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BIOL 3324 Human Physiology - 3324_lecture12_1004
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00:01 open. Alright, so here we , the day before the exam,
00:14 all excited. Well I mean I'm my brain works in this class and
00:21 class. This, you know, stuff in between. Doesn't matter.
00:24 just like sleep, you know? , so remember we have an exam
00:29 thursday that means we don't show up . Everything we cover today, everything
00:33 supposed to cover today is gonna be the exam. Good news, muscles
00:37 easy. You look at me like . All right there, easy and
00:43 show you that they're easy. They're one time one semester my computer died
00:49 I had to give the entire muscle off the top of my head,
00:54 , We can draw it out and will take us 10 minutes. The
00:58 that I spent an hour and a talking about is just me wasting
01:01 is me using your time appropriately. . Before we get there though,
01:05 just want to finish out with the . We were talking about different ways
01:08 the brain is organized and the way information is sorted into the uh into
01:13 structures of the brain. And this is more uh kind of an
01:18 thing to let you understand that there a high degree of organization. And
01:21 when we were talking about the I example, it maps to the retina
01:25 what we didn't talk about is the other different layers that actually talk about
01:29 and movement and all the other fun we kind of ignored that. We
01:33 about how the body's map. there's , there's this amount of sensory quarter
01:37 it maps your body to the specific of the post central gyrus and basically
01:42 , okay if something is touching your , this is the part of the
01:45 that's gonna be stimulated. When I something, we look at the motor
01:49 of the brain that's actually the pre cortex and the pre motor cortex also
01:54 in a very specific way. So can say if I want to move
01:58 foot, I can go to this of the brain and that's the area
02:01 that's being mapped with regard to the lobe and with sound it matches the
02:07 of the cochlear so you've got high on one end and low notes on
02:10 other end and those fibers are going into the temporal lobe. But what's
02:15 about the way that we process sound also has to do with how our
02:20 and how that sound reaches our So for example, we're probably all
02:26 with that we hear stereoscopic lee, ? You guys just listen to one
02:32 but when you're when you're listening no. And if you take one
02:36 out, doesn't it sound weird. , because the way the sound engineers
02:40 this is they're trying to make it like you're in the place where they're
02:44 recording it, whether it be in concert hall or whether it be in
02:46 studio and so they want to give a sense of being surrounded by the
02:50 . So sound is coming at us all sorts of different directions. And
02:54 way that our brain knows where it coming from is because the way that
02:58 sound hits our ears and the last I told you on thursday I said
03:01 at each other's ears and then many you cover up your ears really quickly
03:05 you're like, I don't want you look at how weird my ears
03:07 But you can see up here this what your looks like. It's
03:10 And if you go and stay at here for long enough you're gonna
03:12 yeah, it's really weird but it's to bounce sound in very specific ways
03:18 that acoustic miatas are miatas so that sound hits the tim panic membrane in
03:23 ways and in specific timing. So example, we actually detect where sound
03:30 coming from because of two different Sound comes in the vertical plane?
03:34 know, vertical plane is? that's up and down. So where
03:37 we know where sound is coming from from the horizontal plane, where is
03:42 coming from this side? Or is coming from that side? And so
03:44 the vertical plane you only need one . Right? And so if that
03:49 is coming from high or low it's bounce off the different parts of the
03:53 in different ways. So that when reaches your ear you understand, oh
03:58 it's come up high this is because bounced a certain way and if it
04:02 low it arrives at my ear in different timing and it bounced a certain
04:06 off those ear structures. Kind of . So that weird looking here,
04:12 weird. Promise go look at it a bit Is allowing that to happen
04:18 regard to the horizontal. Has to with the sound waves themselves and it
04:22 two Ears. Okay, so here is showing you both high notes and
04:29 notes. Alright, so high notes high frequency, right so that the
04:33 waves are traveling very very close Low notes, you have very very
04:38 wavelengths. So the sound waves are far apart. So when you have
04:44 notes, what happens is when it one side. So if it's let's
04:47 it's coming from like it's showing here the right side of your body,
04:50 gonna hit both ears fairly close together the sound waves are just up
04:54 up up moving very very quick. what's happening is is that it creates
04:58 shadow and so that shadow is reflected how the left ear, if it's
05:04 from the right hand side detects Alright, so it's not the exact
05:09 sound that you're hearing on both sides I'm gonna show you how it does
05:12 and then on the right side it its sweet time. So long waves
05:16 hit one side and then the other with a delay between the two sides
05:20 when that delay occurs, that's when knows oh it's coming from this side
05:24 that side in this case would be right side to the left side.
05:27 . But how this ultimately works has do with structures in the brain.
05:32 right, So what we're looking at is the medial, superior Olivari
05:35 If you have a superior Olivari that means you have an inferior one
05:40 well. And these are the these the structures of the brain stem that
05:44 you to turn your head when you sounds, for example, when you
05:46 the word hey and you turn you know, that's that's what the
05:50 nucleus is responsible for. The other is responsible for site, you
05:55 when you see something moving, you your head to watch it move.
05:58 . But what I want to point here is just the the amazing uh
06:04 that we're looking at here. So structure you have, remember you have
06:08 coakley on either side of the brain you're trying to detect which way the
06:12 is coming from. So each of have these neurons that travel and they're
06:17 very long, what we refer to delay lines. And so you can
06:21 that both sides, both Olivari nuclei innovated from both sides. So you
06:26 a long fiber going in in a fiber going in and within those we
06:30 a coincidence detector. Now a coincidence basically just says here's a point.
06:36 if I receive a signal from both those, both of those neurons at
06:38 same time, then I can detect side based on that delay. Because
06:43 already calculated when the delay occurs, know which side the sound is coming
06:47 . So if they don't come at same time, I'm not detecting if
06:49 don't come at the same time and you'll find a pair of matching pair
06:54 says oh it's coming from this side from that direction or that direction or
06:58 direction. All right now, this where we get to geek out a
07:01 bit here because I can ask some you guys because I know some of
07:04 guys actually play video games, And you guys have really really nice
07:09 , right? And they have virtual sound in them, right? To
07:14 speakers and virtual surround sound what they're . They're taking advantage of this and
07:18 placing the sound to to mimic that sound is moving. And it's taking
07:24 of these coincidence detectors to give you sense of oh I'm in the midst
07:28 whatever the game is. Now you do this with a 5.1 speaker system
07:32 7.1 speaker system as well, but really kind of stands out when you're
07:35 at two little speakers sitting on your . Alright, So that's what this
07:40 trying to show you. Here's the lines and these are the coincidence
07:47 So where I'm actually stimulating this this one this one kind of gives
07:51 a sense of am I where am in the horizontal plane? So that's
07:56 your brain knows which way sound is from, even though both ears are
08:00 hit? Yeah, I see the coming up, hmm. How does
08:08 inferior curricula different? So, um that's a good question. So I'm
08:14 screw this up. I haven't thought it today, I haven't looked it
08:16 . But inferior and superior one deals vision, one deals with with
08:21 And I want to say inferior has do with vision, but I know
08:24 I say that I'm guaranteed that it's to be wrong. Oh, the
08:29 sauce. Right? So again, remember what we're doing with each of
08:35 things is we're pre processing information before ever actually gets to the cortex so
08:39 you can have a not so much understanding of what it is that you're
08:43 , but say direction and uh I'm just gonna go direction for right
08:50 , if that makes sense. The of understanding what it is coming from
08:54 where it is coming from around you really what? So it's forcing your
08:57 to turn is really what it actually . It's like, oh,
09:01 it's coming from this direction. I too many of you guys walking around
09:04 headphones. So my examples are not to be really, really good
09:08 right? So stop wearing your headphones I can have better examples, but
09:12 when you're in the street and that honks at you or when that friend
09:16 your name or when someone says hey everyone turns around, right? So
09:20 idea here is my turning of my is a function of hearing that sound
09:25 how about the duck? Right? ever hear duck? No, no
09:30 . You never duck, you do , right? But then what do
09:35 do when you duck kind of look . So that's that's the idea.
09:41 I think superior curriculum if I remember , eyesight in various sound. So
09:47 right, so I want to just of just give you all that stuff
09:49 to kind of give you that little of that understanding of this pre processing
09:53 kind of taking place before it arrives in the cortex and what I wanna
09:57 now is I want to just spend is all about muscle other than what
10:00 just talked about here. So when talk about muscle and almost 90% of
10:05 textbook, whenever they talk about they're gonna spend the majority of the
10:09 talking about skeletal muscle. So, did I tell you when you spend
10:12 majority talking about skeletal muscle ignoring the two types not as important or there
10:19 similar. Alright. So using skeletal as our as our our background or
10:26 , we're gonna look at cardiac. we're gonna look at smooth. All
10:30 . And so first off, when talk about a muscle, right?
10:34 you're when you like a named muscle your body, what you're looking at
10:37 basically a series of muscle fibers that been wrapped together in connective tissue to
10:43 a single function. And then if look at a larger muscle or like
10:47 like your leg where you have like muscles in their multiple name muscles.
10:53 you're looking at is a multiple structures are wrapped together again to perform similar
11:01 . All right. So, you named muscles. And then you have
11:05 of muscles. And then if you downward, you'll see that within that
11:09 muscle, you're gonna have bundles of and within those fibers or bundles,
11:13 see the individual fibers themselves and each these levels. You're gonna have these
11:18 surrounding connective tissue. And so the of the connective tissue is one to
11:22 the individual fibers so that you can each individual fiber without stimulating the other
11:27 . It's like putting insulation around the . If you take a whole bunch
11:30 copper wires without any installation, you a signal down one of those copper
11:35 . It's gonna go to all the wires. Right. That makes
11:39 So what do I do? I them all in plastic or rubber?
11:43 . And so then now I've So when I send a signal down
11:46 fiber, copper fire, none of other copper fibers are gonna be
11:51 All right. So that's that's gonna the lowest level. And then I
11:54 up into bundles. And so bundles multiple fibers that can be stimulated as
12:00 group. But they're being stimulated independent each other. Alright. It'd be
12:05 me pulling on a rope and I have enough strength. So, what
12:08 I gonna do? I'm gonna recruit friends to help me pull the
12:13 Alright. So we're each doing it , but we're doing the same
12:16 And then I take bundles of And what I'm doing now is I'm
12:21 greater strength so that I can accomplish the goal is of that particular
12:25 Alright. And so that's what this trying to show you. Alright,
12:30 themselves are individual cells. So, talking about muscle fibers. That's where
12:35 going fibers. Not the fibers They're wrapped in connective tissue separating themselves
12:40 each of the individual fibers. But group is then wrapped together as a
12:45 . That's a fast ical. And fast calls are bundled together to create
12:49 bellies, for example. All And so we have names for those
12:54 levels. So the one that's around individual fiber is going to be called
12:58 endo missy. Um Then we move the paramecium. That's the fast
13:02 And then the surrounding one epic And then each of the individual muscles
13:08 gonna be wrapped in deep fashion which just connective tissue. And then the
13:13 groups of muscles that separate them like whole body muscles is separated from another
13:19 of fashion which is called superficial. this is where I get to ask
13:22 question if anyone ever gun hunting An animal is where like one or
13:27 people are gonna raise their hands, ? And they're all like you're all
13:30 . Like. No. This is what we do we do that If
13:33 never done that, have you ever to prepare a whole chicken?
13:38 Okay. When you buy without plucking , right. But you go and
13:41 get the chicken. And what do see underneath the skin you can see
13:45 the muscles are kind of already pre for you and connective tissue,
13:48 And then um when you get gross and you actually get to start start
13:53 cadavers, you'll actually get to start know playing with that stuff and actually
13:58 out muscles themselves. So what you're here is you're just looking at the
14:02 layers of connective tissue. That kind hold the whole thing together.
14:05 So, this is the most outermost tissue up there. That in a
14:10 is the innermost connective tissue around each the individual cells that separate them from
14:14 other. Um I point out also bone is connected via a tendon.
14:20 , when you take this connective tissue bring it together, we're talking about
14:23 Indonesian paramecium. And in these three layers, they come together at the
14:28 of a muscle and they create the and it's a tendon that's attached to
14:32 bone. So, when you contract muscle, what are you pulling on
14:36 ? And what's the tendon attached to pulling on the bone? Alright.
14:41 , to make my arm move. contracting a muscle which causes the tendon
14:45 stretch a little bit. But it pulls right? Cause tendons have a
14:49 bit of given them. Right. then that pulls on the bone and
14:53 moves the bone and that's what local is. Simply moving the bones in
14:57 to muscle contraction. All right. , I wanted you to be aware
15:02 those of what we're talking about when talking about movement here. All
15:07 We got a diamond. An anatomy little bit. And the reason we
15:11 into is just because one there's special that's used in muscles, Right?
15:16 number two, we're gonna be looking gonna be setting up a rube Goldberg
15:20 . You know what rube Goldberg Right? That's when you knocked the
15:24 and then at the end of it captured a tiger or something.
15:28 All these different little contraptions that go the way. So that's what this
15:32 . So the way that this makes easy is just think of the steps
15:36 they're going along. So we're gonna at step eight and step B.
15:39 steps D. C. And then almost skipped over sea. Right?
15:43 then that's gonna be how a muscle of works. So we need to
15:46 the parts, right? If you're how a car works, you're gonna
15:52 up in the engine and you're gonna pointing out structures and you're gonna
15:55 what's that? That's a carburetor, does it do? It does this
15:59 then you're gonna name all the parts then you put them all together and
16:02 you know how the engine works. , physiology is a lot like working
16:07 cars. I don't know anything about . All right. First off the
16:12 membranes called ASarco lemma. See they're people. So they got to name
16:16 cells specially and so their parts get specially Sarko Lemma not plasma. Lemma
16:22 . Alright, the plasma the sight plasma is called ASarco plasma, sorry
16:28 plasm Gosh, I'm so tired. right now, is it different than
16:34 other cytoplasm. Not really, but are some unique things that kind of
16:38 out in it. First off there's are just fancy way of saying sort
16:44 glycogen Granules. So why would I to start glycogen Granules? A.
16:50 . P. Right. Do I to wait for sugar to be delivered
16:54 my muscles? Know if I'm being by a tiger? I want my
16:57 now and I just want to just right to the stores. Alright,
17:02 . Myoglobin is found inside these It binds up auction. It's a
17:07 to hemoglobin. So hemoglobin binds up in the blood. That's what helps
17:11 greater oxygen to our cells. Do want to wait for my lungs to
17:15 pumping more? No, I'm going have auction readily available to me so
17:20 can see already have the stuff ready do what I need to do.
17:24 right, lots of mitochondria. What have mitochondria A. T.
17:28 Alright, muscles use a lot of . T. P. I need
17:32 of mitochondria to make that a And lastly their multi nucleotide. Why
17:36 you think I'm multi nucleotide? This a trickier question. A lot of
17:49 , I mean that's that's a good . It's actually yeah. What do
17:52 think? Okay so so that's a and an egg thing. So they
18:02 so long but why are they so . Do the cells start off
18:08 No they don't start up big I'm you guys said no. So where
18:12 you think the big sell comes from of smaller cells. So why do
18:17 think they have many nuclei? Because these cells merged together and created a
18:22 very long cell. That's actually the region. Reason for that.
18:27 this is a developmental thing that's actually . So that's why I mean,
18:32 know, I'm not sitting there you don't know the answer. It's
18:35 of like this is kind of Right? I mean, there's a
18:38 places the body where we have these nuclear cells and really, it's a
18:42 of cells combining their their cytoplasm to a better response for whatever that is
18:48 they're doing. And this is one those cells. All right.
18:52 the one thing that's interesting or different these cells is they have what is
18:55 a saarc Amir. A sarcoma is functional unit in a cell. All
19:00 . So, an individual cell can very long. It's as long as
19:04 muscle itself is. All right. the muscle fiber, right. Just
19:10 my bicep for example is attached here attaches down here. Right? So
19:14 would be the origin and the And then so the fibers that make
19:19 that bicep are the entire length of muscle itself, that name muscle.
19:25 , So within their it's about this and that means it's gonna have multiple
19:32 tiny Sakai mirrors within it. And of those sockeye mears represents the unit
19:37 we're looking at? So, there be 1000. I don't know how
19:40 there are in an individual state, there's thousands of them. And so
19:44 we're talking about the contract, I'll of a muscle. We're talking about
19:47 little itsy bitsy, teeny tiny unit which there are many of them right
19:51 to one another. All right. so, the defining uh structure of
19:56 sarcoma here. So, you can here is a This is actually the
20:00 fiber. All right. And you can see here these are mild
20:04 brill's And inside that mile five you can see there's a defining line
20:09 called a Z disc. What you're is you're looking at a bunch of
20:12 in a lattice from this angle. you look at something from that
20:17 it's flat, isn't it? But you turn it, you're gonna see
20:20 there's actual structure to it. All . And so, that's one Z
20:25 is this lattice work, and then travel a certain distance away and you'll
20:28 another Z disc. You travel a distance away. There'll be another one
20:31 another one and another one. each of these from Z. Dist
20:35 Z. Disc is a sarcoma. so when we're talking about the microscopic
20:39 that's going on. We're in that tiny space inside of a side of
20:43 larger cell. That's however long the that you're looking at. All
20:50 Now, when you contract, what gonna be doing is you're gonna be
20:54 the circle here. Alright, so that contract. I'll unit when you
21:00 . So, remember when you started life, how big were you?
21:04 a bit of your single cell, . You became a fetus and you
21:07 born. And how big were you you were born? That's really the
21:10 . I should have looked at you this big. All right. And
21:13 look how big you are. You're big. All right. It's
21:20 Looking at a little kid's hand relative your hand. All right. It's
21:24 this little tiny dot, right, speaking. So, when they grew
21:29 muscles grew and when their muscles what they did is they added sarcoma
21:33 the ends or within the structure of muscle. And so that's how they
21:39 . So a muscle increases in length adding those circum ears. So,
21:44 a growth thing. All right, , the sarcoma is a finite length
21:53 structures. Alright, so, we're to this side of the cartoon right
21:58 , within that structure we have in plasma critical um smooth and a plasma
22:03 um uh particularly. And it's been to store up calcium. And so
22:08 given it a special name. We it the psycho plasma particular um
22:12 the cytoplasmic particular um has this unique . So you can see here we've
22:16 it out and as you can it's fairly thin. The small cyst
22:20 like they do. But then when get to the end of that psycho
22:23 particular, it bulges out. And this bulge is referred to as a
22:27 cistern E. So this is where predominant portion of the calcium is going
22:32 be stored up because there's just more . And then right next to that
22:36 end that terminal cistern E. In . Uh moving along the length of
22:42 , the structures are what are called T tubules or the transverse tubules.
22:46 , transverse tubules is simply a tube opens up to the surface of the
22:51 and then travels through the cell and up onto the other side. It's
22:55 tunnel, alright. And so it basically bringing the surface deep to the
23:04 . That kind of makes sense. right. So, I think we
23:08 a picture here. I'm gonna show little bit in about two slides.
23:12 right. So, what I want to think about this little structure
23:14 This transverse tubules is a tube that's up to the external surface and brings
23:20 external surface down deep through the Kind of like a hole in a
23:25 , right? Or like a straw surface deep two, and then opens
23:30 on the other side. Alright, , that's what it kind of looks
23:33 . And you can see here structurally blue represents the t tubules, yellow
23:38 the cytoplasmic articular, the bulge to at the end of the cycle plasma
23:42 , right next to the t Is that uh terminal cistern?
23:48 So what we're gonna do is we're walk through all these structures and what
23:52 doing when we stimulate the cell. . And then we're gonna pause and
23:57 we're gonna go and talk about a more things. All right, so
24:00 we are. This is a Alright. What we're looking at is
24:05 motor in plate, see the special . It gets a special name because
24:09 is the interaction between a neuron and muscle fiber. So the post synaptic
24:14 is actually referred to as the motor in play. What you have is
24:18 have tons and tons and tons of receptors. And then you have a
24:23 bunch of vesicles just lined up full acetylcholine. And so when an action
24:28 travels down that axon down to the terminal, it causes the opening of
24:34 or opening of these calcium channels, calcium comes in, causes the vesicles
24:38 be released, releases all the acetylcholine the motor in place or into the
24:43 cleft to the motor in plate that binds up to those channels and cause
24:48 those channels to open. And what's about this is that here we're not
24:53 an E. P. S. . Down in our post synaptic cell
24:56 , what we're getting is we're releasing much acetylcholine that the the greater potential
25:02 produced here has a magnitude so large it results in an action potential.
25:07 for every action potential in that motor you get an action potential down here
25:12 your in your muscle cell kinda All right. So you can imagine
25:17 getting a greater potential that reaches threshold an action potential. The potential begins
25:21 along the surface of the cell and nothing new that we've learned here.
25:26 . The difference being that we just a muscle cell instead of a neuron
25:29 this side. Right? So you see we refer to as the in
25:33 potential. So E. P. becomes an action potential along it travels
25:37 the length of the cell and on surface of the cell. So here
25:40 is traveling along the surface of the and it comes across you can see
25:45 would just keep on going. But also has these t tubules and what's
25:50 tubules, it's just surface moving closer the inside of the self. And
25:53 those action potentials continue on down through inside of these t tubules and they'll
25:59 keep going to the other side. here is where we're gonna encounter something
26:05 . All right so in the t we have a series of channels.
26:11 or not channels we have a series of receptors are called D.
26:15 P receptors. And these D. . P receptors are closely associated with
26:20 type of receptor called or iodine Alright. And so the D.
26:24 . P receptors in their iodine receptors gonna go to a better picture I
26:29 . Okay here we go. So have the D. H. P
26:33 and here's the ride on receptors notice on the terminal sister knee and what
26:37 is is as as an action potential down it causes the opening of these
26:41 . H. P receptors which are or attached to the right and receptors
26:45 basically pull those open and that causes release of the calcium into that
26:52 And so when an action potential occurs we're seeing is a massive rush of
26:57 from these sarko plasma critical um into cytoplasm or the sarko plasm of the
27:06 so far. You with me so one action potential or actual causes release
27:12 acetylcholine. Acetylcholine causes opening of those , causes an ep ep ep ep
27:18 big enough that it causes another action . Action potential travels along the length
27:22 goes into the T. To be down through the T. To be
27:25 causes the opening of the D. . P receptors. D.
27:28 P receptors are associated with the right receptors right Iron receptors open up calcium
27:33 out of the of the terminal sister , out into the cytoplasm so so
27:39 it's just a whole bunch of calcium a whole bunch of different places in
27:42 to an action potential so far. good. All right. Yeah,
27:53 Yeah. So so what we're doing is we're parsing words. Alright,
27:58 this is like moving from like freshman two now to the junior level.
28:03 it's just saying the portion of the , plasma particular um that is engaged
28:09 holding the calcium. So it's the structure, It's just the region.
28:13 . So putting in the context of room, you're sitting in the middle
28:17 the room on the aisle side, you? But you're still in the
28:21 . So we're just adding another word to make you feel smarter than the
28:27 . Yeah. Oh you're jumping ahead the game. Hold that, hold
28:38 thought. If I don't answer the and a couple slides then say you
28:42 answer the question, a couple of and be mad at me and I
28:47 answer it. What's that? Because we need to understand is that circle
28:57 and this is what this is all ? So first off, you've probably
29:01 a slide like this at some point your academic career where you have to
29:04 muscle. Do you all have to muscle at some point? I
29:07 bands, bands, bands Yeah, looking at a couple of people and
29:12 like and I have never seen this in my life. All right,
29:15 remember we have Z lines. So I'm gonna start here with the
29:18 line. So you can see the line is clearly delineated right there.
29:23 that's why they picked that and they that soccer. Now, remember these
29:27 scientists who are looking at this and knowing what the hell they're looking at
29:29 they see are light and dark And so what they're doing is they're
29:32 , oh look, here's a dark . Then we got a light line
29:35 we have a dark line that we kind of a light line. Then
29:37 have a dark line that we have kind of a light line, looks
29:39 that one. And then oh it repeats itself in the opposite
29:43 All right. And so that's why define this. They could have picked
29:46 of these things to start the point definition. Alright, But they happen
29:51 pick right here. So, you see on either side of that Z
29:55 , what we have is the eye . The band represents the thin filaments
30:01 the maya filaments, the structure the of the side of skeleton of the
30:07 fiber. We'll get to what that in just seconds. So, that's
30:10 filament. Alright. This this The a band is from where this
30:15 band begins. And even though you some light stuff in there, It's
30:19 it ends on the other side. , So there's stuff that's going on
30:22 the center of the a band. the a band is that thing and
30:26 represents the thick filaments. Alright. then within the context of that thick
30:31 , we have this kind of lighter , even though there's a dark one
30:34 the inside of that, that little region is referred to as the
30:38 Band. All right now the a really what it is is the overlap
30:45 thick and thin filaments. So what have here is you have a thin
30:49 . Then you have thick and thin and this little H. Band right
30:52 represents where there's just thick filaments. then the M. Line is like
30:57 Z. Line, it's where the filaments are attached. So the
31:00 Line represents the point where the thin are attached. The so that's the
31:05 band is the thin filaments and the filaments keep extending onward and they go
31:09 the a band. A band is the thick filaments are overlapping with the
31:13 filaments. And then that little Band represents where thick filaments are.
31:18 then we repeat on the opposite side the in line. Now, just
31:21 make this easy so that you can , we're gonna pull up to
31:25 you can stand up again and since furiously writing, I'm gonna pull you
31:28 and make you do stuff too stand side by side in the center,
31:33 straight into the light. Don't go the light. Alright. Stick your
31:39 straight out. So you're gonna be in line. See he's an
31:43 Line. Doesn't look like an in to you, yep. So look
31:48 you know what those are? Those that's thick filaments, right? Thick
31:55 . She is a Z. Alright now there would be another line
32:01 the other side. Right? So the line. Stick up your
32:06 Look at that. She has thin . Look at this. Alright,
32:13 you see are they overlapping? So have a Z line from here to
32:18 . That would be the I. . That's half an eyeball and the
32:21 half would be over on that There's an eye band. What would
32:24 be? That would be a the . Continues on that direction. But
32:28 it stopped for sport short period, a little interruption. That would be
32:34 . M H A I. Thanks. You see how easy that
32:42 , you have a visual of that . Okay, you're gonna be called
32:47 again in just a moment. so just be ready to be in
32:51 and the line again, you're like thanks. All right now here you
32:55 see that representation of what's going on and there's a lot more than what's
33:01 being shown here. But I just to point out a couple of
33:05 Alright, when a contraction takes place muscle doesn't stay in this contracted state
33:10 it relaxes, it springs back to original shape, doesn't it? So
33:14 a spring like molecule in there that it to spring back. That molecule
33:20 going to be titan. All Not to be confused with another molecule
33:26 titan. Alright. And it actually you can see here the little blue
33:31 things that's even in the spring shape remind you. That's what it does
33:33 what it is. It's associated to very end of that a band.
33:37 it's basically holding on to the end the thick filament. So when I
33:41 I squeeze tighten down so it's not a spring. And when I
33:45 what happens it's brings back out So it's serving as a spring to
33:50 us back into our original shape of sort here we also have a R
33:56 tenant tenant is found on the end the bands. And it's what attaches
34:03 um thin filaments to the Z. . And the last molecule is nebula
34:09 and is also found attached to the and it sits and goes right down
34:13 center of that thin filament. And it does is it makes sure that
34:18 thin filament is heading straight outward and sag down or sad or point
34:25 And what this does is it increases interaction between the thick and the thin
34:30 so that you can get a contraction that circle mirror right? So you
34:35 how when their arms they were like of doing conquered stuff. What you
34:39 is you want fibers that are gonna parallel to one another so that they
34:42 interact with one another. And what is actually trying to show you is
34:45 you took a cross section, this what the thin filaments would look
34:49 This is what the thick filaments would like. And then together you can
34:52 that if they're arranged in such a . So that for every thick filament
34:56 have six thin filaments or you can the opposite for every thin filament you
35:01 a couple of thick filaments around or thick filaments. And so what you're
35:05 is you're having multiple interactions within these mild fiber pills. All right through
35:12 side of skeletal elements. Yes sir ma'am? Sorry. Well we haven't
35:20 that yet. So just thick and . Or which one is thick.
35:23 , so the a band right It's this right here. So it's
35:30 it's where the band begins, it with the H. And then it
35:35 at the M. And then you a new one. H. All
35:37 way to a. So everything in here is a thick filament,
35:44 That's where you'll see the overlap of thin filament. So I by itself
35:48 thin H. By itself is thick . Is thick and thin crossing over
35:52 other. H. Is thick. ? So there you go. There's
35:56 thick filament right there? Okay. right. So what are these thick
36:00 thin filaments. Alright. And I part of the answer over there,
36:13 . You keep getting ahead of the both of y'all? Yeah.
36:16 The answer is yes. All And we're gonna I was gonna demonstrate
36:19 up here I guess I don't have anymore. No. No. They're
36:22 you know you guys please show Sorry. But yes, that's that's
36:25 . In with regard to a sock a contraction. We're gonna see the
36:29 . And the H. Band shrinking . Still coming back to your question
36:34 . But we got to understand what thick and thin filament is.
36:37 thin filaments have three parts and actually than that because your opponent actually has
36:43 parts to it. But we're gonna to keep this really really basic.
36:46 . So first off the thing we're interested, it's acting all right.
36:50 learned about thin filaments being acting? . Acting is the portion that actually
36:55 in the contraction. It interacts with thick filaments, the myosin heads of
37:00 miocene in the thick filaments. So it functionally binds to because it
37:06 that functional site or that active site bind the miocene problem is. You
37:10 want to always by the Mayas and want to protect it? You only
37:12 to buy the medicine when you want create a contraction. So it has
37:16 portion to it called trophy mason with name like triple Medicine. Do you
37:19 it's related to medicine? Probably And it is. And so what
37:24 does is it sits and hovers and mildly attracted to that mice and binding
37:30 . And so what it does is covers that mice and binding site.
37:35 you can see it here, this tiny pink band that goes back and
37:39 . I think that's pink. You , that kind of surrounded basically sitting
37:43 covering up all the mice and binding . So it's in the way you
37:47 interact with it if you're Miocene, though you might be ready to.
37:51 the only way that you can interact this thin filament with the act then
37:55 if you move the trump out of way and that's what proponents job
37:59 Troponin is bound up to the triple . It's bound up to the acting
38:05 kind of serves kind of as a a as a link to hold it
38:09 place. But holding the trophy Miocene place. And then the third part
38:13 up calcium. Now you might start , oh, maybe I understand now
38:17 I'm releasing calcium right? Because if binds up calcium and it's helping to
38:22 the trope of Miocene in place, if I had calcium, it's gonna
38:25 it out of the way. So acting becomes free. And the answer
38:28 that's what it's gonna do. But get back to that. Hate trying
38:32 tell you the story before the story there. All right. So let's
38:36 to the thick filament, thick filaments like golf clubs that someone got really
38:39 angry about. Right? They wrapped shafts together. And really that's what
38:46 is. Just basically these really really bodies with these heads. And there's
38:50 there's a hinge portion that allows the to actually move. And so you
38:54 kind of think remember the picture that that boxer from the 1860s like
38:58 you know? And he's like this how he boxes. That's what the
39:04 heads do they move because of these portions. Now, that hinge portion
39:09 what what separates attitude? It's basically heavy chain is what so you got
39:13 light chain of the heavy chain. heavy chain is where you have the
39:17 binding site. So you can see here, that would be the heavy
39:20 . All right, that's where the site is gonna be located. It
39:23 has an A. T. A. Site whenever I have an
39:26 . T. P. A What am I trying to do?
39:29 to release energy from a T. . So here you can see,
39:34 I'm probably going to be using energy move that head around. All
39:39 Um We also have the light chain which we'll get to in just a
39:43 . Um But in essence what its is is to help stabilize the structure
39:49 it's gonna be um It's gonna be primarily in the other cell types.
39:55 right. So, what I want to focus on is the head and
39:58 how they're all wrapped up together. get a whole bunch of these
40:02 They're always paired up together as a a pair. And then you take
40:05 pears and then you just start creating bundles. And so each of those
40:11 and heads are gonna be working independently each other. But they're all those
40:14 heads are working on the same acting . It'd be like being able to
40:18 to or or hold on to a . Right? If I grab the
40:21 with one hand and let go and on a spring. What's it gonna
40:24 ? It's gonna keep going back. , what I can do now is
40:27 can grab and pull the acting like with the two heads. But remember
40:33 got lots of these heads that are with all these different acting molecules.
40:38 right. Let's see if we're back the story. Yes. Alright.
40:42 , when we think of a muscle , we usually think of energy and
40:45 think of a T. P. is not what's causing the contraction.
40:49 thing that causes the contraction is the of the calcium. So, let's
40:53 back to where we started acts potential the in the motor neuron causes release
40:57 acetylcholine. Acetylcholine binds to those channels causes sodium. Come in we'll get
41:03 E. P. P. P. P. Results in an
41:05 potential in the muscle cell. The along the muscle cell travels along goes
41:09 through the T. Tubules activates the . H. P. Receptor which
41:12 activates the right brain receptor which causes release of the calcium into the
41:16 Where is the calcium gonna buy troponin the thin filament And when it binds
41:25 that troponin, what it does is causes a change in the shape of
41:29 troponin molecule which causes the triple miocene be pulled out of the way,
41:34 the acting on the acting that myosin site. Now that head of miocene
41:40 already in position, it's ready to right all you gotta do just move
41:45 out of the way So by moving out of the way. Boom you're
41:48 able to bind when the mice in act and bind. What do you
41:53 happens? Power stroke. That's the thing and that's the next step.
41:59 you need that interaction to occur So the calcium allows for the binding
42:04 take place so that the power stroke take place. Power stroke is just
42:10 fancy word for saying Madison, pulling the acting. All right now this
42:14 where A T. P. Becomes . All right so all we're doing
42:19 my son is the one we're just looking at one head. But you
42:23 imagine I got those two heads doing same thing and an opposition. One's
42:27 one is not there. The other buying the other one releases. All
42:31 . And so, what I want to look at here is where that
42:33 T. P. Is Alright. do we see the A.
42:37 P. Come in right here. is a TPS job? It's to
42:42 the head from the from the So, really what we want to
42:48 is let's pretend this is our starting , right? Instead of this being
42:52 starting point. So, here we in that normal state. A
42:55 P. Is bound to myosin when T. P binds to myosin,
43:00 A. T. P. A that 80 P releases the energy and
43:05 that head to get into the cocked . All right. So, the
43:09 you can think about is here's my . Then I'm over here. I
43:12 interact. But what happens is the . T. P. Comes along
43:15 me and gets me ready to All right. So, now all
43:20 gotta do is be able to interact it. But because I've got trouble
43:23 in the way I can't interact, comes along, moves it out of
43:26 way. Now I can interact when interact with the act. And what
43:30 I do? I pull And that's this is showing. All right.
43:34 mean the cock state I'm able to . So I pull. And what's
43:40 happen is I'm going to release the phosphate. Right? And then there's
43:46 power stroke. And now after the stroke I'm no longer attracted to the
43:51 . So the ADP is released and need to get a teepee once again
43:56 come in to cause me to release going on. So 80 peacocks
44:03 Once I interact I pull I have release the A. D.
44:08 A. T. P. Comes releases me. I do the
44:11 T. P. S. I'm cocked. I'm ready to go
44:16 . And how do I remember How do I remember the role of
44:19 . T. P. What is of the characteristics of a cadaver after
44:24 died? What is the state that goes into stiffens up? Which has
44:29 special name, rigor mortis. Why does rigor mortis even occur?
44:34 , it's a function of the two that we just looked at. All
44:38 , When your cells are no longer . Alright, so when you're
44:45 nothing is driving the activity of the . Right. But they still have
44:49 teepee and then still have calcium in . But nothing is driving the
44:53 And so what happens is the first is all the calcium gets released from
44:57 cycle Plaza particular goes down to the . So, your cells are flooded
45:00 calcium. Well they're flooded with That's gonna cause the trouble troponin to
45:05 out of the way so that my can interact. You still have a
45:09 in yourselves. What's the A. . P. Gonna do? It's
45:11 allow you to create a series of until you run out of A.
45:14 . P. And then what have done is you've created a sustained contraction
45:19 now you are in rigor mortis. . And then after a little while
45:24 sell, start breaking down and that's you go back into that relaxed state
45:28 your now rotting you. Okay? what does a. t.
45:33 two allows me to break the bond that my muscle is no longer in
45:39 contraction. Right now I'm sustaining the because I'm using the two heads.
45:46 if no calcium is there and A . P. Is present, that's
45:50 break the bond, that's gonna allow to take place. That can make
45:54 . Yeah. Yes. Right so triple the way I remember it
46:03 Triple medicine is related to medicine so mildly attracted to the myosin binding site
46:09 acting. So Troponin pulls the triple out of the way. Right,
46:15 like the chaperone, it's not letting couple get together, you stay apart
46:20 what it's doing, if that makes . Alright. So the power stroke
46:27 because a tee pee breaks the bond then going through the process of processing
46:33 a teepee that allows for the power to occur, that's what's going on
46:40 here at this stage. So how we relax? The muscle take to
46:47 and call me in the morning? one knows what selma is. See
46:51 guys are such a good generation. a muscle relaxant. It's a prescription
46:56 relaxing that was heavily abused in the and 90s. Hmm. Yeah.
47:06 have a friend who's a rarely really attorney now. Um That's what what
47:10 thing was in college. Yeah. . Yeah. Alright. So how
47:20 you relax? Well, simply put are the two things that that result
47:25 a contraction calcium and A T. . So if I get rid of
47:31 calcium, will I have a So what will that cause basically I
47:36 be able to get the contraction. I'm now creating the state for real
47:39 to take place and then if I a T. P. That's gonna
47:43 the bond. So now the muscles back into their original shape. All
47:47 , So what moves the calcium is pump called circa. Alright, circa
47:55 found on the Circle Plaza particular. always on And so you're always using
48:03 TP to pump calcium back out of environment when you have an action potential
48:09 causes the opening of those ride on more calcium leaves and gets pumped back
48:13 . That's why you get the state the state of that calcium influx.
48:17 when there's no calcium or sorry when no action potential, calcium is no
48:21 being released. And so now the is able to do all the hard
48:25 of moving the calcium back out and that muscle goes into that relaxed
48:29 Alright so the key thing here is plays the major role of allowing the
48:36 to occur because it's allowing the mice the action and the acting to
48:41 Okay it's not the A. P. A. T. P
48:44 the bond between the two as long A T. P. Is not
48:47 . You're gonna have a sustained All right so far that makes
48:57 Okay. No it doesn't. Well walk through the whole thing if it
49:02 make sense. Let's walk through the thing. Step one action potential through
49:05 motor neuron step to release of acetylcholine the synaptic cleft under the motor in
49:10 . Get an E. P. . At the motor inn plate that
49:12 in an action potential on a muscle action potential travels along the surface of
49:16 cell. Goes down through the T , binds to an active or not
49:20 to but opens up channels which are D. H. P. Receptors
49:24 are associated with the ride in receptors causes calcium to e flux out of
49:27 cycle plasma particular um into the Right lots of lots of calcium binds
49:35 the opponent moves out of the Makes the myosin binding site available and
49:40 . My son is already in position its act and binding site to be
49:44 to interact with that as long as a teepee available. What we're gonna
49:47 is we're gonna get the power We'll be able to break reset power
49:52 and just keep that to maintain or contractions when I stop releasing calcium.
50:00 other words when there's no action potential gets put back into the circle plasma
50:05 I'm no longer able to interact. so the muscle goes back into its
50:09 state because the A. T. . Allows you to break that
50:14 That makes more sense. I know went fast but see there's a picture
50:17 it and you can see in three I could have explained the whole thing
50:23 by looking at this one picture. you would all like I don't understand
50:26 cartoon. What's this strange looking thing here. Right and that's what I
50:30 to avoid. Is the strange looking . Yes sir sir. Just no
50:37 calcium is being removed circa is the the means by which calcium is being
50:42 . It's always on even in the of of pumping or releasing calcium out
50:47 the cytoplasm. It's just it's a a pump that's slower than opening up
50:51 the right and receptors. Right so what all this just tells you and
50:56 just follow follow along. Right here's motor in place. You can see
50:59 D. H. P. That be the right iron receptor. And
51:03 this is showing what happens when calcium released. So one picture is all
51:07 need. You can draw it out you draw it out it makes 20
51:10 more sense. Yeah, circa No there are So what's happening is circa
51:19 is simply always on. So if if I'm just gonna make up a
51:23 let's say the ratio is 4 to . So if I'm having four calcium
51:27 while one calcium being pumped back Obviously the calcium going out is favored
51:32 when I shut those right iron Now what I'm doing is I'm pumping
51:37 back at a greater rate. So why it's working. I still haven't
51:43 to it yet. I'm going to I don't get to it I will
51:46 stop and say all right. How we get bigger and stronger? All
51:49 . So first off, there are types of contractions. They're what I
51:52 isotonic contractions. And isometric contractions. with with regard isotonic there's gonna be
51:58 types of isotonic contractions when you're changing muscle length. Alright so usually I
52:04 some sort of prop that I can with. I guess I'll just use
52:07 bag. All right. So So I've got all the floppy
52:16 Alright so here I am with my , if I am lifting this up
52:21 curling it. What's my bicep Getting longer or shorter? And it's
52:25 shorter. Good. Alright so when put the bag back down is the
52:29 changing shape again? It's getting what , shortest thing? The same
52:33 Alright, so you just witnessed two types of isotonic contractions. A contraction
52:38 makes the muscles shorter. That's concentric when the contraction that is allowing the
52:44 to become longer, that's called Alright, now the other type is
52:50 isometric contraction. Now isometric is where increasing and I should have said in
52:56 isotonic you're not increasing the uh the that you're producing, the forces being
53:03 . So in other words, the of this does not ever change,
53:08 it? In the in the course me lifting up and putting it back
53:11 again. Right. So I only to create enough force to overcome the
53:16 of the bag. So once I that force to overcome the load,
53:20 maintaining that force to be able to that odd item. Right.
53:27 So what is that? Like So I'm creating enough force to generate
53:31 overcome £5 and I can move the or I can set the £5
53:37 I'm still moving the £5. So the load and the force that I'm
53:43 with an isometric contraction, the length change. But the force I'm
53:49 the tension in that muscle is Alright, so there's never really a
53:54 way to show this. Um So just gonna go up against this wall
53:58 closer so you'll just have to bear me. Alright, so here I
54:02 , I'm pushing up against the right? You can see my
54:05 Look at that and look at that muscle right there, right? So
54:09 can see I'm not putting a lot tension into that muscle to push that
54:12 , but can I produce enough tension knock that wall down? Come
54:17 have a little faith. No, cannot. This this wall isn't.
54:21 , So I can apply force, force, apply force, apply
54:25 And no matter how much tension I into my arm, the muscles not
54:30 its length. Right? So, want to try this yourself? You
54:35 do it in your chair, You got one arm, you got
54:37 arm them again against each other, ? And now produce a little bit
54:41 force. You can do it with . All right. Just a little
54:44 You don't have to push art? I mean, can you feel that
54:47 creating a little bit of tension? ? Put more attention and more and
54:52 and just keep pushing and pushing and to make your arms move. But
54:57 they're moving in opposite directions are pretty . They're not gonna move anywhere.
55:00 what you just did was an isometric . The muscle did not change its
55:05 , but the amount of tension you did All right. It wasn't enough
55:11 move the load if you've ever gone weights and try to lift something that
55:15 too heavy for you. You like, Oh look, here's a
55:19 weight. You know, you're not the load but you created a whole
55:24 of tension trying to do so. , so those are the two types
55:28 contractions. Now, everything we've described to this point has to do with
55:36 little tiny socks here, with the of the contraction portion. Alright,
55:39 looking at the full length when you at a contraction. Remember that when
55:43 talking about the power stroke and We're talking about a sarcoma here and
55:47 circle here represents a single fiber not a fiber. A single
55:51 Right? And there's lots of socks that one fiber. But look at
55:56 muscle. Your muscle is lots of wrapped into fast calls, lots of
56:00 cools wrapped into a muscle. And when you talk about a contraction inside
56:06 , inside that soccer mayor, we that a twitch. Now don't confuse
56:10 twitch in a sock. Amir as twitch like that. That's that's something
56:16 different. Alright. It's something that's with a volt meter. Right?
56:23 you but you're not gonna see it . All right. And so any
56:27 of signal, any sort of action causes the sock'em ear to contract and
56:32 . That would be a twitch. that's not enough to move anything.
56:37 fiber. Can't do a job. need multiple fibers and you need to
56:42 a sustained contraction. So, what can do is you can do
56:47 All right. Now, the hard to think about here is that action
56:51 are not the same things as All right. And action potential is
56:55 signal to cause the contraction. Remember we saw the action potential travel
57:00 the surface of the cell and then cell released the calcium. And it
57:05 the cell to contract as well to action acting in the my the my
57:11 interacting. All right. So, you look at these up at the
57:16 , the little red arrows represent where action potential is. The green graph
57:23 the contraction. They're independent of each in terms of measure. And you
57:28 see here this is what a twitch look like. Right? There is
57:31 potential. You get a little tiny , Get another one. Doesn't do
57:36 . You can get them a little closer together. And that's that temporal
57:40 kind of like what we saw when were trying to deal with magnitude and
57:43 action potential. So you get a of action potential in a row and
57:47 growing on each other. And so get kind of this, this kind
57:50 twitchy activity. It's still not enough actually create a sustained contraction. But
57:57 you get a whole bunch of action together and they're really, really
58:01 what you'll do is you'll get a contraction that's being maintained. That's that's
58:06 sustaining, right? This is what referred to as tetanus. Alright,
58:13 is what allows your muscles to do they do. They're creating that tension
58:18 cause movement and each of the individual , like I said, they're not
58:22 enough to do anything. So twitch really not doing anything but tetanus in
58:27 single fiber can't do anything. What need to do is you need to
58:29 multiple fibers working in concert to get to happen. That kind of makes
58:36 . If I'm pulling on a I can't move it by myself.
58:39 I get me and my buddies we can pull cannons out of the
58:43 if we need to. That's actually tug of war actually really was strength
58:48 cannons out of the mud. All , and that's what we're looking at
58:52 we're looking at tetanus. How do remember what tetanus is? What happens
58:55 you step on a rusty nail in parking lot? You get lockjaw.
59:01 right. That's tetanus, right? do they call it tetanus because of
59:07 the lockjaw. That's the ideology. how it appears. It causes a
59:12 contraction in the jaw muscles. I know why? Don't ask me
59:16 but that's where it comes from. was gonna take a sip but apparently
59:22 . Alright. We're almost getting to answer. Motor units. A motor
59:29 represents the neuron and the fibers. innovating. Alright. Motor units have
59:36 sizes depending upon the activity that they're for. All right. So,
59:42 example, in this little cartoon you see here is a single axon and
59:46 has 123 collaterals. And it's innovating fibers. So this motor unit is
59:54 axon plus those three fibers. And the activity that this one can produce
60:00 the amount of tension that those three by themselves could produce. Different motor
60:07 can be of varying sizes. If doing very fine activity. What you'd
60:12 is you'd have a couple of fibers neuron. What's an example of fine
60:18 ? Fine motor activity. Writing. That's the easiest one to think about
60:23 writing, right? It's having really degree of control so that you can
60:27 all that beautiful calligraphy that you're Right? Or the chicken scratch in
60:33 case. All right. If I'm with course activity, what would be
60:38 example of course activity, lifting Walking, right. What is
60:44 We've already talked about this. Walking not falling. Right? I lift
60:48 my look, right? I that's course activity. And so what
60:54 I doing? I have a single going down to hundreds of fibers to
60:58 contract so that you can lift up clunky leg, relax it fall
61:04 All right, So that is how motor units work. And so when
61:11 talking about an activity. So, example, if I wanted to curl
61:15 , do you think that weighs a ? No. Right. So I
61:19 put it in my hand and I do a curl of this house and
61:22 could see that I would probably not . I don't need a lot of
61:26 units to cause that curl, But I can add weight to
61:30 I'm gonna put my phone in my . So now I've doubled the
61:33 So I may need more motor units be able to do that activity.
61:39 then we can get to bigger and things, you know, sometimes there's
61:43 chair in here and I'll curl the . Right? But this obviously weighs
61:47 than those two little things, Right. So, it's the same
61:52 , the same muscle groups. But recruiting more and more motor units.
62:01 ? Um So, that's actually on different slide, but in essence,
62:07 in order to create a movement and increase the tension, I'm going to
62:12 in more and more fibers. more motor units to to accomplish the
62:18 . Yeah. Oh my goodness. . All right. So let's hope
63:06 don't know how much we've we've missed . Yeah, I don't know,
63:12 oh well the good news, how , how many years I've been teaching
63:16 ? 16. How many lectures have recorded? About 30. So if
63:21 missed this one you can go and to an old one. It's not
63:24 good as this one though. So the other thing is is that
63:32 the motor units themselves are never gonna clustered. Right? So what you
63:36 do is you want to spread your units around the muscle itself so that
63:40 you create a contraction, you're actually a contraction in the same direction.
63:46 ? So just think of my I don't want all my motor units
63:49 one side so that when I create contraction pull this way you want it
63:53 that it creates that one movement that trying to accomplish. So these are
63:57 distributed and there's many of them so they can have an additive effect on
64:03 activity that you're trying to accomplish. know I'm gonna forget those. All
64:11 . I'm gonna answer your question now I don't know if I have a
64:15 for this just 15 minutes. Good . One of these days. I'm
64:22 gonna come in here. You tell what I'm supposed to say and then
64:25 just get it done and then I'll add to it at the end of
64:27 . Alright with regard to getting What you don't do is you don't
64:33 more sarcasm. Here's what you do you add more mild fibers to the
64:37 here. Alright so remember how we that cross section. Right? So
64:42 about when you when you work out your muscles do they go? Which
64:46 did they go this direction or they this direction? They go this
64:49 So what you're doing is you're taking little tiny muscle fiber, that cell
64:53 what you're doing is you're jamming in and more mild fibers so that that
64:56 goes like that. Then you add more and more of those fibers.
65:01 many fibers doing many of my fiber and that's why your muscles get all
65:04 and bulgy. So it's adding mild not acting fiber rules. Alright.
65:11 both white and dark meat, You guys like white meat and
65:15 We're getting close to thanksgiving. We I mean two months. But I
65:18 you should be making plans at this right? Each of your muscles,
65:21 have both fast and slow versus oxygen like elliptic in terms of their
65:27 And really this just tells you there you see fast versus slow. This
65:30 talking about how quick their twitch activity . Fast fibers are gonna twitch
65:35 Slow fibers are gonna twitch slowly. ? And so fast ones are going
65:39 um create these strong contractions. Slow are gonna be sustained contractions when you're
65:47 with oxidative versus glock elliptic? It's telling you what sort of pathway you
65:51 dependent on oxidative phosphor relation. Or you dependent on glycol icis?
65:56 So if you're like Alice is how A. T. P. Are
65:59 gonna use roughly to? Right? gonna you're gonna make to write oxygen
66:04 elation roughly? 32, 34, . Whichever number you happened to land
66:09 the time that they were teaching Right. And so. Right.
66:14 mean, there's gonna be more. ? And so you can imagine I
66:19 fibers that are gonna be dependent upon those steps to make energy which allows
66:25 to sustain activity for longer periods of . So, I become I'm basically
66:31 resistant, whereas if I'm uh dependent glycol assists, I can fatigue fairly
66:37 . All right. And so we three fibers that are based upon those
66:41 of characteristics and that's what these are oxidative fast oxidation fast, like
66:45 Alright, So, you can imagine I am glycol it, I'm gonna
66:50 um very little myoglobin because I'm just gonna need it. Right? Because
66:55 don't have oxygen phosphor relation where these myoglobin. Um These are the least
67:01 . And there, you know, can see red muscle while they read
67:04 myoglobin. Myoglobin has the pigment that up oxygen. That's why they're
67:10 So, I don't know, breasts, that's in chickens and
67:17 That's what you look like. So all mixed. That's a big old
67:23 . Don't memorize the chart. Just of gives you a sense of the
67:28 . Cardiac muscle not very different from , skeletal muscles. That's why we
67:33 have one slide structurally. When you at skeletal muscle, there long strands
67:38 long as the muscle cells. Cardiac are very, very short and they
67:41 connected in the end and they actually . So, you can see
67:44 like this cell right here, you see it has multiple branches to
67:48 T tubules are a little bit Um, they actually form die ads
67:53 of triads. So, the Circle in particular doesn't have the feet the
67:57 way. So that's why they're die um smaller circle plans were particularly because
68:02 are dependent upon the calcium outside the , not just calcium inside the
68:06 All right. And lots of lots mitochondria because yeah, also they're interconnected
68:12 one another. Be a gap So that when you contract one
68:16 you're gonna be contracting all the All right. So, the potential
68:20 from cell to cell to cell. , we're gonna talk about cardiac
68:24 After the test, when we go the cardiovascular system, we're gonna see
68:28 all this stuff adds up. But just some slight differences, but behaviorally
68:33 , very similar similar to the skeletal . This is just showing you
68:38 Oh yeah, calcium. It's calcium the same thing. Just coming from
68:41 outside the cell. So when I to pump it out what I use
68:45 on the surface of the cells. muscle is the weird one. All
68:51 . So what we have here is have cells that are arranged in Cincy
68:57 . Since issue being cells that are with other cells. We can fall
69:01 one of two categories. It's either be multi unit or single unit.
69:04 I saw one person to email me question about this. And so I
69:08 answer because I wanted to just answer when you're dealing with multi unit,
69:12 you have here are individual cells that innovated individually. So you can see
69:18 I have many units. That's why called multi unit. When you're dealing
69:22 single units you have multiple cells innovated one neuron. And really it's not
69:29 even innovated. What what you can here is that the motor fiber basically
69:35 above and over the cells and it along its length instead of a synaptic
69:41 . It has a series of bulges very costly. And it's from these
69:44 costs that releases a neurotransmitter. And kind of washes over the cell.
69:49 that's what it's kind of trying to you is like look see there's very
69:52 along the length, right along there that's what allows it to release the
69:57 . So this acts as a unit single unit. Hence the single unit
70:02 smooth muscle. So multi unit has units individual cells acting independently single unit
70:09 as one group within the single You can have self excitable cells.
70:14 will see those in cardiac as But I didn't want to deal with
70:16 right now. So these actually are that are deep polarizing at a regular
70:21 and then they can cause independent of of the nervous system to cause the
70:27 sense Isham to de polarize into This is what this is trying to
70:33 you is like see here we've got potentials and then if I get up
70:37 threshold I get a series of action which will result in contraction. This
70:40 another type where you're like I'm slowly polarizing. Reach threshold to get an
70:46 potential, slowly polarizing. So these just two different types of mechanisms showing
70:51 you can have self excitable cells resulting action potentials independent of the central nervous
71:00 . Just another picture. So how I doing now? nine minutes.
71:07 see. And how many slides I like three. four. Oh my
71:11 ! I better stop talking then. good lord. They just like multiply
71:16 rabbits. Alright, structurally. very different. Right. No,
71:23 . Here's the same proteins that are Z lines are found in the smooth
71:28 but they create a different structure called a dense body. And so you
71:33 see here it kind of looks like you if you've ever been watched enough
71:37 or if you've cooked enough, you how to bind up meat. You
71:40 like a ham. That's kind of this is like. So you can
71:44 it's basically a bunch of cross fibers create this lattice work and each of
71:49 points of crossing. That's where those bodies are. So, when a
71:53 occurs, you're pulling towards the dense , Right? But if you're basically
71:57 lattice, that means you're pulling them four different directions. So you can
72:01 what happens when that smooth muscle It looks like a hand. That's
72:04 of squeeze through. All right here, we're going to use a
72:10 system. We have thick filaments, have thin filaments. There's no
72:13 If I have no troponin, that I'm not really pulling things out of
72:16 way the same way. All I have intermediate filaments that kind of
72:20 structure here. Now there are two here that inhibit the activity of mice
72:27 cal opponent and Desmond. And what job is is in essence is to
72:34 the the the activity of the interaction the medicine and the acting. All
72:39 , So, that's that's really what do. So, we don't need
72:42 troponin. We have these other molecules . And what I want to show
72:47 here is I think. Let me double check. Yeah. Okay,
72:51 this is just trying to show you in essence we're still using calcium.
72:57 , so calcium is flowing out and is getting into this area but instead
73:02 the calcium binding to Troponin which doesn't , it has to be doing something
73:07 and that's something different that it does it works through a signaling cascade.
73:13 uses cal module in So remember good can imagine it popped up a couple
73:18 days ago. Alright, so here is, calcium binds to and activates
73:21 module in. What cal Madeline does three different things. First off it
73:26 up to the light chain or not like binds up to a light
73:29 kindness. And so remember we said the hinge portion has a light
73:33 So what we're doing is we're activating keenness that activates that region.
73:40 so that's the first thing that binds and activates mice and light chain myosin
73:45 chain kina activates myosin light chain basically increases a TPS activity. So what
73:51 a TPS do in skeletal muscle? the A. T. P.
73:56 that we could get the head to and create the contraction. So calcium
74:03 a contraction through this pathway. It activates a cow model in kenya as
74:09 which phosphor relates are cal opponent. did cal opponent do? Sorry,
74:14 back to slides it's an inhibitor. what we're doing is we're blocking the
74:21 were inhibiting the inhibitor. Right. so when I have two negatives that
74:25 in a positive and everything is hunky and the system moves forward. And
74:29 other thing it does is it actually to and inhibits cal opponent in and
74:32 itself. So calcium does a lot these cells. And instead of going
74:40 that troponin pathway where you have all machinery in place, we're going through
74:45 cascade that's independent and this is why a weird one. Right? All
74:51 same things happen calcium gets released. still get a muscle contraction. It's
74:55 the steps in the middle that are . Right? So here calcium isn't
75:00 to proponent inviting the cal margin which myosin light chain which activates the
75:06 T. P. A. Which causes the contraction. All
75:10 It's blocking the inhibitor. And I that's what all this is trying to
75:14 is just show you the differences between three things. Was that the last
75:19 ? See I told you I could it done. Yeah. Thank
75:23 Yeah, you should see there are when I talk like a million
75:26 All right, before he goes running of here. I mean are there
75:29 questions about this? And I saw hands. Yeah. Okay. About
75:37 the calibration. Did we start that ? Damn it. Alright. So
75:41 regard to the calibration, I thought changed the date because usually what we
75:46 is it's like we have like a to get the paper done. But
75:49 some reason I don't know how when looked at the calendar, we had
75:52 three weeks so I'm gonna move that . So if you read that paper
75:55 the calibration, just hold on to thoughts, we'll come back to it
75:59 the test. I don't want I didn't want you to deal with
76:01 before the test, but apparently my is in other places, so.
76:08 ? Oh yeah. Just no Vegas no Vegas. Uh Hold on.
76:17 got his in
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