressure? So I'm

64:24 gonna make up numbers. Is it if I make up numbers? All

64:27 . So imagine the blood pressure in in the in the the capital,

64:32 side of the or the Venus side a cap players around 10 millimeters of

64:37 . The blood pressure inside your atria about zero millimeters of mercury. So

64:42 slope to go from your little toe your heart is like nothing,

64:49 I mean, that's a 10 millimeter difference, considering that the pressure difference

64:55 the systolic and diastolic is 40 millimeters mean, you're looking at a

64:58 That's, you know, like, steep. You guys can't see

65:01 I'm making a steep slope with my and a very shallow slope. So

65:07 have to that has to overcome which by itself, is gonna be

65:10 difficult. So the way that your does that is just squeeze the

65:14 right. If I squeeze the fluid has no choice but to go

65:19 with one way valves, right? so when you sit down when you

65:23 , when you walk, when you when you gesture, everything you're doing

65:26 muscle squeezing on these veins, which propel the blood back towards the

65:31 It's really obvious in the legs, when you squeeze, you can move

65:36 you know, you're you're really feeling against gravity. Not so much in

65:39 arms, but it's still doing it as well. All right, all

65:50 . So cardiac muscle. We've talked it in terms of structure, so

65:55 nothing really new there. I do to point out the heart in terms

65:58 its structure, is actually kind of . We've got two little things

66:01 First off the left ventricle, Left is on this side. The

66:05 very, very thick versus the right , which is very, very

66:08 The reason being is just by virtue how much blood I have to

66:12 Right. Pulmonary circulation is basically about of my body. Systemic circulation is

66:18 80% of my body, right? the amount of blood that needs to

66:21 moving right. So remember, my is pumping blood. It still has

66:25 move all the blood back around to heart. So it's gonna be doing

66:28 lot more work. That's why the ventricle is thicker. Alright.

66:32 so what we say is right low resistance, low pressure to overcome

66:37 ventricle, high pressure, high resistance overcome. All right. The other

66:42 that's kind of cool is how your develops its develops as a spiral

66:46 So when your heart contracts, even you have a tree in the

66:49 what is doing is it's ringing in heart. All right, so if

66:54 ever milt in animal like a cow goat, a sheep no small

67:04 It's funny, right? Sorry. was a fan of The Simpsons and

67:10 time ago, uh, they discovered at The Simpsons at the school that

67:15 weren't drinking milk. They were drinking . And what Mulk was was rat

67:21 , and they went down. And was the mob that was selling it

67:25 him. And they had, a like, just cages of rats

67:30 up the little time milking. that was funny. I'm sorry.

67:36 right. So when you think about a towel all right, when you

67:40 a towel, what do you do that? That's what the heart's

67:43 And it's and what that does. allows for the muscles to to squeeze

67:46 such a way to propel the blood and out through the simulator valves.

67:52 right, And this is just kind showing you that arrangement. How How

67:55 looks like, um, there's a of information on these two slides here

68:01 you don't need to know. I to try to teach it and realize

68:04 always run out of time, but like to think of that.

68:06 What basically says is that a tree the ventricles. Work together is like

68:10 Atria contract. Together, the ventricles together. While that's true, it's

68:14 100% true that there are off sync just a little bit. And that's

68:18 that those grass are really trying to you. That's not so important to

68:22 . I just mentioned it. I'm gonna ask you on the test.

68:26 , what you should be aware of what does cause each of the individual

68:32 . So there's some detail in there that becomes important. Um, this

68:37 is exact. Same thing on git you how the heart actually does

68:42 So when the ventricle contracts, it's of like squeezing toothpaste. You

68:46 where your propelling it up? Because whole round structure contracts, whereas on

68:51 right side of the heart, it's like a bellows where it's squeezing in

68:55 this direction towards. So it's just little bit slightly different in terms of

69:00 two types of contractions, not particularly , the cardiac muscle contraction we said

69:10 is dependent upon calcium. We've learned what I wanna talk to you about

69:14 quickly here is how do we regulate . So we're gonna regulate at the

69:18 of troponin and we're gonna be regulating at the level of circa.

69:24 That little molecule I just circled right is called fossil Lam Binh.

69:29 see? It's gonna be on the slide, so I'm just trying to

69:32 you where it's at. Fossil right? What fossil ramen is is

69:39 in Hibbert inhibitor of circa? It's brake pedal on circuit slows thetacticsroom circuit

69:44 . Remember what circuit did circus the in a platinum particular calcium pump So

69:50 pumps. It allows for calcium be out of the of the cytoplasm.

69:58 . And what fossil Lam Binh does because it's an inhibitor. If you

70:02 for related, What happens is you the inhibitor. So as you fost

70:07 late, it's going to increase the of relaxation all right. And the

70:13 thing is going to be true Um, if I fast for

70:17 um troponin tie, it allows it causes tnc which binds up calcium

70:24 release um um to release calcium, means you're able to go through a

70:30 faster, allows relaxation to occur so there's I'm just trying to show

70:38 There's some ways that we regulate I think that's what this does.

70:42 brings us down to our last three . All right, so much of

70:49 we're talking about today is just the cardiac cycle. And ultimately, with

70:53 cycle, you're creating a volume of that's being ejected. That's your stroke

70:58 , Alright? And so how do affect stroke volume? One of the

71:01 that we could do to make stroke change. All right, There's three

71:06 . We could do it on the end. We could do it on

71:07 back end. Or what we can is we can alter the degree of

71:11 Il ity of the heart. So front and back end and how

71:16 the heart contracts. So what do mean by front line that this is

71:19 pre load how much blood we returned to the heart. And if you

71:23 your text book, you read all Frank Sterling, and you probably stared

71:27 that for a little while. You're , I don't know, I don't

71:29 . I'll learn about in class, I'm gonna basically bald too boil it

71:33 . There's a lot of words on slide, but this is what it

71:35 down to. All right, Frank . There's two scientists. They examine

71:40 heart, and they discovered this really fact. The heart will pump whatever

71:45 give it. So the more blood returns to the heart, the more

71:50 the heart will pump less blood. return to the heart of less

71:53 The pump the heart will pump. an intrinsic ability, Hart, to

71:57 how much blood is in there. other words, it detects that

72:01 And the more pressure there is, harder it's gonna pump to push out

72:04 greater volume. All right, so you increase the amount of blood returning

72:11 to the heart, that's your pre . Alright, what that's going to

72:15 is it's going to increase how much heart pumps out, right? That's

72:20 stroke volume. And it does so what you've done is you've increased the

72:24 diastolic volume right so much you return the heart, basically, is the

72:29 end. And so how much I in in diastolic volume increases, that

72:33 the systolic volume has to increase is , that's number one. Pre load

72:38 number one. So if I reduce load systolic volume or stroke volume goes

72:46 because in diastolic volume goes down the same thing. All right?

72:50 after load. This is what you're familiar with. All right. High

72:55 pressure. If other words. If if my blood pressure is high.

72:58 resistance to pushing blood into the the heart is gonna have to work

73:02 . Does that make sense? The crap you have in your closet,

73:05 harder it is to get stuff into . Same principle here. Alright.

73:10 as my after load increases, what gonna do is that's going to increase

73:15 system. The in systolic volume, basically serves as a point of

73:20 My heart has to work harder. what ends up happening is is my

73:23 volume goes down. This is why dangerous for the heart. That's one

73:27 why it's dangerous for the heart to high blood pressure because your heart's now

73:32 to get more volume out of All right, so this results in

73:37 increased so basically increase increases if, load increases. Basically, it reduces

73:42 ability of the heart to eject That's what we're trying to get

73:46 All right, So it's a lower volume last one, and then we

73:51 to go home and then we get have a long weekend. We get

73:54 watch football. For those who like further, you'd like to drink pumpkin

73:58 in 90 degree heat. You can that. It's that time of

74:02 right? Pumpkin lattes, pumpkin, latte, Not pumpkin Lottie's.

74:10 All right. I'm on a Agents on a Tropic Agents are simply

74:16 external factors that alter the contract Il of the heart. All right,

74:22 they could be both positive and So they're those factors that are not

74:26 of the heart, their external to heart. So they could be It

74:29 be on autonomic innovation so sympathetic versus . It could be hormones that can

74:35 effect. It could be drugs that take those air all on a

74:40 Alright, so I know tropic not . Oh, so I know

74:44 So generally speaking, what you're gonna is if you are, If you

74:49 a nine a tropic agent. What does is it makes the availability of

74:53 change. When you make the availability calcium change, you're going to make

74:59 orm or cross bridges. So you less orm or contract tile strength.

75:05 right, so this is positive. calcium availability by increasing number of calcium

75:14 , you increase the number of cross . So that would be examples.

75:20 . Any drugs that make your heart harder? That would be an easy

75:24 to it. Negative. On the hand, decrease in calcium. Weaker

75:32 . Simple enough. Kind of, of. So if I I'm just

75:42 challenge you here, make you think a second and then we'll get out

75:45 here, I exercise my heart beats . What's gonna happen to my Venus

75:51 ? Go up, Go down. the same by exercise is gonna go

75:58 . So what happens to my Venus my venous return goes up? What

76:03 to my, um, e T ? It increases. So what's my

76:09 going to do? Put more blood harder. Okay. Excellent. That's

76:18 hard. Right? So that's that's kind of thing that you need to

76:23 thinking about here. What happens Right, you know. And

76:27 of course, to make the blood factor, right? My veins Excuse

76:32 . My arteries constrict so the blood flows faster through them to get to

76:37 tissues that they need to get So what happens to my after load

76:41 after let go up or go down my if I have arterial constriction after

76:50 goes up So what does my heart to do? Beat harder. So

76:54 mean when I exercise? I get blood to my heart, to my

76:57 harder. And it's harder to get blood where it needs to go.

77:00 my heart beat harder. So that's when I exercise my heart beat harder

77:04 , it's basically both of these things simultaneously. Plus, you can throw

77:08 all the sympathetic activity and all the and other things that are also supporting

77:14 . And I'm getting the hormones were to you would be things like

77:18 epinephrine, norepinephrine. Okay, so would be like the tough end of

77:24 trying to understand this stuff. But you see that application if you're sitting

77:30 on the sofa after running, You just went for your five mile

77:34 . Because I know you're all strong . You know, your heart's beating

77:38 , man, you go lie on sofa, put a cold, damp

77:41 on your head and drink a What's your heart rate gonna do?

77:44 gonna go down, right? Well, you no longer have that

77:49 stimulation. So no out of tropic that's going to reduce, um,

77:54 load. It's gonna reduce after All that stuff is going to go

77:59 as well. Capiche. Yeah. . I don't know any other.

78:08 is Hi there. There's Japanese. all good. Any questions from online

78:25 Yeah, eso eso. So the with arterial constriction, right? All

78:33 , so So it's again. It's . It's a broader process. I'm

78:40 to get you to think, trying get them to think about So when

78:44 the heart is beating harder when you're your being stimulated primarily through sympathetic

78:49 which is causing the heart to pump and harder and harder. But part

78:53 that sympathetic activity is going to cause constriction. The reason for that arterial

79:00 is we're trying to get blood faster the heart to the tissue where it

79:04 to go. It's not creating resistance the sake of slowing down them or

79:09 prevent blood. It's actually it's like your finger on the end of the

79:13 , right? You ever do that you're a kid trying to spray?

79:15 we put a finger on the end the hose. You're not there to

79:17 the water from coming out. You're to make the water come out

79:20 and when it comes out, faster further, you know, or further

79:24 . That's why you do that. it's the same sort of principle.

79:27 constriction of the arteries results in quicker , you know, flat faster flow

79:34 that artery. All right, So order to overcome that restriction that the

79:39 has to be harder to do that ? So it zey what I was

79:45 to get at here is there's there load that the heart must overcome during

79:52 in order to ensure that activity. because it's beating harder and more

79:56 you're also increasing pre load because you're so much more blood out they'll put

80:03 way. Um, your heart rate you're sitting right now is about 60

80:06 per minute. Right? When you're , your heart rate could be around

80:09 60 beats per minute, and you're beating harder. In other words,

80:13 stroke volume goes up. So you're instead of moving. Um,

80:19 We could do the math, but 120 million to say it's 70

80:23 times 60. So what is 420. 4200 mils. We're looking

80:30 4.2 mills in a minute. By my math, right are 4.2

80:39 Thank you for pulling out the calculator you just checking your email 70

80:43 70 times. Um, 60 4.2 . Right. Okay, so

80:51 in 11 minute, your heart is . Ladies, you're almost your entire

80:57 of blood, right? But think when you're exercising, Alright. You

81:03 your heart rate to want to 160. Yes, all right.

81:08 let's say we increase our stroke So you're now moving, um,

81:12 of 70 mills, let's say 100 . I'm just making up a

81:17 so 16 liters of blood, So you're part is receiving mawr

81:24 and it's also having overcome resistance, it's working harder to do all

81:29 Perfect. So that's what I was to get out. That's what the

81:35 I'm saying is the heart is working to overcome the after load. I

81:40 I answered the question may have gone a rabbit trail. All right,

81:45 done for the day. You don't to hang out here unless you want

81:49 actually have a meeting with student. other than that, uh huh.

81:54 questions from yes, all made Just nod your head and say,

81:59 course, Dr Wayne is perfect All hundreds. If you have

82:05 don't be afraid to ask. Have great

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