| 00:04 | The term. So short week, guys don't seem particularly alert. You |
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| 00:16 | beat up. Well, not feeling beat up. You're feeling beat |
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| 00:22 | . You're not being, it's you're not being beat up. You |
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| 00:25 | beat up. Mhm. All So, you've seen, you've seen |
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| 00:35 | ? You've seen distributions. Good We still have a half a semester |
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| 00:38 | go. It's, it's not the of the world. If your grades |
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| 00:41 | not where you want them to just remember, we can change what |
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| 00:45 | doing, keep going at, like explained to you and your grades will |
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| 00:50 | in the direction that you want them go. You can't just hope that |
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| 00:53 | grades will go up. We could about grades all day, but that's |
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| 00:57 | why you guys are here. You're to learn a little bit of |
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| 01:01 | a little bit of anatomy. And I think we're going to cover something |
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| 01:04 | , um, at least you've seen someplace else. Probably. Probably in |
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| 01:09 | sciences. Someone talked to you about a muscle works in a very generic |
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| 01:14 | . Right. What we're gonna do we're gonna dive deep, we're gonna |
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| 01:16 | at the anatomy and the microstructure of muscle cell. And then what we're |
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| 01:20 | do is we're gonna start looking at it actually goes through this contraction. |
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| 01:25 | we're not going to do in this is we're not gonna name every muscle |
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| 01:28 | your body. There's 600 muscles in body. I think in the lab |
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| 01:33 | have to learn something on the order 120 of them. I don't |
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| 01:37 | it depends on the school. All . But the idea here is, |
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| 01:42 | know, at this point in your , it's not entirely important to know |
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| 01:47 | the names of all the muscles. more important is, do I know |
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| 01:51 | they work? Because reasons, So, first off, let's just |
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| 01:59 | about what muscles do. All this is in terms of functionality. |
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| 02:03 | is the physiology. What is their when we think about muscles, what |
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| 02:08 | think about for the most part in recording. I am ok. Um |
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| 02:12 | we think about for the most part movement. So it's low commotion. |
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| 02:15 | absolutely true. But it also plays important role in protection and support. |
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| 02:19 | holds your organs into place. Your are not spilling out around you because |
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| 02:24 | muscles say are, are are in state of, of this kind of |
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| 02:29 | contraction. And so they basically hold into place. It helps you to |
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| 02:35 | your posture. I look around the and most of you aren't slouching, |
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| 02:39 | know, but your slouch is also of a, a position you've decided |
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| 02:44 | kind of be in. We've talked stabilizing joints. What we don't think |
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| 02:48 | lot about also is that it generates . All right. This is how |
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| 02:52 | body stays warm because every time you a muscle you're burning and releasing, |
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| 02:58 | burning a lot of energy and you're so in a very inefficient manner, |
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| 03:02 | like your car. All right. know, your engine doesn't burn fuel |
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| 03:08 | . You, you lose like 80% the energy that you're actually, that's |
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| 03:12 | the fuel. That's why your engine gets really, really hot and that's |
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| 03:15 | you have that little monitor that talks hot and cold for the car. |
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| 03:19 | . So you're the same way. that, that when your muscles |
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| 03:23 | it's producing heat energy. And the thing and we don't really think about |
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| 03:27 | at all, but your muscles play important role in communication. If you've |
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| 03:32 | me long enough, you sit see me do this type of |
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| 03:34 | right? I just stipulate, which like a dirty word, right? |
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| 03:40 | gesticulation simply means me expressing things, that's not the only thing that I'm |
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| 03:44 | , right. Um When we we communicate with our face, we |
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| 03:49 | with our speech. Speech is simply movement of my mouth, pushing air |
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| 03:54 | my larynx. That larynx is basically skeletal muscle there that basically moves back |
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| 04:00 | forth to change the flow of the and create different types of vibrations. |
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| 04:04 | change the shape of my mouth. my vocalizations are simply a function of |
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| 04:10 | skeletal muscles and me controlling them. kind of cool. All right. |
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| 04:16 | you're 21st century kids, really adults this point. So sorry. Um |
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| 04:22 | you do a lot of this stuff . So that's how you communicate, |
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| 04:28 | ? Sort of. So when we about muscles, we're primarily thinking about |
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| 04:33 | and all the stuff that we're but overall there's a lot of other |
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| 04:37 | that are going on here. All . So as I mentioned for |
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| 04:41 | you're coming a little bit behind, are 600 named muscles in the body |
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| 04:46 | we don't need to know a single of them in here. I usually |
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| 04:51 | some like yay, but all fine. We can learn them if |
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| 04:56 | want there. Now, I'm getting response now I'm starting to see uh |
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| 05:01 | , please don't make me all So what we're gonna do is we're |
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| 05:05 | , we're gonna break it down. gonna take and think about a muscle |
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| 05:09 | what we're gonna do is we're gonna it down to the cell and then |
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| 05:12 | we're gonna spend our time in that and then we're gonna work our way |
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| 05:15 | out again. All right. And when you think about a muscle, |
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| 05:19 | when you go and buy a What you've done is you've gone, |
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| 05:23 | a cross section, you bought a of muscle, someone has cut that |
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| 05:26 | . So you get a cross So you're looking at it like |
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| 05:30 | I kind of look like a steak . I mean, how about a |
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| 05:37 | ? All right. And what we're at this is a muscle. You |
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| 05:40 | see here is the bone, here the muscle. So let's just call |
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| 05:43 | , you know what your bicep right? I mean, can we |
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| 05:45 | , can we all know what our is bicep? All right. On |
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| 05:49 | other side of the tricep, there's muscles in there, but the |
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| 05:52 | the easy one. So this is bicep. This is what they're trying |
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| 05:55 | do here. They're saying. All , look, here is the named |
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| 05:59 | . And if you look at the muscle, you'll see that inside. |
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| 06:02 | is not only muscle fibers, but connective tissue. And if you work |
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| 06:06 | way down, you'll keep working down you finally get down to the individual |
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| 06:12 | . So what a muscle is a ? Muscle is, it's a cell |
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| 06:15 | in connective tissue. And then you a bunch of those cells which are |
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| 06:19 | in connective tissue and you bun them in other connective tissue. And then |
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| 06:23 | take those bundles of connective tissue cells then you take those and you put |
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| 06:28 | together and then you bundle them up . So at each layer, we |
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| 06:32 | an outer layer of connective tissue and you have a group grouping of cells |
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| 06:36 | a grouping of materials. And then material is itself wrapped in connective |
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| 06:41 | So in this case, now, we're looking at is a series of |
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| 06:44 | and each of the individual cells has own connective tissue. Now the reason |
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| 06:48 | cell has its own connective tissue is that connective tissue serves kind of as |
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| 06:54 | . It isolates that one cell electrically all the other cells. Now |
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| 06:59 | you guys are a generation that has cell phones. You probably have never |
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| 07:04 | a cell or a phone in your that's acquired or corded. Do you |
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| 07:09 | one in your house? No, anymore. All right. So that's |
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| 07:14 | I grew up, right? Everyone one phone number and you had like |
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| 07:19 | phones in the house that had the line. And then somewhere around when |
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| 07:22 | hit like junior high or high that's when like the the phone companies |
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| 07:28 | marketing, realizing, you know, , teenagers want their own phones and |
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| 07:31 | pushing the print access phones big And so then you had multiple |
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| 07:35 | like you could have two numbers in house. Keep in mind there wasn't |
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| 07:39 | waiting back then. I mean, the phone was busy, you couldn't |
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| 07:43 | through and dad got really pissed off their daughter was on the phone from |
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| 07:47 | the moment she got home from school the moment she went to bed, |
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| 07:50 | why they call them princess phones because bought them for the daughters. |
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| 07:54 | This wasn't because they had little crowns them. All right. But the |
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| 07:58 | here is back in those days, could like the phone lines. You |
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| 08:03 | , if, if they were like a bad position, they get |
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| 08:06 | And so instead of having fiber you had metal on metal. And |
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| 08:09 | it rained now you're actually cross linking lines, you could pick up the |
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| 08:13 | and you could hear people talking and couldn't hear you. You'd be like |
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| 08:18 | on my line and they had no . It's because there was this cross |
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| 08:23 | the connective tissue kind of serves as insulation around a wire. It prevents |
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| 08:28 | cell from being stimulated when another cell trying to be stimulated. All |
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| 08:33 | because remember what is, what what are electrical signals? They're just |
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| 08:37 | moving back and forth, kind of power in a power line or the |
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| 08:43 | moving along a copper wire going onto phone. All right. Now, |
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| 08:49 | of these layers of connective tissue have name. So the muscle fiber is |
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| 08:56 | muscle cell. You might even see word myofiber. All right. So |
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| 09:00 | just has a fancy word. But is it? It's a cell. |
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| 09:03 | right. And it's a very long . Each of the individual cells are |
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| 09:06 | , very long, just like the are, they're attached at one |
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| 09:09 | So like my bicep is attached up and then it travels down and it's |
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| 09:13 | down here. So every cell in bicep has that same length. All |
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| 09:19 | . And then, so around that that connective tissue, this is called |
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| 09:23 | Endomysium. All right. So in the inside Missi I'm referring to the |
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| 09:28 | tissue and then you take a bunch these fibers and you bundle them together |
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| 09:33 | connective tissue. We're going to call a facile. So here's our muscle |
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| 09:39 | , here's our facile and surrounding that is the permission not to be confused |
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| 09:45 | paramecium, which is a horrible little . All right. So paramecium and |
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| 09:52 | you take a bunch of facials. this is what those represent. And |
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| 09:57 | can see the connective tissue surrounding each the fales, those fales wrapped together |
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| 10:04 | a group is wrapped by the Now, the Paramecium, the Endomysium |
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| 10:10 | the Epis are connective tissue that go entire length of these structures and they |
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| 10:15 | towards the end and they all join at the end of these cells or |
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| 10:21 | end of these muscle groups and they what is the tendon and it's the |
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| 10:26 | that's attached to the bone. muscle itself is not directly attached to |
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| 10:30 | . Instead, it's the connective tissue surrounds them, which is attached to |
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| 10:35 | bone. So when a muscle contracts it's doing, it's pulling on the |
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| 10:40 | and when the tendon is pulled it slightly stretches, but ultimately, |
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| 10:44 | doesn't have springy stretch, it will pull on the bone and cause the |
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| 10:49 | to move. All right, remember we talked about the periosteum. That's |
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| 10:55 | the tendon is attached to. So muscle in your body is like |
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| 11:02 | we go from everything being wrapped down fast, the fale being wrapped inside |
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| 11:08 | fast you have muscle fibers wrapped in tissue. Now, when you go |
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| 11:15 | a cell, all right. So gonna go back here for the |
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| 11:18 | So here's our muscle fiber, But there's something that extends onward that |
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| 11:23 | pulling out here. So each of are just, we're just pulling something |
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| 11:27 | . And what we're looking at here the cytoskeleton of the muscle cell. |
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| 11:33 | right. And that's what this next is. We're now inside the |
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| 11:36 | You can see here is my plasma . We have a special name for |
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| 11:41 | . All right, Sarco, uh , Lima. Anything when you hear |
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| 11:46 | at the beginning of has to do the muscle. So a tumor has |
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| 11:51 | s you know, has Sarco at beginning. So it's a Sarco. |
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| 11:57 | I'm, I'm blanking right now. brain has turned off just like yours |
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| 12:02 | . So anyway, so when you Sarco or Myo that refers to |
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| 12:06 | so on the outside of the That's gonna be your sarcolemma. The |
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| 12:10 | , the uh cytoplasm, it is the sarcoplasm. Within the sarcoplasm. |
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| 12:14 | gonna have tons and tons of Why do you think we need tons |
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| 12:17 | tons of mitochondria energy? That's This is the muscle that's gonna be |
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| 12:24 | . It's gonna need energy to So. All right. So the |
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| 12:27 | mitochondria you have the more energy you're producing more energy you're producing the |
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| 12:31 | energy you're using. All right, is a weird cell. All |
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| 12:35 | it has within it AAA protein called , which is related to hemoglobin. |
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| 12:41 | is the protein that's found in your blood cell that holds on oxygen. |
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| 12:46 | that hemoglobin and myoglobin are related. do you suppose myoglobin does? I |
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| 12:53 | ask questions that aren't on the slides up oxygen. Why do you think |
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| 12:58 | cell needs to have oxygen? Why you think a muscle cell wants to |
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| 13:01 | up oxygen? So you make a , do you want to wait for |
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| 13:06 | breathing to catch up to your muscle or would you rather have all the |
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| 13:10 | available to you as quickly as Here you are walking down the |
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| 13:15 | right? Shasta pops out of the , right? Whether it's the actual |
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| 13:20 | or the person in the outfit. are you gonna do? Run? |
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| 13:26 | hope you're gonna run someone dressed up Shasta jumping out of bushes that should |
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| 13:31 | the big red flag that makes you . Uh. Right. But |
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| 13:34 | let's just, let's suppose for a , it's the, the big old |
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| 13:38 | . Right. That big old cat you as food. You are going |
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| 13:41 | run, actually. Do not run big cats because that's what they'll do |
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| 13:44 | they'll chase you, stand your ground make big noises. But that's |
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| 13:50 | that's a life saving thing. But now we're running. All right. |
|
| 13:55 | you want to wait for your respiratory to deliver all the oxygen to those |
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| 14:00 | or do you want those muscles to able to start going? Now, |
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| 14:05 | , that's why we store up So myoglobin stores up oxygen so that |
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| 14:09 | can produce a TP so that your can contract and respond immediately and allow |
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| 14:14 | respiratory system to catch up and then respiratory system will deliver oxygen, continue |
|
| 14:19 | oxygen. All right. Now, also glycosides. Glucoses are stored |
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| 14:24 | Granules. Do you guys know what is? What is Glycogen? You |
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| 14:29 | your head. You have to answer question now, stored glucose. Why |
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| 14:33 | I want to store glucose in my cells? Why do you think? |
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| 14:40 | ? Energy? Do I want to for my fat to break down? |
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| 14:43 | I can deliver energy to my muscles I can run away from Shasta? |
|
| 14:47 | , that's gonna take a little Do I want to wait for my |
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| 14:50 | to release Glycogen? Or break down glycogen to glucose so I can deliver |
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| 14:54 | to my muscles. No, that too long. Again, I need |
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| 15:00 | this very second. So, if store up a little bit of |
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| 15:05 | then I'm not gonna have to worry my energy source when an emergency comes |
|
| 15:11 | . All right, I'm no longer upon the other organs. I can |
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| 15:15 | dependent upon myself, at least in short term, long term, I |
|
| 15:20 | dependent upon other things. All So, sarcoplasm or, or |
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| 15:26 | uh sarcolemma, sarcoplasm. And then we do is we have a really |
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| 15:33 | organelle. Now, it's not Organelle's three organelles bound together, they |
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| 15:37 | together. So we call it the . The triad has these, the |
|
| 15:41 | tubules. So again, this is color coded just to make our lives |
|
| 15:44 | . A transverse tubule here is the thing that goes up through. And |
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| 15:48 | basically, it's a hole that's opened onto the surface. You can see |
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| 15:51 | opened up there. It's opened up the surface and then it's a tube |
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| 15:55 | travels the length of the cell and up on the other side. It's |
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| 15:58 | of like a tunnel through the What it does, it brings a |
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| 16:02 | internally. That's its idea, just of like a tunnel allows for a |
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| 16:06 | through a mountain. This is bringing surface so that there's a tunnel through |
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| 16:11 | cell. And there's many, many of these. Now, on |
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| 16:15 | side of this T tubule, transverse . So we just abbreviate down a |
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| 16:21 | tubule. We have this blue structure in our cartoon, that blue structure |
|
| 16:26 | a sarcoplasm reticulum. Now, what you think the sarcoplasm reticulum is if |
|
| 16:32 | had to guess if you had to generically, what is it endoplasm |
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| 16:38 | Yes, that's exactly what it It's smooth endoplasm reticulum modified. And |
|
| 16:42 | can see here that it kind of all over, it goes all throughout |
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| 16:47 | cell. But what it does is comes up next to and near to |
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| 16:52 | transverse tubule and the region nearest the tubule. In other words, this |
|
| 16:57 | here and that region there and not this stuff, this region here, |
|
| 17:00 | region there that is referred to as terminal cni All right, the terminal |
|
| 17:06 | , terminal means and cistern basket big jug. So a cistern is |
|
| 17:15 | that holds things. And so what have here is we have a structure |
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| 17:19 | has um uh sarcoplasm cri and at end, that's a terminal cistern. |
|
| 17:25 | , what is its whole purpose? , the sarcoplasm Curti is smooth or |
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| 17:29 | a smooth ends reticulum whose sole purpose to, well, maybe not its |
|
| 17:34 | purpose. Its primary purpose is to away calcium. In other words, |
|
| 17:38 | a place where I store up tons and tons of calcium. All |
|
| 17:43 | . Now, if I'm shoring something for there, there's gotta be a |
|
| 17:46 | it's got to be important. So gonna come back to why calcium is |
|
| 17:49 | a little bit. All right, terminal cni is a bigger or broader |
|
| 17:56 | . And so this is kind of the calcium ends up, kind of |
|
| 18:00 | away. It's kind of right there to it. And what the T |
|
| 18:04 | does, it allows us to allow potential, which would normally just flow |
|
| 18:09 | the surface to work their way through cell. Right now, it's not |
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| 18:14 | the cell, it's still on the , right? It's just that it's |
|
| 18:17 | tube that allows me to pass close the internal workings of the cell. |
|
| 18:23 | brings the far things near to where needs to be. Now, if |
|
| 18:30 | been looking here, there's a whole of other things that we haven't labeled |
|
| 18:34 | sarcomere, for example, or not . But this Myo fibri. All |
|
| 18:39 | . Now, notice the terms It can become very, very |
|
| 18:42 | I got a myofiber and I have my fibri myofiber refers to the |
|
| 18:46 | Myofibril refers to the structures inside the . OK. So you've got to |
|
| 18:52 | able to kind of distinguish between those things. So here we are, |
|
| 18:57 | again, we're looking at this Myo , all right, and we can |
|
| 19:01 | they're all over the place they're saying artist has shown there's in this |
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| 19:05 | there's seven of them, there's more seven there's anywhere between hundreds to thousands |
|
| 19:09 | them in your, in your, , uh, muscles. In |
|
| 19:13 | um, when you look at a , right, when you see someone's |
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| 19:17 | , you're going, that's a big . Go ahead. Just say that's |
|
| 19:21 | big muscle. Thank you. You the a for the semester. |
|
| 19:27 | Pamper Pamper, the professor who has inflated sense of ego and I guarantee |
|
| 19:32 | it's good. It's good for All right. All right. But |
|
| 19:35 | got, I've got a muscle here before I used to work out. |
|
| 19:38 | muscle wasn't this big and I'm not working out to make money. I'm |
|
| 19:42 | trying to do it. So I die early. Right? The size |
|
| 19:46 | that muscle is dependent upon the number cells that are there, which are |
|
| 19:51 | kind of set for life. All , you're kind of the number of |
|
| 19:55 | that you have, you're kind of with. All right, you don't |
|
| 19:58 | new muscle cells all that much. what you do do, that's always |
|
| 20:05 | when you say that what you do that when you work out a |
|
| 20:11 | when you use a muscle, it the number of myo fibriles inside that |
|
| 20:19 | . So let's just pretend for a that a muscle named muscle, like |
|
| 20:22 | bicep has 100 cells. It but it, if you don't work |
|
| 20:27 | , you have like 100 mile five per cell. But when you work |
|
| 20:31 | . What ends up happening is that increase the number of rills. Let's |
|
| 20:35 | , I don't know, make it to 1000 so that they're big, |
|
| 20:39 | ? So the size of a muscle dependent upon and the strength of a |
|
| 20:43 | is dependent upon the number of mile bris. Now, myo fibri, |
|
| 20:50 | thing, that round thing that we're at consists of and here we go |
|
| 20:55 | , another term myo filaments. so I've got my fibro fibro |
|
| 21:04 | What are the, my filaments? , there's two of them. We |
|
| 21:07 | the thick filament and the thin Now all of a sudden you probably |
|
| 21:10 | flashing back to the first time you heard about muscles and they talk about |
|
| 21:13 | and thin filaments. Anyone here ever about thick and thin filaments? |
|
| 21:18 | 12 in the back, right. . All right. The thick filament |
|
| 21:24 | thick because it looks bigger. It fatter. All right. And really |
|
| 21:28 | it is, it's a whole bunch , all right. So my kind |
|
| 21:32 | looks like this. It basically looks a golf club. It actually looks |
|
| 21:35 | golf clubs where you have two golf and they kind of wrap them |
|
| 21:39 | So you have these two heads that associated like, so, all |
|
| 21:43 | And so, uh we, we're to look at in more detail, |
|
| 21:46 | we're just kind of looking at this . So you can kind of see |
|
| 21:49 | one head and there's, the artist done a really poor job of putting |
|
| 21:51 | other head right there. All And the two heads are like |
|
| 21:54 | I mean, you basically take my, my and you kind of |
|
| 21:58 | wrapping them. And so what you up with is you have these two |
|
| 22:00 | to it, you have this long , which is the tail and then |
|
| 22:05 | have the head portion, which is all the action is taking place. |
|
| 22:09 | there's a hinge kind of activity that's there. And then there's two binding |
|
| 22:15 | . One binding site is for The other binding site is for a |
|
| 22:20 | . All right. And so it as an A TP ace. It |
|
| 22:23 | has its own enzymatic activity. So A P binds to it, I |
|
| 22:27 | break the A TP release energy and that energy to do something. |
|
| 22:31 | because this is a hinge. What gonna do is I'm going to move |
|
| 22:34 | heads. OK. That's all With regard to the thin filament, |
|
| 22:40 | thin filament is a little bit more . All right. So the thick |
|
| 22:44 | bunch mys wrapped together. It looks a bunch of golf clubs with two |
|
| 22:48 | and these heads are repeating themselves over over again. There's hundreds and hundreds |
|
| 22:51 | hundreds of these. When we get the thin filament, the thin filament |
|
| 22:57 | as f acting you, we're just call it acting. We don't need |
|
| 23:00 | know the F act in the little parts are called G act and |
|
| 23:04 | blah, blah, blah. All . So this, this Alpha Helix |
|
| 23:08 | yellow things here that's acting and acting as part of its structure, a |
|
| 23:15 | that's attracted to and likes to buy right and act in a center like |
|
| 23:21 | at a prom. They want to together. Have you ever been to |
|
| 23:25 | dance? Did you guys get dances was COVID too far in the |
|
| 23:31 | Be ad halfway been to a Did you have chaperons at the |
|
| 23:37 | Once chaperones are the things that keep from pouring alcohol into the punch. |
|
| 23:42 | keep people from dancing too close and sure that you aren't doing all sorts |
|
| 23:46 | horrible things. Right. Yeah. there's kind of a chaperone to prevent |
|
| 23:53 | act and the min coming together and what this green thing is and what |
|
| 23:57 | doing is that it's, this structure called Troop Min. It's related to |
|
| 24:02 | . So it has a soft affinity a near affinity to that min binding |
|
| 24:07 | . And what it does is it in the way it prevents the act |
|
| 24:11 | the min from actually interacting. All . Great. So a muscle doesn't |
|
| 24:17 | inappropriately because of these two structures or of the structure in between them. |
|
| 24:22 | when I want the muscle to it's in the way. So what |
|
| 24:24 | I need to do if I want have a muscle contract, I have |
|
| 24:28 | move. What's the name of the ? Troop min? All right. |
|
| 24:35 | so to move that I need some of molecule to help me move |
|
| 24:38 | So here we have our third molecule are part of the thin filaments. |
|
| 24:41 | is troponin, which is represented by purple thing. Now, the thing |
|
| 24:45 | this is trying to show you that three parts to it. All |
|
| 24:48 | there's a part that's bound to there's a part that's bound to the |
|
| 24:52 | and then there's a third part and third part is attracted to or binds |
|
| 24:55 | calcium or calcium, binds to Now, I said calcium was kind |
|
| 25:00 | important here. So I'm storing up and so I have something that binds |
|
| 25:06 | to calcium. So maybe these two kind of go together. All |
|
| 25:11 | Now I have acting. I have thing that sits in the way triple |
|
| 25:19 | . I have my up here, two things want to get together so |
|
| 25:22 | they combine and do our contraction And then I have this little hinge |
|
| 25:26 | sits in between. So troponin serves a hinge. And so when calcium |
|
| 25:31 | to it, what it does is changes the shape of the molecule and |
|
| 25:35 | on the troy that's in the way it makes it available so that actinomycin |
|
| 25:40 | interact. So calcium serves as a to move the trip through the troponin |
|
| 25:49 | . OK. So, acting and want to get together to triple in |
|
| 25:54 | way trap. When calcium binds, helps to move the triple my so |
|
| 25:58 | the acting and the my can OK. Now you're going to see |
|
| 26:03 | multiple times. We're going to come this over and over and over |
|
| 26:06 | But I need you to understand the that we're dealing with here. All |
|
| 26:12 | . Now, what a lot of like to do is they like to |
|
| 26:15 | about the sarcomere and the sarcomere is unit. It's what we call the |
|
| 26:20 | unit of the muscle. When we're about a contraction, this is the |
|
| 26:25 | structure that undergoes a contraction. All , see what I got here. |
|
| 26:34 | right. So what does the ark here? Well, if you look |
|
| 26:38 | a muscle under the microscope, you're see a series of light areas and |
|
| 26:41 | series of dark areas and here's an darker area, dark light, dark |
|
| 26:46 | , so on and so forth. you can't see it there, the |
|
| 26:49 | on the side are a little bit . All right. And so when |
|
| 26:53 | first started looking at muscles, what could do is we could look at |
|
| 26:56 | microscope and we could see these dark . And so what do scientists do |
|
| 26:59 | we observe something, we name So we gave names to them. |
|
| 27:02 | you can see up here we have names, we'll go through them in |
|
| 27:05 | a moment. And then what they is that when you stimulated the muscle |
|
| 27:09 | , the line thicknesses changed. All . And this was a repeating |
|
| 27:15 | So what they did was they identified heating pattern occurred. And so here |
|
| 27:19 | have what is called the Z line another Z line. So the Z |
|
| 27:24 | serves as the boundary of the So when a contraction occurs, you |
|
| 27:29 | look at a single score and the Z lines move inwardly, OK towards |
|
| 27:34 | another. Now, a muscle is up of hundreds and hundreds and hundreds |
|
| 27:39 | sarcomere. And as you grow, adding on sarcomere to the end of |
|
| 27:44 | muscle cells or maybe internally, it's , but you're getting more of |
|
| 27:49 | So when you were a little you get fewer sarcomere. Now you're |
|
| 27:52 | , you have more sarcomere. All . So we have the Z |
|
| 27:56 | The two Z lines serve as the in the middle of that sarcomere is |
|
| 28:01 | dark line. It's called the M . All right. Now, what |
|
| 28:05 | looking at when you look at this you're looking at two dimensions. So |
|
| 28:09 | seeing something that looks like this, ? Does that look like a line |
|
| 28:12 | you? Does it look like a ? Yeah. But if I turn |
|
| 28:16 | hand, it's not a line, it, it's my hand and that's |
|
| 28:21 | we actually see here is that what are, are a lattice work. |
|
| 28:27 | is not showing the Z line, Z line will look like this |
|
| 28:30 | It's a lattice work of proteins to these myo filaments are attached. So |
|
| 28:36 | M line is the line through which filaments are leaving. And the Z |
|
| 28:42 | on the edges are the are from side are where the thin filaments are |
|
| 28:48 | . And so what these lines represent areas where you have thick and |
|
| 28:53 | thin filaments overlapping each other. it's probably easier for me to draw |
|
| 28:57 | so that you can see this, . So if I have a Z |
|
| 29:01 | and a Z line, then I'm to have thin filaments going this |
|
| 29:06 | I've made them too long. Let's that. All right, I'm gonna |
|
| 29:12 | AM line. All right. So just more proteins. And what you |
|
| 29:16 | is you have thick filaments going like . And so you can see now |
|
| 29:27 | these fibers and I'll do another one , how these fibers overlap one |
|
| 29:32 | And so they create different densities. that's your Z line at your M |
|
| 29:41 | . And then you have this area here that is just thick filament. |
|
| 29:46 | then over here you have this area is just thin filament, right? |
|
| 29:51 | you're, and it's gonna repeat. this would come over here like that |
|
| 29:54 | that one would go over there. we call this region where there's just |
|
| 29:58 | filament I band. Hey, it's on there. And then we have |
|
| 30:04 | region here. Where does thick We call that H zone? Why |
|
| 30:10 | call the zone and a band? don't know, it just is. |
|
| 30:13 | right. And then this region of . So you can see right |
|
| 30:18 | there's a region of overlap and a of overlap. Well, what we |
|
| 30:23 | is we say where does the region overlap begin? And where does that |
|
| 30:26 | of overlap end? And we refer that to, to that as the |
|
| 30:31 | band? So I should just call Ian. All right. So all |
|
| 30:43 | things, all they represent is just , this idea of these thick and |
|
| 30:48 | thin filaments and their, their interaction their lack of interaction. And because |
|
| 30:55 | filaments are bigger than thin filaments, area is darker than this area, |
|
| 31:01 | eye band. So you can see zone is slightly darker. If you |
|
| 31:04 | at the picture, you go over , it's slightly darker. It's not |
|
| 31:07 | dark though as where I have both and thick filaments. Does that kind |
|
| 31:12 | make sense? If I have things like that, they're taking up more |
|
| 31:17 | , more space darker. Now, reason we go over this is because |
|
| 31:24 | a contraction, remember all we're doing we're bringing Z lines closer together towards |
|
| 31:29 | M light. I'm pulling this way I'm pulling that way. So that |
|
| 31:33 | whole thing is going to shrink if whole thing shrinks, what's going to |
|
| 31:37 | is the sizes of specific bands are to change. All right. And |
|
| 31:42 | called the sliding filament theory, which get to in just a moment. |
|
| 31:47 | , so far, what we've done we've talked about anatomy, right? |
|
| 31:50 | looked at inside the cell, we about the sarcoplasm, the sarcomere, |
|
| 31:54 | talked about there being mild fibrils, talked about the triad, all the |
|
| 32:00 | these things are important. Did any you guys ever play mouse trap as |
|
| 32:03 | kid? One person, do you know what the game mouse trap |
|
| 32:07 | Did you actually ever play the game did you just like set it up |
|
| 32:09 | push the marble and see what it do? That was, yeah, |
|
| 32:12 | don't know anyone who's ever actually played trap. I think everyone just kind |
|
| 32:16 | built it and really what it is all we're doing is we're just taking |
|
| 32:19 | the parts and we're just kind of them right now. And we're saying |
|
| 32:22 | are the parts, we're gonna put all together and we're gonna see how |
|
| 32:24 | all work together. All right. right now we're kind of going through |
|
| 32:29 | definition phase of, of the Now, there's some other proteins that |
|
| 32:36 | , are worth knowing about. All . And so this is what this |
|
| 32:41 | of lists here. We have. . Nebule is an in elastic |
|
| 32:45 | And what it does is it sits the middle of the act in fiber |
|
| 32:49 | it makes sure that that act in stays nice and stiff and goes directly |
|
| 32:54 | instead of lags downward or pushes And the reason for that is we |
|
| 32:59 | to make sure that the thin filaments the thick filaments have the most um |
|
| 33:04 | have the greatest amount of interaction. that's the whole purpose of the nebula |
|
| 33:09 | to make the inside of the acting so that the act and stays straight |
|
| 33:14 | if it goes off, it's not to be able to activate or, |
|
| 33:18 | interact with the thick filament, we have this molecule called Titan and the |
|
| 33:24 | here represented by these little springs. I have a little spring, what |
|
| 33:27 | that suggest? If I pull, going to happen to the spring |
|
| 33:33 | it stretch. And then, so I relax the stress on that |
|
| 33:36 | what's it gonna do return back? right. When you contract a |
|
| 33:41 | it doesn't stay in its contracted it relaxes and goes back to its |
|
| 33:46 | form. All right. And that's reason for that is because of this |
|
| 33:51 | molecule. And you can see that attached to the my, the thick |
|
| 33:57 | . And so when I pull I'm actually compressing the spring. And |
|
| 34:03 | when I compress the spring, it back outward. All right. Last |
|
| 34:08 | is dystrophin, so as you get and further towards the edge, you're |
|
| 34:12 | going to get these nice, simple uh uh my fibros instead you get |
|
| 34:17 | really wonky structures and they wouldn't behave . So what dystrophin does, it |
|
| 34:23 | to anchor the myo fibros to keep affiliated or associated with the sarcolemma, |
|
| 34:27 | that you can actually continue doing the . And then finally, alpha |
|
| 34:32 | which is different than acting is the that the thin filaments use to bind |
|
| 34:38 | to the Z line. All So it's what allows this to |
|
| 34:47 | So what we have is we have series of structures that allow me to |
|
| 34:51 | a contraction and a relaxation, contraction relaxation. That's what all these things |
|
| 34:56 | together. All right. So when trying to learn these, just |
|
| 35:01 | what's the word, what does it ? What is it, it, |
|
| 35:04 | is it, what does it That's as simple as that. |
|
| 35:07 | ma'am. It's, it's just it was uh it's named for what |
|
| 35:17 | affiliated with. So the act. it's, it's associated with the |
|
| 35:21 | So that would be the thin So the A band again, I |
|
| 35:25 | know where the nomenclature comes from. A, the I, the |
|
| 35:28 | the M makes sense because it's the band. That's, that's the only |
|
| 35:32 | that makes sense. But why the , why they called it I, |
|
| 35:35 | guess is as good as mine. I don't know. I mean, |
|
| 35:41 | only one that I know that's actually of interesting and I'm just gonna, |
|
| 35:44 | is you can put your pins down this one. So when we go |
|
| 35:47 | talk about the heart in A MP , you're gonna learn about the |
|
| 35:50 | right? The beep, you know you see in all the movies and |
|
| 35:54 | has those different, um, wave and those wave wave forms have, |
|
| 35:59 | names. And that we know the why is it starts as the, |
|
| 36:04 | P, the QR s and T YP QR ST Well, because the |
|
| 36:10 | that created the machines and put them the heart, he started labeling them |
|
| 36:14 | the middle of the alphabet. He tired of doing things ABC or |
|
| 36:19 | So he started in the middle of alphabet and that's where he got them |
|
| 36:23 | . Everything else has a reason why named. I'm just not smart enough |
|
| 36:28 | know. I've never bothered looking it to be honest. So, or |
|
| 36:32 | could be not as smart, who ? All right, when we talk |
|
| 36:39 | a muscle. So we're stepping back again. All right. And we're |
|
| 36:42 | at groups of fibers. So you see here, I've got a group |
|
| 36:47 | fibers, 1234, these are individual . I have two cells there. |
|
| 36:52 | right. And what these are representing two colors represent are what are called |
|
| 36:57 | units. All right. So when look at a muscle, a muscle |
|
| 37:00 | of multiple hundreds of motor units. right, because you have hundreds of |
|
| 37:07 | and depending upon what the activity you're gonna have a different number of |
|
| 37:10 | motor units. So what a motor is, is simply a single motor |
|
| 37:16 | . All right. So it's a that goes out and it innervates a |
|
| 37:20 | of cells. So it represents a unit represents the single fiber, the |
|
| 37:25 | plus the cells that it innervates. , I have two terms here, |
|
| 37:33 | and course. So delicate activity and activity. Give me an example of |
|
| 37:36 | delicate activity. What you think a activity might be eating? OK. |
|
| 37:45 | more coarse. There's probably some fine in there. I mean, I've |
|
| 37:49 | uh that what I did this weekend I bit the inside of my mouth |
|
| 37:52 | times. So um yeah, so might be some delicateness in there, |
|
| 37:57 | I think it's kind of falls in , but let's think of, let's |
|
| 38:00 | of a physical movement, you raising your head. What would that |
|
| 38:05 | ? Mm No, it would more think about. Am I? Is |
|
| 38:09 | take a lot of in uh fibers intellect to do that or I shouldn't |
|
| 38:12 | intellect. It's not the right threading a needle. That'd be what |
|
| 38:18 | , what's something that you guys do day that you can think about and |
|
| 38:21 | on a test here. I'll help . I have no idea what to |
|
| 38:30 | with this though. Writing when you're . Would you say that's kind of |
|
| 38:36 | that you have to do fine motor ? That takes a lot of effort |
|
| 38:40 | ensure that your handwriting is legible. least to you. Right. That's |
|
| 38:46 | delicate. Threading, a needle Anything that requires fine motor skills would |
|
| 38:51 | delicate right now. Of course, know, like I said, so |
|
| 38:56 | eating, you know, when you're about some things, there's both, |
|
| 38:59 | two things that are involved. So , what I want to think about |
|
| 39:02 | of course, what would be an ? Of course. How about |
|
| 39:06 | Right. What is walking? It's falling, right? I lift my |
|
| 39:13 | up, I shift my body weight and I catch myself before I |
|
| 39:18 | Oh Frankenstein could do it. What's swimming course? But I |
|
| 39:27 | what is it? Walking is not with swimming, not drowning. |
|
| 39:31 | Yeah, it's movement to prevent All right. So here when you're |
|
| 39:36 | with delicate activity, what you're gonna is you're gonna have fewer muscle cells |
|
| 39:43 | with that neuron. And so what means is that you can slice the |
|
| 39:48 | up into smaller units. All A course. Activity is going to |
|
| 39:52 | lots of fibers, right? It'll more fibers for that unit. So |
|
| 39:58 | you do is there's not a lot nuance, right? So I don't |
|
| 40:03 | a lot of muscle. I I need, let me see, |
|
| 40:06 | do I do to lift my It, I'm using lots of muscles |
|
| 40:10 | do it. If I put weights my leg, it's still the same |
|
| 40:13 | . I'm just recruiting fewer motor motor , but they're all big motor units |
|
| 40:18 | the idea. All right. So principle here is when an activity is |
|
| 40:29 | , what we're gonna do is we're have lots of motor units involved because |
|
| 40:32 | gonna to make subtle shifts to increase activity. But when I'm dealing with |
|
| 40:37 | , I'm not gonna have a lot motor units involved. I'm just gonna |
|
| 40:40 | big motor units involved to do the , right? So if I have |
|
| 40:44 | increase force, my force is increasing big leaps and bounds is the |
|
| 40:52 | The second thing I want to point here with the motor unit is that |
|
| 40:55 | you look at a muscle, the units are not gonna be clustered, |
|
| 40:59 | ? They're gonna be spread around. the reason for that is as, |
|
| 41:03 | you recruit in motor units, what trying to do is you're trying to |
|
| 41:06 | a specific sort of movement. All , each of your muscles are designed |
|
| 41:12 | a specific movement. And so what want them to do is you regarding |
|
| 41:16 | much force is involved, whether it's little bit of force or a lot |
|
| 41:19 | force, you want it to be to do the same thing. So |
|
| 41:21 | all your motor units are clustered to side of the muscle, you |
|
| 41:25 | then what's going to happen is the is going to behave differently. So |
|
| 41:28 | don't want that. So you can of it like the motor units, |
|
| 41:31 | cells themselves are not like this, might have just using, um, |
|
| 41:37 | , I'll make up a muscle. what you'd have, if this were |
|
| 41:42 | large muscle, you might have a of the motor unit there, a |
|
| 41:47 | of the motor unit there, a of the motor unit there and the |
|
| 41:49 | of the motor unit there so that crating this even pull on the |
|
| 41:54 | Right? Oh, but I'm lifting bigger now. All right. |
|
| 41:57 | I'm gonna bring in more motor but they're spread around as well. |
|
| 42:04 | that as each motor unit is you're creating a greater force that's doing |
|
| 42:09 | same sort of directional pull. That of makes sense. So there's no |
|
| 42:17 | and the muscle behaves the same Now, to envision this here, |
|
| 42:21 | gonna curl some stuff for you. right. What do you think this |
|
| 42:26 | ? A lot? All right. , look, if I curl |
|
| 42:30 | watch this. See, I don't a lot of motor units to do |
|
| 42:33 | , do I? Because it doesn't a lot. It's pretty easy. |
|
| 42:41 | think that weighs more than the I can curl it. See, |
|
| 42:47 | , same same movement, but I'm more motor units. Oh, I |
|
| 42:54 | those are, there are some early . I'm gonna have to come over |
|
| 42:57 | , Mike. That chair is not be easy to do this chair I |
|
| 43:00 | do. All right. So do think I can curl this one? |
|
| 43:04 | you for thinking that you're still getting a right? So, you |
|
| 43:09 | same movement. Am I recruiting more units? Yes, because it obviously |
|
| 43:14 | more. I need more muscle cells do the activity. We can keep |
|
| 43:17 | this until we get to the point I don't have enough motor units to |
|
| 43:20 | the object. I don't want to out where that is because I got |
|
| 43:25 | big ego, right? So that's a motor unit is. It's basically |
|
| 43:31 | groups of cells that are innervated by single neuron to perform the action of |
|
| 43:36 | cell, the more motor units that recruited, the greater strength that I |
|
| 43:42 | . Yes, I tell you. Correct. Fires Council, you're not |
|
| 43:52 | , right? You're not adding neurons you're not adding cells. What you're |
|
| 43:56 | when you exercise, right? And getting stronger to do whatever the activity |
|
| 44:01 | , you're increasing the number of myofibril the cell. So the cells are |
|
| 44:07 | bigger and bigger and bigger because of number of myofibril that are on the |
|
| 44:14 | that are supposed to be here. just get, they get stronger, |
|
| 44:20 | ? I mean, um I'm trying think of something that, I |
|
| 44:25 | a tennis player would be an easy to see. Like, you |
|
| 44:29 | there's a nice little muscle right there gripping. Right. And so |
|
| 44:33 | you do that, you squeeze, know, you'll see that muscle get |
|
| 44:36 | over time. But what's it really for? It's for position and reposition |
|
| 44:43 | opposition and reposition? Right. So can make that stronger. Have you |
|
| 44:48 | been pinched by somebody? Right? just creating more strength. But there's |
|
| 44:53 | , there's a limit, right? there's a number of cells and each |
|
| 44:56 | can only grow so big. There's limit to our strength for each of |
|
| 45:00 | muscles. Correct? The only way can improve your control is practice. |
|
| 45:13 | , the movie my kids were watching night was the karate kid movie. |
|
| 45:17 | right. And the, and the it was the new one, |
|
| 45:20 | the wax on, wax off. was pick up your jacket, throw |
|
| 45:23 | on the thing, put the jacket , take it off, throw it |
|
| 45:26 | the ground, pick it. I'm , really? I like the wax |
|
| 45:30 | , wax off. It was much . Although Jackie Chan is a better |
|
| 45:35 | than with the other guy. All . So this shouldn't look strange to |
|
| 45:43 | . What does this look like Something that we just learned, whatever |
|
| 45:48 | call it synapse? All right. the neuromuscular junction is simply a synapse |
|
| 45:55 | the neuron and the muscle. So different. Everything behaves exactly the same |
|
| 46:01 | . All right, we have a knob. We have a synaptic |
|
| 46:05 | but we call the region underlying the knob. We call that the motor |
|
| 46:09 | plate, the neurotransmitter that is released a neuromuscular junction is always, |
|
| 46:15 | always, no, no exceptions to rule. Aceto Cole. All |
|
| 46:20 | So that's what you're gonna see. all these vesicles are stored up Aceta |
|
| 46:26 | and they're ready to go. So you get that a pile that travels |
|
| 46:31 | , it opens up those voltage gated channels, calcium comes in that serves |
|
| 46:35 | a signal to release the acetylcholine. acetycholine goes across the neuromuscular junction, |
|
| 46:42 | me, across the synaptic cleft binds the receptors on the motor in plate |
|
| 46:47 | is going to cause the opening of channels and then you're going to get |
|
| 46:51 | to flow in the cells. And you're going to do is you're going |
|
| 46:54 | get an A Epsp. But in case, the EPSP is so strong |
|
| 47:00 | it creates an action potential inside the cell. And what we call that |
|
| 47:10 | we call it a twitch right A twitch is not this OK. |
|
| 47:15 | twitch is not perceptible, it's measurable a volt meter. It's not perceptible |
|
| 47:21 | sight because we're talking about an individual and a single action potential. But |
|
| 47:26 | I want to point out here is the twitch itself is not a |
|
| 47:29 | right? A twitch refers to the potential. And so you can see |
|
| 47:34 | here we have here's our stimulation, ? We're seeing the ax potential travels |
|
| 47:39 | . So here's a neuron, There's its action potential, here's the |
|
| 47:43 | potential in the muscle cell. Do see how this one precedes that |
|
| 47:48 | All right, like right there. a potential begets an action potential and |
|
| 47:56 | look where the potential is. It's , look where the contraction is. |
|
| 48:01 | follows the action potential is not the that we're interested in. It's what |
|
| 48:08 | from the stimulation, but we're interested the contraction. The contraction is the |
|
| 48:13 | of the stimulation. OK. A results in the contraction cell goes through |
|
| 48:20 | period of contraction and a period of . Now this contraction is not a |
|
| 48:29 | contraction. As I said, it's , it's not enough to do an |
|
| 48:35 | . In fact, what you'd see that this is, here's your twitch |
|
| 48:38 | down there, right? It shows and there's this is a graph that |
|
| 48:41 | you tension, right? If I to create tension, I want to |
|
| 48:47 | up the the the the series of . And that's what this graph is |
|
| 48:53 | of trying to show you. It's temporal summation of twitches. So when |
|
| 48:57 | create a contraction, what I'm doing I'm doing a little twitch and I'm |
|
| 49:02 | a series of action potentials that are fast enough. So that for each |
|
| 49:05 | , I'm getting a contraction, but not able to go back down. |
|
| 49:07 | not able to go back to Instead, I keep building on top |
|
| 49:10 | it and building on top of it building on top of it to the |
|
| 49:13 | where I'm going to get a sustained . A sustained contraction is what we |
|
| 49:21 | to as tetanus. Tetanus is what get when you step on a rusty |
|
| 49:25 | in an old abandoned building, Is that what mom said? Don't |
|
| 49:29 | play in the abandoned building because you're go step on a rusty nail and |
|
| 49:33 | get tetanus. You remember that? , no one got tetanus because we're |
|
| 49:38 | enough not to step on the rusty . Don't do that. They call |
|
| 49:42 | tetanus that disease state tetanus because the how it appears is you get, |
|
| 49:52 | know what lock drawers, when you're locks, get lock the muscles in |
|
| 49:57 | sustained state of contraction. Hence the tetanus. When you contract a |
|
| 50:05 | pick up your drink, you could contracted your muscle. You're in tetanus |
|
| 50:10 | now, put your drink down. not tetanus, contract it. |
|
| 50:14 | put it down, not tetanus. right. So, Tetanus is a |
|
| 50:18 | of a series of action potentials that in temporal summation of twitches so that |
|
| 50:24 | can get a sustained contraction in a motor unit. So strength in a |
|
| 50:33 | is the recruitment of a bunch of units, right? You saw me |
|
| 50:37 | the different cur uh the different right? Tetanus is me just using |
|
| 50:45 | of the motor units to move the that I'm trying to get done. |
|
| 50:51 | the force of a contraction is dependent the degrees of recruitment. When I |
|
| 50:57 | the simple curl like this, I'm moving this. How much do you |
|
| 51:00 | that weighs? What do you Who can be a carnival sideshow? |
|
| 51:07 | much do you think that works? ? Oh, my goodness. You're |
|
| 51:11 | grams. She's II, I I wouldn't even know I'm going ounces |
|
| 51:14 | my head. All right, we're go 200 g. That sounds |
|
| 51:17 | All right. What do you think weighed? Maybe a kilo? |
|
| 51:28 | Well, there's almost a liter of in there. So a liter is |
|
| 51:33 | to a kilo of water, That's the, the, the |
|
| 51:37 | Ok. And then what do you the chair weighed? I think a |
|
| 51:44 | bit more than that. Give me , give a little credit. Keep |
|
| 51:48 | . Thinking maybe about five. All , I think. All right. |
|
| 51:55 | in each of those cases I only a couple of motor units and then |
|
| 52:00 | gonna say, oh, well, gotta move that next thing, those |
|
| 52:03 | of motor units to lift up that gonna recruit in a couple more. |
|
| 52:06 | , wait to lift up the I need to recruit in a couple |
|
| 52:10 | . So that's what recruitment is, just bringing in more and more motor |
|
| 52:14 | to do the job. Yes. , in that case, that's, |
|
| 52:22 | a constant state of stimulation. with regard to the lock, I |
|
| 52:26 | know what the actual method of what's going on there. If it, |
|
| 52:30 | it's what's happened is you're getting the or what's happened is you've opened up |
|
| 52:34 | the calcium channels. My guess is probably the latter again. I don't |
|
| 52:38 | . But that would be an educated . All right. That does, |
|
| 52:41 | doesn't require the stimulation. Instead, a pathology occurring inside the cell and |
|
| 52:48 | we haven't talked about uh calcium, make more sense in a minute. |
|
| 52:52 | right. Um Another example. So used to come in here with like |
|
| 52:58 | £13 textbook just for fun because I'd the strongest guy in the room and |
|
| 53:03 | have him stand up here holding a like this. How long do you |
|
| 53:08 | you could hold £13 directly from your ? You know, it's really kind |
|
| 53:14 | funny. You start watching them and like this and I say, |
|
| 53:16 | no, pretend your grade depends on . So all of a sudden now |
|
| 53:20 | happening is, is that you're getting , right. Holding this out £13 |
|
| 53:25 | weighs a lot more than probably a a liter at this point since I |
|
| 53:29 | quite a bit of it. But what happens is, is your |
|
| 53:35 | actually alternates and recruits different muscle motor to maintain activity. All right. |
|
| 53:43 | what happens is as a, as motor unit gets fatigued, your body |
|
| 53:47 | switch and start alternating which motor units using. Now, if you don't |
|
| 53:52 | a lot of weight that you're trying bear, then you have plenty of |
|
| 53:56 | units to recruit from. Right. let's just pretend for a moment. |
|
| 53:59 | know, if you're like a factory runs 24 hours a day, you |
|
| 54:04 | have how many different shifts in a that runs 24 hours a day? |
|
| 54:09 | that a full shift is eight. many shifts would you have? |
|
| 54:13 | All right. So you basically to a factory going as long as you |
|
| 54:17 | three shifts, you're able to go indefinitely. But the moment that you |
|
| 54:20 | a shift, you're now basically there's period of time where you can overwork |
|
| 54:25 | shift, but then they're just gonna too exhausted and they can't come in |
|
| 54:29 | . Right. And that's kind of fatigue is is. I've exhausted my |
|
| 54:33 | units. I've, I've recruited too at a time. Right. And |
|
| 54:38 | they're, they're becoming fatigued and they to rest up in order for them |
|
| 54:41 | work. So again, if I'm there trying to hold something like |
|
| 54:45 | I could hold this for. How in this position. What do you |
|
| 54:50 | indefinitely? I mean, I'd probably bored before I got tired. |
|
| 54:56 | But what about the chair? Maybe couple of seconds. Right. And |
|
| 55:03 | because it requires more motor units. so they're gonna become fatigued and there's |
|
| 55:07 | else I can recruit. And that's the fatigue is. All right. |
|
| 55:11 | the inability to maintain that muscle tension you're doing this asynchronous recruitment, asynchronous |
|
| 55:17 | not at the same time. I'm recruiting ones. Then I'm letting |
|
| 55:21 | of them arrest, but I'm going recruit new ones. And so there's |
|
| 55:24 | asynchrony that's taking place. All your body prefers to recruit fatigue, |
|
| 55:32 | muscles first and then fatiguing muscles last it doesn't know like you do how |
|
| 55:38 | the activity is going to be? cheesecake. A little beefcake for |
|
| 55:49 | All right. So what is muscle ? Well, it's basically, it |
|
| 55:54 | and passive partial contraction. All Why we are attracted to muscle tone |
|
| 56:01 | because it indicates a degree of All right, doesn't mean you're |
|
| 56:06 | It just indicates that there is fitness you're, well, that you're not |
|
| 56:09 | parasites, which is means that you're be a good mate and you can |
|
| 56:14 | and everything comes right back to I told you right. Reproduction. |
|
| 56:18 | many, how many offspring can you ? All right. Now, why |
|
| 56:24 | tone is actually important as opposed to , what we're attracted to it about |
|
| 56:29 | that it's important for your posture. important for balance and it's important for |
|
| 56:36 | injury, right? When you exercise use the muscles, you're going to |
|
| 56:42 | injury. Now, notice I have here. The less body fat here |
|
| 56:47 | mean that you have less muscle tone more muscle tone, right? Muscle |
|
| 56:52 | is a function of using the All right. So you can have |
|
| 56:57 | that have more body fat and who , that have a high degree of |
|
| 57:01 | tone is just hidden by that uh fat, for example. All |
|
| 57:07 | you can have someone who doesn't work all the time has no body fat |
|
| 57:11 | you can tell that they don't have . Alright. For those of you |
|
| 57:18 | exercise when you're young still, I , I know you're young still. |
|
| 57:21 | you noticed that you have a high of flexibility? Like like when you |
|
| 57:26 | and stretch, can you touch your ? Can you touch your toes? |
|
| 57:30 | , I my toes are might as be in Africa because they're, |
|
| 57:35 | they're not reachable. Wow, my back right here. Long gone. |
|
| 57:43 | mean, that's the one thing I dead lifts, but it does nothing |
|
| 57:48 | my flexibility at this point, The muscle tone that you have, |
|
| 57:54 | gonna be determined by the connective tissue we just talked about and the size |
|
| 57:58 | the titan. So basically, it that stuff that we're actually attracted |
|
| 58:03 | And then again, is it active responsive? Well, that means do |
|
| 58:07 | do physical activity. All right, have a greater number of motor units |
|
| 58:12 | are being stimulated even at rest. that shape that you're looking at there |
|
| 58:21 | a function of motor units in this state of contraction. I have never |
|
| 58:30 | a question on this and I've never the slide, but I'm gonna say |
|
| 58:34 | anyway, because someone's going to ask this at some point and your |
|
| 58:37 | So you need to understand that muscles a length, tension relationship. In |
|
| 58:41 | words, there's a sweet spot of length that they exist in that they |
|
| 58:46 | do their activity. If you stretch too far, they can't do their |
|
| 58:50 | . And if they're too compressed, can't do their activity, right? |
|
| 58:54 | again, we're dealing with that little , but you can visualize this in |
|
| 58:58 | macro sense, like if you're doing and your arms are hyperextended, it's |
|
| 59:05 | , much harder to move the right? Because the muscles have been |
|
| 59:11 | to the point where there's very little of those myo fibrils. All |
|
| 59:17 | So it takes more work to get back into a position where it's |
|
| 59:20 | OK, now I have enough interaction that I can get the contraction. |
|
| 59:25 | they're too close together, I can't any further. All right, there's |
|
| 59:29 | where nowhere for me to go with mile fibers. So we're looking for |
|
| 59:33 | point where they can that there's a spot in terms of how they can |
|
| 59:39 | . All right. Just call it . Not too long. Not too |
|
| 59:44 | . Just right. All right. are we doing? We're ready to |
|
| 59:53 | see what's going on with all these parts. What do you think? |
|
| 60:00 | . You ready? All right. truth of the matter is everything that |
|
| 60:05 | just taught you and everything that we're to learn, we can learn in |
|
| 60:08 | minutes. You're like, well, are you wasting my time? |
|
| 60:12 | because I found that most people want full hour there. I, I |
|
| 60:17 | given this class once to my upper students, same, same material and |
|
| 60:23 | , I didn't have my power cord my computer died and I had to |
|
| 60:27 | the talk as a chalk talk. basically, I had to do it |
|
| 60:31 | up here, right? And I this is the easiest way to do |
|
| 60:35 | . You just show you once and say here are all the steps and |
|
| 60:38 | know the steps, right? A B, then C, then |
|
| 60:42 | then E, then F and G then you're done. But you need |
|
| 60:45 | know all those parts. And so already named the parts. And what |
|
| 60:48 | looking at here is the overall view everything that's gonna be working together. |
|
| 60:52 | those parts that we just named, ? So here we have the neuromuscular |
|
| 60:57 | right over here. You can see green thing is the T tubule. |
|
| 61:01 | this right here is the triad. your terminal cni over there. Those |
|
| 61:06 | the sarcoplasm Curtis. And then down you can see that is our |
|
| 61:11 | You can see here, here is M line, there's the Z |
|
| 61:14 | there's your thick filaments, there's your filaments, you can even see the |
|
| 61:17 | that's been drawn on there. So that we just learned is already |
|
| 61:21 | OK? And we're just going to , how does it all work? |
|
| 61:24 | do we put them all together and them do stuff? Right? I |
|
| 61:28 | mentioned calcium. You remember I said reticulum is responsible for sequestering calcium. |
|
| 61:32 | , here's calcium, it's even highlighted , right? So what we're gonna |
|
| 61:37 | is we're going to go and we're to look at this first step. |
|
| 61:40 | does a muscle contraction get started? , it starts at the neuromuscular |
|
| 61:46 | All right. A potential travels down down the neuron down to the terminal |
|
| 61:51 | of that neuron, down to the knob. Those ax pencils basically the |
|
| 61:57 | closing of sodium potassium channels, And then you get down to the |
|
| 62:00 | knob. You know, you have potassium voltage gated channels, you now |
|
| 62:04 | calcium voltage gated channels. So those calcium rushes into the uh into the |
|
| 62:11 | which causes the vesicles holding the Aceto to open up. So you release |
|
| 62:17 | into the synaptic cleft binds to receptors the motor in plate. So far |
|
| 62:25 | you with me, that results in EPSP it's actually called an Epp in |
|
| 62:32 | potential. All right, that plate is so strong that it results in |
|
| 62:36 | action potential. The potential is gonna along the surface of the cell. |
|
| 62:40 | because the tubule is basically the surface the cell traveling internally or through the |
|
| 62:46 | , the ax potential is gonna travel through that T tubule so far. |
|
| 62:52 | good action potentials are traveling on the of the motor of of the uh |
|
| 62:59 | mile fiber fiber. Excuse me so , that makes sense anyone lost because |
|
| 63:07 | doesn't get harder. It's just there's steps as you're traveling down through those |
|
| 63:13 | tubules. Remember the T tubule is associated with the terminal Cine, which |
|
| 63:18 | associated with the sarcoplasm reticulum. There two types of channels here. All |
|
| 63:23 | , there's a voltage gated channel and what is called a iodine channel. |
|
| 63:27 | right, the rio channels are associated the sarcoplasm reticulum. The voltage gated |
|
| 63:33 | channels are inside the T tubule and actually associated with each other. They're |
|
| 63:38 | shaking hands. So if I open channel that's going to cause me to |
|
| 63:42 | the other channel, the T remember it is open to the |
|
| 63:47 | So what I'm doing is when I that up as a result of an |
|
| 63:51 | potential that's gonna pull on and open the gates of the iodine receptors and |
|
| 63:58 | iodine receptors which are part of the CIA are going to open up and |
|
| 64:02 | going to release calcium into the Remember I said calcium must be |
|
| 64:09 | So I'm hiding up calcium. Now releasing calcium into the cell. |
|
| 64:15 | In this case, is serving as signal that signal which we already described |
|
| 64:20 | it's binding up to troponin. All . So here we are here, |
|
| 64:26 | can see the min head there. can see the acting. This is |
|
| 64:30 | purple thing as you can see in . That's the troy and then all |
|
| 64:35 | color coded stuff around there that is troponin. All right. And you |
|
| 64:39 | see that this stuff is in the of the act and the mayas and |
|
| 64:45 | when calcium comes along, it takes that Tropomyosin and pulls it away. |
|
| 64:51 | it's done is the calcium is bound to the troponin which causes a change |
|
| 64:55 | the shape and it pulls the troponin of the way. And since troponin |
|
| 65:00 | attached to TROIA, it moves out the way as well. So now |
|
| 65:06 | min can interact with the acting and the act and the min interact, |
|
| 65:13 | happen. OK. Now what's the that happens? The thing that happened |
|
| 65:19 | called the power stroke. Now, a lot of steps involved here. |
|
| 65:24 | right. And you can walk through one of them. It doesn't matter |
|
| 65:26 | you start. I always start up All right. And the reason I |
|
| 65:31 | up there is because that's where we're see a TP. When you think |
|
| 65:34 | movement, you think about energy being , don't you? That's what you've |
|
| 65:37 | taught when I move. I use . Right. Well, calcium is |
|
| 65:47 | causes you to move. What does TP do? Well, it resets |
|
| 65:52 | so that you can move again. right. So let's kind of walk |
|
| 65:55 | and see here. So here I , I've activated and I've already gone |
|
| 66:00 | all the, all the stuff. what we're doing is we're going to |
|
| 66:03 | everything, right? So, a comes along and it binds up to |
|
| 66:09 | , my head at the A TP site, right? This a TB |
|
| 66:14 | site has a TP A activity which I can release the energy from the |
|
| 66:20 | TP, which is what happens. here you can see, I bound |
|
| 66:23 | , I've released the energy. And that does is it takes that head |
|
| 66:27 | I've already used and it recock It's like taking a pistol and cocking |
|
| 66:32 | head so that you can fire the again. All right. And that's |
|
| 66:36 | I've done is I've reset, but no longer able to interact yet. |
|
| 66:40 | have to have something else come All right. So that's when calcium |
|
| 66:46 | along and I'm make, make it . So now I've bound up to |
|
| 66:51 | uh acting, but notice I haven't on the acting yet. All I |
|
| 66:55 | was I remember I was started in position. A TP caused me to |
|
| 67:00 | it and reset it and now I'm up again, but I haven't |
|
| 67:05 | So what causes me to pull? , when I release that energy and |
|
| 67:10 | release that or when I release that , that's gonna be what causes the |
|
| 67:15 | stroke. All right. So I've , that's what the A patp |
|
| 67:20 | I bound because calcium let me, now when I release that energy I |
|
| 67:28 | and so how do I separate Well, after release the used A |
|
| 67:32 | , which is called A P, ? Ain di phosphate and then I |
|
| 67:37 | it with a TP which breaks the , reset, bind, pull by |
|
| 67:46 | the energy. Now, how do remember this? Well, you already |
|
| 67:49 | this. You just don't know, know it. All right, you |
|
| 67:59 | down to the morgue and you see dead person, you see a |
|
| 68:03 | What do we call a corpse? me, give me some words that |
|
| 68:06 | use for a corpse, dead What else could have? What |
|
| 68:12 | Something that is sounds kind of offensive . Why do you call it |
|
| 68:19 | It's, it's stuck in a And what do we call that state |
|
| 68:25 | mortis? Right? Rigor mortis. right. So why do we have |
|
| 68:28 | mortis? Why does rigor mortis All right. This is how you'll |
|
| 68:32 | this, right? Rigor mortis occurs the system that pulls holds calcium |
|
| 68:38 | So remember, calcium is what allows thick and thin filaments to come |
|
| 68:42 | right? So the system is designed sequester away calcium. When you're not |
|
| 68:48 | a state of contraction, relax muscles have calcium floating in them, |
|
| 68:53 | But when you die, you no produce a TP. And so the |
|
| 68:59 | that are responsible for pumping calcium allow the calcium to be released and you |
|
| 69:03 | have some A TP around, And so what will happen is that |
|
| 69:06 | calcium allows the muscles to bind or thick and thin filaments to bind. |
|
| 69:10 | they'll start doing the whole thing because have a TP. But when you |
|
| 69:14 | out of a TP, you get in the bound state. And so |
|
| 69:21 | what you have is you have a of muscles that are tight and |
|
| 69:27 | And then couple of days later, when the tissue actually starts breaking |
|
| 69:31 | And that's when it gets all loosey again, which is gross. |
|
| 69:38 | this is where I tell you a . My grandfather told me, I |
|
| 69:42 | he made it up, said when was y'all's age that he worked at |
|
| 69:48 | funeral home for one night, said was the night watchman. You |
|
| 69:54 | he said he was walking through with flashlight and they had a corpse on |
|
| 69:59 | table, you know, for embalming and it went through its state of |
|
| 70:04 | mortis. It was like somebody that brought in or whatever. And he |
|
| 70:07 | it sat up, he said he that thing set up, he said |
|
| 70:11 | was done. He was out of . He left, I think he |
|
| 70:15 | it up. But still a fun . Yeah. Uh-huh. Oh, |
|
| 70:27 | , it's horrible. Yeah. the noises coming out of a corpse |
|
| 70:33 | horrible. Yes, ma'am. Yeah. So, the reason for |
|
| 70:40 | again has to do with everything we've of described here, if you create |
|
| 70:44 | environment that causes the release of that , right, then it will go |
|
| 70:50 | the period of contraction and relaxation. as soon as you get rid of |
|
| 70:54 | A TP and stuff, they get in their state and so they won't |
|
| 70:57 | anymore and then they're no fun. then you have to go get a |
|
| 70:59 | frog right now. You can't do with an embalmed leg, right? |
|
| 71:04 | have to do, you have to it from a frog that you just |
|
| 71:08 | we call sacrificed, right? That's you would do. So, the |
|
| 71:15 | stroke, what we're saying is a allows for the power strip to |
|
| 71:22 | Calcium is what's necessary for the contraction take place and then we're back to |
|
| 71:29 | over here. All right, because the whole purpose here is to create |
|
| 71:34 | contraction in the whole muscle, but whole muscle is a sum of all |
|
| 71:38 | its sarcomere. So if we look what's happening in the sarcomere, we |
|
| 71:41 | understand what's happening in the whole And here, what we're saying is |
|
| 71:45 | those thick and thin filaments, you , the mice and heads are doing |
|
| 71:49 | , pulling the thin filaments towards the . And so what ends up happening |
|
| 71:53 | this moves inward and as a we will see changes. So what's |
|
| 71:59 | change that takes place? Well, this moves in the overlap gets |
|
| 72:06 | the lack of the, the, no overlap gets smaller. So the |
|
| 72:11 | band gets smaller, the H zone smaller but the A band stays the |
|
| 72:18 | . Now, the reason for this because of something called the sliding filament |
|
| 72:23 | . All right. And to demonstrate , I'm gonna come up here and |
|
| 72:26 | gonna have these two help me out that you can see this. All |
|
| 72:32 | . So you two stand up. right. So I'll be the M |
|
| 72:38 | , you're gonna be a Z you're gonna be a Z line, |
|
| 72:40 | gonna face them and you know, pretend like you don't see them, |
|
| 72:42 | look above their heads. All So you need to go out a |
|
| 72:45 | bit further. All right. So our arm arms, so they're, |
|
| 72:47 | slightly overlapping. So come, come way, both of you a little |
|
| 72:50 | , just a little bit. All . So in a contraction, you |
|
| 72:54 | what I would be doing is, basically be pulling them. So you |
|
| 72:57 | imagine these are the thick filaments, ? And so as the thick filaments |
|
| 73:00 | the thin filaments, the Z lines inward right now, notice that the |
|
| 73:07 | of overlap got smaller, right? then we relaxed and they go back |
|
| 73:11 | again to go back out. So , do you see that? And |
|
| 73:14 | we pull them again and they move . Do my hands or my arms |
|
| 73:19 | uh shorter, do their arms get ? But the space between us |
|
| 73:25 | And that's what a contraction is. the two Z lines came closer to |
|
| 73:29 | M line, but the filaments themselves not get smaller. And this is |
|
| 73:34 | it's called the sliding filament theory. right. Does that make sense? |
|
| 73:38 | . Thanks guys, it's much easier you visualize it. So, even |
|
| 73:46 | these bands change sizes, that's just of the degree of overlap, |
|
| 73:54 | That's a degree of overlap over the a band doesn't change because the |
|
| 73:59 | filament stays the same length. when a muscle contracts, it has |
|
| 74:06 | period of contraction, then we're going have a period of relaxation. So |
|
| 74:10 | does relaxation occur? Well, out in the neuromuscular junction, we have |
|
| 74:16 | Acetic Colon asteroid. That's an enzyme breaks down Acela Coline. So that |
|
| 74:20 | says I'm getting rid of the So you always want to get rid |
|
| 74:24 | the signal first. All right, sarcoplasm reticulum have these pumps. The |
|
| 74:29 | is called circa and you don't need know. I mean, it's, |
|
| 74:33 | probably should know. So, endoplasm calcium channel, that's where it comes |
|
| 74:38 | . All right. So it's just pump and it just pumps in calcium |
|
| 74:42 | the expense of a TP. basically what you're doing is you are |
|
| 74:44 | the calcium. If there's no then troponin doesn't get moved out of |
|
| 74:49 | way And when troponin isn't moved out the way troy is in the |
|
| 74:53 | And so my and acting can't So that's what relaxation is, is |
|
| 74:59 | reversing all the things that we So does the muscle contraction make |
|
| 75:09 | Power stroke makes sense, right? How the triad works, all that |
|
| 75:15 | . And really all you gotta do if you just walk through those |
|
| 75:18 | go here, I'm starting over you know, starting with the neuromuscular |
|
| 75:23 | , go down through the triad opening channels, calcium flows out all those |
|
| 75:28 | . You know, now you have terminology to make, make sense of |
|
| 75:31 | that stuff. And it should just straightforward. Now, while calcium is |
|
| 75:37 | important part. A TP is important if we don't have the A |
|
| 75:41 | we can't pump the calcium, we release the uh the thick filaments from |
|
| 75:44 | thin filaments. And so we have ways to regulate or are responsible for |
|
| 75:50 | uh producing A TP. All we have the three systems that we |
|
| 75:55 | something that's called the phospho system. is for like intermediate um uh |
|
| 76:02 | short term activity, we're going to anaerobic acceleration, uh cellular respiration. |
|
| 76:06 | this would be the first step and long term, um uh actually, |
|
| 76:11 | is the anaerobic long term. This be like just for, you |
|
| 76:15 | long activities, the stuff that you on a regular basis and then we're |
|
| 76:18 | use aerobic in this case. here's the good news for those who |
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| 76:22 | taken biology or you haven't learned these . You don't need to know we're |
|
| 76:26 | gonna walk through all the steps of aerobic activity, right? Oxidated |
|
| 76:33 | yada, yada, yada. The thing here is, where are we |
|
| 76:36 | our A TP from? All So this is the phospho system. |
|
| 76:41 | is kind of like what you It's, it's, it's what your |
|
| 76:45 | already have in place and we're just to burn through it as quickly as |
|
| 76:48 | . So, the first one, say is we just have a TP |
|
| 76:52 | available. So we have about five six seconds of activity in a muscle |
|
| 76:57 | based on the amount of A TP there. I'm gonna make up a |
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| 77:00 | , let's say it's 100 molecules of TP. All right. Now, |
|
| 77:04 | I want to increase the amount of TP, I can't increase the actual |
|
| 77:10 | of API, have to find ways store it up. All right. |
|
| 77:13 | one of the ways that I store up is I use this system right |
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| 77:16 | is the creatine phosphate system. All . So let's say I have 100 |
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| 77:20 | of creatine. What I can do I can phosphor those 100 molecules of |
|
| 77:25 | . So I have 100 molecules of phosphate. So basically, I can |
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| 77:28 | back and forth between those two But where do I get that |
|
| 77:31 | I get it from the A So every time I move a phosphate |
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| 77:34 | a creatine, I make another AD that can be reflated. So I |
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| 77:39 | refill my A TP pool. So I fill up my creatine pool to |
|
| 77:45 | 100% creatine phosphate and I refill my TP pool. So I'd have 100 |
|
| 77:50 | 100 I'll burn through my 100 then can then take that phosphate and add |
|
| 77:55 | back and then I have my other . So I basically doubled my |
|
| 77:59 | That kind of makes sense. The is, is that I can't make |
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| 78:03 | A TP, but I can store phosphates to add to a TP to |
|
| 78:08 | the energy and it doesn't cost me . All right. So if I |
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| 78:13 | five seconds of energy here, I add in another 12th in 10 seconds |
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| 78:17 | energy through this mechanism through creatine And then I have another one, |
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| 78:26 | have this enzyme called myo kinase and says, look, every time I |
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| 78:32 | a TP, I get AD All right, what I wanna do |
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| 78:36 | I want another phosphate back to that I can get my A TP again |
|
| 78:39 | just kind of keep this going But sometimes I'm burning through energy pretty |
|
| 78:43 | and I don't have enough time to this. So why don't I just |
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| 78:46 | a phosphate from that AD P? , really from that one, add |
|
| 78:49 | to this one, then I can my A TP. So I can |
|
| 78:52 | that energy again. You're asking, you're probably not asking. But |
|
| 78:57 | the question that you should be asking , hey, why do I have |
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| 79:00 | make the A TP? Why can just keep breaking down A TP? |
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| 79:03 | I'll answer here in seconds, the that it takes to release energy from |
|
| 79:09 | last phosphate is very small. Whereas closer I get to the uh the |
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| 79:16 | , it requires more energy. So want a TP because it's the |
|
| 79:21 | Yes, ma'am. Right. So purpose here is I want, all |
|
| 79:30 | , ready for the lie and you're for the truth. OK. The |
|
| 79:34 | is the creatine is gonna be broken because the peptide. And so anything |
|
| 79:37 | put in your digest system that the gets broken down and turned into little |
|
| 79:41 | amino acids. All right. The is that what they're saying is, |
|
| 79:44 | , I know my muscles need right? So I can do this |
|
| 79:49 | I can increase my stamina, But that's not how it works. |
|
| 79:54 | not absorbable, it's break, it down. This is where I kind |
|
| 79:59 | tell you your digestive systems are pretty . So for people who are freaking |
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| 80:03 | about like bovine growth hormone and that's a peptide, it just gets |
|
| 80:07 | up into amino acids. So there's of stuff you don't need to worry |
|
| 80:13 | that. You probably have been told worry about, but that's the career |
|
| 80:19 | . So this is how we get energy. This is the quick |
|
| 80:24 | All right, when it comes to term and short term, um um |
|
| 80:31 | supplies. Um I just realized I stuff to the lecture here, but |
|
| 80:38 | probably don't have the slides for Um But anyway, so long |
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| 80:43 | this is going to be aerobic. what you're doing is you're breathing in |
|
| 80:46 | , you're using the oxygen as the of electrons. And so what you |
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| 80:52 | do is you can make tons and of A TP. And so this |
|
| 80:55 | when you go and take biology and learn about glucose metabolism and oxidative phosphorylation |
|
| 81:01 | the crab cycle and all that All those steps are going to result |
|
| 81:05 | you producing tons and tons of A from a single glucose molecule. But |
|
| 81:10 | only happen if you have oxygen All right. So our bodies prefer |
|
| 81:15 | this because you, you are able get that a TP, that your |
|
| 81:20 | needs. The problem is, is there's so many steps that it takes |
|
| 81:23 | long time to do it. And this is something that you do where |
|
| 81:27 | not in a hurry. But if burning through your A TP, |
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| 81:31 | this is how you'd go through it oxygen. It's basically taking the first |
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| 81:35 | of steps, the glycolic pathway and making just enough a TP to keep |
|
| 81:41 | going. Right. But it's not sustainable system, you'll fatigue very, |
|
| 81:46 | quickly. So the body kind of this kind of as a last |
|
| 81:56 | Do you guys have the slate? do? All right. Then I |
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| 82:00 | screw it up. Oh, so was like, oh, smooth muscle |
|
| 82:05 | I kind of had it set up the next lecture for some reason. |
|
| 82:08 | right, before I move into smooth , what we just talked about was |
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| 82:13 | skeletal muscle. All right. And kind of what we're gonna do is |
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| 82:17 | go through smooth muscle here and um, when we come back on |
|
| 82:23 | , it's so weird. What day is? It's Wednesday, right? |
|
| 82:26 | hump day. So it's all downhill here. We'll come back and we'll |
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| 82:31 | with skeletal muscle again. But all mechanisms that I just described is also |
|
| 82:36 | cardiac muscle kind of works. There's subtle differences, but basically everything I |
|
| 82:40 | told you is, is exactly the . All right, the smooth muscle |
|
| 82:45 | very similar stuff, but it's behavior it goes through this contraction is different |
|
| 82:51 | structurally it's different. All right. what we're looking at here is a |
|
| 82:56 | muscle cell. Notice it's not like skeletal muscle. Remember the skeletal muscle |
|
| 83:00 | this long tube that goes the length the cell. These are really individual |
|
| 83:06 | that are itsy bitsy teeny tiny and kind of exist together as um uh |
|
| 83:13 | know, sheets of cells attached to other. Now, I have up |
|
| 83:17 | , I say it's uninucleate and I mention it. I know I didn't |
|
| 83:21 | it but I have it on the that skeletal muscles are multinucleate. So |
|
| 83:26 | start off as individual itsy bitsy tiny cells. But as you're going through |
|
| 83:30 | development of muscle cells, they actually together and create these larger cell |
|
| 83:35 | which is why they're multinucleate. All . So the myoblast become myocyte through |
|
| 83:44 | , smooth muscle doesn't do that. , they're spindle shaped. So you |
|
| 83:49 | kind of see what a spindle kind looks like. They don't have any |
|
| 83:51 | instead, the proteins that make up Z lines are arranged in such a |
|
| 83:56 | that they create these dense bodies. what these little purple, pink, |
|
| 84:01 | , orangeish looking circles, purple and . I don't know where I got |
|
| 84:05 | from, but um they're actually scattered they're held in a place by intermediate |
|
| 84:11 | . And so you have some intermediate and then thick and thin filaments that |
|
| 84:14 | affiliated with this. And so when creating cross bridges, what you're doing |
|
| 84:19 | you're pulling dense bodies towards each And that's since the dense bodies are |
|
| 84:25 | of scattered around, you end up a kind of weird looking wrapped hand |
|
| 84:29 | right. They just the cell itself kind of squishes down in all these |
|
| 84:33 | directions. So the smooth muscle behaves because structurally it's different, but you're |
|
| 84:42 | getting a contraction. Now, the themselves, as I said, they're |
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| 84:53 | a group kind of in, in structures that are called SIA. So |
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| 84:57 | cells attached to other cells, they're to each other by a series of |
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| 85:00 | junctions. They do have a sarcoplasm . It does require the sequestering of |
|
| 85:06 | , but we don't have any t . So how we go about creating |
|
| 85:10 | muscle contraction is different. Same Ultimately, calcium and A TP are |
|
| 85:18 | . But instead of you having troponin Troy and min, interacting with actinine |
|
| 85:25 | act and interact without having the troponin in the way, it's gonna be |
|
| 85:31 | little bit different. Now, smooth is found primarily in hollow organs. |
|
| 85:36 | We usually have two sheets. So can kind of see here one sheet |
|
| 85:41 | they're on the hollow organs are going go around the organ. So that'd |
|
| 85:44 | circumferential and then they come outward so they're elongate along the length of the |
|
| 85:50 | organ. And so what that means that these, these muscles and you |
|
| 85:54 | see the two lengths. So this be circumferential, this would be coming |
|
| 85:57 | at you. What this means is when you contract the circumferential, the |
|
| 86:01 | gets smaller, right? And then I contract the one that's coming |
|
| 86:07 | the elongate, it causes the tube shrink in length. Now, you |
|
| 86:13 | control these voluntarily. This is all regulation. And so when we're talking |
|
| 86:20 | its activity, we're talking about like like blood flow, you can't regulate |
|
| 86:24 | blood flow, right? The movement materials for your digestive system, you |
|
| 86:28 | speed up or slow down your You can't speed up, slow down |
|
| 86:32 | your urine is being made. It's being done independent. All right. |
|
| 86:38 | everything you see in this list, , uh you can think in terms |
|
| 86:42 | the uterus during pregnancy or actually during and delivery, you don't control |
|
| 86:47 | These are involuntary. So smooth muscle an involuntary system where a skeletal muscle |
|
| 86:52 | you all contract your muscles? You know how to do that. |
|
| 86:56 | you do this? So your tongue skeletal muscle, right? You |
|
| 87:03 | and here's a fun one, you're at skeletal muscle. I won't close |
|
| 87:08 | eyes, you can open your see you can control that, but |
|
| 87:13 | has, has a mechanism. So you're doing automatic, wet my |
|
| 87:20 | right? So it's an involuntary action it's in voluntary control as well. |
|
| 87:25 | have you ever played the steering I'll lose. Alright. So this |
|
| 87:37 | the weird part. All right. here's how it works. All |
|
| 87:45 | we're going to stimulate the cell, potentially causes the opening of calcium |
|
| 87:50 | So calcium channels will open up but isn't binding to troponin. It is |
|
| 87:55 | to a different molecule. This molecule called calmodulin. So, calcium modulating |
|
| 88:02 | that's where it comes from calmodulin, ? Calmodulin is gonna work in a |
|
| 88:07 | cascade. So you can see this a signaling cascade kind of like what |
|
| 88:10 | saw in that first unit, And so calmodulin activates a KA A |
|
| 88:16 | is a molecule that phosphors another And you can see here it's called |
|
| 88:21 | . All right, Mlck is min chain. K ase. All |
|
| 88:27 | My I said it has two it has a tail and it has |
|
| 88:29 | head. The head is the light , the tail is the heavy |
|
| 88:33 | All right. So my chain KSE , the head of the My. |
|
| 88:40 | right. Now, what we're doing we're phosphorylation, this head so that |
|
| 88:46 | can have a TP A activity. is the purpose of the A TP |
|
| 88:51 | to make the head wiggle? All . So instead of it having its |
|
| 88:56 | activity, it's dependent upon the my and light chain chia to activate the |
|
| 89:04 | . So we're using a series of events to cause the muscle demise and |
|
| 89:12 | acting to interact. So it's a slower, right? Your muscles, |
|
| 89:18 | smooth muscles a bit slower. It longer to contract, but it sustains |
|
| 89:22 | contraction for a longer period of But you'll still get the same power |
|
| 89:28 | . You'll still get the cross bridges like you saw. It's just the |
|
| 89:32 | to which we did that was What about relaxation? Well, everything |
|
| 89:38 | turn on, you turned off, rid of the calcium. Everything else |
|
| 89:41 | into place. Each of these things something that desolates de phosphors. |
|
| 89:47 | while I have an activated Mycin light , K, there is something that |
|
| 89:51 | come along and it will Deos with phosphate. All right. So the |
|
| 89:57 | here is for everything that turns on switch, there's something that turns off |
|
| 90:00 | switch. So relaxation occurs. But , it occurs slowly, some characteristics |
|
| 90:11 | you should be aware of and you know about them. All right, |
|
| 90:16 | muscle have something that's called a stress response. And basically what that does |
|
| 90:20 | it allows for a greater volume and degree of stretch without resistance to |
|
| 90:26 | All right. Think about Thanksgiving dinner Thanksgiving lunch. Have you noticed that |
|
| 90:33 | you eat? You're basically like, keep bringing the plates and all you |
|
| 90:37 | have to have is the stretchy If you have the stretchy pants. |
|
| 90:39 | good to go. Right. Because you can keep putting food in |
|
| 90:43 | stomach says ok, I'll take a bit more, put more food |
|
| 90:46 | I can take a little bit put a little bit more food |
|
| 90:49 | Ok, I think I'm done here pumpkin pie. Right. That sound |
|
| 90:54 | right. Or anyone here like I mean, are you like super |
|
| 90:58 | ? And you go to a buffet it's like, I've got to get |
|
| 91:00 | $12 worth. It's like, I've to get like eight plates of food |
|
| 91:04 | so I could feel like I've, spent my money. Well, all |
|
| 91:07 | , same sort of thing. I'm digestive system as, as an example |
|
| 91:10 | . But this is also true for uh vasculature for your lymphatics, for |
|
| 91:16 | urinary tract. Everything that has a organ with smooth muscles, it can |
|
| 91:20 | expand without having to resist. It can do so it also creates resistance |
|
| 91:27 | it experiences it. So we talked that muscle tension curve just briefly, |
|
| 91:34 | ? We're like, ok, there's perfect length. Well, smooth muscle |
|
| 91:37 | weird that it can actually be stretched , really far and still function just |
|
| 91:43 | . All right, it is able be efficient. Still finally, um |
|
| 91:49 | smooth muscles like of the uterus are weird in that they're hyperplastic. |
|
| 91:53 | can actually get more and more of and uh have uh um whereas muscle |
|
| 91:59 | themselves, skeletal muscles don't do that all. So, what about the |
|
| 92:08 | junctions here? How do we do ? Well, here what we have |
|
| 92:13 | we haven't talked about this, this. So the very last lecture |
|
| 92:16 | gonna have this semester is about the nervous system. And you're gonna hear |
|
| 92:20 | refer to it multiple times so that not telling you what it is. |
|
| 92:25 | doing it on purpose. Ok. apologize for that. But here what |
|
| 92:29 | have is we have innovation via the nervous system. Now, when you |
|
| 92:34 | at that word, autonomic, it kind of say it works by |
|
| 92:37 | It's, it's independent, it's responsible involuntary control. All right. But |
|
| 92:42 | here that we don't have those synaptic instead, this is the neuron and |
|
| 92:47 | get these bulbs that appear over and . All right. These are called |
|
| 92:53 | and the varicosities act like a synaptic except that you don't have one at |
|
| 92:58 | terminal in the neuron just keeps And then you have these areas where |
|
| 93:02 | going to Sequera vesicles and it's going lie overlie the cells and it kind |
|
| 93:06 | like kind of acts like a sprinkler . So when there's, when the |
|
| 93:10 | potential travels down at each of these or sorry, each of these |
|
| 93:16 | you're going to release out neurotransmitter, don't have a neuromuscular junction underneath. |
|
| 93:20 | what you have is you just have on these cells. And so when |
|
| 93:24 | release that neurotransmitter, it just kind flows out and when it can find |
|
| 93:26 | receptor, it does. So that's reason why it's a little bit |
|
| 93:31 | So even though you may be and even though a signal may have |
|
| 93:35 | down, you may not always get contraction. All right, you have |
|
| 93:40 | have a strong enough signal to get contraction. Whereas in skeletal muscles, |
|
| 93:43 | time you got an a potential, got an Epp and you got an |
|
| 93:48 | potential, you got a contraction, not one that created tetanus, but |
|
| 93:52 | got a contraction, right? So is a little bit different and then |
|
| 93:59 | arrangement of these cells can be in of two states, what we call |
|
| 94:05 | multi unit and what are called single . All right, you guys familiar |
|
| 94:11 | houses and homes, what's a Is it a multi unit or is |
|
| 94:15 | a single unit? If you live a duplex, are you living in |
|
| 94:20 | multi unit home or a single Home? Multi unit, single |
|
| 94:24 | try it again. So in a , how many people are living in |
|
| 94:29 | ? In that building two? It in the ink duplex, right? |
|
| 94:35 | you live in an apartment, are in a multi unit or a single |
|
| 94:39 | ? You live in a multi unit , right? You have neighbors who |
|
| 94:42 | not related to you, right? cooking cabbage, I'm just teasing. |
|
| 94:48 | not cooking cabbage, right? Multi . If you live in a neighborhood |
|
| 94:53 | you have a house and a driveway you have a lawn and, and |
|
| 94:56 | like that and then the house next you has the same thing. What |
|
| 94:59 | those homes called? Single units? ? Now? Notice we're not talking |
|
| 95:04 | all the weird dynamics. So, mean, you can have homes where |
|
| 95:06 | have multiple generations and you can have and families living together in that. |
|
| 95:10 | they're still designed as a single All right, those terms have some |
|
| 95:15 | specific uh connotations to them. So units, what we have is we |
|
| 95:22 | a lot of discrete motor units, ? So all the cells are not |
|
| 95:27 | , they're independent of each other. they act independently, all right, |
|
| 95:32 | have kind of a neuromuscular junction. here you can see this is a |
|
| 95:38 | unit, smooth muscle, right? cell is innervated. This cell is |
|
| 95:42 | , that cell is innervated, that is innervated, that cell is |
|
| 95:46 | They each act independent of each So I'm getting different types of |
|
| 95:51 | all right, they act independently of other with a single unit. |
|
| 95:59 | I'm innovating the region. So they act as a group, they're all |
|
| 96:04 | to each other via a series of junctions. So even if this cell |
|
| 96:09 | get stimulated, a cell in that may be stimulated, which allows for |
|
| 96:13 | of the cells to spread that stimulation the cell next to it. All |
|
| 96:18 | . So the contraction spreads from cell cell to cell to cell here. |
|
| 96:22 | individual cells are being stimulated one by . All right. So the examples |
|
| 96:30 | , I uh just different ones you see here. So for example, |
|
| 96:33 | hair follicles, um you can think like this II I mentioned this the |
|
| 96:36 | day. It's like you had uh bumps on like one side of your |
|
| 96:40 | , but not on the other. like, what's going on over |
|
| 96:42 | What do you know that this side know? Right. So that would |
|
| 96:46 | the reason for that is because they're independent of each other, they're being |
|
| 96:51 | independently. Whereas when you're dealing with unit smooth muscles, the whole sensi |
|
| 96:58 | being stimulated. So that would be cells that are found in the digestive |
|
| 97:03 | , right? If I start a in the stomach, that contraction follows |
|
| 97:07 | entire musculature of the stomach as a , it's not just a couple of |
|
| 97:13 | , it's the whole group of All right. So the whole system |
|
| 97:19 | going to be stimulated at that Oh yeah, we should talk about |
|
| 97:28 | excitability. One thing that's unique about muscles that they produce their own, |
|
| 97:35 | capable of producing their own action They basically have these series of waves |
|
| 97:41 | where they're basically creating um they're moving near the threshold and back down |
|
| 97:47 | So basically, they're opening and closing , they may not actually produce an |
|
| 97:52 | potential, but they get really And so when you stimulate them, |
|
| 97:57 | going through these waves actually may produce action potentials, greater contractions so on |
|
| 98:03 | so forth because of this self In other words, there may be |
|
| 98:07 | within them that are responsible for some activity. Now, when you think |
|
| 98:12 | the heart, you think about but you don't usually think about it |
|
| 98:16 | other things, but I don't necessarily to stimulate the vasculature to constrict or |
|
| 98:25 | . I don't need the brain to that. It can do so on |
|
| 98:27 | own because of its own self That makes sense. All right. |
|
| 98:36 | this is where we're stopping today. , a little bit early. But |
|
| 98:41 | you guys go running out of are there any questions about the |
|
| 98:45 | Any questions about grades? Anything like that the announcement last night didn't |
|
| 98:52 | Yeah. Yes. So I have person taking the exam today. Um |
|
| 98:59 | and then as soon as they're I'll open up the test to look |
|
| 99:01 | and then I think the extra credit up tonight at 6 p.m. So you |
|
| 99:06 | look at it then, right? other questions like I said, |
|
| 99:11 | you know, honestly, the you , not that this helps you or |
|
| 99:16 | you happy or anything the average on on this second exam is exactly where |
|
| 99:20 | want it. 12, it's better it is than it was in the |
|
| 99:24 | for the last couple of years. , you guys are, you're performing |
|
| 99:27 | than the fall did. But like I said, in the, |
|
| 99:30 | the email, it was like people did one on the first one flipped |
|
| 99:34 | then people who did poorly went the direction. So overall the unit itself |
|
| 99:38 | kind of behaving in a weird but that's not a point to |
|
| 99:41 | All right, we've got plenty of , at least finish out this |
|
| 99:46 | And then if you're like, really panicking, then we'll have a real |
|
| 99:49 | about, you know, whether or to stay or go or whatever, |
|
| 99:53 | decision you're trying to figure out. . I don't think anyone should drop |
|
| 99:57 | class. I don't think anyone is the class right now. So, |
|
| 100:03 | that good? Is that, is good? Ok. So, just |
|
| 100:06 | that no one's failing right now. just gotta do better though. I |
|
| 100:10 | all A's, I want a I haven't had a party yet. |
|
| 100:13 | right. You guys have a great . Yeah. Yeah. |
|
