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BIOL 2301 Human Anatomy & Physiology I - 2301_lecture10_0621
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00:02 You'll get so quiet in the I can't tell if it's that you
00:06 woken up yet or you're nervous or what we're looking at. This is
00:13 distribution for the second exam. Average 61. Um Standard deviation is crazy
00:21 out the roof. If you don't the standard deviation is, it basically
00:24 you how spread or how wide the sizes and so Very, very
00:30 Usually we're shooting for about a Really good sample or really good standard
00:36 would be about 12. See the grade was 94. Low grade was
00:40 . The median grade is a and you can see the difference between
00:43 average of the median grade. Remember grade, you guys remember how to
00:47 that stuff way back when the median is lined up all the grades and
00:51 work your way to the middle and the medium grade. All right.
00:55 , you can look at this and can say, all right, I'm
00:57 panic and freak out and run Like it's the end of the
01:01 the end of the world. You , It's not actually when I look
01:04 this, what I see is a of really good grades bunched up here
01:08 then kind of this downward slope that kind of slides off. Alright.
01:13 it's one test, who cares? 20% of your grade. No big
01:17 . You're looking at me like now one it's it's more than a
01:21 It's my life. I've got I've to get into school school test
01:25 No, it's no big deal. . One test is not anything.
01:29 is a comparison. I'll probably come to that. No, no,
01:34 , actually, this is fair So, this kind of shows you
01:39 over the two units. So the one, the blue is unit number
01:43 . So that's that's all the grades you earned in unit one, The
01:48 , all the grades you earned in two. And it doesn't include any
01:50 the unit one stuff. It just of shows you how how have grades
01:54 of shifted and stuff. And you see there's a slight uh shift.
02:00 , I mean, technically the the aren't that far off. I
02:04 I think the average between the two is like a point. But you
02:07 kind of see there's this kind of that's kind of shifting this way.
02:10 then a couple of people have kind given up. I mean, I
02:14 know these students aren't coming to class didn't take the test. They stopped
02:17 homework. So, you can almost those last two as not being part
02:22 this. So, you know, there anything to be concerned about?
02:27 and no. I mean, in the sense of like, are
02:30 doing as well as you could be you given up if you've given
02:32 stop giving up and actually try. And if you haven't given up,
02:37 at your grade and say all right I doing what I want to do
02:39 if not let me try harder. ? I mean we don't we don't
02:44 in to win. People who coast people who strive and work hard
02:51 Um I don't know how to tell anything other than that. I mean
02:57 not disappointed with the grades. I the grades are just fine. They're
03:00 where I expect them to be. mean I prefer all A's. I
03:03 I wanna have a kegger. None you guys want keggers. And so
03:06 like I've kind of resigned myself to idea that never going to have that
03:11 . But anyway this is what the look like. I mean overall.
03:16 if we were excluding extra credit Remember you've got to get out of
03:21 brain and stop thinking that A. is failing what's failing in the class
03:26 . Thank you. And so what means is you use these numbers to
03:30 the range in which you fall in you can go and calculate your own
03:33 and see. And then if you to throw your extra credit on that
03:35 can see where that pushes you as . But it's saying look right now
03:39 know A. Is still a That doesn't surprise me. This curves
03:43 help out the A's. But you a regular semester. This kind of
03:46 down a little bit but summer semester usually sticks around there, A.B.
03:52 about a 76 right now And that's gonna change a little bit by by
03:56 .1 way or the other and then begins about A. 56.7 and then
04:02 D. Begins at A. 50 then anything below that. So if
04:05 again if you find yourself here, not out of the running, we
04:09 have 50% of our grade, in ? I mean that means you still
04:12 half the class to go if you here. And let's just say you
04:16 50% better. That's gonna push you to here. A lot of people
04:21 see that. A lot of people see oh my grades are bad.
04:24 just gonna suck now and you you law school, that's where we get
04:28 the lawyers because they can't hack it here and the real stuff. Sorry
04:34 parents or lawyers. My dad's an . I get to make fun of
04:38 all the time. Actually. I think he ever practiced law in his
04:42 life. Um Anyway um The point is that don't get caught up in
04:49 numbers, right? Your job here to learn the material. If you
04:55 on learning and don't focus on I need to learn this material.
04:59 don't want to go to a doctor a nurse or physical therapist who hasn't
05:04 how to do blank. If that's attitude, say I'm gonna be that
05:09 , I'm gonna be the person that everything. So that when someone asked
05:12 a question about Covid, I'd be to answer, someone asked me a
05:15 about cancer. I'll be able to . If someone asked me about how
05:18 big toe works, I'll be able answer it. Alright. You strive
05:22 be that person. You're great. naturally going to go up and if
05:25 find that you're studying, you're studying aren't getting you where you need to
05:28 , go back and look at what recommend it to do. Alright.
05:32 know it works. I've seen it . I've seen it. Turn my
05:36 story. I know you guys love I tell stories, right? See
05:39 excited you get. I had a football player, played for the for
05:44 Ravens promised his mother that he would from college had one semester to
05:51 Alright. This is like eons And he was in my class and
05:56 was getting D's over and over again you know, it was driving him
06:00 . Because if you didn't know athletes ridiculously competitive, Alright. Competitive beyond
06:07 . And so he said they're why can't I do well in this
06:10 ? I know that I'm capable so . Let's see how you're studying.
06:12 he told me he was like, yeah, you're studying, like you
06:14 to do when you were in when people would just hand you grade
06:18 that you can keep playing football stop that. Let me tell you how
06:21 do it. Right. I told how to do it right. He
06:23 a D into a B plus over tests. Everybody is capable of doing
06:30 . Doing well. You just have want to do it. Don't get
06:33 by the numbers. Ask yourself to , you learn, you'll do just
06:40 that I'm not trying to beat an . Just it's humid and hot and
06:46 of this. You want to have good news? There's only eight more
06:51 to go. Only eight more days you having to put up with
06:57 All right. I think the stuff we're moving into is interesting and
07:01 It's part of the reason why you went into this in the first place
07:06 . We're going to talk about muscles . We're gonna talk about muscles and
07:09 rest of the entire class is about nervous system in all sorts of different
07:14 . Didn't you ask me if we're to do the eye? Yeah,
07:17 gonna talk about the eye how it . It's not a camera. All
07:24 . Although we like to think like . All right. Anyway. So
07:27 you're looking at this and you're a panicky email me come by and see
07:32 if you have, you know, up an appointment, we can talk
07:34 off the ledge when I say talk off the ledge. That doesn't mean
07:38 you off this way means talk you this way. Okay. You know
07:42 you find yourself in this area, panic just yet. You guys know
07:46 the drop date is because I know of you are like sitting. I'm
07:48 the class right after he turns I'm gonna drop the class. I'm
07:51 run out of here. Right. you know when the drop date is
07:57 looks next monday? You can literally three tests, do all your homework
08:03 and then determine whether or not your good enough to move on. They
08:07 do that when I was in man. If you didn't know about
08:09 first test, you were screwed. just have to work your way through
08:12 . All right. So don't drop harder. See what you need to
08:19 . See how you can change if keep doing the same thing over and
08:21 again, don't expect any changes. right. That was eight minutes of
08:27 ranting 8.5. Let's learn something Pictures of sexy people. A little
08:36 of cheesecake. A little bit of . All right. What we're gonna
08:41 today. Sounds like I've been drinking we're gonna do today is we're gonna
08:47 at how a muscle works. So there's a couple of things.
08:51 going to go through the micro anatomy a muscle cell. All right.
08:56 going to ask the question, How the contraction actually occur? Yeah.
09:01 . And so the idea of a cell, and then we're gonna ask
09:04 group questions like, how does a contract. Alright. That's kind of
09:10 big picture of today. And then we're gonna do at the very end
09:12 we're gonna look at smooth muscle, is boring and and and not as
09:17 . We spend most of our time about skeletal muscle. All right.
09:21 how many different types of muscles are ? Three? Right. If you
09:25 skeletal muscle, you understand cardiac They're very, very similar.
09:28 we don't go over it again. . There's it's structurally there's some differences
09:32 that's about it. All right. , we're gonna be doing skeletal muscle
09:38 . Smooth muscle. Second. so, that's our starting point.
09:42 is the function? Remember, we ask the question first, What are
09:45 trying to accomplish? Skeletal muscle has functions? The easy one. When
09:51 turn on your device, There we . The easy one is to produce
09:56 . And so, what we talk movement here, we're talking about
09:59 Alright, So any sort of movement you're doing where your hands are gesticulating
10:04 mouth is moving. That type of is what we're talking about skeletal
10:08 Alright, secondly, it's there for and support. It basically holds your
10:13 organs into place, particularly in the and in the thoracic region, it
10:18 you maintain your posture, it stabilizes joint which we've already talked about.
10:22 also generates heat Alright. So when contract it uses energy. The energy
10:30 of muscles like most things in your is fairly low. So the byproduct
10:35 that energy that's being converted turns into and that's what actually warms your body
10:42 we don't think about it too much we also plays a role in
10:45 Now you can think alright well I'm my fingers around and typing and writing
10:48 and that's true and that's a form communication but really it has to do
10:52 speaking and facial expressions as well as gestures. You know when I look
10:57 you and I do this, what you think? Right, it's like
11:02 I understand what that movement makes. you ever tried to understand somebody through
11:07 ? What they're trying to trying to ? I mean I mean usually it's
11:12 okay but have you ever like oh don't know misinterpreted the words that they
11:18 Yeah right. It's because there's we when we communicate we use primarily facial
11:26 to express our emotions. They try include Emojis but only like 30 of
11:32 understand what each of those emojis We just kind of randomly throw them
11:35 there hoping that someone gets an idea what that poo means right? I
11:42 a friend, I was talking with . She's she's my age and she's
11:46 right? And so she was trying figure out from a text from somebody
11:50 she was dating whether that was a face or not. And we started
11:54 different emojis down trying to determine which ab absolutely represents being flirty or whether
11:59 being silly, like ha ha I mean that, right? But if
12:04 tell you something and I raise my and kind of give you that kind
12:08 look. You know that I'm kind joking around if I'm frowning at
12:11 You know I'm angry, right? got all these muscles on my face
12:16 convey communicate to convey information. All . So muscles have all these multiple
12:24 Now in the lab, you'll get explore about 100 of them. And
12:28 to let you know there's about 600 muscles in the body. All
12:32 So depending on who your anatomy professor in the future, you're gonna have
12:37 learn a lot or not a Alright? So at our level we
12:42 learn that means about 100 of them they force you to learn. But
12:45 you go to medical school, your in every single solitary one of
12:49 I don't know about nursing school. right. For this class. We
12:54 name the muscles. Alright. It's hard to just sit there and point
12:57 picture and say memorize memorize memorize. I'm gonna leave that to the lab
13:01 have you learn the names of the . Now, what that means is
13:05 Wednesday we will talk about how muscles named. You know, it's like
13:11 slide to give you a hint of to go about looking at a muscle
13:15 going, okay, I can pretty figure out what the name of that
13:17 is. All right. So a is going to be supported by connective
13:28 . And when I say that, I mean is that when you look
13:31 a muscle, if you go to store and look at a steak,
13:34 what a steak or a roast is a muscle that has been removed from
13:38 animal. And if you look at cross section, you'll actually see how
13:42 muscle is being held by connective Alright. And your muscles are the
13:47 same way and there are multiple layers this. We basically have three concentric
13:53 . Now, what we're gonna do is the nomenclature gets a little
13:57 All right, because everything sounds like like the nervous system where the first
14:02 who are exploring it was like, these are special cells. And so
14:05 gonna name everything this, we're gonna everything a prefix of my oh and
14:10 you finally kind of learn it's It's all the same. It just
14:14 on what we're looking at. So muscle cell is here. Alright this
14:21 the muscle fiber. It's also referred as a maya site. Alright.
14:26 then inside that that's where you So, it's a mile fiber or
14:30 fiber. So, they're trying to it less confusing. But it's my
14:34 fiber. And then there's things inside that will be mild fibrosis and maya
14:38 . So, see how confusing that . It's a fiber. Alright.
14:44 what we have is we have these of connective tissue that takes an individual
14:49 and wraps it. So, you'll individual cells will be wrapped in uh
14:53 tissue. And then what you'll do you'll bundle those up and wrap that
14:58 a connective tissue, and then you that up and wrap that in connective
15:01 . You bundle that up and you wrap it in connective tissue.
15:05 the layers that we're most concerned about the three. We're not gonna be
15:08 primarily about this sarcoma, which is plasma membrane. Alright. What we're
15:13 about is the three above them. the names are really easy.
15:16 So, when you're referring to this tissue, the prefixes missy. Um
15:21 . Not Museum. Museum. you probably heard of a paramecium which
15:24 basically a little tiny single cell That's bad for you. That's not
15:29 that is. All right. you can see there's a pair of
15:32 . Um All right. So, sound very similar. But they're very
15:35 different. So, the outermost layer the epa macie. Um All
15:40 And so when you think of a that connective tissue that wraps that whole
15:44 , is that epic museum? When you're looking at a bundle of
15:49 and remember fibers and single cells. , if you take a bunch of
15:52 and wrap them together, what you're do is you're gonna create something called
15:55 fantastical. All right. A fast . Basically just a bundle of
16:01 Really? And that's kind of what done is we're going to call this
16:04 tiny bundle of sticks and this tiny is surrounded by the pyramids Ium.
16:09 right. And then individual cells are have the indo missy. Um All
16:17 . So, you can imagine here's circle, Emma. And what I'm
16:20 is I'm rapping in connective tissue. , the reason we wrap an individual
16:24 with connective tissue is that these are potential cells. Alright, think of
16:30 like wires. If you take a bunch of copper wires and bundle them
16:34 , will each individual wire work by ? Or will they actually send charge
16:39 the cells that are or the charges the wires around them? Right.
16:46 want to connect and create create a wire. You just basically take copper
16:50 added to copper. The charge passes one wire to the next.
16:54 if I have a bunch of naked touching each other. They cross over
16:58 other. So, if you want keep a charge to an individual
17:04 you wrap it in insulation. And what we're doing here. Is each
17:08 muscle is wrapped in its own connective so that it's separated from all the
17:13 . So that when you electrically excite cell, you're not electrically electrically exciting
17:18 that you don't want to excite. kind of makes sense. Now,
17:26 of this connective tissue travel along the of the cell. These cells are
17:30 long as the muscle itself is all ? So the bicep starts here ends
17:36 here. Really, actually, starts , ends down there. That's one
17:41 , right? And it's that So, the cells inside that are
17:44 long. So each individual cell is to be wrapped in connective tissue bundles
17:50 those individual cells are wrapped in connective bundles of the bundles are wrapped in
17:55 tissues. We call that the right? And then those connective tissues
18:00 continue past those individual wrappers that we've and they form the tendon. All
18:08 , So, here's the tendon. that epic museum. You can imagine
18:11 paramecium is going up beyond the wrapping joining up with the epa museum.
18:16 can imagine the endometrium is going past this stuff joining up with the other
18:21 connective tissues. And they're forming this like structure. This tendon which allows
18:27 muscle to be attached to the And the purpose of that muscle is
18:31 bring the two bones that it's attached closer together. All right.
18:37 that's the purpose here. So, you think about that tendon muscle itself
18:42 not pulling on the bone, muscle pulling on a tendon tendon is pulling
18:47 bone. So, when a muscle , it's causing the tendon to be
18:52 . And since the tendon wants to stretching, what it does is it
18:56 and it pulls whatever it's attached which happens to be about. And
19:00 is attached the perry Osti um on bone. So, that's the
19:07 And that's a big macro view. what we're gonna do is we're gonna
19:11 to that mile fiber and we're going slice it and we're gonna take a
19:14 inside. Alright. And the reason do this is so that we can
19:20 how that electrical signal is going to in that cell shrinking squishing on itself
19:27 through that contraction. Now, as mentioned in the muscle, what we
19:31 is we name things with that muscle . So, we have that my
19:35 , if you ever see milo just muscle and the other one is Sarko
19:39 right. So, when you see plasm, it's referring to the cytoplasm
19:43 you cease our kolyma, it's referring the plasma membrane. Alright.
19:48 it's just fancy words for this type self. All right now. What's
19:54 about the Sarko plasm here is that can see that it's jammed packed.
19:59 right. This is not just an trying to shove a bunch of things
20:02 here. It's really saying, there's not a lot of space in
20:06 . Now, what we will see we'll see some Glick assumes like a
20:10 are basically packets of stored glycogen. the reason we start glycogen in our
20:16 is because we don't want to wait sugar to show up to the muscle
20:20 in order for them to do their . It's easier just to keep something
20:24 site if you like to eat. don't put all your food in the
20:29 , you store it in the night or the nightstand, right? Anyone
20:35 have a bunch of twinkies hiding in . Okay, Don't don't tell
20:39 I don't want to know. All . Another thing we have myoglobin.
20:45 , myoglobin is a molecule that's related hemoglobin. You've probably heard of
20:49 hemoglobin is the molecule that sits in blood cells that binds up oxygen.
20:54 my globe in sits in muscle cells it binds up oxygen. Again,
20:59 reason being is you don't want your cell waiting for oxygen to arrive,
21:04 ? If you're walking down the street a bear attacks you because that's what
21:08 , right? You want to sit and start breathing gotta get the oxygen
21:12 my muscles. You want to be to have the muscle to begin contracting
21:15 you can fight the bear because that's you do, right? You find
21:19 bear, okay, there's a whole of mitochondria. Why do I need
21:26 ? What do mitochondria do in a way? Make make a T.
21:32 . So in essence, what I here is the rule of thumb is
21:36 you have mitochondria, you're making A . P. The more mitochondria you
21:39 the more 80 P are making. we have to have energy generating
21:44 And so there's lots and lots and of them. And then the weird
21:48 about this is that this cell is multi nucleus itself. The reason it's
21:53 nucleotide because during development, what you is you had a bunch of milo
21:58 when you hear the word blast. does that mean? It's a building
22:02 immature cell. It's not a mature yet. And so what happened is
22:05 mile blast. Our signal to fuse one another and they begin fusing and
22:10 blast our Itsy bitsy tiny cells. mean they're like the size of normal
22:14 , right? And what happens they and they form these cylindrical structures which
22:19 your mild fibers. So the individual that's really, really long is actually
22:25 whole bunch of cells that fused together form this structure, interestingly, the
22:31 that precedes a mile blast is also same cell that precedes the adipose
22:37 So basically if you give the right , you can send that cell down
22:40 the fat pathway or down the muscle and that doesn't mean that you can
22:44 your muscle into fat and vice It's just an interesting idea that those
22:48 have the same origin. Now, I want you to do is I
22:52 to focus in here on a couple items inside. Now here, these
23:00 right here we're going to deal with just a minute. These are your
23:03 side of skeletal elements are the mild . Alright, So you can see
23:07 the whole thing is just jammed full side of skeletons and it's an organized
23:11 of skeleton. But surrounding these are things called the triad. Alright.
23:16 collectively the triad consists of three Alright. The first item is this
23:22 item that you see kind of in cartoon. It's not actually yellow,
23:25 that's how the cartoonist drew it. right, this is the T
23:28 the transverse tubules. This creates a that opens up from the surface and
23:34 kind of is a tube that travels the way through the cell and around
23:38 the other side. In essence, you have something like this, whenever
23:42 have a tube through something, what done is brought the outside close
23:47 right. In other words, you've more surface area and that surface area
23:51 deep to whatever the structure is. when you have like a tunnel,
23:54 you're doing is you're that tunnel is going into a mountain or into a
23:58 , what you're doing is you're bringing inside the hill very close to the
24:03 . That kind of makes sense. . Alright. Think of of of
24:08 , right. Or we'll do something , we'll talk about a donut.
24:12 right, jelly, donut has jelly on the inside, right? But
24:16 I draw a donut and put a , that hole right there is not
24:22 its outside, isn't it? And what I've done is I've brought the
24:27 near to the middle of this or this uh pastry, right? Think
24:33 another donut where that would be filled . Right. So now I've got
24:38 lot of surface area in which I interact with the external environment and that's
24:43 of what the t tubules doing, basically saying the inside of the cell
24:47 to interact with the outside environment. what I'm doing is I'm bringing the
24:51 environment as close to I can to inside of the cell and really the
24:57 that it's trying to interact with is next structure. The sarko plasma
25:02 Yeah, yeah. You already know psycho plasma articulate is, what is
25:08 , what's in what's the word we for for the generic cell.
25:13 Endo plastic particular. Yeah, that's right. I'm not gonna be mad
25:16 you if you get it wrong, not what we do here, we're
25:20 testing our boundaries and our and our a little bit. Alright,
25:25 the sarko plasma particularly is a modified particularly, it's actually smooth ectoplasmic
25:31 And what it does here is that surrounds each of these side of skeletal
25:36 . And so you can see all blue stuff represents that S.
25:40 That's abbreviation for circle plasma particularly. right. And this structure, its
25:47 purpose is to store up calcium. right. So, you can imagine
25:52 calcium gets in the cell, it's there's pumps that pump calcium into the
25:57 plasma critical. Um And then the of the Sarka plasma critical um nearest
26:02 transverse tubules called the terminal cistern. . Alright, so sister knee remember
26:07 to kind of a sister in a area that's kind of flattened and and
26:12 and it can hold stuff. All , so, you think of like
26:15 cistern of water? Well, that's they're looking at. They're like,
26:19 , it holds something and what the cistern er just those, those wider
26:24 that are of the part of the Plaza particularly that are nearest that t
26:30 . And so what we've done is now brought the outside near to the
26:36 particular throughout the entire cell must be reason why that is necessary. And
26:43 the Circle Plaza particularly holds calcium, must have something to do with
26:48 All right. It would help if going the right direction. Alright,
26:55 let's look at that side of skeleton quick. We call that the mild
26:59 fiber. Well, depending on the , you will have hundreds to thousands
27:03 it. When you talk about being and building your muscles, you're not
27:08 adding more cells to the muscle. muscle basically stops growing somewhere around the
27:16 of puberty. Right? So the of cells stop. They don't keep
27:20 and dividing and dividing. What happens when you exercise, you're increasing the
27:25 of mild fibers. The strength of cell is dependent upon the number of
27:30 that are there. All right. each of these mild fi bruls because
27:35 are in essence the structure that allows cell to contract. You're gonna see
27:41 they extend the entire length of the cell along with that structure. And
27:48 within them, that's where you're gonna the maya filaments, the actual molecules
27:52 make up this. Now. This where we probably get into an area
27:55 you've already learned something. So the filaments consist of two things. It's
27:59 thick and the thin filament. And some point in your life someone taught
28:02 it's like, oh the thick filament a bunch of my ascent and thin
28:05 is a bunch of acting. Does sound familiar. Anyone never learned
28:10 Okay. one person. That's Two people that's good. Alright.
28:14 finding out who has has had really bad biology teachers because they usually
28:19 of focus in on this stuff. , Alright, so you have a
28:23 filament and you have a thin Alright. And really what you have
28:26 are two molecules that like to interact each other. The thick filament is
28:32 and so what you see here and gonna see different cartoons of this and
28:36 thick filament looks kind of like a club, would you agree with me
28:38 that? It kind of looks like . All right. And what these
28:41 filaments are is basically it's a head this long tail. And what you
28:44 is you bundle them all up. see if I have a better
28:46 So you can kind of see here is all these bundles have been kind
28:50 put together, right? The head what interacts with the thin filament.
28:59 when you think of that myosin think if it's going to interact with the
29:03 , it's gonna be something along those . And the tails. These long
29:07 are basically what allows to bundle itself . Now in the head, the
29:12 that interacts with accent has what we an acting binding site. And that
29:16 be obvious when you see that it's act in binding site. But the
29:19 thing that it has, it has A. T. P. A
29:22 . And so what that means is that it acts as an enzyme.
29:26 basically when A T. P. in it breaks the A.
29:29 P. And releases the energy and for movement in the miocene had.
29:35 the head is kind of wobbly. thin filament which we usually say is
29:39 it's a bunch of acting is actually little bit more complex than that.
29:43 right. Yes, there's acting And so these molecules that you see
29:48 are basically um strands of acting now call it F. Act. And
29:53 don't need to know that just call acting should be fine. But the
29:56 we distinguishes it because each of these is G. Acting. And you
30:02 see it kind of forms this really of unique helix structure kind of like
30:05 D. N. A. Has helix. So acting is this is
30:08 strand that's a helical structure it has its surface a binding site for
30:14 We call that the myosin binding And if that site is available to
30:20 then it will bind to it. don't necessarily want it to bind to
30:24 all the time. And so what going to do is we're going to
30:26 it. So we have another molecule triple meus intro is this green chain
30:33 goes along the surface of the active . And you can imagine for each
30:38 these acting there's a Myosin binding And that green strand of trouble my
30:42 is blocking or hiding that mice and site. Otherwise it would interact.
30:50 there's a point where we wanted to . So we gotta move it out
30:54 the way. So we have another called Troponin. And troponin is kind
30:59 like a um a hinge. And when it binds up to calcium what
31:07 does, it changes the shape of and it is bound up to the
31:11 mice and it's bound up to the . And what it does is it
31:13 the triple my son out of the , making the mice and binding site
31:18 . And if my sins their binds and you're gonna get a contraction.
31:23 right so Acton is the confusing one it has all these parts to
31:29 But we're going to walk through every along the way to see how this
31:34 done so far. Everybody with me the molecules. So you're two filaments
31:41 filament thin filament thick filaments. Myerson an A. T. P.
31:45 . Has an active binding site. filament three parts acting. Triple
31:50 Troponin troponin is the hinge. It's one that binds calcium acting binds
31:55 Troponin is the blocker. I said . Excuse me. Triple Madison.
32:05 if you were to take a slice muscle and look at it. What
32:10 see is you see something that looks this you'd see kind of a little
32:13 dark band a light band dark band little darker band dark band light
32:18 dark band and just kind of repeating . And of course whenever there's a
32:22 pattern that means something interesting is going . And so very early on what
32:28 did was they identified this band and , okay, we're gonna define this
32:33 by looking at this dark, this of dark band and then we're gonna
32:37 until we find another one of those bands. And they call that a
32:40 here. And what this circle here is the functional unit of a
32:46 When you say functional unit, remember said that the purpose of muscle is
32:49 create contractions. And so what we're is that this unit is where the
32:54 is taking place. And so when stimulate the muscle, you'll see the
32:58 ends of the soccer mere draw near each other and so each muscle is
33:02 is a series of repeating circle. as you grow larger or taller,
33:07 should say, or longer. You sarcasm ears to the end of your
33:15 . Okay, so remember you used be this big now you're this
33:19 So what you did was you added ears along the the muscles themselves just
33:24 get longer and the soccer players don't longer longer. What you do is
33:27 keep adding these little tiny units. of course when you have a
33:33 you name the patterns and so there bands that are associated here, the
33:38 one, the boundary lines we call Z lines. And then once we
33:43 learning and understand, you'll see the sometimes used Z disc. And
33:46 what you're looking at here is you're at a structure from this side.
33:50 ? So soccer is basically like my hands. If you look at my
33:53 hands, it's basically two lines, ? Until I turn and then now
33:58 can see my hands, Right? so that's what you're looking at,
34:02 you're looking at a structure from the . That's his massive, massive latticework
34:08 proteins that allow structure to be bound them. And so what you have
34:12 you have micro filaments or Myo filaments are extending from the Z line and
34:19 the other Z line. And they're from both sides. So, what
34:25 did then, or what the first were looking at this did they
34:29 all right, well, let's start things. And so they basically
34:32 all right, so, right we're going to call that the eye
34:36 . And then where it's dark. really dark area, we're going to
34:40 that the a band. But there's zone inside that's a little bit
34:44 We're going to call that the H . And then there's this dark band
34:47 the middle. That's an in The in line is a lot like
34:50 Z line. If you turned what you'd see is there's this massive
34:54 of proteins to which a bunch of filaments are bound to. So what
35:01 they? Well, the in line the point where the thick filaments are
35:07 . So the thick filaments extend in directions from the in line. All
35:13 . The Z. Line as I , represents where the thin filaments extend
35:19 they extend in both directions. So eye band is a bunch of thin
35:24 and what we have here are a of thick filaments. And so the
35:28 zone is an area where you just thick filaments and there's going to be
35:34 between the thin filament and thick filaments where they cross over each other,
35:38 make a darker band. So that here the a band is where those
35:44 are crossing over. Okay, so kind of one of these things you
35:52 have to memorize. I banned thin . A band thick and thin
35:59 H Zone thick filament only in That's the attachment side for the thick
36:05 and then you just go same thing this is still H's own so
36:08 thick and thin thin here we are the Z line again and then just
36:13 repeat. Okay, so it's just you have to remember. Rise.
36:18 if you can't visualize this. I it's time for a visual representation since
36:23 near the end and easy to get . Why don't you come up here
36:25 quick. He's like crap. Seaworld Shamu splash some. Alright,
36:33 over here. Right. Don't be . I'm not gonna I'm not gonna
36:37 pants you or anything. All Why don't you put your arms out
36:40 up? No, no. Like . Alright, So he's like an
36:43 line. All right. We're gonna you the in line. All
36:46 And I'm a Z. Line. . So if he's the in
36:49 what does that represent? Thick or filament, thick filaments. Right.
36:55 I'm a Z line, what does arm represent? Thin filament.
37:00 I'm gonna get right here and so can now see So, I'm the
37:03 line. This right here is thin only. So that would be i
37:09 all right. It's okay. You memorized it yet. Alright, So
37:14 we have this point here where we're over each other. What would that
37:19 a band? Right? And then here from here to there, what
37:23 that be? H Alright, when we contract, what's going to
37:28 , we're going to get to a later. I'm just not going to
37:30 him up again. Is that when contraction occurs, the band moves towards
37:35 in line and so you can see , I just moved closer.
37:39 What happened? Which got shorter? I got shorter. What about
37:46 Did that get shorter? Yeah, the a band didn't change size?
37:54 , well, no. All Put your other arm out again.
37:59 both arms out. Alright. pretend, pretend I'm moving. Did
38:03 a ban change sides? Does that things get bigger and smaller as the
38:09 band changes? Do his arm Do they shrink? Do they
38:19 No, his arms stay the exact length. The a band is defined
38:23 the point where the thick and the filaments begin crossing, Right? So
38:28 is where the eben begins. So I get closer to them, the
38:32 hasn't changed size, right? The band has the eye band has but
38:39 A band doesn't because when we're talking a contraction, nothing changes size.
38:45 the distance between the two Z. . And you can imagine there's another
38:49 . Line on the other side. . This is what is called the
38:54 filament theory. Alright. It's not theory, it's just what it was
38:59 . Right. And so what it's you is when a contraction is
39:02 and I do see your question, ? When a contraction is occurring,
39:05 referring to how the filaments don't change length. What they do is the
39:12 between the lines change length. Thank . Yes ma'am. So, so
39:26 A notice what the a band So, it's the point of those
39:30 lines or sorry, that that thick coming out to here? So,
39:34 my thick filament goes to there and bringing this closer, There's no change
39:39 that distance and that point right? the thick filament doesn't do this?
39:45 stays just as is And what we're see in just a minute, is
39:50 the thin filament is basically being pulled the length of the thick filament?
39:55 so the thick filament doesn't change the . The thin filament doesn't change
39:58 It's the distance between that Z. the M. Line. That
40:02 And so if the a band is by where the thick and the thin
40:05 begin to overlap, that thick filament changes length. It can't. So
40:10 this thing gets closer to that thick , the eben stays the same
40:17 Well, they do they always Right, let me just do it
40:20 way. All right. And I see your question, right. Two
40:45 . All right. The hard part me drawing the same length.
40:49 so here we have the in All right, so, notice those
40:58 do not change length. What I'm do is I'm gonna bring them closer
41:05 and we're just going to have to that it was So notice what's happening
41:19 contraction. All right, So, a starting point, right? There's
41:28 starting point, So what got I that's half an eye here's the
41:40 half. Right? Here's the Alright sorry, there's the M.
41:49 the H. Zone. Right? , did the hse change size?
41:54 . What about the A. Did age change? No, there is
42:02 exact same because remember the ages represents point of overlap where it begins,
42:08 of overlap begins there right there. of overlap begins right there. So
42:13 A band is always constant. The is the one that changes that's half
42:25 eye. So just remember that's the . I band is one that changes
42:33 is just that middle line. That's . Remember it's a latticework that sits
42:37 the middle on which everything is Yes ma'am. Yeah. And this
42:43 gonna be true for the Z. as well. We're gonna come back
42:45 see another picture. But the in represents a series of proteins right
42:51 you're looking at from the side like and those proteins are the proteins to
42:56 the thick filaments are bound. so if you're looking at like this
43:00 looks like you have a whole bunch thick filaments coming off. But if
43:02 turn it, what you'll see is see a latticework that looks like
43:06 So each of those big dots represents thick filament coming out at you.
43:12 , Same thing is true. It not showing you for the I
43:14 but the band would be very very to that. Now. There's a
43:22 of proteins in here and some of get kind of confusing and stuff.
46:23 wanted to go back and make sure understood this. Thank you for pointing
46:26 that I didn't explain it completely. when we're talking about a contraction,
46:31 talking about the two Z lines that up the circle here. Alright,
46:35 the Z. Line number one. . Line. Number two. It
46:38 matter which order. Everything in between the saarc Amir. So when you're
46:42 about a contraction, it's bringing those Z. Lines closer together. All
46:48 . And they're moving to that in . So there's the lines coming towards
46:51 in line. That's the line is towards that in line. So when
46:55 contraction occurs, what we're doing is bringing that Z line inward. So
47:02 causes the eye band to shrink as as that I band. And really
47:06 are half I bands. The eye represents the point where just thin filaments
47:10 located, right? So, remember we understand the definition, it makes
47:15 makes things a little bit more The H. Band is gonna get
47:19 as well. So this represents the . Band and so that half gets
47:23 , that half gets smaller. So get smaller itself. But the thick
47:28 themselves don't get any different change inside thin filaments don't change inside. So
47:33 happening is when you're pulling those Z , the band always stays the same
47:38 because the filaments themselves do not decrease length, right? All you're doing
47:44 pulling those Z lines closer, which that space of overlap become smaller.
47:52 , The thick filaments don't change You're just bringing the two Z lines
47:57 . So the gap between those two change in size. Does that explain
48:02 little bit better? Did I to ? A little bit? You can
48:09 no. I mean I don't mind again. Okay. Okay. Yes
48:26 . Work. Mhm. That's a question. I don't really know how
48:35 answer that. It's finding that place inside you to recruit that last little
48:40 of muscle. I mean, I know. I mean it probably has
48:44 little bit to do with the you , it's probably a sympathetic response is
48:49 it's life or death, you kind convince yourself to do anything to
48:55 And probably that's what you're you're kind digging into. But I couldn't tell
48:59 for certain whether if that's true or ? Yeah. Girl, your weight
49:18 . Mhm. Right. But so would be that would be a sympathetic
49:23 whenever you hear the word adrenaline, sympathetic. And again, we haven't
49:26 about sympathetic yet. That's like I to say it's like the second and
49:30 lecture in this in this uh And so what a sympathetic is fight
49:36 flight. It's you know, how I how do I keep myself
49:41 So am I gonna fight the bear am I going to run away from
49:43 bear? You know there's going to that time when you get cornered by
49:46 bear and you're going to have to it out and you're gonna do everything
49:50 your power to win. And so now diving deep into those places.
49:55 it adrenaline that causes your muscle to that? I don't know. It
49:58 just be you know, I'm I'm to dig a little bit deeper to
50:04 that last little bit work. Here go. If you want to
50:16 Mhm. So, that has to with um written. All right.
50:22 basically your ability to how much oxygen carry in your blood. All
50:27 And so um as you go to elevations, uh the oxygen density of
50:33 air gets a little bit lower, not that much lower, but it's
50:37 to be effective on the body. really it's because your oxygen carrying capacity
50:41 the blood is reduced. And so ends up happening is is that you're
50:45 delivering enough oxygen to the muscle And so they fatigue faster. All
50:50 . And so, what we're dealing here when we haven't really talked about
50:55 like glucose metabolism, and we purposely over that stuff. Because I don't
51:00 to frustrates you all with that. mean, it's that's more of the
51:05 workings of how cells work. But essence, what happens if you don't
51:07 an oxygen in your body can only through that pathway to make a teepee
51:12 it's a very very small amount of T. P. And I guess
51:15 talk a little bit about that And so instead what does it uses
51:20 this other pathway that builds up metabolites also tell you stop doing stuff.
51:25 don't have enough 80 P. if you use up all your
51:27 T. P. You're gonna die we're not gonna allow that to
51:30 All right. Um And I know kind of a weak sauce way to
51:34 it, but that's that's also the why there. Alright, so let's
51:40 on and let's get back to the and the beef cake. Because you
51:43 I mean, muscle tone is uh gonna look at it in the sense
51:49 you know, what's its purpose? does it represent? But it also
51:53 of the things that it does when see someone that has muscle tone,
51:56 kind of represents healthiness, right? we kind of know that inherently.
52:01 I'm not I'm not this is not place where I'm trying to trying to
52:04 you make I mean, you want talk about a person doesn't have muscle
52:07 . I mean, I got plenty muscle tones just under all these layers
52:10 fat, Right? Um And that's that's not what this is about
52:15 What muscle tone represents is continuous and partial contraction. All right. And
52:21 your muscles already in a state of . And so I'll point out first
52:26 is that if you have less body , that doesn't mean you have muscle
52:29 . All right. So, like roommate I had in college guy that
52:33 work out with right now, He have muscle fat or sorry, muscle
52:37 . He doesn't have body fats, know, in any way, shape
52:40 form. He's just a thin We work out. It's really kind
52:43 funny because I'm much much bigger than , but he doesn't have that that
52:48 that I do, right? Because just a I'm a bigger guy.
52:52 , what we say is that muscle has is an association, you
52:56 So if you have lots of muscle typically associated with strength and power,
53:00 ? And if you don't have much , it's usually more flexibility.
53:05 So, remember how we talked about a joint becomes strengthened because the muscles
53:09 it, you know, the more you have in the greater the
53:12 All right. Different muscles have different . And so where tone is and
53:18 it looks like, it's gonna be on uh those specific types of muscles
53:23 the connective tissue that surrounds them and their shape as well as the size
53:27 the tibetan to show how springy it . Right? So, remember what
53:31 is is a passively contracted muscle. right. So you've probably noticed that
53:37 you work out you look pretty Yeah. Right. So that would
53:41 an example of an active muscle tone active response. Right? So that's
53:46 result of little activity. And basically you're saying is you just have more
53:50 motor units that are being stimulated given . Yeah. You don't have
53:59 All right. I mean, lack better terms. So, right.
54:02 your if your muscle is not already a contracted state, then that means
54:06 you're able to move that structure around , right? So, I'm gonna
54:14 making fun of somebody right now, hopefully he's no one in this
54:18 All right. But have you ever that the true lunk? You know
54:22 a lunk is there? The guy works out? 24 7? You
54:25 , they wear the muscle shirts, ? If they don't have the muscle
54:29 , they've cut out the sleeves and can't put their arms down.
54:34 They their arms stick out like this , why is that? Why do
54:39 arms stick out? Is it just they're cool, walk around and you
54:42 , why do their arms can their not go down? Their muscles are
54:47 a constant state of contraction. And got these big old lattes and they
54:51 move their arms down, right? don't they're not as flexible,
54:57 Mhm. No, that would just like in that particular case, that's
55:01 over exaggeration, right? But that's I've got so much muscle tone that
55:05 muscles are in a constant state of and I'm not able to because they're
55:09 bigger, I can't put my arms now. Think about my week saw
55:14 Alright. Actually I'm probably a bad cause I'm old. So I'm
55:17 I see. I'll get you in second. Right? So think about
55:22 ? You're young, you're bendy, mostly cartilage still right and again.
55:28 . I mean, how many guys yoga? Right. I can look
55:32 and yoga, right. You you put me in any sort of
55:36 can't even do watch this. I it's like Yeah. All right.
55:43 but part of that yoga nous I think about people who do yoga for
55:47 most part they're not like our lunk we talked about. They typically are
55:52 bendy and more stretchy because their muscles in a relaxed state. And so
55:56 more tone you have. That's not say that someone who does yoga is
56:00 toned, they can be very but they have a certain degree there's
56:04 certain degree of more flexibility when your not already contracted. Right? If
56:09 if I'm contracting this it's hard to it backwards. But you know when
56:13 relaxed. That's a stupid example. just Yeah, go ahead. When
56:23 have like more muscle your muscles and . Yeah. So what we're saying
56:29 is that All right. So we're use him because we can look at
56:32 stomach and see Yeah. Alright. that's a six pack. All
56:37 We want to go to the beach that. It's not a it is
56:40 eight pack. That's right. It's a keg. Right? And so
56:46 we have there is we have muscles are already in a state of contraction
56:50 contracted because those muscles have been worked are in a state of optimal readiness
56:58 probably the better way to put Put it. Alright, let me
57:01 back there. You had a Well, that could be one of
57:12 things, Right. It could be lack the flexibility, right? Or
57:17 could be that I'm in a state contracted nous and I can't I mean
57:20 can't do that. I got a old monstrous chest. Right?
57:26 I'm just not flexible. I can't anymore anywhere. Mhm. Like because
57:35 do they do all the time as stretch and flex and flex and
57:39 And what they have to do is they also use muscles to actually
57:44 I mean they have to they have work out and get those muscles to
57:48 the things that they do, but not to build muscle strength, it's
57:53 the work that they do. Their get stronger to accomplish the jobs that
57:57 do. Alright, so remember the strength is dependent upon the type of
58:03 you put on it. Right? you become stronger because your muscles are
58:07 I have to do this kind of . Just like your bones, your
58:11 bones get stronger because they say I to do this particular work.
58:20 Yes, mm contraction. Mhm. . But it's a sustained contraction.
58:29 not it's not contracting, relaxing. . And that's kind of what this
58:33 slide, that's why it's kind of ahead because I know what you're what
58:36 what you're getting stuck on. I like it. So there is what
58:39 called an optimal length for a All right, and again, we're
58:44 I don't want you to try to this stuff like oh it's what is
58:47 ? What is the optimal length? basically sits between 80-120% of the resting
58:51 . So basically what it's saying is , we want the fibers to to
58:56 in a resting state where I can stretch them out a little bit more
59:00 I can compress them in about 20% both directions and I'm still within the
59:05 strength or the optimal length of these to produce the strength that they that
59:10 need to do the work that they . But if I push them too
59:15 together, I'm now not capable of further contraction. Now my thick filaments
59:20 thin filaments are bunching up against the . Lines, right? I can't
59:24 anything. So I can't produce a contractions already is already there. So
59:29 I compress a muscle too much and stays and it starts off in that
59:34 . That's too too bad. It's too it's too short.
59:38 if I pull the muscle apart if stretch too far and those thick and
59:42 filaments are not overlapping as efficiently or frequently as they used to, I
59:47 create enough strength in order to get contraction that I need. Now.
59:53 is just a dumb example. So use this as an absolute But it's
59:57 that you've you can imagine if I overextended like this, it's harder for
60:02 to lift something up than to start something up with my arms are already
60:06 a pre contracted state, right? I have to overcome at least with
60:11 arc I have to overcome, you that. Wait. And it's kind
60:15 the same thing. It's like I'm able to create the cross bridges necessary
60:21 create the contraction. If there is overlap or very little overlap. Once
60:27 get to this point where there's plenty overlap, I can create as much
60:31 as I need to create the tension I want to produce. But if
60:35 jammed up, it's not gonna work . So, the point being is
60:39 there is an optimal resting length for muscle. All right, and I
60:46 try to do that now. What gonna do is we're gonna kind of
60:51 back again to where we started things . All right, we're going to
60:54 at how do I create a And we've talked about these little tiny
60:59 bitsy parts, we said, we have this neuro muscular junction,
61:04 have um this triad. And what going to do is this is kind
61:09 the the the overview, basically what going to see is that the neuromuscular
61:13 release a neurotransmitter that's going to result an action potential and then an action
61:18 is going to cause the release of into the cell. And calcium is
61:24 going to signal for the formation of bridges to occur. And that's basically
61:29 the thick and the thin filaments to . Alright, We're just gonna it's
61:33 did you guys ever play as a ? The game mouse trap was that
61:37 ? No one ever really played the . What you do is you just
61:39 it up and let the marble go see what would happen, right?
61:43 don't think I know anyone who's ever the game, but but that's kind
61:46 what this is. This is a Goldberg machine, which is what mousetrap
61:51 . Right? And so what we're , we're just gonna walk through the
61:54 All right. So when you learn , just walk through the steps with
61:58 and kind of write it out. , so this is kind of the
62:01 overview. It's not really clear when look at it, but all you
62:05 do. This is probably a better . So, the idea here is
62:10 going to have an action potential that's to arrive at the neuro muscular
62:15 So it's here, it is on neuron. It's gonna cause a release
62:18 acetylcholine. The acetylcholine is going to to receptors on the um on the
62:26 cell. And what's interesting is this one of those places where we don't
62:30 little tiny rises, there's so many and so much to see the choline
62:35 the potential that you get here is enough to result in an action potential
62:41 is going to travel along the length the cell. All right, remember
62:46 is occurring at the level of the Emma. All right. Just like
62:49 a neuron it's having its that exchange ions back and forth across the plasma
62:55 . Alright, so you can manage there it is. It's just going
62:58 the surface. But what we've done we brought that surface through the
63:05 right? The tube represents surface of cell and it's just traveling through the
63:09 . So even though the actual potential going across the cell, it also
63:13 down the tubes. There's gonna be of tubes everywhere so far you're with
63:18 . So, action potentials are simply the passing of neuro of not neurons
63:23 ions back and forth across the It's going across the membrane of our
63:27 but it's also going down the tubes has also membranes of our cell.
63:31 right now we said that T tubules right next to the cytoplasm in particular
63:38 particularly that region called the terminal So, here's the terminal cistern.
63:43 you can see the circle Plaza particularly your t to be able So in
63:46 two, what we're gonna do is action potential is going to open up
63:51 gated calcium channels. Right. These called GHP channels. All right.
63:57 their voltage gated calcium channels, all . Um And I'm I think I
64:04 even bother telling you, D P. Is die hydro I can't
64:08 . It's not important for y'all. . But these channels that are on
64:14 inside of the tube are closely affiliated closely associated with channels that are found
64:24 this terminal cistern. And these are the are y are there called the
64:28 can call them foot proteins, you call them ride eIN receptors. They
64:31 all different sorts of names. But you can think of like this,
64:34 got a D. H. P on the outside and it's closely associated
64:38 I mean, they're literally interlinked. if one is stimulated the other one
64:42 stimulated and so when you open up voltage gated channel over here, you're
64:47 up this channel over there and when channel gets opened up, what that's
64:53 do is it's gonna allow all this to flow out of the cycle Plaza
64:56 particular. Um And out into the . All right. Remember the purpose
65:03 the psycho plasma particular is to hold . And we said calcium is the
65:09 to a muscle contraction. All right , this is a really really,
65:13 complex picture. Yes, I'm sorry I get dehydrated. What?
65:47 No. So, when you're dealing fatigue and that's really what you're saying
65:52 going on there, what you're doing you're having a build up of lactic
65:56 . Alright. And that's not entirely . That's mostly true. We call
66:01 the build up of lactic acid and not through it all. But basically
66:05 a build up of lactic acid. what your body is basically saying is
66:08 running out of the fuels that I to keep going. Now. If
66:11 become dehydrated, what you're doing is increasing the concentration of solute. Remember
66:15 we said when we said, what the salute? It's the stuff in
66:19 fluid, right? It's not defined it's this specific stuff. It's just
66:23 stuff. So, if I take water, what has happened to the
66:27 of my salutes? It's gone Right? So your body perceives that
66:34 in a state of of high lactic or whatever it is that it's monitoring
66:40 determine fatigue. And so if your is being friendly and just calling them
66:46 . Right. Because if you ever to a physician, they'll never talk
66:50 to you, Right. Because they presume that you're all morons, my
66:56 hates me because I know this stuff so I start talking to him as
67:01 I was his professor and he has go way back into like second year
67:05 school to answer my questions. But idea is that what he's basically saying
67:10 when you're dehydrated, you're not providing body an opportunity to to build up
67:16 fuels that you need. And so you don't have those fuels, your
67:19 is going to perceive you know itself being exhausted or fatigue lack of better
67:27 . All right. So can you me where we were since you interrupted
67:34 ? Where were we? I know know that. But what what were
67:38 steps Step one was what action potential goes through the T. Two beauty
67:47 . You'll you stimulate the D. . P. Receptors. Here we
67:51 . D. H. P receptors stimulate stimulate the ride in receptors.
67:55 those stimulate they open up. When open up the right sideline receptors,
67:59 flows out into the cell. All . And what's the calcium that we're
68:04 in And here we are. There's miocene head. This is your thin
68:10 . You can see here here's my the purple line represents the trope
68:14 It's blocking the binding site. It's the chaperone at the party and it's
68:19 letting you kiss my skin is thick in thin film. And if I
68:26 I apologize. So we've got triple and then this big bunch of different
68:33 represents the troponin. It's very easy confuse troponin and Trapani Yasin,
68:39 Troponin has three parts to it. that's bound to act in one that's
68:43 to triple me austin and then one a calcium binding site. You see
68:49 we got here, I release calcium the psycho plasma particular. Um it
68:54 to the troponin troponin. Do do want to remember? It does it's
68:59 hinge and what it does is when binds to it, it gets pulled
69:04 of the way and now here are the binding sites, there's one there
69:09 well, you can see the head already in position when you pull that
69:13 of the way it binds and now got interaction. And when the interaction
69:18 , what we're gonna do is we're a cross bridge and we're going to
69:22 what is called a power stroke. , you ever watch crew? What
69:27 is no one. Yeah, I in college. What crew was,
69:32 more popular in the Northern States where one's blowing up from the heat.
69:37 crew is when you get that that's really, really long and you
69:39 the people on there with the one or and it's usually like eight
69:44 four people or one person I think can also do a two person when
69:49 in the eight person, you're a kid on the front or a really
69:51 person's going stroke stroke stroke. And they're doing is they're doing this stroking
69:57 they're moving the boat into the All right, So this is like
70:03 a power stroke going in and I'm a contraction I'm releasing and I'm doing
70:09 over and over again. As long calcium is available, I'll be able
70:13 do this. But I need something . When you think of a muscle
70:17 , what do you think of? molecule? A. T.
70:21 That's what everyone thinks about 80 It's like, oh, if I
70:23 out of a T. P. can't do a contraction. And that
70:26 true, but it's calcium that causes contraction because it makes those two sites
70:31 . But what we're gonna do here we're gonna see a contraction is dependent
70:37 on a T. P. what we're gonna is we're gonna start
70:40 where we finished off, right, put ourselves up. You can see
70:44 in a cocked position. I'm bound to the thin filament. And what's
70:48 happen is I've already gone through the . All right. Otherwise we would
70:53 someplace down over here. It's It is. There's the power
70:56 Alright, so I'm already in a state now. You can see
71:00 I'm like this right here. I'm cocked and ready to go here as
71:04 already done it. So I'm attached the first thing that happens is we're
71:09 to bring in a teepee. What teepee does. It allows me to
71:14 the interaction. All right. So ATP remembers binding to the thick filament
71:20 I release. And then what happens is it uses its a TPS activity
71:25 cock and put that molecule into into so that it can then interact
71:32 And then when it interacts again it's to release the ATP and the inorganic
71:37 and create the contraction. Alright. then a teepee comes along causes me
71:43 release cox. Using the A. . P. A. S.
71:46 along, bind again. Rinse repeat long as I have a T.
71:52 . I can separate out the two that have interacted. If I don't
71:57 ATP they're stuck together. All as long as calcium is available,
72:03 not blocking their binding sites. So need calcium to allow them to
72:07 But I need a T. To break them apart. Alright
72:11 the easy way to remember this is about rigor mortis. You've heard rigor
72:16 , rigor mortis is the state that body gets in after you die.
72:20 become a It's an impolite word. weaken me stiff? Ever heard that
72:30 body is a stiff. Why is called a stiff? Because you're
72:39 All right now. What happens is when a body dies, all the
72:45 that kind of control things begin to apart, basically nothing's producing a teepee
72:51 . And so the A. P. That you have is what's
72:54 the cell and it gets used There's nothing holding the calcium in calcium
72:58 out of the cell. Out of stark applies particularly floods in. And
73:01 you can imagine I've now made the possible. Right? So I get
73:07 contraction contraction and the muscles begin to up and then there's no ATP and
73:14 muscles are now stuck in that That's where the stiffness comes from.
73:24 , I had a grandfather who told the story. His grandfather. So
73:28 probably not true. But he said he was y'all's age, He worked
73:33 one night in a mortuary. It during the depression. Right? So
73:38 was like get a job and he to be in the night watchman.
73:41 why I kind of like probably telling a lie. He said he was
73:46 around and of course there's a cadaver the table and it sat up.
73:53 said he dropped the flashlight and never back. Is it true? I
73:58 know. But it can cause a to sit up. All right.
74:05 ATP is what breaks the bond calcium what allows the interaction to take
74:14 So a T. P. Is resetting and cocking, right? So
74:20 break it. Right? That's presence ATP breaking the A. T.
74:25 . Allows you to cock and set head in a position where it can
74:30 cause the power stroke. All And when you release the A.
74:35 . P. And the inorganic That's when you get the power stroke
74:37 now you're available for the new TP to come in to break the
74:41 one more time. All right. a complex process. But this is
74:49 role of ATP. So all that we talked about over there. That's
74:54 this is describing right here. That's the sliding filament mechanism sliding filament
75:00 , basically the uh H. Bands talked about. So, here's your
75:05 band, there's your H. The eye bands get shorter. The
75:09 zone gets smaller. They've done a job of demonstrating their showing them
75:14 They should never overlap. Right? then the a band stays the exact
75:19 size. So how do we relax muscles? Well, you go sit
75:27 the pool, order a cool Yeah. So that is what causes
75:40 . So you can imagine each what am I doing is I'm pulling
75:43 thin filament with the head so each of those brings the sarcoma here a
75:48 bit closer. So as long as have calcium available and as long as
75:52 a teepee available, you'll keep bringing circum ears until they can't move.
76:01 that's a that's a really. So we're trying to what you're trying to
76:04 is you're trying to translate something that's into something that's macro and that's
76:10 Alright, so think about a right? A muscle is a whole
76:15 of bundles of bundles of individual cells each type of those, each of
76:20 individual cells are thousands of sarcoma So what you're looking at is you're
76:25 at a whole bunch of these cells a result of other soccer mares shrinking
76:33 terms of contracting in size. So what you're doing is you're contracting and
76:38 you're doing is you're pulling on that , the tendon causes the bone to
76:43 until you say stop and you get . That answer. So what is
76:50 relaxation? Well, it's just basically all the things you just started,
76:55 ? So no more action potentials. , if you don't have any action
77:00 in acetylcholine, they see the colonists there. That's that enzyme that says
77:04 , chop, chop chop chop and destroys everything, but you get no
77:07 potential. If there's no action then you can't stimulate the cycle plasma
77:13 . So calcium is not leaving the instead. What you have is you
77:17 a bunch of pumps, they're called pumps. And if you want to
77:20 what circus stands for this smooth into a particular calcium pump. So,
77:25 mean, that's that's how we name in biology. So whenever you see
77:28 sort of abbreviation kind of look for obvious, right? But we have
77:32 pumps that are associated with uh circle particular um that are constantly turned on
77:39 they're constantly pumping calcium into the circle critical. Um So if I have
77:44 leaving, that means it's all going . And so you're removing calcium from
77:48 environment. If there's no calcium available , then what happens is that you
77:53 no longer get interaction between the thick the thin filament. There's no interaction
77:57 the thick and the thin filament. just goes back to its original
78:08 How we doing on time? Got 10 minutes More or less.
78:14 eight minutes. I know. All . So we've said ATP is important
78:20 it's not what causes the contraction calcium what causes the contraction allows it to
78:25 place. All right. The thing that your body stores A T.
78:30 . It has limited stores it makes and then it just kind of stores
78:33 away. And it can there's different that we can kind of increase the
78:39 not the A. T. Itself, but the the the punitive
78:44 basically how much we can actually And so we're gonna use these three
78:48 systems. We have foss vision We have anaerobic celebration or cellular respiration
78:55 we have aerobic cellular respiration. So probably most familiar with these if you've
79:00 taken a biology class and we're not to go into all the details of
79:03 of these steps. We want you just kind of understand conceptually what we're
79:08 . All right. So you can we've got short and we have prolonged
79:12 so when we're talking about short, is what we're kind of talking about
79:16 phosphate jin systems. When you're phosgene basically saying, how do I make
79:21 easily available energy in the form of . T. P. All
79:24 I don't need any sort of What I can do is if this
79:28 my normal reaction right here, I this stored up in terms of
79:31 T. P. If I take 80 p, I can break it
79:34 release that energy. So with what have stored you have about five seconds
79:38 energy available to you. All And not very much. Alright.
79:45 one of the things I can do I can take that byproduct that.
79:48 And if you're not familiar, A . P. Is simply a
79:52 Oh, sugar draw this poorly. that nitrogenous base. Right. And
80:01 it is is a series of phosphates off onto the side. So that's
80:05 denizen triphosphate 123 phosphates. So when break it, what I'm doing is
80:10 breaking that bond right there. And that bond gets broken now I have
80:14 D. P. Di phosphate. see and if I broke the last
80:18 then I'd end up with mono Alright. So what I'm doing is
80:22 of those bonds represents amount of energy being able to be released.
80:28 if I have this molecule, what can do is I can break that
80:32 send that phosphate back to another molecule looks like this. I can create
80:36 A. T. P. what that means? I'm gonna have
80:39 gonna take more work to get back making my pool of A.
80:42 P. But at least it's a of energy. And so it gives
80:44 about two seconds worth of energy. , now I'm up to about eight
80:49 . So, when that bear is me, I can get away for
80:51 five seconds. It's like Alright, add another two seconds on top of
80:55 . But we also have this. right. And this is another way
80:58 store up energy in a different Alright, So, I'm just gonna
81:02 up numbers here. So, don't these numbers for But let's say I
81:05 hold 100 80 P molecules. All . But let's say I also have
81:10 molecules of creatine in my muscle So, what I can do is
81:14 can do a reaction where I can the energy from a T.
81:17 That last phosphate. Right? And I can do is I can send
81:21 phosphate over here to creatine to create phosphate. And this now serves as
81:27 storage pool for energy. So, I can do is I can store
81:32 , you know, energy into 100 is to make 100 creatine phosphate and
81:37 I can rebuild my A TP back . And so now I have 100
81:40 P 100 creatine phosphate. That's like 280 P. I've doubled my
81:46 I've just stored it in a different . And if that's not clicking for
81:49 , think about it like this you can have $100 and you can
81:52 buy $100 worth of gold. Let's that it doesn't change its value.
81:58 now you have $100 worth of You can earn another 100 bucks and
82:00 you have $200 worth of of Right? So this is just basically
82:06 energy assets. So I can burn my A. T. P.
82:12 boom boom boom. And then once burned through my A. T.
82:14 . I now have this and so can now transfer that phosphate back.
82:18 I now have new A. P. So I have more ATP
82:23 . That gives me another 10 So now I've sprinted away from the
82:28 And for 15 seconds maybe that's enough get away. If you want to
82:40 these steps, you need to go a biology class, they'll spend plenty
82:44 time talking about all these steps. other two systems are how we go
82:49 um using or making energy. So long term basically requires oxygen and multiple
82:57 , you have glucose metabolism, you pyrite oxidation, you have the citric
83:03 cycle or Krebs cycle. You probably those two terms. And then at
83:07 end of all that you have the transport chain. Do any of those
83:10 sound like things that you've heard Even if you don't know the
83:14 Right? Great. So, lots steps. Lots of time, lots
83:19 energy. All right. But in pinch, if you don't have oxygen
83:24 if you need to get energy you can bypass the latter stages and
83:29 do the first step, the glycol step. And then you can use
83:33 different pathway to recycle some of the you need. You can still get
83:39 teepee out of it. You don't a lot of it. So,
83:41 that might produce somewhere between 34 and molecules of a teepee. This will
83:46 about four molecules of ATP. this will take you a little
83:51 but not very far. That will you far right. That's the stuff
83:58 for marathons. That's the stuff you for long distance or long term energy
84:05 . Lots of oxygen and glucose you can take the glucose, but
84:10 don't use oxygen. You don't get much. This is the last
84:14 That's what our body when it's in last little stages of I don't have
84:17 available. That's where I'll go. I didn't even get to muscles
84:23 we're gonna stop here. And the we're gonna stop here is because if
84:26 start talking about smooth muscle right I mean, we're already falling
84:30 right? Yeah. When we get , we're gonna talk about smooth muscle
84:38 I'm just gonna give you a preface you're wrapping things up here with smooth
84:42 , many of the same things that just learned are happening. But because
84:46 it's very different. We're gonna see tweaks to the system that make it
84:50 of weird. Just gonna warn you . Yes. Have fun in the
84:56
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