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00:08 whole bunch of stuff going on your where I have to turn on so

00:11 different things to get this stuff Let's see what? God here.

00:19 , start recording that service double And I think we are good to

00:26 . Yes, all right. They only having a good week so

00:32 Everyone enjoying the horrible, horrible, air quality we had today. I

00:37 . I drove in. I could see downtown. I was like,

00:41 , there's no work. Yeah, , anyway, um, for those

00:46 you who are online, I'm gonna you to go to the chat real

00:50 and give a thumbs up or thumbs on a question I have with regard

00:53 the calibrations. Do you think the you read was a good paper or

00:58 paper and we'll find out the Here's and foreign class. What you

01:02 think? Good paper. Bad Good paper. So you said

01:11 You think you shook your head and like, No. What do you

01:14 think? Okay. Said okay. then what did you think of the

01:23 when you read it, or did not do it? It's okay.

01:25 you didn't do it. I'm not be mad at you. This

01:27 you could do whatever the hell you , right? What? What's that

01:31 , Um, or thumbs up with thumbs down. A lot of

01:35 All right, so let me talk briefly about the calibrations. This would

01:39 a lot better if we had 150 in the classroom. We could talk

01:42 a paper, but we can't do . So I'm gonna have to kind

01:46 tell you what it's like. All , So first off, the purpose

01:50 these calibration you can see down here the bottom is toe Look at papers

01:53 the perspective of the rubric. We can look at a paper.

01:57 can say this is good or this bad. Just fundamentally. Does it

02:02 to me? Right. But what tend to do is we tend to

02:06 very emotional about the person. We bad for him. He will hear

02:10 bad for the writer when you read bad paper. Yeah, you're

02:14 Oh, well, and you wanna him the benefit of the doubt?

02:19 , if you thought this was a paper. You're darn right. This

02:22 a bad paper. This was a written paper, okay? And this

02:26 actually a student paper from a couple back. Don't ask me how many

02:29 ago. I pulled it out a time ago. And the idea here

02:34 to look at the paper through that because what happens is is when we're

02:40 evaluators. We tend to want to sorry for the writer. Oh,

02:45 feel bad that this person didn't get grammar right. Maybe they're not English

02:50 . So maybe that was probably a or Oh, you really don't understand

02:55 have command of the subject. So want to just kind of give you

02:58 benefit. The doubt? I don't you to get a bad grades.

03:00 grades suck, right? They do , right? Would we all agree

03:04 bad? Great suck. Yeah. the idea is to remove all that

03:09 , and what we're really trying to is pure evaluators. And we're trying

03:12 help that person become a better And if all you do is coddle

03:18 , they're not gonna get better at , all right? And it doesn't

03:21 you have to be an ass. don't have to be brutal. You

03:23 have to be mean. You don't to call them names or say they're

03:26 stupid or make fun of their ancestry whatever it is that you feel like

03:30 when you're reading a bad paper. trust me, every single one of

03:33 things comes rolling through my brain. wonder how they ever got into

03:38 You know, there's there's all sorts stuff when you read a bad paper

03:41 this is true when you're reading papers your colleagues and there. I

03:45 trust me. There are bad writers there, but the idea here is

03:51 . I am judging them on the based upon the rubric, and you'll

03:57 those questions that I asked You were straightforward, weren't there? Is

04:00 does the title do this? Does abstract do this? That's what you're

04:06 to do, and if you're honest that, you're gonna quickly find where

04:11 paper lies. Now. The truth , is that there is a degree

04:16 subjectivity, and so some of you getting partial credit the first time you

04:19 there, you probably got a really score and you're like, What the

04:22 ? And then you started trying to and modify. And really, what

04:26 trying to do is I'm trying to you to kind of modify yourself stuff

04:29 you're all kind of working in So, for example, I

04:33 this paper, I don't have my here because they're up in my

04:35 Um, but like I gave the person basically all ones, with the

04:39 of, like, the title, know, e think that's what it

04:42 . But, you know, if are like, well, it's not

04:45 a one, but it's more like two. You got credit for

04:49 and that's okay, all right. that's the idea is like you and

04:52 can agree that something is bad, I might think it's worse, and

04:55 might think it's a slightly better than . And so that's that's agreeable,

05:01 ? We can identify something that's but you might think it's like

05:05 really awesome. And I might be , Yeah, well, it's not

05:07 , but it's a close to as you're gonna get right and So

05:11 kind of the idea here with regard the subjectivity part. But we should

05:15 be falling one way or the other it comes to evaluating these things.

05:21 , with that in mind, you two other calibration. So there is

05:24 total of three papers. So you seen what a bad paper looks

05:29 So you can also use that as model of like I don't want to

05:31 what this person Did you notice that grammar was was terrible, that the

05:35 kind of wandered? There was no story. And probably after about the

05:39 or second paragraph, you kind of pissed. Did you Did you notice

05:42 you get mad when you read about ? I mean, I've said that

05:45 was like, Come on, you do better, you know? Trust

05:49 when the t A. You you've had a great pay presented

05:53 Yes. What happens after about the paper? You're just angry. You

05:57 read a murder people, right? is why you don't want one person

06:01 your papers. You want just a of people. All right. But

06:04 we're gonna do we're gonna go through next couple of papers, you're gonna

06:07 different types of papers. You've seen bad one. So what do you

06:11 ? You think you're going to see good one? At some point?

06:14 . You might see an average paper some point. I mean, those

06:16 really your three choices. Good, . And and okay. And so

06:20 you're reading them, use that rubric help. You kind of say,

06:24 , Are they achieving the goals? if they're achieving the goals, what

06:28 of gray does this mean, How do I feel? Do they

06:32 a good job of meeting the Are they falling on this side of

06:36 scale? Are they falling on that of skill? Are they falling in

06:39 middle? Now? I got a questions about Well, how does this

06:44 great out? Where does this great ? Well, it's part of your

06:47 grade, but it za negative grades penalty grade. But when I say

06:51 , I don't want you like all right, because it's meant to

06:55 . It's not meant to punish. only punishes if you don't do

06:59 So you can see right there. you don't do them, you're losing

07:01 points off your paper. So just and trying to calibrate you're going to

07:08 working in the right direction. So I do every paper you have two

07:12 . Obviously, the first time you it, like today, you probably

07:14 , like, I've had people like get twenties the first time. They're

07:17 like, what? Why? And they go back and they try to

07:21 , and they finally get to Great. So what? I'm always

07:24 take the highest score. Whatever those attempts are. All right, That's

07:28 gonna be the case. And then I do is because I know that

07:31 calibrations could be kind of difficulty. gonna take the top two scores within

07:36 three. All right, So high of each three throughout the lowest

07:40 Now you got two scores. They wait, uh, two scores,

07:44 I'm gonna take that average. Once I take that average, If

07:49 average is greater than 80 then I count anything that you have calibrated,

07:53 I'm happy. All right, So you're within 20% of what I call

07:57 perfect calibration. You're in good And after that, I'm gonna take

08:01 couple of points off. Like if off by five points and it's 50.25

08:05 off 100 point paper, that makes . Is that Is that is that

08:10 ? Is that the end of your ? No. 99.75 is okay if

08:14 have 100. Not your perfectionist. right, but you can see it

08:21 doesn't harm you. Its's the small to the carrot. All right,

08:26 what we're trying to accomplish. So online fight. Have them still

08:32 There might be three attempts. Is three attempts? Okay, you got

08:36 attempts. Bonus. See, I change anything. I guess one year

08:40 moved up to three attempts. So you go. Three attempts. So

08:44 better. Still take the highest of . So three temps. And if

08:49 get 100 or if you get 80 can stop. You don't have to

08:52 doing it right. But that's the , Really. The goal here is

08:58 to start practicing riel peer evaluations, these are real student papers that you're

09:04 They're not stuff that I've made I pulled him. I called him

09:07 old classes. So that's what I you to do. So we had

09:11 today. We have a test on . That was a hiss,

09:18 Boo. Right. And then on next week, that will be the

09:23 calibration. And then there's the third on Thursday. Did this take long

09:29 do when you did? The calibration like you took long. You work

09:32 hard. That's okay. I'm not not mad at you, you

09:36 But if it took you more than minutes, then you probably spent way

09:40 much time on it. Okay? it's basically as you're reading, just

09:44 of try to answer the questions is what we're trying to go for

09:47 And this is actually when you read papers, your peer papers, it's

09:51 of the same thing. You're basically kind of rolling through. If you're

09:54 more than 10 minutes per paper or 15 minutes per paper, you may

09:59 putting way too much effort. Don't to correct somebody's grammar on these on

10:03 papers. All right. If their is terrible. And I've seen people

10:07 that where they, like, start to correct the grammar like No,

10:09 , no. Just say your grammar work and then count them for

10:13 right? Can you believe that? mean, you know, affections.

10:17 what we do. Any other questions ? You've got that look on your

10:22 . Uh huh. No requests. chance that? Nope. Nope.

10:30 to the hard world. Nope, . Nope. Building Crecion, You

10:37 one last night. This is the . So again, in a setting

10:42 this, where half of you 94% you are online and on Lee a

10:48 of your ear in the classroom. calibration is simply aligning yourself by

10:53 So if you could get within 80% a perfect score, right? So

10:57 you have 80 or above, then are calibrating. All right, that's

11:01 idea. And you should be able look at a paper based on those

11:06 and ask that question instead of instead being emotional about it. Ask

11:10 Are they meeting the rubric? Are doing a good job? Are they

11:14 an okay job or they're not doing at all. And if they can

11:17 that out than their calibrating Yeah, , Yep, Yes. No,

11:31 , no figures. Thank goodness. . Or would it be hard?

11:36 to have figures? Yeah, No . You got them all in your

11:42 , right? You store them, jammed him over on this side.

11:45 now. You know all the lyrics all your favorite songs. Don't get

11:49 up. That's funny. Thank you laughing. All right, you guys

11:57 to move on to something interesting You want to keep talking about

12:01 No. Interesting. Okay, so , what we're gonna do is we're

12:05 talk about muscles, all right? want a picture of Popeye, but

12:10 run out of time. All So this is one of those weird

12:14 90 minutes to talk about something that takes about five minutes to explain.

12:18 I apologize for that in advanced. right, So what I want to

12:22 with first, I want to deal structure when we talk about a

12:25 All right. When you think of muscle, you think of a named

12:27 like, what's that muscle right there bicep. Alright, that's good.

12:31 , Those online you can't see Ha ha ! You could pick whatever

12:34 you want. All right, That , that name muscle is a composite

12:39 a whole bunch of muscle cells. this is what this picture is trying

12:42 show you see? Look, there's muscle and is trying to break it

12:45 . And what we have here are smaller and smaller groupings of cells.

12:50 within a named muscle, you have Bunches of fast sickles, and that's

12:56 they're trying to show you. Here they're pulling one out of fast

12:59 And a fast cool is simply a of these, uh, muscle cells

13:03 are are bundled together, and that's of the next level down. And

13:07 the last level that you're looking at is we're looking inside the cell at

13:10 mile fiber, and so part of is a little bit of language.

13:14 , Because you're gonna hear my oh Myo Fi Brill. You'll hear my

13:20 . You know all these my oh Oh my Oh my oh always refers

13:24 muscle Just like Sarko is a It always refers to muscle, all

13:29 . And so if you look at , think about a steak or a

13:32 when you go to the store and buy one and they take that

13:34 And really what you're doing is doing cross section through and you can see

13:37 bundles of fat. These what? fast sickles. Alright, They're separated

13:41 connective tissue. And so if you at the larger fast ical, it

13:46 connective tissue around it. If you at the individual cell, it has

13:49 tissue around it. And if you at the whole muscle, it has

13:52 tissue around it and it has All right, so the EPA

13:56 um, epi means outs are So that would be the one that

14:00 the entire muscle. The paramecium, paramecium like p a r a.

14:06 pay er I, which means near our next to, is wrapped around

14:11 of the individual cells. I'm Each of the individual fast sickles and

14:16 the Indo Me Z, um is most form of connective tissue that would

14:20 around the individual cells. So if take an individual cell rapid connective tissue

14:24 is the enemy's IAM. Take a of those wrapped him again with connective

14:28 . There's the pyramids. IAM. a bunch of those fast calls.

14:32 them again. That's the epitome Now you've got your name muscle,

14:35 then we actually have more connective tissue it. We have what is called

14:39 and superficial fashion. The deep fashion external to the museum, so it's

14:45 right there around each of the And so you can imagine several muscle

14:49 muscles are bundled together, and that's you kind of wrap them up.

14:52 then you have the superficial, which what separates muscle from skin. So

14:56 you ever gone hunting and you ever an animal, you take up the

14:59 and it looks like the animal without just basically all muscle. That's the

15:05 fashion now. Muscles always connected toe to cause bones to move, and

15:12 way we connect the muscle to a is through connective tissue. What we

15:16 tendons. All right. Now what is is the tendon when the muscle

15:22 that causes the tenant to pull on muscle, but the tendon is,

15:28 , created from the convergence of all different layers. So around the individual

15:34 around the individual fast tickles and ultimate the whole muscle come together and they

15:39 out the other side. That is tendon. Okay, so that's kind

15:46 a basic level of organization here. , what I want you to

15:50 and this is a concept that a of people don't seem to get.

15:54 right. So neither in anatomy we're . Is that when you look at

15:58 name muscle like a bicep? The length of the cells in that

16:03 is the length of the entire Right? So the individual cells are

16:09 from where the insertion is, really origin down to the insertion.

16:15 That is one cell length. So of those cells within this name muscle

16:20 equally as long as the others. all parallel to one another, and

16:24 incredibly long. So you can imagine quadriceps. How long with those quadriceps

16:28 be quadriceps. Is this muscle in thigh? How long do you think

16:34 like that? Yeah. Each cell that long for those go online about

16:39 and a half. 2 ft. one else. I'm pretending. Big

16:44 . Okay, so you kind of the sense here. Long cylindrical

16:51 So what we're gonna do is we're focus in Yes, sir.

16:58 No. Fascia is, um is name of that form of connective

17:03 So typically speaking, it's kind of thicker, denser, connective tissue

17:08 uh, basically wraps the entire All right, so, um,

17:15 without naming muscles. And on the of my head, I can't even

17:18 all the names of the muscles in forearm. But there's about eight different

17:21 in the forearm, And so each muscle is wrapped in a deep

17:28 and then the entire structure now wrapped superficial fashion, All right, but

17:34 don't sit there and go Look, know, there's my for my got

17:37 of muscles. See? Look, work out. You see it online

17:41 , admiring my Adonis like arm. all nod your heads and say,

17:45 course, yes. Live in your world, Dr Wayne. Okay.

17:52 we're gonna do is we're gonna focus on the individual cell. All

17:57 We understand how the individual cell We don't understand how the whole muscle

18:01 . All right, so the individual is called a myo fiber. All

18:11 , Very early on. When Physiologist . We're looking at this stuff they

18:16 using, You know, they're Latin their Greek and so not recognize that

18:21 cell is not unique. Rather all basically the same component. They started

18:27 things. And so when you hear word sar Kolyma, what you should

18:30 hearing is plasma lemma or plasma When you see Sarko Plasm, you

18:34 be thinking, Oh, that's, , cytoplasm. It's just the cell

18:39 . And so, just like they in the nervous system, they thought

18:42 was unique and special, and so gave him special names. Now there

18:45 some characteristics of the Sarko plasm that should be aware of. There's

18:48 lots and lots of like a zones basically glycogen stored away. Now you

18:53 learned way back and buy a What's glycogen? Exactly when, um

19:00 . It's stored What? Sugar? good. That's why I'm looking for

19:05 simple answers here. We're not. isn't the M cat. We're just

19:09 to go for simple storage sugar. would muscles want stored sugar because their

19:15 they need say it again. And that's what sugar is its energy

19:20 be used. All right, so not waiting for the liver. We're

19:23 waiting for fat stores. We already sugar in our muscles. All

19:29 for those who like to do keto and stuff like that, all of

19:31 sudden, it kind of makes Okay, why can't humans be or

19:36 carnivores being meat eaters? Well, are getting our carbs because the carbs

19:40 already there in the meat. There's not a lot of them.

19:44 But they do exist there. We get sugar from them. We also

19:49 myoglobin. Myoglobin is related to Hemoglobin we're gonna see carries oxygen in

19:54 blood myoglobin holds on the auction in muscle cells. Why don't I want

19:58 my muscle cells because of all that you learned about way back when you

20:04 about Glide. Collis is right. gonna take that glycogen, gonna break

20:08 glucose, take glucose and convert it carbon dioxide and water. And the

20:12 way I could do that is if have oxygen present and Why do I

20:15 wait for my lungs? If I'm cheap being chased by a bear,

20:20 , Let me start as much oxygen I can, and then as I'm

20:23 it, then I'll replenish it by harder and faster and pumping my blood

20:27 . So we're gonna start boxing as . And then we have a high

20:31 of mitochondria because we remember mitochondria. is their job? Energy production?

20:38 . That's what we're looking for. . And then this is interesting.

20:41 a multi nuclear did sell. Why I have a multi nuclei?

20:46 the answer to that is that it's . Remember I said, these cells

20:49 very, very long when they first development. Your cells are very,

20:54 small individual cells. But what they is they fuse with their brothers and

20:58 , and they create these incredibly long . So it's multi nuclear did because

21:03 created a fused cell. That's where multi nuclear comes from. Now the

21:09 of interest, what we call the unit. The thing that we're gonna

21:13 dealing with is called the SAARC The SAARC Amir is a specifically defined

21:18 within a muscle cell. It lies two things that are called Z

21:22 All right, now, without knowing about Z disk, you're just

21:25 okay, I'm just gonna nod my . Just know the definition right

21:28 We're gonna get to what it all to deal with the Z disk you

21:31 see in our little picture. Here basically a line that you can see

21:36 the striations. All right, so you have to Z discs, there's

21:42 , number one z dis number That right there is called a Sark

21:46 . So what happens is, is when the muscle contracts, what you're

21:50 do is you're gonna see the SAARC getting smaller, All right? And

21:54 you have thousands of sarcoma, you imagine all these Sarka mirrors are getting

21:59 in terms of the distance between the z disk. We're gonna learn how

22:02 works. Thea. Other thing is when your muscle grows because

22:06 you start off about this big in , right? And now you're this

22:10 in life. Or maybe this big on who you are, right?

22:14 did that happen? Well, the added Sarka mirrors on to its

22:20 So it's basically elongating as a function adding Sark. Amir's the SAARC,

22:26 themselves don't get longer. Okay, the SAARC Amir is a fixed length

22:31 a muscle south. All right, , this is a functional unit,

22:35 that it has business. Now, we're gonna do is we're gonna dive

22:38 . So here we are. There's cell again, and we're looking at

22:41 structure here called the Triad. I'm just gonna point some stuff out

22:45 the picture so that you can kind kind of figure out where we

22:48 You can see out here. Here that plasma membrane what we call the

22:52 membrane SAR Kolyma. Good. All , so the star Kolyma and then

22:57 can see inside these air the Mile . Brill's not the mile fiber.

23:02 mile fiber is the cell mile fibers the side of skeleton inside the muscle

23:08 . All right, and then we're have in a plastic particular um,

23:12 give it a special name. We it Sarko Plasma. Ridiculous. Um

23:17 . And what? The Sarko plastic . Um does It has a unique

23:22 function to this this is a It's a type of smooth,

23:27 in the plaza in particular, and stores up calcium. So in our

23:31 here, you can kind of see Sarka Plaza in particular. Um,

23:35 kind of wrapped around everything. Looks like the Swiss cheese in the

23:40 . Alright, it is wrapped around the fibers and then at the very

23:44 of that you have these tubes that of run from one side of the

23:49 to the other, like tunnels. right, so you can imagine the

23:52 applies in particular, has a hole then burrows through to the other side

23:56 a tunnel that whole and that burrow the way through is called the trans

24:02 tube. You'll or T tube you'll short. All right, And you

24:07 see in our little pictures here it's blue thing. So here's the opening

24:11 one side you can imagine it goes the way through and there's an opening

24:14 the other side. And really, we've done here is we've actually brought

24:21 into the into deep into the muscle . So if you need an

24:28 think of it as a doughnut, ? A donut has a hole through

24:31 . So the surface is even the . And that's kind of what's going

24:36 here is we got a little tiny that are like holes that go all

24:39 way through. Now the Triad says there's three things. So we've got

24:45 Plaza in particular. We've got the to Bill. What's the third

24:48 The third thing is the edges of Sarko plasma. Particular Um alright,

24:53 kind of spread out and become fairly . And you can see in our

24:56 over here What's going on? And is the terminal sister knee, meaning

25:02 end fat end alright of the SAARC in particular. And so those three

25:08 together make up the triad. So I have is I have calcium stored

25:13 away the Sarko Plaza in particular. , I have a close association with

25:18 T tubules, which is basically the coming through the cell. And then

25:23 got these fat ends that air near T tubules of this Arco Plaza in

25:28 . All right, so this is of where we hold the calcium.

25:33 I'm gonna pause here for a and I'm gonna answer a question.

25:38 questions off. It's like a triad the exam. Oh, who cares

25:47 the exam exams next week? Or on Thursday. Who cares?

25:51 what's the question? No question. many of you think classes 50.

26:02 listen to the orientation video. next one in the developing body,

26:08 growth fusion. You think muscle cells off formulas for self? Yes.

26:16 ? So very early on in the individual cells, these air called

26:20 premium. They're called mile blast. pre Maya sites mile blast fused together

26:25 form what are called, uh, Maya site itself. And that's actually

26:29 in extending structure that's becomes a fiber structure. It's actually kind of cool

26:34 scary. If you want to think the the cell that becomes fat in

26:36 cell that becomes muscle is the exact precursor yourself. All you gotta do

26:40 give it one, uh, on goes one direction or the other.

26:46 you wish we knew how to turn that gene right? This very moment

26:49 our lives, I mean, I've I've got a lot of muscle that

26:53 to be reborn. Okay, so that's where from, All right.

26:59 so what happens is these little tiny round cells or whatnot will then kind

27:05 elongate and create kind of a straw cell when I say straw, like

27:10 straw. Okay. And that's what seeing here is the entire structure we're

27:15 at is the individual cell, All . And what we're looking at is

27:19 looking inside that individual cell. All , so let's take a look and

27:28 the big picture, and we're gonna it down. Yes, I was

27:34 . Uh huh. I'm coming. drink my teeth. Go ahead.

27:46 ? Uh huh. Yeah, Well, this will make a little

27:56 more sense. So think of it this right now. I am introducing

28:00 the players in the play. I told you how the playworks yet.

28:03 , I haven't told you the but yes, so the SAARC applies

28:07 the terminal cistern e are basically one together. It's just that there,

28:12 terms of structure, their unique one a little bit broader and wider.

28:16 so there's Mawr calcium that's localized. relative to the rest of the Sarko

28:20 . Ridiculous. But the Sarka plasma , um, still is responsible for

28:24 up and storing up calcium point. purpose of the who feels that where

28:29 actually like I said, wait till to haven't gotten there yet. That's

28:34 That's part of part of the fun here is telling how it all

28:37 This is the mouse trap. You mousetrap. You guys all played

28:41 right? No. Uh huh. to get you guys out. Mousetrap

28:47 a game where you start putting the one by one, and at the

28:49 end, you get to run the mousetrap in it. It's really,

28:52 cool, but I'll get there in a couple minutes. Literally three or

28:55 minutes. All right. Any other ? All right, let's Yes.

29:00 ahead where you're working. Terminal A is on the It is.

29:08 , sure thing. I'm gonna erase ink real quick so that we could

29:11 that. All right, so when looking at the terminal cistern e think

29:17 is working? Nope. Had turned my pen. Hold on on.

29:22 back. So the terminal sister knee be this portion right here and

29:26 I apologize. It's hard to write a background. That's so. These

29:31 all be terminal sister, the right to. So if you're looking at

29:35 t tubules T two bills running maternal Ernie sits right up next to

29:40 So it's the portion of the Sarko particular, um, that lies or

29:46 next to the T tube, You'll ? Thank you. You bet,

29:51 . All right, So you're saying going well, Gosh, there's a

29:53 of anatomy. What kind of it's like looking at the engine of a

29:56 and saying, Alright, how does run? If you don't know the

29:58 of the things, How are you know how each thing works together?

30:02 right. And so this is kind the big picture, Alright? And

30:05 far, what we're looking at shouldn't very different. What we're looking at

30:09 here is we're looking at a neuron a neuromuscular junction, and you could

30:14 here that the neuron the arrow represents action potential notice that they labeled it

30:19 signal. Carol, that was a to my head. Alright, so

30:25 an action potential. The potential travels . The length of the axon comes

30:29 to the acts on terminal causes. opening of voltage gated calcium channels.

30:33 comes in causes that vest ical to up to the synapse, right at

30:40 motor in plate. That's what this is referred to as this underlying

30:45 The motor in plate so that neurotransmitters is. You know, Colin binds

30:51 the receptors at the motor in plate causes deep polarization in the muscle

30:57 So remember what is an action An action potential is a signal for

31:02 toe happen. Alright, it's not event. It's a signal to cause

31:08 . And so that action potential is a change in the membrane potential.

31:12 , what's interesting in muscle cells and potential that's that's traveling down through the

31:18 is going to cause release of this see the Colin that is going to

31:22 a greater potential. But the greater is a very strong or powerful greater

31:27 . So what we call this is E P P and in plate

31:32 See, the cleverness there is happening the inn plate, so all

31:37 The E P P is strong enough produce an action potential in the muscle

31:44 . All right, remember, we did the wave in the

31:47 It's just a movement of ions across surface. And so that's what's gonna

31:51 is we're gonna produce an action potential now travels from the in plate across

31:59 surface of the cell. All and it's just washing over. It's

32:02 like a a wave, just like did in the classroom with our eight

32:07 who were here that day, which very sad and pathetic. It's much

32:10 fun with 150 of you, all ? And so it's just opening and

32:14 voltage gated channels, just like we see in a neuron. But what

32:18 is is remember, we have these thes trans verse tubules, And so

32:24 the action potential still travels along the in this direction, wherever there is

32:29 trans verse tubules, theatric tensions going travel down the tube, and when

32:33 travels down the tube, it's going come into contact with very specific receptors

32:41 open in response that change in Those receptors are located in the

32:52 Cistern e, You're actually in the tubular, but they're associated with receptors

32:56 are also located in the terminal sous . So let's go back to our

33:00 once again. All right, so we are. We're coming in close

33:04 , so it's the same place where were. You could see the trans

33:08 tubules T tubules in the middle. could see the terminal cistern. You

33:11 see the extension of the circle plasma . Um, further down. All

33:15 , So all the stuff on the is exactly what we saw were just

33:19 in here on the tried a little closer. And what we can see

33:22 is we have these calcium channels, . They're referred to as D.

33:27 P receptors. They're the things that responding to that change in membrane

33:34 All right, so it's a voltage channel. It causes opening. It

33:37 deep polarization. And because they're associated another channel, this channel right over

33:44 that are on the surface of uh, the terminal cistern e.

33:49 air called Ryan Dean receptors. When open one, it causes the opening

33:54 the other and What happens is is comes rushing out of the stark A

34:04 particular, um, into the surrounding of plasm. All right, so

34:08 we're doing here is an action potential a nerve causes a deep polarization in

34:14 muscle fiber which causes these channels in triad toe open up to allow calcium

34:21 go into the cytoplasm. All And we're gonna pause there, and

34:26 going to now change the story for moment. Okay, so we'll come

34:31 to What is calcium doing in just second? This is kind of like

34:35 soap opera. You're really on the , The edge of your seat,

34:38 you to find out what happens? , so when you look at a

34:46 , all right, so this is slice through a muscle, right?

34:50 you can see it has stripes. you all see the stripes?

34:54 Thes stripes or striations represent fibers overlapping another where it's dark, you see

35:03 where it's light, you see a of overlapping. Okay. And so

35:08 of these bands, when they first in there, they looked at him

35:11 said, Oh, let's see how repeating they started labeling them and they

35:15 giving them names. And so these have special names. All right,

35:20 just gonna walk through him. Here rz disk. So there's r to

35:28 discs right there. So what's that call between the two z discs?

35:33 Amir. Okay, very good. right. So on either side of

35:40 Z disk, you see a light and those two light bands together on

35:46 side of the Z disk is referred as the I banned. Alright.

35:49 the I band represents is the presence thin filament. Now, what you

35:55 do is you can look down here you can see that representation a little

35:59 more clearly in the cartoon. I'm sit so I can draw while I'm

36:03 this. All right, So there's Z disk right? Right there to

36:07 there. That's your eye band. you can see there is my thin

36:13 on this side. There's my thin . All right, then what do

36:18 have that I have this very, dark band? All right. You

36:22 it from there to there. So begins here, and it goes all

36:25 way to their that a band represents presence of thick filament. Now,

36:32 , what we say is where it's dark. That's where the thin filament

36:36 with the thick filament like So that's why it's darker. But

36:42 in the middle of the A we have an area of light again

36:48 that area of life means there is overlap. So all we have there

36:54 thick filament. So if you want way you'd be thin, filament thick

36:58 thin filament, then thick filament and in the middle of the H

37:03 which is where there's just thick That's the in line. That's the

37:07 that divides the SAARC Amir in because then we repeat the opposite

37:12 So the in line represents the proteins the thick filaments are bound to.

37:18 you can't see me in the classroom this. But in the classroom,

37:23 looking at the picture like this. right, so fine here, Right

37:31 I look this way, you can see my actual mass, right?

37:35 you're looking straight down, you could that I'm broader than I am when

37:38 this direction just pretend. Okay? appreciate the laughing I really do,

37:45 it's if if you guys didn't it wouldn't be fun, All

37:49 And then you can imagine, over this is the Z line,

37:53 And the Z line has what's coming of it. If that's thick

37:57 it's over on the in line. coming on? The Z line?

38:01 the opposite of thick then thin So I got thin filaments and I

38:06 thick filaments. Can I borrow you a second? This is why you

38:14 to come into the classroom. but charm that. All right,

38:17 he is what? The Z line thin filaments. I am the in

38:23 and I have thick filaments and what doing is we're crossing this so you

38:28 see there's an area here that's just . And then together there's thick and

38:33 . And then over there, that's fin. So that's I band a

38:37 H band, and then you'd see repeated on the opposite side. Does

38:41 make sense? Excellent. Thank Now you can see there's other little

38:49 down here inside the SAARC. we have a protein called Titan.

38:53 . If you look at the little , what do you see in the

38:55 cartoon? Was it looked like, you tell up there even online?

38:59 can answer it if you want It's a little blue things. What

39:02 they look like? They look like . Okay, so imagine what you're

39:08 is you're contracting and contracting and And after you contract, you want

39:12 muscle to return back to its original . So what is the spring?

39:15 dio springs things back into their original . That's the purpose there.

39:20 It also serves to stabilize because what want is we want the thick and

39:24 filaments to be parallel to one All right. It does no

39:27 They can interact with each other if all co anchored. So having thick

39:31 thin filaments parallel is accomplished through Titan well as, um, the protein

39:40 . And we have another molecule. called Alfa Act in, In which

39:45 attach is the thin filaments to the discs. Probably not quite so

39:50 So you hear these terms thin filament thick filament. What do these

39:54 Well, way back when you took , you won. You probably learn

39:56 and you learn that thick filaments were assistant and you learn thin filaments were

40:00 . And then everything was hunky during went on your way. That's good

40:04 freshmen. For juniors, in a class, we need to go a

40:08 bit deeper. Thin filaments is actually different molecules, and even then,

40:14 even smaller components to them. All , so the obvious one is acting

40:19 acting basically is a, uh it's dime. Er that basically change itself

40:24 , and it gets attracted to another acting. All right, Uh,

40:29 what they do is they basically form Alfa Helix and you can see in

40:32 cartoon the alpha helix. It's basically yellow strand and the the purplish and

40:39 strand. I hope I got those colors, right. All right.

40:44 looking at the ladies guys. Just at it. We see purple,

40:47 right, so you can see there's Alfa Helix there right now on the

40:52 molecule, there's a spot that my likes to bind to. It's called

40:55 Myosin Binding Site. When we look Miocene, we're gonna look. There's

40:58 spot that likes to bind act and call it the acting binding sites.

41:02 how clever this is. The binding on acting binds to Miocene. Hence

41:06 name vice versa on myson. The thing is, is that we

41:12 to make sure that acting on Lee with my ascent at very certain

41:17 Kind of like a dance. You remember going to the high school

41:20 You dance too close with your What happens? Who shows up?

41:27 their name? You probably had a for a teacher, but the

41:32 the chaperone comes in and says, , no, no, no Separate

41:36 and then they walk away and go somebody else and back together again.

41:40 right, so we have a molecule behaves like a chaperone. It is

41:44 a chaperone. We have another molecules that. This is troppo myson with

41:49 name like troppo mice and it must really to my medicine. And it's

41:56 attracted to that binding site and it's rope structure you can see here that

42:01 kind of like these little tiny, pinkish I don't know, Rose colored

42:07 that kind of wrap around with it that album. And what is doing

42:11 buying into each of these mice and sites, and it sits there,

42:15 it covers and protects the Mayas and site Liasson. It literally is in

42:21 way, all right, but I my son to be able to bind

42:26 , to act in. So I to be able to move that out

42:28 the way. And so I need hinge protein to kind of be able

42:31 pull that aside at the right This is what the third molecule

42:34 It's a proponent. Troponin has three to it, and you can see

42:39 first part of the name is That's for troponin, and then the

42:43 initial in it tells you what it . So we have tea and I

42:47 inhibits contractions. All right, so it's there, you know, in

42:54 . We have another part, the that binds to triple Matthiasson, so

42:59 kind of serving as in, so have one part that's bound upto

43:02 one part that's bind up to My ascent on We have a third

43:05 called tnc that binds up to What happens is when calcium is

43:10 that's gonna bind to that. And gonna change the shape of the

43:16 It's gonna change the shape of the . And so when I change the

43:19 of the troponin, I pull on Miocene and I move triple Miocene out

43:24 the way. And that allows my to interact with the acting.

43:29 so troponin is the hinge that allows thing to move back and forth.

43:40 the thin filament is not just acting parts. Make sure you know all

43:44 parts the thick film. It's a easier. You ever played golf?

43:51 , that's good thing. Golf is angry, angry sport. You go

43:55 there thinking I'm gonna get good fresh . I'm gonna go and hit a

43:58 around and I'm gonna have fun. what you end up doing is you

44:01 beating a little ball and wood and start yelling at people and you fling

44:06 golf clubs because you get angry because ball never goes where you want it

44:09 . And then what happens is is you get one golf club and you

44:12 it around another golf club and it like this. See, this is

44:20 we make physiology fun. All It looks like to golf clubs have

44:24 wrapped around each other. All that is what a Miocene molecule looks

44:29 . And you get a bunch of mice and molecules and you align them

44:32 that in line, and you can Now I've got hundreds of these wrapped

44:36 golf clubs that have been jammed in , all facing one direction, like

44:42 right. Imagine the old tiny pictures the 19 thirties. The guy ready

44:46 box. That's kind of what it like. Fright. Hands up.

44:50 fists on the other side, The thing back to back. All

44:55 And so what they're going to try do is they're gonna try to attach

44:58 the thin filament and pull the thin towards the M line, which means

45:02 bringing the Z disc towards the M . All right, now you can

45:08 here There's a lot of information about shapes and stuff, But the key

45:12 here, if you look in the the picture on the top, right

45:15 . Here's the two golf clubs you see. Here's ahead. Here's the

45:19 tail, all right. And the in between those two is where we

45:25 a hinge. All right. And this is where the This is what

45:29 call the heavy chains versus the light . You can see in the bottom

45:33 . It's a little bit more So the light change our regulatory,

45:36 heavy chain is the interacting chain. the part that has the acting binding

45:41 . It's the part that has an p ace. When you hear the

45:45 80 p ace. What that means it takes a teepee and it breaks

45:49 into inorganic phosphate and a d. . And releases energy. All

45:54 so the heavy chain is doing the and it's gonna require energy. The

46:00 chain is basically what allows you to the head around, all right?

46:06 this is that structure. So you've just hundreds of these. So some

46:10 facing in this direction. Some are in that direction, and we're gonna

46:14 pulling towards the in line. So get back to our story now.

46:22 is like what in so proper terms now a month later, we've we've

46:26 of moved our way around and now gonna come back to calcium.

46:30 we had the action potential. The potential causes an e p p e

46:34 p travels along the surface of the goes down the transfers to bill activates

46:39 D H P receptors, which are with ride in receptors. When the

46:43 on receptors opened up, calcium flows in the side of plaza. What

46:48 up calcium. Do you remember I told you a couple seconds ago.

46:55 . That's right. Troponin. Very . So troponin, when calcium is

47:00 , gets bound up, and that's pull troponin off to the side.

47:04 that's what this picture is trying to you up there in the top,

47:07 could see I'm blocking the acting and and interaction. Basically, the mice

47:12 binding site is unavailable. Calcium comes , binds up to the TNC the

47:18 , right, the C part, it pulls it aside. Nothing is

47:22 me from binding to act, and so troponin goes in and bind and

47:28 is well, except it's a little more complicated than that. I

47:32 this part is the easy part. just because calcium is available and just

47:36 mine is an act and interact doesn't you're gonna get a pull. What

47:41 looking for is we're looking for what called the power stroke. Now,

47:47 could start anywhere in this circle. right, but we're going to start

47:50 the top. All right, so taken the calcium. The calcium is

47:55 for the mice and the acting to . And so now that's what the

47:59 is. That shows us our It's called the attached state. All

48:03 , So the presence of calcium is single most important event here because that

48:08 for the interaction. No calcium, interaction. So we need to get

48:13 interaction first. But when the calcium along, it doesn't cause the actual

48:18 . Stroke C, This is when teepee comes in. Now, this

48:22 kind of interesting. Alright. When comes in what it does,

48:28 So there's your ATP. What it . It allows for you to disconnect

48:33 acting in the Miocene. Wait. want to create a contraction. So

48:39 am I trying to. We're just that's our starting point. Right?

48:41 the calcium still available? What I've is I've I'm breaking the interaction now

48:47 this particular instance up here in this state, this is after I've gone

48:52 Ah poll. Have you ever seen gun with the trigger? Right.

48:57 the trigger has been pulled and the has been down, the bullet has

49:02 off, right? Can I shoot bullet yet? What do I have

49:06 do? I have to reset. hammer has to be reset and pull

49:11 right or I pull the trigger. you're dealing with a revolver, the

49:15 will pull when you pull the This is what the steps are

49:19 It's very similar to resetting the So what I'm doing is I'm setting

49:26 by binding of 80 p. I the bond between acting and Maya Seuin

49:33 breaking ATP into inorganic phosphate ADP I cocking the hammer. All right,

49:41 for those of you in the picture it this way. I've gone

49:45 my contraction. I'm bound up, . So what I wanna do if

49:49 wanna keep pulling this direction I have separate and I have to re cock

49:56 I have to have that site So here I am with that

50:00 Right? So I've got ADP and phosphate bound up. I'm able to

50:04 now in order for me to get actual contraction, the power stroke.

50:09 why I released the inorganic phosphate. now I've moved the acting forward.

50:16 , how do I get out of again? ATP Break the deep in

50:22 ADP and inorganic phosphate bind up again the phosphate and I get the

50:29 Do you see the steps here? right, so it's just going around

50:32 circles, racing all the income of one more time so that you guys

50:37 this. I've already gone through the . That's my starting point. So

50:42 is breaking the interaction by adding ATP ATP into inorganic phosphates. ADP allows

50:52 to interact again. Removing the phosphate me to pull on the acting.

51:00 right, the hinge moves and this the power stroke. And you can

51:06 I've got my assassins that are all this simultaneously and what that does is

51:11 drags a thin filament towards the M , which means the Z discs on

51:17 side are moving towards the in causing that SAARC amir to get

51:23 All right, that's the idea. SAARC Amir gets smaller. I wanna

51:30 sure that I even mentioned this I don't All right, so this

51:35 not on the slides, but I I asked this question. So you

51:38 to come up again and and and this with me? Okay, we're

51:42 do this. So I want you envision the Z disc in the M

51:47 . Right? So just put your out like, yeah, just like

51:50 . All right, so right now can see there's the A line right

51:54 is the I banned. There's our . There's the eye band. This

51:57 the H band in a contraction. Miocene is pulling the eye line towards

52:03 way. Now, have our arms smaller? No. But what has

52:08 smaller? The distance between the end the A band and the Z.

52:13 so the i band got smaller and distance between the A band and the

52:19 line has gotten smaller. So the band has gotten smaller, so a

52:23 in the SAARC Amir results in the of the I banned in the H

52:29 , but the A band stays the length. Do you see if

52:33 if he's moving closer and nearer to , do you see that our arms

52:37 the same length? But the distance us changes. All right, thank

52:44 again. There would be easier for in the classroom if I had a

52:47 camera on me instead of that. I want you to envision which bands

52:55 getting smaller, all right. The bands, the thick and the thin

53:00 of themselves do not get smaller. always the same length. It's the

53:06 between the M Line and the Z that is shrinking. And it's a

53:11 of those two bands or the thick thin filaments sliding over each other.

53:15 right, it's called the Sliding Filament , all right, It's not really

53:21 theory at this point, but that's his name is. A band stays

53:26 same length, but the I Band the H Band gets smaller because of

53:31 distance between them getting smaller, so is a result of calcium being released

53:41 the stark A plasm at P being for the contractions to take place

53:49 at death, when you die, is one of the primary characteristics of

53:55 corpse? What do we call a in the vernacular? In the regular

54:01 ? What's what's one of the slanguage use for corpse? Dead body A

54:10 . Excellent. Someone's playing. a stiff. Why is it called

54:13 stiff? What character? What? is the feature that a stiff goes

54:18 to make it called a stiff? . Rigor mortis is the word I'm

54:23 for. Okay, Well, what rigor mortis? All right,

54:26 remember, when you die, you're pumping. You're not pumping.

54:31 uh, you know, sodium, , you know. So all the

54:34 the cellular machinery is dying, But it's still working for a short

54:39 of time after death, right? so you can imagine all those pumps

54:44 everything taking place are going to stop . So calcium is gonna flood in

54:50 the cells, and then as a , you're going to get a whole

54:54 of contractions, right? And you enough a teepee there to kind of

54:59 the contractions of the muscles, get and contracted. But then, when

55:03 A t. P. Is not , there's nothing that's gonna allow you

55:07 relax the muscles. So you stay a contracted state. That is rigor

55:12 . It's simply the calcium pumps and 80 p not being made that causes

55:19 rigor state. You ready for the story? My grandfather, when he

55:23 young, worked in a mortuary for night. He told me this

55:28 and so I have to believe it's . You probably lied to me,

55:31 I have to believe that it's All right, so he served

55:35 like the age of 17. this is pre World War Two.

55:39 , mortuary goes in. He's the watchman, 17 year old 18 year

55:44 kid, right? And you just of walked through and just make sure

55:48 one's going into steel in the He walks into the, uh,

55:52 where they're doing the actual body And there's someone they had brought in

55:58 in the evening, and that body up just as he walked through,

56:04 said he dropped his flashlight and never back. Why did it sit

56:10 Rigor mortis. Okay, I thought was a fun story. So how

56:18 we relax? Well, calcium causes . Let's get rid of the

56:22 So naturally, what we have is have pumps. All right, so

56:27 SAARC applies, particularly as a It's called circa See smooth and

56:31 in particular calcium pump. That's the . So it's called circa. It

56:36 it so much easier once you Oh, that's how they name stuff

56:40 they're lazy and they just abbreviate Yes, so circle what it

56:45 It's always pumping, you know, just pump, pump, pump,

56:48 , pump. And if calcium is released, its moving mawr calcium

56:51 then that could be pumped in. once you stop the release of

56:54 in other words, you close those on receptors. Then what happens is

56:58 that the calcium pump is able to all the calcium back in. The

57:01 applies for particular. That's one all right, we also have calcium

57:06 that Aaron the surface. These aren't as active in skeletal muscle as

57:11 um, uh, cardiac muscle, we primarily trying to get calcium into

57:16 Sarka Plaza in particular. Um, also a molecule called calcite Question.

57:22 , clever. That is calcium sequestering . Yeah, so Cal sequester.

57:27 there's all Cal, Cal. um, they basically serve a role

57:30 binding of calcium so that when you open up the channels, it takes

57:34 little longer for the calcium to get . And basically the last statements here

57:38 you don't have action potentials, that you don't open up the D.

57:42 P receptors, which means you don't . The Bridon receptor means calcium doesn't

57:45 out. Calcium stays in the Sarko in particular, and you have no

57:50 for contraction. Pretty basic. When potentials calcium is released. No calcium

57:58 no extra pencils, no calcium. I said, everything I'm telling you

58:05 could be done in five minutes. what this slide is. It just

58:09 you through all the steps. So you're studying, this is the This

58:14 the best place to be is to a picture like this so that you

58:18 the whole process, right? What we say after neuron neuron causes?

58:24 an actual chance that goes down causes release of our the influx of calcium

58:28 the the motor motor neuron that caused release of ASIO Colin at the motor

58:33 plate that binds to, uh, receptors at the motor in plate,

58:38 causes an acceptance that travel along the of the muscle cell. He goes

58:42 the T to bill that action uh, activates these D H P

58:47 , which then activate thes ride in , which are associated at the terminal

58:52 of the of this Arco Plaza in . Or the terminal cistern cause release

58:56 calcium calcium binds up to troponin. causes the movement of triple myson off

59:01 acting that makes the myosin binding site . Myson comes along, binds upto

59:07 , and if ATP had been we had already cleaned the eight p

59:10 the inorganic Theo, a DPD inorganic . So now that they're bound up

59:15 , all we got to do now released the inorganic phosphate and that causes

59:19 pull or the power stroke in that and fiber. And in doing

59:26 we've caused the two Z discs to close together right towards the M

59:31 and that is a contraction in a cell. Now a name muscle is

59:38 maney muscle cells lots. That's the . I'm looking for lots. So

59:44 is happening in lots and lots and of cells all at the same

59:48 That is what a contraction is. , so that's what this big picture

59:54 in terms of what's happening inside the . And you can imagine this is

59:59 in lots and lots of cell Yes, sir, when it's considered

60:06 whole cycle that we saw, it's the Power Stroke Cycle. So the

60:11 is, is when we when we in terms of the power stroke,

60:15 power stroke is dependent upon a TPE cause the release of and then ultimately

60:21 reset of the Mayas and head so it's capable of interacting with acting

60:26 And then the release of the inorganic causes the actual stroke. But the

60:31 thing together is the power stroke. it's it's all the little pieces together

60:39 do you see how you could write all in one picture just by looking

60:43 this? It was a long but I got us there. All

60:51 , Let's see if we can get the rest of this stuff really,

60:53 quickly. All right, So this that's That's the key stuff, how

60:57 work. And so if you know how skeletal muscle works, you can

61:01 see how it's just gonna kind of outward. There are two different types

61:04 muscle contraction. One that's called isotonic , one that's called isometric isotonic.

61:11 is where the muscle tension remains All right, but the muscle link

61:16 . Uh, usually I have a in here. I'll use this chair

61:19 O that you guys could see those . You could do this at

61:23 pick an object and pick it All right. Does this chair

61:27 Wait when I'm picking it up. , it's a constant weight. So

61:31 amount of tension I have to produce order to move the chair is

61:36 Okay, turn around this way. think I'll be a little bit

61:39 Pick it up. Alright. So chair never wait. But in order

61:44 my me to lift it up, happens to my muscle? It got

61:48 , didn't it? Right? And I put the chair back down.

61:51 my muscle doing? It's getting Oh, wow. So we're looking

61:55 the bicep? Yes. So, , when I'm putting it down,

61:59 the the reciprocal muscle is getting shorter this one's getting longer. So

62:05 understanding that we're not just looking at muscle. We're looking at multiple muscles

62:10 , but just looking at the bicep can see when picking up the

62:14 The muscle got smaller during the and as I put it back

62:19 the muscle was getting longer, even contraction was taking place. This is

62:25 as the muscle is shortening with Alright, so I'm still producing the

62:30 amount of tension that is called con . So lifting it up was the

62:34 centric move. Three e centric move putting it down, all right,

62:38 I'm maintaining the tension so I don't the chair right. If I release

62:43 tension, the chair would just Isometric is when the muscle doesn't change

62:49 , even though I'm increasing the amount tension. All right, so here's

62:55 simple. When this back in the , this was a very, very

62:57 way to exercise its using muscle against . So if I push against my

63:02 like I am right now, I'm a little bit of force,

63:05 And I can increase that force and and increase and increase. But neither

63:09 is moving. Is it right? an example of isometric. I could

63:12 it against the wall, right. can push up against the wall like

63:16 right. I'm not putting a lot force in there. I could put

63:20 force and more force, but the is not gonna move. But I'm

63:24 more and more attention as I So yes, Thank you. Say

63:32 , Doing a plan? Yes. a plank would be a type of

63:37 because what you're doing is you're just . Um, Well, actually,

63:40 know, it's probably a combination of , right, because what you're not

63:45 is you're not changing muscle. I , you're as you as you're sitting

63:49 . You're increasing muscle tension, just trying desperately not toe to stop the

63:54 . Right? But it's not like applying Mawr Force to try to accomplish

64:00 goal. And so there's there's an move first and trying to get into

64:04 position of the plank, right? creating the contraction to lift your body

64:09 off the ground. Once you're once body's up off the ground, you're

64:13 in creating an isotonic. Excuse an isometric contraction. All right in

64:19 say the forearms. Usually all I planks air right in the belly,

64:23 I'm praying for death so that I that kind of made sense. And

64:28 , I'm not going to sit there and give you a whole bunch of

64:32 moves and saying, What is What is this? What is

64:35 The definition simply is if I'm trying If the muscle length changes, that's

64:41 . If the muscle length doesn't but the tension does, that's

64:46 That's a that's the strict definition. , when I make a single muscle

64:55 contract, we call that a All right, a twitch is not

65:02 . Okay, that's me twitching. was trying to think of Twerking,

65:08 that's a different word. Entire slightly . But a twitch is simply that

65:15 in that single cell. Now what we said is, a muscle

65:19 made up of multiple cells. Do think you could visually see a

65:24 No, It's too small and not enough to actually do anything. All

65:30 . And so what you need to is you need to have an additive

65:33 . Now, to be clear here action potential is a signal. A

65:38 is an actual event. Right? the action potential leads to the

65:43 So do not confuse the two And so what this is trying to

65:47 you is the twitch up on the where the arrows are That represents the

65:52 potential where the action potential occurred. the result of that action potential is

65:58 little blip in terms off. What in the muscle? That's the

66:03 Alright. Too small to see. we could measure it with,

66:07 you know, a single fiber, could measure it. So how do

66:12 get a muscle to move something? , let's make it additive. Let

66:17 send mawr signals. Right? Because my muscle contracts and relaxes and can't

66:22 anything if I want to get a contraction, what I do is I

66:25 to send a whole bunch of and they can some eight. And

66:28 what they do is I create the little bit, and I just keep

66:32 it upwards. That is what is what we refer to as tetanus.

66:36 tetanus is sustained contraction in a So remember when your kids your parents

66:42 let you out of the house because afraid that you're gonna go play in

66:45 playground, step on a nail, I know that you're gonna get

66:50 right? We played in dirty places we stepped on nails. That's why

66:56 stronger, more powerful than you. having more fun. They No.

67:06 idea here is why did they You've heard that. What is

67:10 You've heard that, right? What it? What? What is the

67:14 ? What is the main feature of ? When if you get tetanus,

67:17 you step on a rusty nail, do you think happens? What do

67:20 get? That's right. Block Jaw the primary ideology. You're basically your

67:28 clinches in your cheeks and right, is tetanus. All right. That's

67:38 they got the name from its tetanus those muscles. Temporomandibular joints, the

67:44 around that. All right, so why they call it that. And

67:47 you have to go get, the tin things in your belly.

67:51 know, it's just awful. Don't tetanus. Don't step on rusty

67:54 All right? So you can see here at the bottom of the picture

67:58 showing you what fused tetanus looks That's just sustained contraction, e.

68:03 mean, and it doesn't have to a lot, right? I

68:05 here, I've got my little How much do you think this pin

68:10 ? What do you think? Maybe if we're if we're really,

68:15 , you know, putting our weight it. Maybe, But can I

68:17 I sustain a contraction with that? certainly I can. Right Doesn't require

68:24 lot of work. Now, could have a sustained contraction holding that chair

68:29 ? Sure, but it would require little bit more work. And so

68:33 we have here is not just a results in a great amount of force

68:39 tension. What we're gonna do is gonna recruit muscle fibers to create greater

68:47 . So what we need to understand that a motor unit represents the number

68:53 cells associated with the single neuron. we have a neuron and we're gonna

68:58 this picture as an example You can here this particular acts on goes in

69:02 innovates 123 cells in that particular fast that they've pulled out here. And

69:09 what it's saying is that this particular motor unit is equal to that

69:14 So the one neuron and the three and innovates So when a signal comes

69:19 that neuron, all three fibers undergo contraction. Alright, So to move

69:26 pin, I might use one motor . So not a lot of

69:33 If I need to move the which weighs about four ounces, I'm

69:37 to use a couple mawr motor units it comes time to move my nice

69:44 beverage here, it's t. I it was something else. It's going

69:48 require more motor units, and when get down over here to the chair

69:55 up the chair, it's gonna require Mawr. So the idea is it's

70:01 same muscle big name muscle, but requires mawr or recruitment of motor units

70:08 create the amount of tension necessary. is what is referred to as multiple

70:15 summation, bringing in mawr and mawr to do the necessary work to create

70:20 amount of tension needed for the job hand. All right, now,

70:25 different activities, we're gonna have different of motor units. So, for

70:32 , if I am writing right using , I need very, very discreet

70:40 , Right? So for a motor , I'm gonna have very few fibers

70:44 the motor unit. So that kind makes sense, right? Because I

70:48 want to have a big, jerky . I wanna have really, really

70:52 and defined. So adding in one at a time into the activity is

70:58 my benefit. But walking on the hand to lift my leg and to

71:04 my body fall forward, I'm going recruit lots of fibers. So I've

71:08 very large motor units. So remember we're talking about, like, the

71:14 areas between rods and cones and the of a number of self. It's

71:18 same sort of principle, you delicate or fine tuned. Um,

71:24 requires very few muscle fibers in the unit, whereas very coarse activity.

71:31 gonna have big um uh many muscle within that motor unit. Now I

71:41 these slides towards the end of the , moved him up forward because it

71:44 made more sense. So there's different of muscle fibers. There's fast fibers

71:50 slow fibers that all that refers to how fast they're able to pump

71:53 So you get fast. Twitch is slower twitches. And again, this

71:57 relatively speaking. All right. Slow , which is not like it's still

72:03 , but it's not as fast as . We also have what is referred

72:08 as oxidative versus like politic muscle Oxidative fibers rely on taking glucose and

72:17 and converting into water and carbon It's basically using the entire pathway to

72:21 as much. A teepee is possible that you can have all that A

72:25 T A t P to do the like politic, on the other

72:28 are basically like I don't have the to waste, too. Produce all

72:32 ATP. So just let's just break Glucose and used like Collis is so

72:36 gives me quick energy. Quick quick activity, and I run out

72:40 energy quick so I can fatigue a faster. So like a like a

72:45 fatigue. Quickly, oxidative fatigue. , if at all. All

72:50 so that's that's the idea. So basically we break them down by

72:54 We actually have terminology for these. know, you've heard of white and

72:58 meat, you know? Look at chicken. It's like, Oh,

73:01 , there's white meat. There's dark . We have white and dark meat

73:03 well, the differences are fibers are , so, like your all your

73:08 have both black politic and oxidative. don't have them separate like you see

73:12 in a chicken because we don't taste good. I'm That's not what they're

73:19 for. All right, So these the three muscle types we have slow

73:22 . This is the red muscle. to remember. Oxidative has oxygen,

73:26 it means it has more myoglobin. why it's red. So it's red

73:30 . There's type one and type two um, basically, they're there for

73:35 and powerful contractions. Alright, thes What marathon runners and where you're doing

73:41 activity over long periods of time. what you'd use those for fast like

73:46 on the other this is white These were the most prevalent fibers that

73:49 available. Very little myoglobin. they're smaller in diameter. They're able

73:55 do burst activity for very short periods time. So lots and lots of

73:59 , very short periods of time. the way I think about it,

74:03 sprinters have lots of this. the thing is, is you can't

74:07 convert one into the other form. when you work out, basically you're

74:11 with whatever your ratio is of too slow. And when you work

74:16 , you actually maximize what you So, for example, I

74:21 um, primarily oxidative. So when work out, I get bigger and

74:25 here. I don't lose weight. gain weight. And I look like

74:29 Hulk. All right, which is sad, because when you wanna lose

74:33 , you don't wanna look like the . You wanna look like Bruce

74:36 which is smaller, tinier. But my roommate in college, he was

74:40 elliptic. He'd work out the guy with right now he's like elliptic.

74:44 more he works out the wiry he . So he's like this thin,

74:48 thing, and he just gets Er and wire and wire for those

74:52 run track, right? I you got your sprinters. What do

74:55 sprinters look like? Cult, don't ? Right. But if you got

74:59 distance runners, what do they look ? They look like they've just fell

75:03 a boat and haven't eaten in 30 . Right? But they're equally as

75:11 . They just have different muscle How are we doing on time?

75:15 five minutes. So, um, is just a chart to compare those

75:18 things. Cardiac muscle very similar to muscle. The differences in terms of

75:25 the cells interact. They don't have , really long cells. You have

75:28 small cells, um, their So they interact with each other.

75:33 , uh, kind of a unique . So, whereas in skeletal

75:37 they're they're stretched, you know, just one long sell. Here.

75:41 have small cells that branches, so attached in the end, and so

75:44 each pull on each other in the that they're attach is called inter collected

75:48 . And you can see in the up above. This would be an

75:53 disk. There's one. There's one on. And this is kind of

75:55 looks like you have Desmond's OEMs and junctions so that the cells can communicate

76:01 each other. And when they pull each other, don't rip each other

76:04 , all right. But the same that we saw in skeletal muscle and

76:09 muscle there a little bit smaller. , I mean, not a little

76:14 smaller. They, uh, they a diet instead of triad.

76:19 they pump their calcium out of the instead of into the sarka plastic,

76:23 they still have it. But majority the calcium pumped back out. And

76:28 cardiac muscles always working, there's more . That's that's kind of the key

76:34 , all right? Oh, and also self generate action potential. But

76:37 talk about that when we talk about heart later. This is just kind

76:41 showing you the same sort of thing skeletal muscles or as as skeletons.

76:46 is cardiac muscle, but you'll see pattern is basically the same, the

76:50 being that the calcium is primarily on outside rather than on the inside smooth

76:58 , and I've got what, four here to kind of explain food,

77:01 muscle, smooth muscle is very Same sort of issues. I

77:06 we still want to create contractions, structurally, they're very, very

77:13 They exist in what are called census . All right. And so

77:16 the individual cells or bundled together, they act independently of each other.

77:21 the names. Alright. Multi unit many discrete units. Alright. Doesn't

77:26 many cells in the unit. So unit means they all act individually or

77:32 , um they act independently of one single unit. This is more of

77:36 census. She, um, where the cells are connected. So if

77:38 cell is stimulated thing, entire Bunches . All right. Single units could

77:43 self excitable, meaning that they produce own action potentials. Um, they

77:48 be modified in terms of the type signal that that they'll respond thio.

77:55 , the neurons don't form an in motor in plate. Instead, what

77:59 do is the neuron kind of travels the surface of the census.

78:03 which is again sensation literally means Alright. So it kind of traveled

78:08 the surface, and you have these cost is kind of these bulges along

78:12 length of the acts on terminal, it's from there that you kind of

78:15 the neurotransmitter onto the sensation. So is no motor in place. You

78:21 kind of like sprinkling neuro transmitter out the cells. And hopefully they'll

78:26 Sometimes they do. Sometimes they Sometimes you respond well, not quite

78:30 well, so we go through these of of contraction. All right,

78:39 what we refer to the pacemaker. so basically, you send you spend

78:42 time underneath threshold, and you just of rotate there. And then if

78:47 stimulated, that might bring you above , produce a whole bunch of action

78:52 . Here's an example of the pacemaker going up, up. You

78:55 I'm spending time down, but then bring myself up. So these are

78:58 types of of responses that smooth muscle have. They go through these patterns

79:05 slow wave potentials or pacemakers, and is just an example of what that

79:10 of looks like. So I'm not walk you through it. That's just

79:14 just the kind of the functionality. , this is how smooth muscles look

79:20 it's very different. You can see there is no um there's no

79:25 There's no Z discs. Alright, no in line. Instead, What

79:29 have is you have these structures that attachments near the surface there called basil

79:35 , same proteins that are found in discs but not Z discs themselves.

79:39 then you have thick filaments and thin and intermediate filaments which are just,

79:44 know, in every cell. But thick and thin filaments are interacting in

79:48 the same way that you see um in skeletal muscle. The difference

79:54 is that because you're attached to a , Thio said, basil body,

79:57 in dense body. Um, because attached to a dense body when you

80:02 your basically pulling one dense body towards . So it kind of looks like

80:05 taken a ham and you've wrapped it right, and you're not squeezing the

80:10 so that you know what I'm talking . That's what it looks like.

80:13 so you're not contracting in a You're contracting in all directions. So

80:18 cells are getting smaller or their when relaxing. They're getting larger. All

80:25 , The key thing here that I you to take away is that smooth

80:29 contraction while they're dependent upon calcium, have to answer the question at the

80:35 , all right, It's all the material. It's just it's done

80:39 It's a signaling cascade, as opposed calcium being released and binding up the

80:45 . There is no troponin in this , right? So again you can

80:48 the ride in receptors, you can the voltage Gated calcium channels were not

80:53 involved. You can see circa calcium involved. The difference is that we're

80:57 be using a signaling cascade, and signaling cascade is done through Cal module

81:03 . All right. And so the this works is that here you can

81:08 there's our myson. It looks exactly same. It's not. It's slightly

81:14 . Alright. Instead, what happens of a teepee coming along and and

81:19 phosphor awaiting it? What happens is calcium comes along and activates Cal module

81:25 Cal module in Once it's activated, that first step. That's calcium.

81:29 activates a kindness called myson light chain . Remember I said, that hinge

81:36 is the mice and light change and modest in light chain. Kinney's coming

81:41 and it falls for relates that And when it falls for relates the

81:46 that changes its activity. All that's how the activity works here.

81:54 right, so it changes the And so it increases theeighties pH activity

81:59 would naturally be there. And this what allows smooth muscles to interact.

82:04 instead of it, just calcium comes and allows me to bind. I've

82:09 to go through the signaling cascade. no true opponent. Normally, my

82:14 very slow. This speeds up the of my reaction. Now there's other

82:21 involved as well. Um, uh, modeling kindness to plays role

82:27 , um, false foiling Cal And if you go back to the

82:30 slide, let's think it's here. not. Ah, component is an

82:38 and basically, uh, slows down rate at which the mice and

82:43 And so, basically, if I in and phosphor relate, the

82:47 in other words, inhibits the I'm basically allowing the activity to go

82:52 , so that's three idea. Here a signaling cascade. So this is

82:58 last slide. This is you get go home now. It's basically comparing

83:02 three if you know skeletal muscle, know, cardiac muscle minus the small

83:08 . If you know how a muscle , it's gonna be true for smooth

83:12 with the exception of the mechanism. it's still calcium, and you still

83:16 a teepee. But the differences in muscle cardiac muscle, we're binding up

83:21 troponin and causing the movement of machinery , we're using a signaling cascade to

83:27 the myson. That's the That's the of everything. So I had a

83:34 online, and if you want to now, you can go now.

83:36 I'm gonna answer questions just to be , you're wrong with that question.

83:44 , you can think of digestive So digestive tract would be mawr of

83:49 single unit, right? So if cause one cell in that smooth

83:53 it would cause the entire digestive tract in that in that well, within

83:59 context of that one motor unit. right, But think about your

84:03 Your eye is is multi unit, individual fibers air being activated that causes

84:09 dilation or the contraction of the pupil or Here's a fun one. You

84:15 watched a scary movie and only one of your body gets the chills.

84:18 , like, the hair stands up Leon like one arm. And you're

84:21 , That's odd for a reason. multi unit. All right. If

84:26 was single unit, all of the on your body would stand up.

84:30 that be the examples? Anyone All right. So on Thursday,

84:35 put this in the in the I still will have office hours,

84:39 I have to end office hours at . 45 because I have a meeting

84:42 12 that I have to get to my house. So, um,

84:46 be available for short period of So if you have questions, you

84:50 ask any other questions. Anyone is go to the game on Thursday

84:59 So you all know I went to ? I have to wear the two

85:02 . I'm just gonna be a hard for me. I'll be happy whoever

85:07 that will just put it that Our muscle contraction what's instead?

85:15 so the question is what shrinks and stays the same. I'm gonna see

85:18 I could do this on a white . I don't know if I could

85:21 this. I'm gonna try. let's see. All right.

85:30 um, what I'm gonna do is gonna open up the white board

85:34 and I'm gonna change my screen, just give me a second,

85:44 I am a share. Um, white board. All right. You

85:50 can see this. Yes. All . So here's my Z disc

85:56 Probably help if I actually have a . So here's my Z disk on

86:01 side. Here's my M band. right, so I'm gonna draw one

86:06 for thick, the other color for . All right, so this is

86:25 a band. This where there's just little bit of overlap is remember the

86:31 band and then over here, that's I banned those two things together.

86:37 you can imagine on the other side would be That would be so.

86:41 I have a contraction, Maya Seuin in this direction. I should probably

86:49 do a different color. But I I want right now, all

86:53 And so what ends up happening is that the Z discs get closer alright

86:59 band stays the same. I am this out of the way.

87:08 Here's my am's Here's my Z And here is my thin filaments again.

87:20 a good day. So what has ? My a band stays the same

87:30 , writes a But my age has smaller, right? What used to

87:35 way out here is now starting their similarly right. And then what about

87:42 eye bands? My man's used to this big Now they're smaller. Thick

87:49 didn't change size thin filaments didn't change on Lee. The distance between here

87:55 there change size on Lee. The between there and their change size.

88:02 that means it's the H and the band that changed lengths because it's just

88:07 distance. Does that make more Yes. No. Maybe Give me

88:16 thumbs up. Thumbs down. Thanks. Fantastic. Alright. If

88:21 are no more questions. Oh, are some questions. All right,

88:37 that ze probably not the best way ask the question. What I would

88:42 is is if you have a non muscle type In other words, ones

88:48 sorry anoc sedated muscle type that usually means you have a wiry frame,

88:54 , and that wiry frame allows you do things with stamina. So that

88:59 be, for example, distance running things like yoga. You know that

89:05 of stuff where, um, um, who have the Glock politic

89:10 where it's the fast burner, those who typically conduce exercises like sprinting or

89:17 training. And when they when they out, they bulk up because those

89:23 get larger in terms of their And that's kind of the key thing

89:27 is when you work out, you get more muscle fibers. You end

89:31 with fatter muscle fibers. They end with more of those thick and thin

89:37 inside them so they can create stronger . I hope that was the answer

89:42 the question, Professor. One Let's see, we got one.

89:49 ahead. Uh huh. 50. always 50. You're welcome. Go

90:10 . That's that's actually a good So let's go back to that slide

90:14 . It's gonna take me a second get there, So what I want

90:19 I won't Oh, I know

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