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BIOL 3324 Human Physiology - 3324_lecture11_1005
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00:00 100. Mhm. Mhm. All . You guys it is time I'm
00:12 hit a timer for five minutes. what I'm gonna do here is we're
00:17 to spend about five minutes. exactly. five minutes. That's less
00:22 five minutes talking about the calibration, paper that you guys are.
00:27 if we're gonna keep this really, simple, I want you to tell
00:29 what your thoughts were of that Just spit them out. Don't don't
00:34 shy. Just I didn't think it that bad? Atrocious. Simple,
00:45 . What's that? Too much or enough? I couldn't hear you too
00:52 . Paragraphs were incredibly short, complicated things, context because Okay,
01:05 , I'm getting this. Let me some over here. What feedback?
01:09 , sir, tenses were wrong. . Okay. So, we're getting
01:16 good sense that when you read the , when you were when you were
01:20 two thirds of the way through the , Were you angry or happy?
01:25 ? Okay. So by the end the paper I'm looking you're like,
01:29 wouldn't find the guy and punch Yeah. Why are you wasting my
01:33 ? Right. All right. at the end of the paper,
01:36 it was time for you to grade or as you're grading, how did
01:39 grade the paper? You you great badly. Too nice to nice to
01:49 . And you found that when you your calibration score? It was
01:53 really bad. Okay. All What you're finding out is that your
02:00 don't know how to Right now. you all of you know how to
02:03 , but you're gonna find out your don't know that. All right.
02:07 right. No. So, what was was that was actually an example
02:11 a bad paper. All right. what's going to happen is you're gonna
02:15 across a paper like that. You actually produce a paper like that.
02:18 right. Now, remember, the of the paper assignment in the peer
02:22 assignment is to learn how to write to learn how to how to to
02:27 at a paper and determine whether or it's good writing in other words.
02:31 trying to see how to communicate and trying to inform the person who's trying
02:34 communicate whether or not they're communicating All right. So, if you
02:38 yourself with a score calibration score, was way, way off. Then
02:43 you're doing is you're being too nice you're not helping out that writer.
02:48 . What you're doing is like, just gonna I'm making some assumptions
02:51 So, again, this paper like or five years old. Oh,
02:58 english is obviously not their first So, I'm I can't possibly count
03:03 wrong. All right. That's It might have been english as a
03:08 language student. Right? But how they going to learn how to write
03:11 english as a first language If you sit there and go look um your
03:16 languages off your your tenses are Right? You're not using the proper
03:21 structure. All right. Now, doesn't mean you have to be a
03:25 . Nazi, good news. You have to correct anybody's paper. There's
03:28 of you are like, I've got correct the paper. You don't have
03:31 do that. But the idea here you're going to help them because
03:35 we have a first draft and then have a second draft, right?
03:40 final draft. And so by speaking to the writer, what you're gonna
03:46 is you're going to allow them to where the flaws are so that they
03:49 correct them. If there's a flaw your paper, that doesn't mean you're
03:52 terrible person. I write terrible crap the time. I get up here
03:56 make mistakes all the time. You me make mistakes. Thank thank you
04:00 affirming me. Right? But here I should check to see if I'm
04:05 right. The idea here is no, no, no. We
04:08 want you to be better. And we you don't go into it with
04:12 idea that, oh, I've got be the bleeding heart for this person
04:16 that their feelings aren't hurt. Doesn't how good or how bad you grade
04:21 , They're being judged. Their feelings going to get hurt. Right?
04:25 trust me, each one of you really a subset of you are going
04:29 email me and say it's not fair this guy said or this this reviewer
04:33 about me. I've already heard What I'm one of these small
04:39 Not fair. They didn't do. like, no, no,
04:41 no. It's entirely fair because your does matter right? Some of you
04:46 going to be a little tougher than . But what we need to do
04:49 we need to kind of come into agreement and kind of say we recognize
04:52 bad is, we recognize what good and we recognize what kind of sits
04:56 between there. All right. So what this calibration is about. So
05:00 we in agreement that this person was ? Is it okay to give them
05:05 bad grades. Now, again, bad grade is going to be kind
05:09 subjective, right? The worst you do if you turn anything in,
05:13 you like literally if you turn in title and a couple of sentences,
05:16 getting a 50 that's like the worst can do. You see of since
05:20 , oh man, maybe this assignment as horrible and terrible as I thought
05:23 was right. Uh, there's my going, nope. All right.
05:28 the worst that can happen. All . Now, some of you are
05:32 to want to say, everyone did and they want to get perfect
05:35 reserve those perfect scores for perfect Papers, do you think are going
05:40 come out of this class. That's . Big fat goose sake. All
05:44 . Now, there's gonna be stuff see that. Yeah, that was
05:46 of good. I really like So again, you can give good
05:50 . Don't don't hold back if something really good, but don't just go
05:53 all the way down because it's not to happen. I mean there's no
05:58 writer. All right. So let just give you a sense of what
06:02 graded this paper as I have to to the old folder. All
06:05 So this first paper I had given a really good score on their
06:10 I thought their title is just Give him five. All right.
06:15 then it was (111) 111 111 1111111112 maybe a three because they didn't include
06:25 and I was going to kill them of that gave him three for the
06:28 is not used 11 A two and one that comes out to as an
06:34 Um 32 points out of a possible 10 or 54. So that was
06:39 crappy paper. All right. what would they have done? They've
06:43 to make corrections come back and probably forth forward and average to a better
06:49 average to better, Does that make ? And that's not a bad
06:53 Right. We want to see So don't be afraid to do
06:58 Now thursday we have a test. not excited about the test.
07:05 It means the classes halfway over. that's C. A. Which means
07:11 halfway to christmas or christmas break. you want to celebrate. All
07:16 So so you know on thursday we an exam and then on that Tuesday
07:22 week you have your second calibration now the heart paper? I mean apart
07:28 irritating you, Was it hard? mean to take a lot of time
07:31 effort. It did well. I just to grind through it.
07:37 So imagine I just want you to this for a second. I know
07:40 going over my five minutes. Imagine professor at T. A. Reading
07:45 of papers like that. Okay. . It's it all of a sudden
07:50 start understanding why we're grumpy people. ? But in the peer review
07:55 if five people can come to an , remember everything is blind. You
07:59 know who your reviewers are. You know who you're reviewing unless you actually
08:02 your name on a paper which please . Right? You will actually see
08:07 a lot of commonality in your So watch for those. Okay.
08:11 next week that's our 2nd 1. and since I know you're gonna ask
08:15 . How are we graded on How does this count? What does
08:17 mean? All this stuff you have calibrations. I take the two top
08:21 and I average them. All right whatever you have from those two
08:26 If it's lower than in the 80 you're going to start getting a penalty
08:30 your paper before you freak out. that penalty looks like basically what I'm
08:34 . Can you be within 20% of I think these grades are? So
08:39 it's a really, really wide margin . So let's say you get like
08:42 75 average then you'll have 750.1 points .05 points taken off your paper so
08:50 really matter. Okay. What if 60 points where 70 points away?
08:55 like double that point to and then kind of goes up. But if
08:58 stop start blowing them off then it counting against you. So do
09:04 It's really not much of a penalty you never ever calibrate or you don't
09:08 them. That's really the idea. . You're like, I don't like
09:15 . Trust me. It's not that of deal. Just do the
09:18 Try to do your best. That's why you get two shots,
09:22 shots. So if you like really up you can bring it up.
09:26 . Is that all right? Yes, yes, we are
09:32 We are live and the thing is back and forth. So what happened
09:38 thursday? We actually recorded the whole . But then I got excited talking
09:41 people and then I click the the little X on the top corner
09:44 of actually pressing the save button. all that recording disappeared. That's why
09:48 don't have a recording. All couple of things we're going to cover
09:53 . All right. First off, gonna look at circuits. All
09:56 We're gonna talk really really fast. . We're gonna look at uh mapping
09:59 the brain. All right. how does the brain map information?
10:03 ? We're going to jump over to . We're gonna talk about skeletal
10:07 And then we're going to try to cardiac muscles and smooth muscles.
10:10 I've already submitted all the test stuff to caSA. So everything we're supposed
10:14 talk about today is already on the . All right. Good news.
10:18 not hard bad news. It's still we have to cover. So,
10:22 start circuits, circuits are easy. , circuits are basically synaptic lee,
10:29 networks of neurons. You see it there on the slide. It must
10:32 true. Okay. Now circuits can both local or they can be um
10:40 a short region of the brain. right. So, when we're talking
10:44 circuits, we're gonna be focusing here these local circuits. And so they
10:47 have the same. Yes, Right. No, no. That
10:55 what we went through. Yeah. , when I asked how did you
10:58 like the paper that was us going basically the paper. Yeah. When
11:03 guys say it sucked. I don't we need to elaborate on that.
11:07 mean, we could And how did suck. I mean, well you
11:10 did so right. But we could at all the different parts of But
11:14 aspect of this paper really sucked. . So All right. So when
11:20 look at a circuit, remember it's to have an input. It's gonna
11:22 outputs. And there's gonna be this . And really what you're trying to
11:26 with is you're trying to uh take information and integrated so that you can
11:31 some sort of response. So, idea is information comes in, you
11:34 that information goes out. All And there are things called microcircuits,
11:38 we're not going to deal with. so, what I want to show
11:41 here is basically what a local circuit like. And so this is an
11:44 of the local circuit. All You'll see it's over here as well
11:48 board and over there on the Right. So what do you have
11:50 have input? So that would be information coming in in this particular
11:55 it sensory information coming in and then might actually have descending axons coming out
12:01 also are not interfere with. But interconnect. And join with inter neurons
12:07 are going to be in the process processing processing takes place at the inter
12:11 . So they take all that whatever it happens to be. And
12:15 what you're gonna do is going to some sort of output which is going
12:17 be a motor neuron and a motor . All right. Simple example of
12:22 local circuit. All right. What in the brain? Well, brain
12:27 kind of the same thing. We input coming in. So these would
12:29 a sin. The axons might be neurons coming from other areas but basically
12:34 other adjacent murals neural circuits. But comes in. You have inter neurons
12:40 process and information leaves to be able projection fibers to some other point in
12:44 brain or some point down in the cord so on and so forth.
12:48 what do we have input processing Very very basic. Okay, so
12:54 reflex arc is an example of a circuit. Here's our reflex arc.
13:00 right. What do we have? have an input that comes in?
13:04 have processing at the inter neurons and we have an output via motor
13:09 Now, just so that you the spinal cord is responsible for the
13:14 part for all your basic reflexes. that mean there are no reflexes up
13:18 the brain? No, there are further up. But we want to
13:22 on those basic reflex. What is reflex? It's a song by
13:27 Duran from the mid 80s but it's a rapid pre programmed involuntary reaction.
13:34 muscles or gland to a stimulus. right. That's the strict definition.
13:40 , so these words all have So, what is the stimulus?
13:42 just sensory input that initiates the It's a rapid response. Very few
13:47 are involved. You can get you use the model as an example.
13:50 programmed. You will get the same every single solitary time. Have you
13:54 done that to yourselves? It's a of fun. I mean, you
13:58 get a hammer or you can use hands. Okay? So all you
14:00 do is cross your leg and just there and just hit that tendon over
14:04 over again. And you're going to because you're golgi tendon. It's basically
14:10 you'll always get the same response. can't stop it. All right.
14:13 involuntary. You don't consciously do it you can't suppress it. So,
14:19 what reflexes. Now. There are types of reflexes. There are basic
14:23 . These are the built in Have you ever smiled at a
14:26 Look at a cute little baby. you get in there. You was
14:29 baby. Due smiles right, back at you. I'm going to eat
14:35 all up. Right. You don't what you're saying. He's just mimicking
14:41 . Right? That's a baby's innate . But there's also conditioned reflexes.
14:47 right. When you're in high the bell would ring. What would
14:49 mean? Get up pack my bags to the next class? All
14:54 You all learned about Pavlov? All . You're basically Pavlov's dog. The
14:59 is not they're not bringing the bell dinner there ringing the bell. So
15:02 can go to your next torture I mean next educational experience.
15:08 So, you can have a conditioned as well. All right. That's
15:12 a learned practiced reflex. Here's an one for you were talking about this
15:18 before everyone came to class. You're along the street light turns yellow.
15:22 do you do? You speed It's a conditioned reflex like yellow light
15:27 I've got to go faster. All , So, this is the basic
15:33 reflex art again, drawn on either of the board, and you'll notice
15:37 this is a pattern that we've seen and over as we've talked about the
15:41 system. All right. And this how it works. We have a
15:45 that responds or receives the stimulus, signal that it produced. An action
15:50 travels up the axon via the a pathway. We use a parent because
15:56 fair and different sound an awful lot when you use it with the texas
16:00 , right? Afrin and different. , so a favorite pathway. Then
16:07 going to terminate onto the interneuron where get integration. In other words,
16:12 it results in a response that travels the accent of the motor neuron,
16:17 would be the different pathway and then effect er is the muscle or the
16:22 downstream where you get the response. right. So, you stab yourself
16:26 the electric nail, you're gonna move hand away if it happens on the
16:31 side. Where in other words a in the effect on the same side
16:35 that is called an IFC lateral spinal a contra lateral reflexes when the effect
16:40 the receptor on are on opposite Okay, I'm going to show you
16:44 example of that because you're probably thinking can't picture this right? If I
16:49 my hand, I'm not gonna move hand away. Okay, but you
16:53 see an example of a contra lateral . So those are the five set
16:56 . A different path. The integration and then effect or now your reflexes
17:02 either going to mono synaptic or poly . If it's basically a simple uh
17:08 pathway, there's no interneuron and there's one motor neuron, that's only one
17:13 hints. Mono synaptic. The example this is a simple reflex. Like
17:18 stretch reflex. Right? The uh we see. Probably synaptic. What
17:23 you have? You have to? if you have two or more,
17:26 would be probably synaptic. The example the withdrawal reflex again. Ever done
17:30 in the lab stick your hand over Bunsen burner good. You guys are
17:35 lap safety protocols. Yeah, don't that. That's bad. All right
17:41 the interneuron is processing information you can have more than one neuron feeding
17:47 So the stretch reflex we've already looked . And what you can see here
17:52 there It is. Here's the mono there's one and then you can see
17:55 coming back and then here this isn't is not contra lateral, this is
18:01 its lateral. But what we're doing we're inhibiting over here. And so
18:04 would be policy synaptic. But this the actual reflex arc right? There
18:08 the one working on that individual All right. Here's the gold you
18:13 . And again, it's just showing that it's uh polly synaptic.
18:18 So it's basically says the same thing the other slide told you.
18:21 withdraw affliction is the example of both IPs lateral and contra lateral.
18:28 So here we are standing on the snail shell. Alright. You step
18:32 that. What are you gonna You step on something sharp? What
18:35 you do you lift up your Right, so there's your reflex.
18:39 you have to think about it? . So, it's all taking place
18:44 up here at the level of the cord. All right. But if
18:47 lift my foot up without putting my foot down, I'm gonna follow my
18:51 all right. So the contra lateral of that reflex is to send a
18:55 to push the other foot down. right, So there's the contra
19:00 So its withdrawal and inflection is on other side. All right.
19:06 here's the cool one. All It's the same thing withdraw affliction If
19:10 is attacking you, this is the and grabs your arm and pulls you
19:16 other side, naturally pushes away. withdrawal reflection. All right. Uh
19:23 . No. So, for if I grab you to pull you
19:26 me and you don't want to come reflexes to push with the opposite
19:31 So it's a natural reflex withdrawal Alright, so you extend while you're
19:38 pulling away. So crossed extensive All right. Ever watched catwalk
19:53 So cool. Right? You scare ? They still walking like Yeah,
19:58 not scared actually. I'm not a fan of cats, but I just
20:02 way they walk is cool. They're like not going to put up with
20:05 of your nonsense and when you close eyes and when rip out your
20:10 Yeah. Yeah. Cats just tolerate food in their house. All
20:16 What I wanted to show you why have this cat here is the
20:19 P G C P G. S basically the rhythmic moves are responsible for
20:23 rhythmic movements that we have in our . And so here's an example of
20:26 walking. If you ever watched a walk. Not just a cat,
20:29 we do the same thing that a does. Do. We walk like
20:34 . No. Right. When we this foot goes forward, this arm
20:38 forward. We tend to walk like . You're all going to leave the
20:42 . Gonna start watching people walk. right and it's basically it's a combination
20:48 reflexive and voluntary movement that are taking . Chewing is the same thing when
20:52 chewing gum right now. I mean when you ask a question no one
20:55 to admit it because it's like for you've been trained not to chew gum
20:59 class right? But anyone know okay people see now they're admitting it
21:05 Oh you're in trouble, spit it , spit it out, spit it
21:08 . Right when you chew. What ? Are you thinking about showing?
21:12 it's like choco choco choco choco bored that side. Stick to the other
21:18 . You don't have to think about right? It's a natural response because
21:21 happens is is you create a pattern being generated that basically as I create
21:28 , I'm gonna open my mouth, pressure, open my mouth over and
21:31 and over again. That's the All right now what this is is
21:37 a cluster of neurons that are creating cyclical time signals to create this
21:44 All right. And so this is in the brain stem and the and
21:46 higher cortex. You do not need know the structure of the picture.
21:50 about to show you. This is to demonstrate the complexity of the
21:55 P. G. S. See got here we got two neurons that
22:01 descending along two pathways which have inhibitory and excitatory neurons in between them.
22:06 , as one pathways excited inhibits the and then it creates a reciprocal cycle
22:12 basically inhibits the first pathway and excites 2nd 1. So what you do
22:16 you end up with these opposing series action potentials that look a lot like
22:24 . Okay. And that's why you . Well, sorry, I can't
22:28 it now. It looks weird when walk like this. Right? It
22:32 be okay. That's right, opposing . All right. This is what
22:42 referred to as the half center model it's just one example of the type
22:47 patterns that are produced through a CPG what they picture these neurons to look
22:54 . Alright. Or these circuits look . So, I've told you,
23:01 think I've told you over and over . The brain is highly organized,
23:06 I? Said that. Okay. all right. It's not just a
23:09 of wires going all sorts of The way information is processed where it
23:14 in the brain and how it goes the to the brain all of it
23:17 the way has an incredible amount of to it. And what we refer
23:22 the area in the central nervous system the cortex where information is processed actually
23:28 organization to it. And what we is we call this neural mapping,
23:32 other words, there are parts of brain where you can point to it
23:34 say this is where blank occurs. is where I recognize uh touching my
23:40 . All right. This is the where the motor neurons originate to cause
23:44 toes to wiggle that sort of And this is true for all sorts
23:48 places now. In terms of information in, This is what all this
23:52 to, right, is that there different modalities, so different things that
23:58 receive sensory input from that are found different places and mapped in different
24:03 So visual and somatosensory. Use spatial . In other words, the position
24:10 the stimulus within the context of whatever map is. Alright, auditory.
24:15 use frequency maps. In other there's a order in terms of the
24:19 in which um stimulation is curtain. you can map parts of the brain
24:23 okay over here are high notes. your low notes. All right.
24:27 you look at the olfactory gustatory they're really complex here. We're dealing
24:31 chemical shapes. So you'd be like here, this is where we have
24:35 that are like acetate and over here things that are like, I don't
24:39 , make up some of some other molecule and everything in between. And
24:44 when you stimulate those different parts of brain, your brain then says,
24:49 , this is what I was stimulated . All right. That's how it
24:55 the unique things that you're looking All right. What I want to
24:59 to do is I'm gonna try to you what these maps look like
25:02 Before we move forward, I want to understand what I have. We're
25:05 here. Is that neural maps are precise there fuzzy, right?
25:10 Kind of like 20th century are like century maps of a coast,
25:15 They lack the accuracy of you I don't know, google maps,
25:23 images, Right. It's some guy a pin going and it looks kind
25:27 like this. Alright. That's what maps are. And that means they're
25:31 plastic meaning they can change depending upon the brain uses that part of the
25:39 mean, of of that map for area. All right. So,
25:44 we're looking at here is the somatosensory and the motor cortex. So one
25:48 input, one is output. All . And if you look at this
25:52 up here, this would be status down here is motor. It's what
25:56 refer to as the somatosensory homunculus and motor. Homunculus. Anyone here not
26:00 human Oculus is Okay. What's the ? All right. So that's that's
26:14 . But I mean, you're you're the right track. You're trying to
26:16 very specific. Homunculus is simply Like Alright, it's not quite
26:22 but sure. Does have a lot features like a human, Right?
26:26 most of you are sitting there okay. I saw full metal
26:29 I know that my uncle uncle. , I know, I know what
26:33 don't know, I know exactly what guys are thinking and the rest of
26:36 are saying. I don't know what know what you're talking about guys need
26:39 get out more. All right. right, but can you see
26:42 Can you see the body up Right. There's a body shape over
26:46 . Here's a face shape. There's mouth shape so and so forth.
26:48 all this stuff that belongs to human there? It's just not quite
26:53 is it? Alright? But what is showing you is where within the
26:58 we receive that stimuli. So if foot is being touched then it would
27:04 this portion of the cortex that is being stimulated within that region. That
27:10 . Alright, suppose Central Gyrus, would be pre Central Gyrus.
27:14 so that specific location. All Now, the other thing you'll notice
27:19 is that different things have different So for example the foot and the
27:23 are pretty big. The faces huge so are the lips. Why?
27:28 , Well, the reason is that are areas where we actually contact the
27:33 environment most frequently and probably are getting most input so that we can understand
27:38 environment. Right. Hands we touch a lot. Not anymore. But
27:44 mean at one point did you touch all the time. Yeah.
27:49 What about your lips? What do touch a lot? If you say
27:53 people's lips we'll need to have a But but it's actually food. That's
27:59 first place where you know, we're note where danger is coming from for
28:05 internal organs. Right? So if if you're like, like me and
28:10 like spicy food, your lips are to start burning and it's kind of
28:13 you, oh, guess what you're for a long night, right?
28:18 a bad example. But you can the same sort of thing. Look
28:21 the tongue, tongue is huge as . All right. But you can
28:24 the areas where, you know, to get a lot of sensory input
28:28 my elbows. Not really. So a very very small area.
28:31 ma'am, know that. Yes, where the processing is taking place.
28:39 . And so what this is showing is where that signal goes, so
28:42 its process so that we can understand . And so the human Oculus,
28:45 terms of the map, shows you much sensory input, how much processing
28:50 actually being done in that area. , it's a size thing,
28:55 It's relative to its size. It's shown on the map or on the
28:58 Oculus. Alright. And then down , here's the motor and again,
29:02 doing the kind of the same thing the hand is huge. And you
29:05 imagine why. Right? I mean are creatures that use our four limbs
29:10 manipulate our environment. And so we're , very dexterous when it comes to
29:14 hands and our fingers. Right? so sending motor signals and motor processing
29:19 going to take quite a bit of cortex in order for that to
29:23 Right? What if I lose my ? Well, I'm not going to
29:27 my hands so this area is gonna shrinking down and the areas that make
29:31 for it are going to actually kind grow. This is a plasticity that
29:34 described. Yes ma'am. Alright, phantom itch is a good question.
29:40 ? You've heard about phantom itch? lose a limb and you get that
29:42 strange sensation right? It's like there's itch that I feel over here but
29:47 have no hands. So why? remember the neurons from the somatosensory cortex
29:53 ? Are still being fed by nerves are at the end of that
29:57 Well, where do those nerves map back to their location up here?
30:02 don't re map to the end of stump there still mapped a hand that
30:06 exist. Yeah. So, so if the shrinking would be here
30:14 the case of the motor, if damage those neurons in other words have
30:18 just excise then the somatosensory cortex would because I'm no longer having neurons feeding
30:24 particular location. But the phantom itch from. Is that neuron is still
30:30 as if it were receiving information and brain perceives that the hand is still
30:36 . Which is why the ends of fingers still itch that don't into my
30:39 that don't exist. Still itch. makes sense. That makes sense over
30:43 . Kind of Yeah. Okay, this is the retina topic map.
30:49 so what you can do is take retina, flatten it out and basically
30:52 just figure it as a as a that light hits, right. And
30:57 information is sent to very specific regions the visual cortex in the back of
31:02 brain. So this kind of shows are binocular vision how Yeah, the
31:07 vision and then binocular vision on the and how each eye is responsible for
31:12 of that receptive field and that information broken down and sent to the visual
31:18 . All right. And then this just again trying to show it from
31:22 different angle. So you can see if you divide that up where within
31:26 visual cortex it goes. Now I'm to do is just keep this
31:29 really simple, right? If you the I this stuff will take you
31:34 to understand. I mean there are continue to a website that literally has
31:39 and pages and pages on trying to this and I sat there I threw
31:43 hands up because most complex thing is . You know, they call the
31:47 that process color, they call them . Once you start calling an area
31:50 the brain of blob as far as concerned, you're done because it just
31:55 make sense right now. What's the way that the brain works and
32:00 way that the I works is that that you're looking at is not a
32:04 , what it does is it takes visual input and breaks it down into
32:08 components so its color movement and form each of those things are sent to
32:14 parts of the brain process so that understand something is moving, say in
32:18 explain Oh, I also have an that processes information moving in the wide
32:25 . And then I'm looking at areas density or color and stuff like
32:29 All this stuff is processed independently and is brought back together so that you
32:32 and you're going, okay, now get it. All right, So
32:37 mapped, sent to specific areas and brought back together. It's not like
32:45 . Mhm. On the left right, on the right, So
32:51 ? One? Harvest snipped. You're , right. So, you're you're
32:59 about something is really complex. So a left and right brain that can
33:03 independent of itself and one I don't time to get into it and to
33:07 don't really understand it all that. rather than saying something wrong and and
33:13 falling into that pitfall of old he's just an idiot. And I
33:16 believe they gave him a platform. just going to stay away from
33:19 Mhm. Right. Because it's I mean there's like I'm not gonna
33:22 not gonna remember everything but yeah, there's a the left and right side
33:27 the brain can when you sever the closing can where they are completely unaware
33:32 the other side. It's really Alright. The ear we don't spend
33:39 lot of time talking about the we talk about the mechanism but the
33:43 of your look at the person next you, just kind of look at
33:46 real quick. Yeah. Is it looking if you look at someone you
33:50 at the shape is like you it's . It's funny it's actually designed or
33:57 so that sound actually is directed to auditory canal. All right,
34:04 Yes. Weird. Certainly. But , very functional. All right.
34:09 so there are actual two planes that getting sound from. So when you're
34:14 with the vertical plane. So where the sound coming from? It's coming
34:17 from high basically how that sound is off the different structures of the outer
34:24 tells your brain from where the sound coming from. So it's not quite
34:29 echo but there is a timing issue one side. It says if it
34:33 this way and I get to these bounces, it tells me the
34:37 horizontal plane, a little bit more in both ears, high frequency sounds
34:42 picked up by both ears, They both ears at the same
34:47 All right. So you can't distinguish , oh, it's coming from this
34:51 because it hits this one first present they're hitting but roughly at the same
34:54 . All right. But you get intensities, so really loud over
34:59 a little bit softer over here. must be coming from this direction.
35:02 you don't perceive that but your brain remember amplitude is something that you're perceiving
35:08 then low notes. Well that's going be slow. So you hit one
35:11 first and then you hit the other second. So it knows oh,
35:14 coming from this side, not that . And those two things kind of
35:18 your brain a sense of why? here's the cool part ready if you're
35:24 Do I have any engineers in And every now and then I get
35:28 one biomedical engineer engineers love this slide this is what the circuit looks
35:34 All right. It's very, very circuit. All right. What we
35:37 and this is where I'm trying to in on is here, this is
35:39 delay line and a coincident detector. right, So here's your two sides
35:44 here on the left here, you hear the sound hitting this first hitting
35:47 second. So you have a nucleus you have these coincidence detectors And so
35:54 the line comes in and so when two sounds stimulate the same neuron at
35:59 same time, then that's an indicator distance of which side is coming
36:06 So if it's out of sync, brain just ignores the signal. But
36:09 it's in sync, it's telling you is where the distance it's coming
36:13 it's because of the delay line. of these is longer than the
36:17 And so when they synch up, telling you exactly which side is coming
36:24 . Well, how's it mapped? of a piano? All right.
36:28 when you get up to the uh auditory cortex, this is not the
36:33 cortex would be a pyre. But in the auditory cortex when you look
36:37 the cortex, it's like a piano one end. You have high notes
36:40 the other end. You have low . Right? And so basically it's
36:44 like the cochlear wherever you stimulate along cochlear. So over here would be
36:48 high notes right way down at the end where those low notes. And
36:51 wherever that nerve is, it's going to the auditory cortex in that specific
36:56 , say I'm stimulating right here. it's a high note now to make
37:01 really, really confusing or maybe So to understand this, let's pretend
37:05 Frankenstein not the monster. That's Frankenstein's , I'm talking to the doctor,
37:11 know, he was really doing some stuff with brains until he got an
37:14 brain and stuck it into a That wasn't right. Right. You
37:18 didn't read Frankenstein, did you? . Okay. Dr Frankenstein was a
37:28 biologist. That's what he was And he wanted to see if he
37:32 create life. All right. So manipulated things. All right.
37:37 if you could manipulate things, imagine in and clipping the neuron that goes
37:42 the high note in your ear and cochlea over to the high note in
37:46 auditory cortex. You clip that and clip below note and then you crisscross
37:52 like there were two wires. So of being straight that you flip
37:56 So now when you stimulate the high , you're perceiving low note. Do
38:01 understand organization Now? It's like a . One side is high, One
38:08 lo what's your cochlear like high versus . Just depends on where you're
38:12 That's how you perceive it sounds got doesn't make sense. Three people are
38:20 in the head the other, the of you are just sitting there.
38:23 . Get to muscles. Yes. . The point is in all of
38:36 is that the brain and these different cases. I guess that's the right
38:43 are organized just as the information is , right? If I'm touchy if
38:53 receiving somatosensory information from my hand, going to a specific price place in
38:57 brain so that I perceive that I'm touched on my hand, if I'm
39:06 a specific pitch, it's going to specific place in my brain. So
39:10 perceiving the pitch. All right. what I'm using here is perceive,
39:17 ? If I stimulate a portion of retina, I'm perceiving the where that
39:25 light is actually touching and relative to other points of light that are touching
39:29 retina. Right? Have you ever that light shadow? You can stare
39:35 the light and close your eyes and can still see the light. All
39:39 . Why? Well, you bleached portion of your eye and so you're
39:43 gonna perceive that shape until your brain no longer being stimulated by the neurons
39:49 are downstream of those photo receptor Okay, that's why it takes a
39:54 for for you to lose that, makes sense. You perceive it because
40:01 the part of the retina that was that got stimulated. Looks like I've
40:07 your I got your board. It's of those two. No questions.
40:17 , way over here. I'm Out in the corner of my
40:20 Yes, sir. Go ahead. . Don't want. I think that's
40:27 tumor. No, I'm sorry, just kidding. It's probably Ortho static
40:39 hypertension, basically, basically drop in pressure for a moment, basically causes
40:44 brain to respond a little wonky I'm not certain. I have no
40:49 . And if you're wondering I think a tumor that was from kindergarten
40:54 Arnold Schwarzenegger. He's a cop in kindergarten trying to do something stupid.
40:59 know, it's like a sitcom plot little kid. Every time he says
41:03 like I have a headache, a kid goes, it must be a
41:06 . He finally explodes. It's not tuba. Mhm. Mhm. You're
41:17 generation without a shared a culture. right, muscles. There's a muscles
41:28 be hard or easy, depending on you want to approach it. Do
41:30 want to approach it? Easy or ? Mhm, cowards. All
41:37 All right. No, I'm just . Alright, So, first
41:40 we need to understand what we're talking muscles. We're talking about a muscle
41:43 . For the most part, muscles a structure that's named so, like
41:49 up there. What is What is pointing to my pointing to? That's
41:52 bicep. Right. So, it's name muscle. That's basically a bunch
41:55 muscle fibers that have been wrapped and together and then wrapped again and wrapped
42:00 so that you create this name All right. And so the fast
42:04 are basically fibers that have been joined . Right? So, here's the
42:09 muscle cells that have been wrapped together form that fast cold. And you
42:13 a bunch of fast cars and wrap together. That's where you get the
42:16 muscle from. This is going to inside the muscle. All right.
42:20 is a side of skeleton that we're at here. All right.
42:24 we have names for the wrapping. a connective tissue. So, Epic
42:28 is the one that surrounds the whole . If you've ever had a skin
42:33 breast. Or if you've ever hunted skin an animal and you look at
42:35 animal, you'll see that all the looks like it's been encased in something
42:39 connective tissue. So, that's Museum. When you go down to
42:42 individual fast tickles, that's Paramecium. to be confused with para museums,
42:48 . Which are uni cellular organisms. ? All right. So don't don't
42:55 those two. And then the individual have their own connective tissue wrapping.
43:00 the purpose for that is to create environment that the action potentials are uh
43:06 to. Right? So, you want to stimulate one cell that automatically
43:09 other cells around it. You just to be able to stimulate the one
43:12 at a time, depending on what's structures, muscles are attached to bone
43:19 tendon. All right. So, , what's happening is when you do
43:22 muscle contraction, like the whole muscle , what you're doing is you're pulling
43:27 muscles the fibers themselves are contracting, on the tendon. The tendon pulls
43:31 a bone. So, the bone being moved because you're stretching or pulling
43:36 this tendon by the muscle. All . And it's these connective tissue layers
43:40 give rise to that. And then if you look at the whole
43:44 they have fascist. So muscles themselves deep fashion, superficial fashions. Just
43:49 , it's just wrapping what I wanna is like I said, I want
43:52 focus in on a single cell because understand the single cell works. You
43:56 how the whole muscle work. All . So, what we're looking at
44:00 is people first started studying mussels thought were special. So they started giving
44:04 of its special names. So the kolyma, simply the plasma membrane.
44:09 , the plasma Lemma sarcoma. That's special name. The site of plasma
44:12 called Sarka Plasm. Now it's not special except in the sense that it
44:18 some unique stuff in it. for example, there's lots of
44:21 Myoglobin is basically like hemoglobin is related hemoglobin. It binds up and holds
44:26 oxygen. Alright, so your muscles onto oxygen. Does that surprise you
44:30 the least? No. Okay. like a zones which is basically a
44:34 of like uh glycogen Granules. Does surprise you that your muscles storm sugars
44:40 its own use? No. lots and lots of mitochondria mitochondria do
44:49 of the cell. Yeah, we remember it batteries. Yeah. So
44:54 got powerhouse and sell you got oxygen power the cell. And you've got
44:57 to power the cell and you got do that. Right? So,
45:01 we have is we have a whole of mitochondria in there. And really
45:04 you look at the cell, if see lots of mitochondria, you gotta
45:06 ah ha lots of energy usage must doing something. So this is now
45:12 uh muscle cells are really uh a that is formed from many many tiny
45:19 blasts. So my blaster, the cells then they converge infused and they
45:24 these longer elongate structures. And so have multi nucleotide because they're no longer
45:29 Individual cells are now one big giant happy settle. All right, So
45:34 the multi new Clayton. Now, functional unit of the muscles called a
45:39 amir. And if you look at side of skeleton, right? So
45:43 is gonna be a kind of We're gonna know this for a
45:45 That side of skeleton has some unique . You've got these lines and the
45:51 and it's the striations that we first noticing under the microscope. And so
45:55 scientists sitting there was looking like, , we got a thick fat line
45:58 dark, a thin little line. then it was like, oh the
46:01 starts repeating itself. So where the didn't you know where there was no
46:06 , became a sark amir. And that was the functional unit because they
46:09 that if they stimulated things would And so I was like,
46:12 between these two points, that's the mirror. Now, those two points
46:17 called Z discs. All right, gonna look at a picture of this
46:20 just a moment. Now, remember looking at a muscle from this
46:24 Right. And so you're seeing a that looks like this That's going to
46:27 the Z disc. But if you to take a cross section through and
46:31 it, you'd actually see a structure proteins that are like a latticework.
46:37 right. So when you look at lines, just remember that is not
46:41 line. It's actually it's a it's mesh or a lattice of protein.
46:46 right. Now, when you grow you all grew right? You started
46:52 about this big and now you're as as you are. Right? So
46:56 muscles grew And so when your muscles , what you're doing is your adding
47:01 SAR compares to your muscle, your are not getting longer. Okay.
47:06 our cameras always stay in the same . You're just adding another unit on
47:10 . Okay. Maybe it's in the . I don't know where it's actually
47:13 added to be truthful. All So, we're going to focus in
47:19 this structure. All right. There's little things in there that you
47:22 we call this the triad. Cardiac have di ads So when you get
47:26 the cardiac muscles it's the same Except it's missing one of these
47:31 All right. So we have is have the trans verse to be also
47:34 tubules the abbreviation. So, see tiny dots over here. Those are
47:39 of the T tubules. So, this is the plasma membrane, the
47:42 tubules open up to the Plaza And then it's a tube that goes
47:45 the way through the Stellan opens up the other side. It's like a
47:48 . Okay. So that's how you think of it. T tubules like
47:52 . All right. So here it . Here's a T tube. You'll
47:55 like a tunnel going through the cell to the T tube. You'll is
47:59 this yellow structure. This is called Sarka plasma critical um which is modified
48:04 plasma critical. Um And nearest a tube you'll it widens out and gets
48:09 , really big. And so we to this as a sister anna.
48:13 right. So it's a Sarka plasma the terminal cistern. So, it's
48:17 part of the circle plasma particular um stands out and it's big and
48:21 All right. So the three things is the triad. Now, why
48:26 we care about all this stuff? , the saarc applies in particular.
48:30 job is to hold on to Okay. And so the purpose of
48:36 we're going to see is really really or important for the muscle contraction.
48:41 , the circle plasma particularly where we're get our calcium from. So we
48:45 calcium. There there are pumps. what they do is they pump in
48:48 . They hold on to calcium until comes along and says hey, time
48:52 release the calcium. All right. where did that signal come from?
48:56 , here is the neuromuscular junction. . This is literally just like an
49:01 B. C. D. So I have a slide. I'm
49:03 to point it out to you I'm going to say this is a
49:05 that has everything we just talked about . Okay, it's the easy
49:11 This is a neuromuscular junction. So as a motor neuron. Right down
49:14 is the motor in plate. We're a cd colon. C colon binds
49:18 the channels that channel opens up sodium into the cell. You produce an
49:23 plate potential which is really really it resulted in action potential. So
49:27 potential then travels along the length of cell. Anything so far. Anything
49:33 new interesting. Different than what we've learned. No. Very good.
49:37 . So here we do exponential traveling . So potassium we're moving out of
49:42 cell and then here we come along here is our T tubules. All
49:46 , so the expectations are going to going. But because this is part
49:49 the outside of the cell now, , it's just a tube then what
49:53 ? The exponential travels down the tube as it travels along the surface and
49:58 we have receptors that are closely associated the T tube, you'll All
50:05 They're called foot proteins are gonna look him on the next line. That
50:08 potential causes the opening of those channels causes calcium to leave the Sarka plasma
50:17 . Yes I think of it as wave. Right? So if you
50:20 a big old rock and you have wave the wave goes around the rock
50:23 ? And so this is kind of same thing the way it's gonna go
50:25 the tube, it's also going to going along the surface. That's a
50:29 question because sometimes it's not quite so like well when they just go down
50:32 tube well it's two dimensional. So but it keeps going all right.
50:39 this is that same slide we just at but we're looking a little bit
50:43 here at this relationship. So here can see these are calcium channels called
50:49 channels are G. D. P receptors And their closely associated with
50:53 channels that are are found here in circle. Plants are particularly these are
50:58 Ryan iodine receptors. So you'll usually R. Y. R. And
51:02 . H. P. So these in response to an action potential when
51:09 open because of their close association with riots nadine receptors. The Ryan nadine
51:15 when those D. Hp receptors open rioting receptors open and that causes calcium
51:20 flood out into the cytoplasm of the cell so far. You with me
51:26 open one causes the opening of the causes calcium to leak out.
51:32 so step one action potential in the neuron. Step to action potential in
51:37 skeletal muscle. Step three X potential down the down through the T
51:42 stimulates the DHB receptor, which stimulates iodine receptor Brianna diamond Ryan a dime
51:49 . Because calcium to flood out into cytoplasm so far so good. You
51:53 write a song like this if you to. Oh, time out
51:59 All right. So, what we're at now is we're looking at a
52:04 of this striations. Can you see situation? Light line, dark
52:09 Light line, very very dark dark line, but not quite so
52:12 , much darker left. And then can kind of see the pattern does
52:15 reverse until you get to there. from here to here, that Suzie
52:19 and that's a dizzy disk. Now they chose which one is going to
52:22 . Which again, it had to with the contractions. So right now
52:25 just going to say right here, is RZ disk. So there's one
52:29 amir. And so you can see , it's like, oh, I
52:32 this light area. That's dark A slightly darker or darkish area.
52:38 darker area. Then it goes the . So they called them bands.
52:43 right. And they said, all , well, what is this?
52:45 then eventually we got better technology so could go and look. And what
52:49 seeing here is we're seeing side skeleton with each other. So, the
52:55 of the darkness is a result of much overlap you have. All
52:59 So, now I'm gonna pull people and we have you to come up
53:03 you're right there. It's very very . I'm looking at the time and
53:06 very scary because I only have like minutes. All right, you're gonna
53:12 in the middle. Here's my Z . Okay, put your wings
53:18 All right. So, we have is we have filaments, right,
53:22 , over here. All right. have an in line. That's it's
53:27 exact center. All right. And can imagine over here there'd be another
53:31 disc. Put your wings out. right. Now, look right
53:36 there's no overlap over here. There's overlap. But over here there's
53:40 So, if you can imagine if took a picture, this would be
53:43 than this. And this would be than that. Is What would you
53:46 with me? Okay, so, far this is what we're looking at
53:51 disc. Small region of no overlap of overlap. Another region of no
53:57 than an in line, and then doing the opposite direction. All
54:03 Should I make them stand here for entire time? Go ahead and sit
54:06 . I'll come back over here. right. So, the I band
54:13 the portion on either side of the . Disc. Alright, the eye
54:18 represents thin filaments. All right. thin filaments very, very light.
54:24 overlap. All right, then, we have is we see the dark
54:28 . So the dark area begins the of overlap. That's where you have
54:32 and thin filaments. And the A extends until there's no overlap. And
54:37 you end up with this little bit the H band on the inside.
54:41 the that's the only the thick And then the in line which was
54:46 here is basically a series of proteins are attached the thick filaments and then
54:51 just do the opposite back. Too filaments back too thick and thin filaments
54:55 to thin film. And Z disc repeat. This is what it looks
55:00 . And so, what happens is a contraction. What we're going to
55:04 is we're going to see movement of Z discs. So here you're to
55:08 discs. The thick filaments pull on thin filaments, bringing them in.
55:14 right. And so we're going to changes in the size of the a
55:20 . All right, I'm gonna pull too. I'll pull you two up
55:22 you I was gonna say you don't have a chair in front of
55:25 All right. So, I need again as my in line. All
55:30 . Mhm. Z disc. Aren't glad you have that in front of
55:33 now. All right. So, in line has a thick filament and
55:38 thick filament is going to pull on thin filament. So as the thin
55:41 gets pulled, it moves towards the filaments. Now, the period of
55:48 doesn't change. Right, go Do you see right here is where
55:52 overlap begins and then go that Okay, that doesn't change. Does
55:57 arms change length ever? Does his change length ever? Right.
56:01 But what happens is is this period lack of overlap changes sides? The
56:07 of lack of overlap or no overlap sides. So the eye band changes
56:13 the H band changes. But the band doesn't that makes sense. You
56:20 earned a gold star today. Take out for drinks of your choice,
56:26 you like to drink orange juice, . All right now, there are
56:31 molecules in there. We have a called titan titan's job acts like a
56:35 . So when you bring when you're on that Z disc basically you're moving
56:40 out of position. And so that is being compressed. And so when
56:44 relax the thick filament, we're going see how it works, then it
56:48 back to its original shape. So your muscle goes back to its
56:52 shape after a contraction. All We have nebula basically nebula ensures that
56:58 thin filaments don't get out of All right then, film is supposed
57:02 go this direction, not this not that direction. Not in some
57:05 of weird direction. Is supposed to out like that. So the ambulance
57:08 that it happens. We have other like ALfa acting in that basically served
57:13 attach thin filaments to the Z All right. So what is the
57:18 filament? A long time ago you that a thin filament is acting?
57:22 . Remember that? Yeah, they tell you the whole story. It's
57:26 than just acting. All right. actually three molecules. It's acting
57:30 Eliasson. Troponin trouble my assassin is to my assassin. Okay, so
57:37 a small portion in there that has cousin to my son already hanging
57:42 And you can see here acting is alpha helix. It's the two little
57:46 and the yellow and the mustard. what they do is you've got this
57:50 twisted in this alpha helix. All , Triple maya sin is the smaller
57:55 helix. Said, basically covering over of the acting molecule. Now,
58:01 portion is it covering over act and on it as part of its structure
58:06 place where it's able to bind up surprisingly, it's called a myosin binding
58:12 . Okay, so action has a and binding site and you have trouble
58:16 assassin which is related. My assassin the mice and binding site. So
58:23 trump mice in the workplace. My and act and can never interact.
58:28 right. Troponin has three parts to . It's bound up to the
58:35 It's also bound up to the trump my senate serves as a hinge
58:38 The principle here is when I have , it binds up to one of
58:44 subunits, the TNC sub unit. do you think? C stands for
58:49 ? See this is not a hard . Right. This isn't chemistry
58:55 Right. So, what it does comes along and changes the shape of
58:59 hinge. So, if this is you can imagine triple minus and being
59:03 here when calcium binds it pulls a Matthiasson out of the way because Troponin
59:09 and now I make my assassin available trip to Iraq. Make the mice
59:13 binding site available to my son. , Great Doctor Wayne. Where's my
59:18 ? Well, you learn back in . one thick filaments are -1.
59:24 you very much for remembering that. , here's your thick filament. My
59:32 looks like to golf clubs that someone really, really angry about and wrap
59:35 around each other. Alright, and looks like that's like got this nice
59:40 he's like mm All right. So have this very very long tail and
59:46 have this hinge region that allows the to move back and forth. And
59:51 basically have two of these. the heads are kind of like this
59:54 a boxer from the 20s. That not as fun as it used to
59:58 because we're in the 20s 19 All right. So, you can
60:04 there like this. All right. region is basically this hinge region has
60:11 it an ATP ATP activity. there's an ATP there. All
60:16 So, when ATP comes along, we're gonna do is we're gonna impart
60:20 and change the position of the All right. And so, by
60:24 the position of the hand, we lock and cock the miocene in preparation
60:28 interact with the actor. Okay, , what we're trying to going to
60:34 to do is we're going to try create a cross bridge between acting and
60:38 . When they have this interaction, happens, right? Kind of like
60:43 you kiss somebody does magic happen? , it does. Don't check your
60:48 . It's Yes, magic happens. right. So here it is.
60:57 head is cocked and ready to interact acting. By the way, medicine
61:01 has an acting binding site that binds . So my son wants to interact
61:06 the acting. Acting wants to buy my ascent. It can't triple medicines
61:10 the way calcium it binds up to troponin when binds up to the
61:16 it pulls everything out of the I'm already in position. Boom.
61:20 can now interact. I've created across . Okay. Now, in all
61:26 of these little steps right here, you see a teepee anywhere? No
61:33 is responsible for resetting the mayas and . So that you can get across
61:39 bridge. What we're referring to here something called the power stroke?
61:52 I'm ready to poke him burger. . Oh, I could have done
62:07 lot worse. I'm just if you're to sleep, you can sleep.
62:09 just having fun Trying to make sure get this done in 20 minutes.
62:13 right. So, this is how power stroke works. All right.
62:18 gonna start up here at the top we're in what state attached. So
62:23 happened here is we've already gone through and we've pulled on the acting.
62:27 this is where we are. So what happens ATP comes in, binds
62:33 to the Maya sin and causes it separate. So what is ATP's job
62:38 break the bond between acting and All right. That's probably contrary to
62:45 you're thinking that it did. It breaks the bond. Once it
62:49 the bond, we impart the energy Matthiasson breaking phosphate off. So now
62:54 have ADP and inorganic prospect and what that do? It basically cox or
62:59 the head. So that is capable interacting with acting again. Okay,
63:04 think of it like this. This like a trigger not a trigger.
63:07 is like the hammer on a right? If you watch enough westerns
63:11 stuff like that, What do you ? You pull the hammer back and
63:14 now ready to fire. So what doing here is you're acting putting energy
63:19 and cocking it right? But it's causing it to fire. The firing
63:24 going to occur naturally when you what's going to happen is we're going
63:29 release the inorganic phosphate. Now we this strong cross bridge and now we're
63:35 to pull and then we're now stuck that position until a new ATP comes
63:41 breaks the bond and then we break ATP so that we can re cock
63:47 head and then we can repeat this . You guys ever heard of rigor
63:52 ? What is rigor mortis all My grandfather claims That he when he
64:01 18, he worked in a uh . And he said for one night
64:06 a body sat up, he said was out of there the night
64:08 he said he sat up, he . Do I believe him? I
64:11 know, it's a great story. right, rigor mortis. Is this
64:17 you run out of a TP, ? You have a T.
64:20 In your body, you've died, is no longer being pumped into the
64:24 applying protection and it's now out in side is all you have some ATP
64:29 kind of sitting around you basically cycle the ATP calcium moved out of the
64:33 . So you can now interact with . Myson muscles get tighter and then
64:38 can't break the bond because you run of ATP, you're in the rigor
64:43 and then again eventually everything starts breaking and that's why you get a loose
64:50 . So the power stroke is where comes in. It's there to break
64:53 bond. So what is relaxation? relaxation is first get rid of all
64:59 calcium. If you don't have any you can't interact can interact. Then
65:04 go basically the muscles are going to . Right? So that's what we
65:08 . We have pumps. I love , pump the circa pump. What
65:12 circus stand for. We help you in the plasma critical um calcium.
65:24 . Yeah, simple people circa pumps from the side is all in the
65:30 applies in particular. So we're pumping away, right, we're going to
65:34 it away, you know, sequester . We actually have molecules to bind
65:39 calcium in the saarc applies in particular that calcium can't get escaped. And
65:45 so if you have no action well, what's going to happen?
65:49 no calcium, no calcium, no . Pretty easy. Of course it's
65:56 . You can put it all on slide. Right, start off up
66:01 at number one. You can see the motor or the neuromuscular junction.
66:05 the action potential goes down to T , you'll activates the GHB receptor which
66:09 up the riot riot to dine receptor release of calcium calcium comes out,
66:14 up to a proponent troponin pulls on triple Myson moves out of the way
66:18 son can now interact with act and on that, creating the power
66:22 If you have a T. P P breaks that bond resets the resets
66:26 uh minus and head so that it interact and keep doing that. So
66:30 get a contraction. You see easy right at once. It'll be
66:39 The details are on the other This basically summarizes it. Now,
66:44 are lots of different types of We have isotonic attraction versus isometric.
66:49 is when the muscle tension remains But the muscle length length changes.
66:57 , I could show off. Would agree that this weight of this chair
67:06 changes. It's always constant. Has certain mass. Air goat has
67:11 weight because of gravity. So watch . Do you see my muscle getting
67:19 ? Did my amount of tension I to lift his chair up. Did
67:22 change? No muscles getting longer, getting shorter amount of tension stays the
67:30 isotonic contractions. Right. Concentric is the muscle gets shorter, E centric
67:35 when the muscle gets longer isometric the amount of tension being produced changes
67:41 muscle length doesn't change. Easy way do this. Find yourself a wall
67:45 up against the wall. I'm not a lot of tension. Would you
67:49 I can start pushing harder and harder harder. Is the wall moving my
67:54 changing shape, nope. But I'm more and more attention. Isometric
68:02 what we're doing, we're looking at individual muscle a little it's a bit
68:06 cell. All right. One cell do a lot of work. In
68:09 , the contraction of single cells called twitch. All right. So don't
68:13 twitch with a twitch. All Take a bunch of twitches put them
68:20 . You've got something that's when you're to produce a contraction. Alright,
68:24 is a sustained contraction. So, a series of action potentials telling that
68:30 to contract and continue to contract. right. And so you get the
68:34 contraction. So, the entire muscle shape. All right. Individual twitches
68:40 longer distinguishable. You're looking at a contraction. Now, you just saw
68:46 do a curl with the chair. . Would you agree that weighs a
68:52 bit, Probably £10, maybe 12. very much. Not a very heavy
68:57 , honey, Come on. I to see me do curls with this
69:03 . Same muscles ready see not Right? Same movement. Same
69:10 Notice I'm not throwing the pin up the air. Right. It's a
69:14 contraction. I only need to produce tension to be able to lift up
69:17 pin. Why does that happen? each muscle name muscle are made up
69:21 motor units. These are groups of cells that are being stimulated by a
69:27 neuron. Right. So, I need to create a lot of
69:30 to do this curl. I need do a little bit more to do
69:34 curl. And if I wanted to a curl with that table, which
69:37 not going to attempt because that would sad and embarrassing. I would have
69:41 bring in more muscles. Right? this is a recruitment of motor
69:45 Right? So the strength or the I'll tension that we need to produce
69:51 dependent upon the load that we're trying overcome. And so, if the
69:56 , for example, is more than motor unit to lift that, I
69:59 one more motor unit and one more unit until I actually produced enough tension
70:03 overcome the load. Alright, that sense. So, to move
70:08 it might be I'm just making up , let's say it's 50 motor units
70:12 to curl that table, it be motor units to curl that thing.
70:15 one motor unit. All right. , if I sat here and held
70:20 out in the iron cross, you my arm's gonna get tired? Can
70:24 see it getting tired already? All . What's going there? Is
70:27 I'm actually rotating through different motor units motor units undergo fatigue and of
70:33 after everything gets tired, I'm gonna the chair. Of course, I'm
70:37 lot faster than that. So, put down the chair before I got
70:41 . Right. And so what you're here is basically saying, all
70:44 if I need to sustain that that being in this position, I need
70:48 be able to go through and recruit motor units at a time. That
70:54 sense. So, it's kind of a factory. If you had a
70:57 hour factory, how many shifts would probably have? 38-hour shifts?
71:03 that's a that's a that's kind of the normal model. So you can
71:06 I've got multiple motor units and so it's something light, it's easier to
71:12 through the different motor units, As they get tires like,
71:14 yeah, okay, I'll go and and then you come in. But
71:18 I'm doing something heavier, I've got motor units recruited in the initial
71:22 And so as they become fatigued, no motor units to replace them
71:27 So the actual muscle itself gets fatigued that's when you have to stop doing
71:30 you're doing or, you know, muscle or do other horrible things.
71:35 right. So, when you're adding motor neuron, basically what you're doing
71:42 you're increasing tension. That's that's some that we're describing there, you guys
71:47 , thanksgiving is coming up. Do like white meat or dark meat?
71:52 meat? Dark money? White Sure you start a fight.
71:59 no. See white meat. Dark people get together. It's good
72:02 That means everyone gets what they want now, we can look at a
72:06 and go, okay, the there is white meat and down over
72:09 that thigh. That's dark meat. if you look at a human you
72:12 go that flight meat or dark meat the muscle fibers that make up white
72:17 and the most fibers that make up are intermixed in our muscles. What
72:21 doing here is we're looking at a through a human muscle and you can
72:25 the light meet in the dark meat at the cellular level. Right?
72:30 that would be your light meat. your dark meat. Okay. And
72:34 reason is light and dark has to with basically the amount of myoglobin has
72:39 how it responds to different https or has different https activity as well as
72:46 sort of pathway doesn't use to produce 80 P. So it's oxygenated versus
72:51 politic. All right. So the way to do this is just kind
72:55 look at the three muscle types. have a slow oxidative. Alright,
72:59 that's gonna be a red muscle because going to take a while for you
73:03 make your ATP. And so basically have lots and lots of myoglobin.
73:07 you're using oxidative a lot of oxygen and you can produce long term contractions
73:14 extended periods of time. Fast oxidative you are still oxidative but you're basically
73:23 to your contractions faster. So the . T. P. S.
73:26 a little bit quicker. Then we the fast like politic where you have
73:29 fast contractions but you don't make a through the oxidative pathway. You use
73:34 electrolytic pathway. And so these are um used for fast burst fast quick
73:43 . So you can think about like and this is not a good way
73:46 think about it. But it's an way you can think of this as
73:49 this is muscle that is used for , that's muscle. Would you be
73:53 for say jogging long distances? But can see if they're intermixed. Why
73:59 I be a fast person? But a marathon person? It's because you
74:04 more of this than that. But can I be a marathon person and
74:08 a fast person because you have more that than this. And so you
74:11 of change the balances of what you . Can you be both? What
74:17 you think? Not really. Can train yourself from one form to the
74:22 ? Not really. Alright. You are what you are but there are
74:27 small or slight modifications you can make , I did not get through what
74:31 wanted. Cardiac muscle is just like muscle. Very very little differences.
74:38 the exception of calcium isn't pumped into plasma critical. Um Instead it's pumped
74:43 of the cell, that's why we to slides. So if you know
74:50 , your new cardiac what I'm gonna since I know you're running out of
74:57 . I want to get to what's important here. Alright, smooth muscles
75:04 are different than skeletal muscles in a of different ways. But the key
75:08 is that you still use calcium still a teepee. But how you use
75:14 is going to be different. All . So we saw calcium was binding
75:19 troponin right? Which moved out the to allow for the interaction between my
75:23 and acting When we're dealing with smooth . The Differences 1st. There are
75:29 sarka mears. Okay, so we have lines that are gonna be contracting
75:34 what we have our we have thick thin filaments arranged in this weird
75:39 So, you see when I squeeze looks kind of like a ham that's
75:41 wrapped some of you guys know what talking about. Right, okay.
75:47 have uh intermediate filaments that helped make of that skeleton out. So,
75:51 you can see here is we have structural difference. The Z discs are
75:56 to the ditch bodies of dead bodies equivalent to Z. Diss So that's
75:59 the thin filaments are attached to. have molecules that are there to bind
76:05 to act. And this is cal and cal Desmond which basically block the
76:10 of mine is in acting. So is the nuts and bolts. What
76:16 going to use is we're going to the signaling cascade instead of Excuse
76:21 The direct interaction of calcium with All right, calcium comes into the
76:28 triggers the release calcium from the smoke the plaza particularly. So it's a
76:31 whammy. So you get what is this calcium spark calcium comes inside the
76:37 and then what it does that's going bind up to a molecule called myosin
76:43 chain kindness. Myosin light chain kindness sorry it's cal module in which binds
76:48 and activates myosin light chain kind myosin chain kindness is what activates and changes
76:55 shape of the head. All So in other words, we don't
76:59 ATP's activity here. That's moving the instead. We have a kind face
77:03 coming along with phosphors relating it that the head to change its shape.
77:08 right now, the other thing that's module in does is that it binds
77:14 to it activates cow module in kindness . All right, that's what I
77:19 module is All right. And what does is it binds up and phosphor
77:24 boast molecules. Right, so, . And where was the other
77:29 I don't have it up here. just happening I guess. Remember we
77:32 kalpoe nin plays a role in cal play a role in inactivating or preventing
77:38 demise them come from from interacting so cal module and calcium, nickel margin
77:44 module into cal module and kind as what we do is we foster right
77:48 and and interfere with its activities and and its activities when you are blocking
77:55 blocker, it's activating And so now getting an act in my Senate
78:03 So, miles in light chain Kinney's for you to change the head
78:08 Cal module in stops the blocker so they can interact and that's when you
78:13 the contraction. So instead of it troponin true promise. And you have
78:18 really weird signaling cascade that allows for interaction to take place. So,
78:25 see if we can go back. doesn't show it here. So,
78:28 guess that was the best picture I , was this one. Well,
78:36 all I wanted to say about Action potentials. I'll mention this since
78:42 have literally two minutes. All You should know the difference from multi
78:48 , single unit, but I don't I need to explain that many cells
78:51 one group of cells. Alright, little thing here has to do with
78:54 potentials, smooth muscles have a natural activity. They basically are slowly moving
79:02 action potentials and slowly moving away so produce exponential get a burst of action
79:08 and then you'll go back to a of a period of rest innovation of
79:13 muscle brings the threshold or brings the closer to that threshold to produce action
79:20 . Right? So you're not dependent the nervous system to create the action
79:24 in smooth muscle. You just make easier for it to happen. All
79:28 . So it's a modification. All . But once you get those bursts
79:32 action potentials, that's when you're getting on, that's when you're getting this
79:41 influx of calcium so that you can that cascade that we described.
79:48 if you're really, really bored, can go use that to kind of
79:52 the compare contrast stuff. Yeah, . Sure. Uh Yes.
79:59 the what you're doing here is um it again, it depends on your
80:06 universes you're single unit. Right? typically if you're what is called a
80:10 unit, basically have a series of that are connected by gap junctions.
80:14 , if you stimulate one cell you're stimulating them all. But it's an
80:17 junction. So the exponential traveling from itself. Mm So, thursday I'm
80:23 going to see it's going to be sad day, aren't we? All
80:28 ? Yeah. Thank you for for my ego there for a second.
80:33 makes me feel better. All come on.
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