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00:04 okay today is going to be interesting we got a lot of ground to

00:10 catch up with the protection of the . Then we're gonna jump into the

00:14 system itself. We're gonna start looking structure, We're going to focus on

00:18 spinal cord. All right. So in anatomy class, what you'll do

00:22 you'll do the brain first and go the spinal cord, then go to

00:25 peripheral nervous system. For some your book does, it kind of

00:28 , it goes to the spinal cord , then it does the spinal nerves

00:32 it goes back to the brain, it does the cranial nerves. It's

00:35 kind of wonky. But I think easier just to follow the book and

00:39 jump around in the book. So kind of where we're gonna go

00:42 And our starting point here is gonna the blood brain barrier. As I

00:47 , we were saying, there's different in the brain. Started with the

00:52 that we moved to the meninges from meninges. We talked about the cerebral

00:56 fluid. Now we're down to this tiny structure. This weird thing,

01:00 is called the blood brain barrier. it's gonna be abbreviated BBB uh in

01:05 and there are different parts of the that have these kind of unique environments

01:09 are kind of separated and really what have here Is a structure that is

01:16 from uh the glial cells and the that are actually found in the

01:22 Now, I know we've never talked blood vessels. So, I've just

01:26 to give you like a 32nd understanding blood vessels, arteries move blood from

01:32 heart to whatever the organs are, , move blood from wherever the organs

01:37 back towards the heart. The place blood exchanges in that organ is called

01:42 capillary. The capillary is a leaky . Alright. It's like taking your

01:48 putting them together with your fingers slightly separated and like scooping up water,

01:53 would kind of drip through. All right. So imagine taking marbles

01:58 then doing the same thing with water so the water would drip through.

02:01 the marbles would stay in your Right, Okay, so that's how

02:05 work through. About oh I don't , 95% of your body then we

02:10 the blood brain barrier. Blood brain . Like taking those same fingers

02:14 And having them separated. But instead separating it, what the what the

02:17 cells the astro sites do is they um let's go ahead and put a

02:21 bit of superglue between your fingers so your fingers are now glued together and

02:25 can't sneak through. And so when scoop up water, water stuck.

02:28 the only way the water is going be getting out is it actually goes

02:32 your hand. Alright. And this a process called Transito sis when you

02:36 through a cell. Transito sis If you go between cells, it's

02:42 . Oh sis. Alright. So you see that word or hear me

02:45 that word? Or see it on picture? That's what it means.

02:48 right now, the reason we have is because your brain is really

02:53 Would you agree your brain is really ? I mean, we have to

02:56 at all the protections. We we have the skull, we have

02:58 meninges, We have the cerebral spinal . We are protecting that brain from

03:01 sorts of physical damage. So here blood brain barrier is there again to

03:07 as a barrier between the stuff that's in your blood. That could then

03:11 transferred to that tissue and causing Let's think of a fun thing that

03:17 put in our bodies that causes our to kind of go conquer for a

03:22 bit right. Can you think of ? Hmm. I saw lips say

03:29 , drugs. Well, alcohol, , alcohol is our favorite thing.

03:35 sorry. Different generation. So, , when I was college, that's

03:40 it was all about. Remember I to school in New Orleans.

03:42 I was just like, how can go out every night and have fun

03:45 . All right, alcohol is one those things can actually penetrate through the

03:49 brain barrier. We'll see why in a moment. But you can see

03:53 adding one small chemical, right, it can affect the brain imagine of

04:00 the different types of chemicals. Because we've already talked about like ions,

04:06 ? And how were carefully regulating where are. Imagine how if we change

04:12 imbalances, what would happen to your ? So this barrier serves as both

04:18 anatomical barrier because it's physical and it's physiological barrier determines what goes in and

04:25 comes out of the brain tissue. right. Any sorts of changes that

04:32 do to the brain or two, fluid, that extra cellular fluid in

04:35 brain can cause disastrous effects. So that in mind, let's kind of

04:41 and see what the anatomical restrictions And then we look at physiological

04:48 These are the structures. Alright, I've already mentioned that we have tight

04:52 that instead of there being uh spaces the capillaries. So, so here

04:58 your capillary, it's the red So you can see where the capillaries

05:02 separated. Instead of that being a junction where things could sneak through that

05:07 a tight junction. This is being primarily by the astrocytes. Astrocytes being

05:12 glial cell, that's the purple cell you see right here. So the

05:16 come along and wrap themselves around the and say, hey capillaries, we

05:20 you to tighten up those junctions. nothing come through. And that's what

05:24 is you seal those tight junctions and we also have these other cells.

05:29 parasites, not parasites, parasites The next to sell. And they're

05:35 as well and their job is to of have this conversation with all the

05:41 cells to kind of determine what's going . So if I have something that's

05:45 the blood that I want out here the extra cellular fluid near my

05:49 it first has to pass through the . If there happens to be a

05:53 there, it has to go through parasite parasite and then it has to

05:57 through the astra site, that means one of those structures has to have

06:02 right receptor, right or the right or the right carrier molecule to allow

06:07 to happen. Right? So you see it's like getting your I.

06:11 . checked every 10 ft as you're down a pathway. All right.

06:16 so not only do we have we also have a basement membrane that

06:20 in between the capillaries and the astro . And so that kind of serves

06:24 a screen door. So even if you can sneak through the capillary,

06:29 it's too big, it's not even near the astrocytes in terms of physiological

06:36 . This goes back to what we a little bit earlier about water soluble

06:40 and lipid soluble substances. Alright, I'm water soluble, I want to

06:44 wherever there's a watery environment. So that means that demands that I

06:49 some sort of carrier molecule passing So I have to have the right

06:55 there to be able to move it cell to cell to cell for that

06:59 sis if I'm water. Remember we water kind of breaks the rules.

07:03 can kind of go where it wants go because it's small. So it

07:06 actually diffuse through the layer. But has to follow the rules of

07:11 right? So if there's less water the brain and more water in the

07:14 , water will flow towards the But naturally there should be balance between

07:20 two. So there should be no specific flow one way or the

07:24 Alright. And then lastly, if lipid soluble you don't want to be

07:28 a watery environment, you want to wherever there's fat. Right? And

07:32 plasma membrane. So what's gonna happen that lipid soluble substance is gonna find

07:36 way through those cells just fine because basically jumping from plasma membrane to plasma

07:43 . The plasma membrane moving just wherever need to go down their concentration

07:52 This is just not working. Oh is. Okay. All right.

08:00 , what we have here is we a way to control what's going in

08:04 what's going out of the brain. . We can determine what's near

08:08 Now. The blood brain barrier is to be found around the blood vessels

08:13 the cerebrum. All right. I we don't know the three women is

08:15 gonna learn more about this a little later. All right. So as

08:21 said this is what we're making is selective transport mechanism. Or elect a

08:26 transport process to move things in and the blood brain barrier at the

08:30 Oid plexus is just gonna be there the epithelial cells and the idea here

08:35 remember the cord plexus. What are doing? We're making cerebral spinal fluid

08:40 we want to be able to pull much more easily from the blood.

08:44 the structure of the core Oid plexus a little bit different. But it

08:48 a barrier. It's still there so anything can come in. It's just

08:53 as dense. And then lastly there parts of your brain that have no

08:58 brain barrier. Alright. And so places are where you want to actually

09:03 into contact with the blood so you see what's going on. One structure

09:07 the hypothalamus. We'll get to where structures are in the next unit.

09:12 the hypothalamus is, its job is determine which hormones need to be released

09:17 you usually dependent upon some sort of coming from the another um structure.

09:23 a hormone as well. So you to be able to have easy exchange

09:26 those environments. Penal glands. The thing. Um I mentioned the court

09:32 . It has to have a certain of permeability but then we also have

09:36 centers. All right. Why the center. The most likely way that

09:46 poisoned yourself by putting something in your . All right. We are creatures

09:53 put weird things into our bodies solely eating things. All right. That's

09:59 we explore our environment. That plant good. I will eat that.

10:04 frog looks tasty. I will lick , whatever. All right.

10:09 the natural way, the most likely to get something that's dangerous to your

10:13 is likely that you've ingested it. once you've ingested it, that toxin

10:18 into your blood and then it circulates your vomit center is kind of looking

10:22 those toxins and says, oh, a toxin. Hmm. I wonder

10:26 it got in the body. Probably something. We threw it away we

10:30 and throw up. Isn't that So, if you get bit by

10:34 rattlesnake and injects you with the You know the one the first thing

10:38 do besides the profuse sweating you vomit your brain says, well, I

10:45 ate something. Didn't follow the 5 rule. Yeah. So anyway,

10:52 that's the blood brain barrier. And kind of just shows you a little

10:55 more clearly so you can see, ? So here's that simple diffusion.

10:58 talking really, really small molecules. talking like water, oxygen. You

11:03 , the gasses. Some lipa. drugs can actually pass through. If

11:07 look at this chart, it even ethanol. It's able to buy pass

11:11 the tight junctions. Just fine because very, very small molecules and they're

11:16 dependent upon any of those much more rules, we have some molecules that

11:24 to have the receptor. So, that trans psychosis I was referred

11:28 That's the receptor mediated transport. the idea is if I have the

11:31 receptor, I combined it, I across and move it into the into

11:36 fluid so that the next cell can it up and so on. And

11:40 , some cells or some molecules will specific carriers that are available. These

11:45 the easy ones to think about, amino acids, for example,

11:48 for example, are things that the would want. So, you're already

11:53 have those carriers available so that you just pluck that stuff from the blood

11:58 you need it. All right. if you don't have the right

12:02 if you don't have the right if you're not that Itsy bitsy teeny

12:06 molecule. If you're not lipa you're not getting in. And usually

12:10 is the place where I tell the about the P for the week

12:14 But I'm not gonna do it If want to find out about it,

12:16 listen to an old lecture. Don't enough time for that story. All

12:23 now, here's where we're going to in for the first time into some

12:27 anatomy. So, sorry. All . What we're gonna first do is

12:33 gonna look at the blood vessels of brain. Alright. And if you

12:37 at the brain, what we've done we've taken the brain and we're looking

12:40 it from the bottom side. this is the inferior view. Here

12:44 your spinal cord coming out and towards . All right. It's really hard

12:48 do in three dimensions. When you're at a two dimensional structure. And

12:52 you can see is I've kind of a line here, this green line

12:55 represents the separation of the anterior portion the brain and the posterior portion of

13:00 brain. Alright. And what we is that we have these kind of

13:05 circulations that serve each half. There's three circulations that we're going to look

13:09 . But I just kind of want separate out in those two. And

13:13 circulation is And here in this post is served by this unique connection in

13:18 brain called the Circle of Willis. basically, what is a series of

13:22 that form a circle so that if include one of those vessels, there

13:27 a way for blood to find its around to the vessels on either

13:32 It's kind of cool. Can we a time out real quick? only

13:36 80% of us have circle of Willis we talk like this is an absolute

13:41 not an absolute But just presume we have it. Okay. So I

13:47 80%. Don't sorry, Don't 80% us do have that circle of

13:53 So, it's just very strange. portion. Alright, So, what

13:58 gonna do is we're gonna name some and and looking at this, you

14:01 see how they've again overloaded the And we're just gonna focus in on

14:05 of them. All right. you've heard of your carotid artery,

14:09 ? If I strangle you, I'm to compress the carded artery, it

14:12 up through the neck and then it up into the brain. This,

14:15 here represents that point where it's now up with the brain. And what

14:19 does is it actually divides into three . All right. It joins into

14:26 we've got this branch right here, middle cerebral, right? We also

14:31 the anterior cerebral. So, those are kind of the important ones.

14:34 we have some other branches as All right. And we're gonna be

14:38 to this is that part of that of Willis, The communicating artery to

14:42 sure that the blood is actually going in that circle to be able to

14:46 blood towards towards the posterior sides. , when you think of the internal

14:52 , what they're doing is they're supplying to the anterior portion of the brain

14:58 that anterior cerebral. So, there's one branch and that middle cerebral the

15:04 branch. So it's dealing with the part of the brain Anterior and middle

15:09 are the two big ones. When talk about the middle or sorry,

15:12 posterior segment, what we're gonna be is we're gonna be looking at the

15:17 arteries. There's a pair of They come together and they fuse they

15:21 this basil or artery and then that artery then supplies not only the

15:27 but the little tiny brain in the called the cerebellum plus mother's structures.

15:32 right. So we say as you see here is that basal artery makes

15:35 the base. Alright? And it an artery called the anterior inferior sarah

15:42 . So, I want you to that this is an adjective sarah Beller

15:46 cerebral. Very very similar. But refers to the cerebrum. One refers

15:51 the cerebellum. Cerebrum is your big . Cerebellum. Is your little

15:56 literally. That's what it means. right. They're not big brain.

16:00 brain, but that's when you look them, you're like, oh

16:03 okay, this would be your This big thing in the back is

16:07 cerebral so anterior inferior. So when hear that, what do you what

16:13 you think of when you hear anterior in front and below? Right.

16:19 that's what it means. So, just shows you where it's going with

16:22 to the cerebellum. All right. forms what are called the ponte een

16:29 . All right. The Ponty means right there. They intervale or

16:34 Innovate. They vascular rise the We don't know the ponds is

16:39 But you can see where the name from, Fontaine refers to ponds.

16:46 also have the superior serra bela Alright, So the superior serra bela

16:52 have lost them here. Okay, right there. Alright? And again

16:56 goes over the top of that The one that I didn't highlight here

17:03 I should is the posterior cerebral So here it is, right

17:07 And so that's gonna be providing blood the post airport of the cerebrum.

17:15 , so the ones that I highlighted really kind of the important ones.

17:18 , what you don't see on here you, whenever you see a drawing

17:22 blood vessels, red is usually going be an artery. Blue will be

17:26 vein. So you notice there's no in here. So they're not showing

17:29 . But the blood returning from your arrives via or leaves via the internal

17:37 . Alright. And how we get the internal jugular is through these dural

17:41 and this combination of other sinuses joining to form these structures here. I've

17:47 everything away so that you can see the brain. So this is the

17:53 . That little tiny thing down there the cerebellum. This is the brain

17:57 and this bulgy part right there is ponds. Alright. So the Pontiac

18:02 would be right there. But it kind of shows you it's like where

18:05 this blood go? And so when talking about the anterior cerebral artery,

18:11 really dealing with the frontal lobe and top part of the brain. We're

18:16 about the middle cerebral artery, which that big one that goes on.

18:19 basically the bulk of the middle of brain. And we were talking about

18:22 posterior sara Bella or cerebral arteries. been seeing cerebellum, cerebral cerebral cerebral

18:28 artery. It's going to be the here, part of your brain.

18:32 , you can kind of see there's organization to how the blood vessels

18:36 And fortunately the nomenclature kind of goes it. And as we mentioned,

18:44 our circle of Willis, right, whole structure right there. And what

18:49 does is ensures that there's an overlap flow of blood to the front and

18:54 the back of the brain. This an important structure. We want to

18:57 sure that nothing blocks the blood so the tissue stays well or alive.

19:04 , what we have this little tiny right there. So, remember this

19:07 the anterior cerebral there's anterior cerebral coming . So you can see part of

19:13 forms that circle of Willis. Is communicating artery in there? All

19:18 So, basically you have two separate that are coming together but it's like

19:22 , no, no. We're gonna ahead and put another little bypass right

19:25 to make sure that blood can go that circle shouldn't need to. All

19:31 . And then here's the baseler Right. And where's that basal artery

19:35 from? It comes from the vertebral and then there's a bunch of spinal

19:41 as well that we're not really going focus on. All right.

19:47 those are blood vessels that you've got know. This is kind of the

19:50 list. Know them. All May .1 of these and say,

19:55 is it so far? You guys me? All right now, we're

20:04 move into the spinal cord. But we do that, let's kind of

20:08 sure we understand which types of cells we're working with. We've been talking

20:11 neurons. Remember the neurons are the cells, they're the quarterbacks there.

20:15 excitable cells that the nervous system We've looked at the multipolar neurons as

20:21 example of neurons communicating. But in central nervous system, the primary neuron

20:27 called a pyramidal cell. Can you me why you think it's called a

20:30 self because of its shape? That's . And you can see it.

20:35 mean, it's it's it's almost stupid I asked the question. All

20:41 It is a type of multipolar But notice that the axon doesn't really

20:47 out quite so clearly. Right. because it's in the small networks.

20:51 so it doesn't need to send a , very long axon, very far

20:55 . It's really just talking to a cell. That would be like right

20:59 here. Okay, so that's kind why it has this unique shape.

21:04 . But it plays a major role you understanding it. I want you

21:12 think about the pyramidal cell. Your cells are processing the idea of the

21:18 cell cognition. Understanding okay, thinking is the best part your brain

21:27 Thinking about. Thinking alright, you're the idea of processing information. Mm

21:37 . Deep thoughts. The rest of cells. These supporting cells are a

21:44 bit smaller. They're not quite as to us but they're very important.

21:49 you didn't have them, the neurons do their things. So what we're

21:53 about now, these supporting cells are glial cells are what we call neuro

21:57 And there are six different types of for that are in the central nervous

22:02 to that are the peripheral nervous We've already talked or mentioned them a

22:06 bit as we've been going along. now these neurons are capable of

22:12 They're the ones that multiply and divide needed even into adulthood and beyond.

22:18 do not transmit nerve cells and they outnumber the number of neurons almost

22:24 So they make up about half the of the brain and about half the

22:28 of the entire nervous system. So everywhere. They're all over the

22:32 They're just much much smaller than the themselves and when I use examples like

22:36 the neurons a quarterback the reason I them a quarterback. Because if you

22:39 anything about football, football teams are up on each side of how many

22:45 Come on guys. Thank you. is what we're looking for. So

22:50 means we have 10 players in one . Right? So this is the

22:56 of the football team, quarterback doesn't good. If he doesn't have a

23:00 quarterback can't throw a pass that can caught if there's no receiver.

23:06 So that's why use as an example the six types, you can see

23:11 broken them down here. So here the central nervous system. We have

23:14 handymen cells. We mentioned them. talked about the L. A.

23:17 sites. We mentioned the astro sites never mentioned micro glia micro glia.

23:22 you want to call it that if was hard, but micro glia,

23:26 ? And then we've talked about Schwann . We haven't ever mentioned satellite

23:30 So these are the peripheral, those the central nervous system. They all

23:36 off life from the oligarch. Dendrite cell. All right, in

23:42 these are the cells that give rise other types of cells. They're all

23:46 the central nervous system. What they is they kind of sit around and

23:50 they sense their environment. They have little tiny growth cones, which is

23:54 fancy word for saying an extension that receptors and it detects chemical messages and

23:59 chemical messages tell them where to And so in this case you can

24:03 what we've done is we've formed an contender site that all good inter site

24:07 located to where it needs to And it sent out its extensions to

24:10 around the cell to create those Myelin in this little cartoon. All

24:18 So where we have damaged areas? are things that can come in and

24:22 . Alright. So they're kind of progenitor cells of a bunch of different

24:25 of cells in the brain. We've talked about the tender side. I

24:31 want to go any much further. than to say When you see these

24:34 , they can't draw how widely spread do. I mean they can myelin

24:39 up to 50 axons. So they that. You can understand why they're

24:43 all ago. It's like all these that go from it and they can

24:47 of wrap around all a bunch of cells. All right. They also

24:51 tell neurons stop growing, stop doing you're supposed to do. They basically

24:55 and say I'm in charge. All . We've talked about the neural insight

25:03 the Schwann cell again it's producing Myelin . This is a kind of better

25:07 at it. So here's that ax this is a cell and you can

25:10 what it had done wrapped itself around times. This is central nervous

25:15 This is peripheral nervous system. So can see now, here's my my

25:19 chief, my own chief, my chief. Each of those represent a

25:22 cell. All right. Where they're , also determines how if we damage

25:31 cell where that damage neuron will actually again. They actually kind of serve

25:36 a path to say, this is you were grow back this way if

25:40 capable of growing, but it only for a short period of time.

25:44 , ma'am. Which yeah. Why they divide? Because you have cells

25:59 it not to? That's right. that sense, the neurons stopped doing

26:05 we would expect to sell to do other cells are telling it don't do

26:10 . Right? So that's kind of of the thing is there's a lot

26:14 stuff in biology. I'm just this just an aside, there's a lot

26:17 chicken and egg stuff that it's like learned something that I find out why

26:21 does it. And you're like, , well, that wasn't quite clear

26:25 first time and it's just gonna happen all of I mean, especially when

26:29 get into these classes where you're starting dive down into the alphabet soup of

26:34 . You know, it's just like yeah, I'm still right. For

26:44 is correct. So what will Yeah, go ahead. No,

26:47 , go ahead. They can repair . Right? So, the reason

26:54 don't see a lot of repair in cns is because the cells remember we

26:57 those pyramidal cells and we go back they're not very big, right?

27:02 only have these very very small extensions the peripheral nervous system. Typically ourselves

27:07 these long multipolar cells. So we these long axons that travel far

27:12 If I chop my ax on I've done no damage to the cell

27:16 , where all the cellular machinery If I do damage here is a

27:22 chance, I've actually done damage to cell itself. So, that's why

27:26 there's less of a chance of All right. So, and we

27:31 talk about I think your book actually about repair. But at one point

27:35 just decided like this really isn't that to know how it creates the the

27:41 . It's just astrocytes named for right? No, no. It's

27:53 because its star shaped the star Alright, Most abundant glial cells in

28:00 nervous system. These are like the tissue. This is kind of the

28:06 that holds everything together, functionally it establishes the physical structure of the

28:11 . So it is scaffolding onto which neurons are actually built. So,

28:16 can see right here in this little , here's my astro side. It's

28:20 the capillary where it should go. telling the neurons where it should be

28:24 it's holding everything into place that's its . Alright? It also controls the

28:31 environment. Remember what we did? had a whole bunch of astrocytes creating

28:36 barrier blood brain barrier. So what doing in the first place is

28:40 I will determine what gets into this here. Alright. I'm telling the

28:45 what to do and then I'm going be the ultimate arbitrator, ultimately one

28:50 deciding what's getting in and what's getting . Because in order to get from

28:54 , you have to pass through that and pass into this cell and then

28:58 cell decides when it's gonna let something into the extra cellular fluid it stores

29:03 glycogen. Glycogen can be broken down glucose. It provides the glucose and

29:09 lactate to these neurons to allow them be functioned be functional. Excuse

29:15 All right. So, very, vital role as a cell that controls

29:22 extra cellular fluid in the environment surrounding astro site. This is another important

29:28 right here. It actually serves at site of the synapse to help maintain

29:34 synapse. So, we look at synapse and go, okay, here's

29:37 pre synaptic cell. Here's the post cell and then stuff happens in between

29:42 . But that synapse is actually held place because astro sites are surrounding

29:48 We talked about a little bit about do we stop you know, activity

29:51 the synapse and we had that You know, if you went back

29:55 looked at it and I was like , sometimes there's these astrocytes that take

29:58 the neurotransmitter. There you go. what it's doing. Alright. It

30:04 to repair the damage that you see nerve cells. Alright. So if

30:11 are damaged, they can actually multiply fill in that space and act as

30:15 tissue and last thing they can do they can stimulate other cells to

30:21 So for example, they tell the good danger sites where to go and

30:25 to do. So astro sites are important? This is this is just

30:29 short list. Astra sites are really important cells. They just don't

30:34 that sexy job of sending signals. no. Astro site neurons can't do

30:42 they want to do or or what designed to do. Epidermal cells we

30:49 produced cerebral spinal fluid. You can here the cilia on it and if

30:52 look closely you can see kind of little hairs there, so remember what

30:56 are they're found or localized within the . The cord plexus is where the

31:01 vessel gets really, really close to surface of the ventricle. So what

31:04 doing is these epidermal cells are actually fluid and materials from the blood and

31:11 that cerebral spinal fluid that then fills ventricle and then it says,

31:15 you move that way I'm gonna make so that's the easiest way to think

31:20 these micro glia, there's nothing we about these things that are useful at

31:28 point. Every time we turn around see a new paper or something new

31:33 them. Alright. We're gonna go what the textbook says. Alright,

31:38 it just makes our life easy About 10 to 15. 10 to

31:43 of the central nervous system is made of these micro glia. Now they're

31:48 microgreens. Micro small glia, small cells, that's what they are.

31:52 just the small ones. And what do is they just kind of sit

31:56 and do nothing for most of the and it appears that they're related to

32:01 monos. Aight all right, That is a modest site. And

32:04 know you haven't learned this stuff. mon a site is an immature macrophage

32:09 a macrophage is a cell that chews and destroys foreign material. Alright,

32:15 learned a little bit about that. it just kind of sits around and

32:19 pretty much nothing, it just kind releases growth factors and says,

32:22 what's going on? Make sure everything functioning right? But when they become

32:26 , if damage happens to the brain that converts that mona's site like selling

32:31 the macrophage and it migrates to where damaged tissue is and begins to focus

32:35 ties it. Lot of research done uh the word stroke, stuck in

32:45 head and that's not what a concussion , what I was looking for.

32:48 lot of concussion research has shown that you get a concussion, you activate

32:53 cells like crazy. They start migrating over the place. It's wild.

32:57 . So, the way you can of this is that you can think

33:00 it as an immune defense cell. . So, it's able to find

33:04 wrong things in your brain. So something leaks into your brain and it's

33:08 supposed to be there, this is cell that's there to fight it.

33:12 right. It also helps to prevent in terms of the immune response.

33:16 that's where we're going to leave But there's a lot of evidence that

33:20 may actually serve as a neural stem . There's a lot of evidence that

33:25 a lot of other interesting things. so maybe in 10 years you're going

33:30 find out that this is the most cell in the brain. It would

33:36 into new neurons. So, the that I've been telling you is that

33:43 nervous system doesn't repair itself. We're go ahead and say it doesn't repair

33:47 . Just just trust me on that . Okay. But it might it's

33:52 a lot of evidence that keeps pointing direction, but we're keeping it

33:57 We're not changing. We're not we're going to go with what the paper

34:00 three weeks ago, right? We're trust what the textbook says and let

34:04 science work itself out and it's actually not true. It's not from three

34:07 ago, it's been around for about or four years. So now we

34:13 the population of the cells. All . We got our neurons which are

34:18 pyramidal cells, but they're not just cells. We've got four different

34:21 So, I didn't even talk about cells. What's the satellite cell?

34:25 cell is like an astro site except in the periphery. That's how important

34:29 is. I just don't even have slide for it. Okay. We've

34:36 about the glial cells. All And when you think about the nervous

34:40 , what what is the nervous What is its job? It receives

34:44 . It processes information. And then transmits a response to the information that

34:50 just received and processed? Does that of makes sense? In other

34:55 if I'm outside and I touched something , I detect that hot. I

35:03 that signal and say, the thing touching is hot. It's probably causing

35:07 . My brain then sends a signal back down and says, alright,

35:10 go ahead and just move that And that is what we're talking

35:14 It's receiving the signal processing what that means. And then how do I

35:20 to the signal that's ultimately what the system is responsible for. All

35:27 It can store information in a right? It can ignore information.

35:34 fact, much of the input, of the sensory input that you receive

35:38 a regular basis is completely ignored. ? If it doesn't have a direct

35:43 on your behavior, right? This your brain goes, let's not worry

35:46 that right now. Right. And this stuff is occurring at the level

35:51 the neuron. Right? So, going to kind of talk broadly,

35:55 remember that we're dealing with how neurons talking to each other through that chemical

36:01 . All right, They send that ultimately onto the muscles. That's

36:06 glands, for secretion and other cells tell them what to do. But

36:12 isn't all that it does. You here and thinking about the brain and

36:16 about yourself is consciousness? You are aware, Your brain, your nervous

36:22 is responsible for that. It is for your perception of the world around

36:29 . Alright. That's dependent upon the of sensory input that you're getting.

36:34 responsible for language, for you being to understand these sounds that I'm making

36:40 have They have meaning to you, . For reasoning. Should I eat

36:46 oreo that I dropped on the It's only been there for three

36:51 You know, memory. Think about , I don't know think about the

36:56 person you had a crush on. you picture him when I when I

37:01 that all of a sudden your brain back there. See that's memory and

37:05 evoked some sort of response to write some sort of emotion, whether

37:10 was good or bad. Right? all in the nervous system. All

37:18 . So when we're looking at this , we're going to kind of point

37:21 the areas where different things are actually . All right. But I want

37:25 to understand that like when you talk a memory, a memory is not

37:28 stored inside a neuron, a memory the way that a neural network,

37:35 bunch of cells talking to each other in a specific sequence in a specific

37:41 . And so all we gotta do just cause a repeat of that sequence

37:45 your brain takes that signal and basically this is what it means.

37:52 your brain is formed during embryo while an embryo and then it continues develop

37:59 . There's a lot of research that that your brain is almost completely rewired

38:06 during puberty. So basically during your , so remember all those horrible fits

38:12 you had and how everyone made you and nothing was ever fair and

38:17 blah blah. You know, all stuff that's your brain rewiring itself to

38:22 a mature brain so that you can a functional in the world today.

38:26 . And what does functional mean? not gonna go there were just basically

38:31 feed yourself and reproduce. How's Okay. The brain uses different ways

38:37 organize itself during development. Alright, very early on we call this development

38:44 neuro brain, right genesis beginning. during early neurogenesis when you're an

38:51 we use this type of this um called radio migration. And hear what

38:58 is is if you look at the , you'll see that there's these different

39:01 . All right. And we're not spend a lot of time talking about

39:04 layers in the in the gray matter it gets confusing and it's and it's

39:07 and and and truthfully for our purposes not really that important. But the

39:12 is that I hear I've got a the green stuff represents glial cells.

39:16 what that neuron does is it migrates layer to layer to layer, usually

39:22 finding a glial cell and then migrating the length of that glial cell using

39:26 chemicals that that glial cell is signaling it to tell it where to

39:30 Right? So that's what radio migration . But once you become an

39:35 you're going to use something that's a bit different. Alright, so that

39:39 , those changes that take that take , say during puberty are going to

39:44 something a little bit different called tangential . And here what you do is

39:49 move within the layer that you're in you move back and forth. Unless

39:54 signal tells you to shift that layer then you move again back and forth

39:58 that's kind of what this is trying demonstrate to you. So what's happening

40:02 is that the way your brain is and changed differs depending upon where you

40:09 in your development. So early on using radio and then later on using

40:17 . All right. But neurogenesis is process of organizing our brain. So

40:22 becomes functional now. Neurogenesis we said dependent upon some signals. Right?

40:29 said. The glial cells here are signals out and then what causes it

40:33 move from layer to layer is a of signals that are telling those cells

40:38 to go. And this process of a chemical signal is called chemo

40:45 It is not only done in the is done all over the place.

40:48 right. Chemo taxes is simply using signal that's usually chemical chemo. And

40:55 that chemical trail. If you've watched shark week, you've watched the shows

41:00 they're talking about a little bit of in the water and the shark sits

41:03 and can follow the trail of That is a form of chemo taxes

41:08 a macro stage. Right? That's you're doing here is you're taking that

41:12 chemical and there's more chemical here. gonna keep following the trail of chemical

41:16 there is more. I'm gonna just going following it until I find the

41:19 of the chemical the portion of the that does this is that growth

41:26 All right. That's what that fancy is. So, it's basically you

41:28 imagine I've got these extensions and other corns and there's these that's what these

41:32 represent. Those little red things. this is the cell as it's stretching

41:37 out and then it has portions of cytoplasm kind of sticking off with little

41:42 on the end, looking for where chemical is coming from and it just

41:45 of follows it along. It can all these really kind of unique

41:51 It can cause branching, right? can cause sensitivity to other cues.

41:56 example, things that repel the acts away or can say this is the

42:00 you need to go. And ultimately happens is we end up creating this

42:05 of cells that are interconnected or they're other cells. And then what we

42:13 do now is based upon where these are. We can make modifications to

42:18 network through a process called neural You've probably heard the phrase can't cheat

42:24 teach an old dog new tricks, ? You heard that? I can't

42:29 that. That's that's too complicated. not true. Your brains are

42:36 not barbie plastic, malleable and And in fact, that's how your

42:42 actually learns and stores information. All . So, what I want you

42:48 do is don't focus on this. want you to focus here. So

42:51 right? Here represents how your brain a bunch of cells. So each

42:54 those dots represents sell each line represents connection between those cells. So this

43:00 is talking to that sell that sell sell on. That cell. The

43:03 is talking to those two cells and on and so on. And so

43:06 . These two cells are all lonely sad because they're not part of the

43:10 . All right. But what happens you create an experience, right?

43:14 little baby, You stick keys in mouth metal tasting right? And so

43:19 happens is is that through this process neurogenesis, through this process of chemo

43:25 and extending you're going to start creating connections. And so you can see

43:31 cell has started creating a connection This cell has started creating connection

43:35 so on and so forth. That's the dotted lines represent. So,

43:38 cells that were initially not part of network are becoming part of the

43:42 As your brain is trying to you know, these interactions. You

43:48 , whatever it happens to me and just have keys in your mouth.

43:50 don't know. But what will happen as you continue doing whatever that activity

43:57 and start reinforcing it through practice is going to strengthen certain interactions.

44:06 And so the signaling between the cells going to increase in certain areas and

44:11 in other areas. And so what up happening is over time you reorganize

44:16 network so that there's this new interaction this is what represents whatever that new

44:22 that you just learned now again, is just cartoon stuff. And the

44:26 here is you start off with something this and you end up with something

44:30 this and that's simply through experience and that our brain changes. All

44:38 How many guys know how to How many 10 years ago? You

44:42 know how to drive? Well, of you should be like, I

44:46 know I mean yeah, you played theft auto, but that ain't

44:50 That's that's that's just fun, Right? You learned how to

44:56 You sat through the boring lectures, watch the videos of the trains running

45:00 people and cars, right? I kids going through drivers at right

45:06 I'm doing the parent teaching ones. it's gonna be a lot of

45:11 But the idea is that, you , this is what your brain was

45:15 before you drove right in that area learned how to drive. And then

45:19 you became more proficient at it Now can weave through cars on the highway

45:24 80 mph, right? Yeah, too hot. So, so the

45:34 here is don't think of a connection so much of a if I do

45:39 connection, then X will happen. the network is going to create those

45:44 . It's kind of like saying I'm to five friends. You're not you're

45:50 to as many connections as needed in to perform whatever the function is,

45:56 ? So if you need to have friends to run for political office,

46:00 gonna find 1000 friends, right? will be strong friends. Some will

46:04 weak friends, right? If you need five friends to walk with you

46:09 the aisle, you're going to figure how to do that as well.

46:12 ? So each of those networks that creating are gonna be unique for whatever

46:15 task is, it needs to be and it's gonna, you're basically what

46:19 gonna see here in just a second that the clusters of cells are all

46:24 be associated with one another because they're involved in whatever that activity is.

46:28 right? And so if you think a baby, then this is kind

46:32 a way you can think about it in that first year of life,

46:35 them learning how to do stuff and their brain to start developing these

46:41 I mean, they they do things you stick out your finger and they

46:45 it right? And then they're you know, they're like amazed.

46:49 what they're doing is they're training their . If I reach for something and

46:53 it, then I'm actually touching something that's training the brain to believe this

46:58 what happens when I reach out. know, or when they grab the

47:01 and start looking, it's like, , this is what something tastes

47:04 I'm gonna explore my environment through right? And when you smile at

47:09 and they respond back, you you smile at them, they smile

47:12 you and you smile back and it's oh when I do this, this

47:16 the response I get. And so building up that activity by reorganizing the

47:22 and how they interact with one right? And that's kind of

47:28 again, that's like the kindergarten I mean I'm not saying you got

47:31 kindergarten, it's just like this is the baseline understanding of the nervousness if

47:35 really want to understand the nervous if at some point you have time

47:38 take the neural path or the neurophysiology doctors burke's teaches. It's a great

47:43 to learn this stuff in more All right, so this is kind

47:48 like, what I was just trying say is like, you know,

47:51 we're gonna do is we're gonna do and integration. So we're learning information

47:56 the neurons already grouped together in these patterns. Alright. And what we

48:01 is we call these things pools. it's a neuronal pool or neuronal

48:06 All right. So if you hear words, just think lots of neurons

48:09 alright. And typically they're going to a functional group as a whole.

48:14 basically they all kind of are able process the same type of information.

48:19 you're doing is you're trying to figure which ones are gonna work together and

48:21 what they do is they then send information off to the next group of

48:24 of cells that then do something and on. All right. So if

48:29 thinking about the neurons, they're either to be very very localized. So

48:32 you've got all these neurons in a place and this is gonna make a

48:35 of sense when we start going through rebrand and saying this is where X

48:38 processed. Like this is the visual . Okay, so that means specific

48:44 of vision is processed in this All right. But you might also

48:49 that the neurons are going to be throughout the cns. So it's not

48:53 that one location. That information is there. And then it's moved to

48:57 different location. Again, I use here because in the brain while the

49:03 visual cortex is the occipital lobe, you're gonna see is there's a

49:07 So that's called V one. That's the abbreviation visual one. There's a

49:11 two and V three, V V five, V six, A

49:14 seven, V eight, V nine V 10, V 11. And

49:17 a Bs and CS from any of things and I think it goes all

49:19 way up to like 17 or We'll never have to learn any of

49:23 . Alright, but the idea is in order for me to look at

49:26 and understand what it is. It to go through all of these different

49:29 of processing before your brain can Oh, lollipop. Right. What

49:39 is being sent to And where that is going to be sent from is

49:43 to be restricted. Right? I'm going to send visual information to an

49:48 that's responsible for processing spell. It make sense. Right? So,

49:53 that information comes from is from the , right. I'm not gonna send

49:57 from the back of my knee to eyes or to the visual cortex saying

50:01 you did you see that? Because there's no there's no input from

50:06 area. All right. So we're where the information comes and goes.

50:11 then those uh circuits can be either simple or they can be very very

50:16 . And what we do is we them down into four basic types.

50:19 I want to show you what simple complex looks like before we go into

50:23 of the four different types. All . Again, that rule that we

50:29 about, the synaptic delay, those apply. So the more complex the

50:35 , the more synaptic delay you the longer it takes to process

50:39 Okay, so this is simple versus . This is just a generic,

50:44 versus complex. Alright. We got , basically. What you see here

50:49 one neuron talking to another neuron. common in the peripheral nervous system.

50:54 very common in the central nervous All right. You'll see this neuron

50:59 to that neuron which talks to that peripheral nervous system often what you mostly

51:04 in the central nervous system are these things. And this is just an

51:08 of a complex. You can see got this talking to this cell,

51:11 then this cell talks to the next , but it also talks back to

51:14 cell that talk to it in the place, that's complex, Right?

51:18 what that means is you now have circuit that's kind of reverberating on

51:24 Yeah, like there's like a physical , so in this case what it

51:33 , it's you can think of it I'm not gonna do a good job

51:37 this because I don't know computers that . But it's like how computers process

51:41 . It's there's like binary responses. something or don't do something excite or

51:48 , Right? And so if you imagine a network of cells where it's

51:51 , okay, my job is to the next cell to become excited.

51:54 next cell in the in that chain say releases a hormone or a

51:59 then whatever stimulates me, tells tells me to tell the next cell

52:04 to do next converge back on the cell. And so what you're doing

52:08 you're creating a pattern of response so at the very end, whatever you're

52:13 to get done gets done. what you're doing, like when you're

52:20 is you're actually creating that pattern. . So, remember what I said

52:24 that when you're dealing with uh thinking memory, it's not stored inside a

52:31 , What you're doing is you're creating neurons to fire at a certain

52:35 They might be inhibiting other neurons, might be turning on other neurons.

52:38 so, what you're doing is you're a pattern that's generated when you stimulate

52:42 network. Again, if you can you can recreate that pattern, you're

52:46 to pull up whatever the memory is whatever the idea is. And so

52:50 studying is is generating the pattern. So that it then remains in long

52:57 , right? In other words, storing up the pattern itself. I

53:01 it's very, very I don't know the word I want to use here

53:07 strange, like, what to Alright, so, this is kind

53:18 cool. And you're making me go a tangent, we'll go down the

53:21 and we'll pause for a break. right. So, like I

53:25 it's about the pattern initial study that done to demonstrate that this was true

53:30 they took a bunch of rats and put them in a maze because that's

53:33 we like to do. All And what they did was they put

53:36 in the brains of the rats and were looking at a specific neural

53:40 Alright. So, they were able hone it down to just like a

53:43 area. And what they did is trained the rats to run, it

53:47 amazing, it was like a figure . Alright, So basically it's a

53:51 , you know? So they had a middle track and in that middle

53:55 they had a wheel. And what did is they train the rats to

53:58 around, get to the wheel, on the wheel, jump off,

54:01 go around, create that figure jump on the wheel again and do

54:04 and then come back again and repeat process, right? So there's your

54:08 , right? And what they did they could actually see the pattern being

54:12 in the neurons while they were training rats. Alright. And then what

54:16 did is they kept those those same stuck in their brains, which is

54:20 a horrible way to run around, ? Because you've got wires and you

54:23 the wires with you. But they the pattern as the rats ran and

54:29 rats would actually create the pattern before got to the wheel, you're

54:35 and it's like, okay, this the pattern they get when they get

54:37 the wheel and they would see that rats would think about the wheel just

54:40 they got to it, right? they were thinking this is what I

54:43 to do next. So the idea that the pattern was stored, but

54:47 could also see when the rat would a mistake before the rat made the

54:51 . So if it wasn't going to through the wheel and said it was

54:54 run straight or run past the they say, okay, the pattern

54:58 changed and so I can't see So to answer your question, what

55:04 you trying to do when you study you're trying to generate or create that

55:08 right now? Does this only current the same month that they came out

55:12 that paper? This isn't like There was a study done in humans

55:16 the same sort of thing, but in the brain made a run around

55:21 what they did is they made them videos, right? And it was

55:26 that they would see watch over and again. Very small clips. And

55:30 they were trying to do is trying see what sort of patterns would be

55:33 . And again, they haven't watched over and over again. And then

55:37 they had to interview them and again the electrodes in their brains and they

55:40 see the pattern that was being generated they're watching the videos. And then

55:43 they interviewed him, asked him questions , they could see the pattern being

55:46 in the brain that matched the right or the wrong answer. Right?

55:52 it was the correct answer. The would would be wrong. Yeah.

56:01 . Well, so both of them two or more right. But it's

56:04 how come, I mean how structured is and we're gonna walk through some

56:10 these in just a sec. And so I mean the two easiest

56:14 are the converging and diverging circuits. you ever wondered why you take physics

56:18 get into some of these graduate programs health? It's because you've got to

56:22 what these words mean. I mean that's what it is, is do

56:25 know what these words mean? So just we'll do these and then we'll

56:29 the other ones and we'll take a . All right. So converging circuits

56:34 pretty simple. This is something that you guys can can see.

56:37 I mean here we got a bunch inputs acting on a single cell and

56:44 single cell then is acting on something . So what you're doing is you're

56:48 a lot of different types of information you're consolidating that information into some sort

56:54 response. Right? So an example salivation, right? Think about sitting

57:01 at a barbecue joint. We all barbecue. Yeah, like it.

57:05 right. So you go into a joint, what do you do?

57:07 don't see the food first? You it and all of a sudden your

57:11 just go right and then you look and you're like there's there's the,

57:16 know, it's a proper barbecue So you're actually just walking and picking

57:19 your barbecue and you see the thing want to eat and it's just

57:22 oh man, I can't wait to my fingers on that and then you

57:25 sit at the table and then you touch it and then you put it

57:28 your mouth and it's just like to for, right? So every sense

57:32 your body is like going winter winter dinner, that's what those are,

57:38 would be like the gustatory. That there is the visual that right over

57:43 is the sense of smell, The old factory and all this stuff

57:47 converging on those salivary glands say get to eat and it's gonna start causing

57:54 to salivate, right? That would an example of converging. It's a

57:58 example, but it's an example nonetheless , in a diverging circuit, what

58:04 have is you have an input that goes to different sources or two different

58:10 . Alright? And so the example like to you here is think about

58:13 , alright, walking is simply the of lifting up my leg, putting

58:17 weight forward and preventing myself from right? So walking is not

58:23 what is swimming? Not drowning It's keeping my body above the water

58:31 , but I'm still getting motion But when I walk it's not just

58:35 lifting up and dropping my leg, also maintaining balance, right, It's

58:40 ensuring that posture takes place. So are muscle groups that are involved in

58:46 that I don't even think about because I think about walking I think about

58:49 and dropping my legs over and over , right? But there are muscles

58:53 my toes, there's muscles in my , there's muscles in my belly,

58:57 muscles all over that allow me to that thing. So the signal might

59:02 time to walk, right? That's that is. And then it's convert

59:06 it's diverging to the different parts of body and those different systems to tell

59:12 time, what do we do? then those cells downstream? Say

59:16 I'm going to tell this cell to excited, I'm gonna tell that muscle

59:19 there to relax, I'm gonna do this. And so all those signals

59:22 going all over the place to allow to create that one simple step

59:29 We got the weird ones. All . The weird ones are the reverberating

59:35 or the rhythm generating circuit, and parallel after discharge circuit. Alright,

59:40 here in the rhythm circuit, you see we're starting off with one

59:44 we're just putting two in this to our lives easier, but you can

59:47 what I have is I have a . So this cell is talking not

59:51 this one but two. That Alright, this cell is talking to

59:54 cell as well, but it's actually , it's actually activating along the axon

59:59 then this cell is actually river to , reverberating back to the original cell

60:05 it's actually stimulating the cell, which also stimulate that cell. So what

60:08 doing is you are creating an activity gets bigger and bigger and bigger and

60:13 and bigger and bigger until something comes from the outside and says stop

60:18 Think about breathing. Right? When inhale, does your inhalation continue on

60:25 , right? It goes and then stops and then your muscle relaxes and

60:31 when you inhale again and you just that pattern over and over and over

60:38 over again. It's because you have series of cells that are reverberating to

60:43 that big, big big, big and then something comes along and says

60:46 all the signals and it all goes and then you relax and then let's

60:50 it. And that signals which then and signals and signals get big,

60:54 , big, big big again and along says kill it all and then

60:57 relax again. All right, this these when you see these kind of

61:02 that's a central pattern generator, It uses these types of circuits.

61:07 one. Think of any sort of activity that you have is walking rhythmic

61:15 right, Here's a fun one but pizza govern your mouth. Just

61:24 can't stop, right, get tired one side, what you do,

61:28 it over to the other side keep , right rhythm, rhythmic pattern

61:33 parallel after discharge is one of those of weird circuits where the responsive cell

61:41 then the cartoonist here tried to do and it's not an easy thing to

61:45 . The response to sell isn't just a burst response or a series of

61:50 or you know like a growing Like you see here instead this cell

61:54 going to receive multiple inputs in So you can imagine like here that

62:01 cell, you know, is probably of the first one that's gonna be

62:04 to send a signal. But over we've got synaptic delay, synaptic

62:07 synaptic delay. This cell is shorter that one. So this one probably

62:11 the second signal. That's probably the signal. This will be the fourth

62:15 . So this cell is receiving a like this. It's like Yeah there

62:21 four there. Okay, so that is a series of 1234. And

62:28 this signal is not just one it's gonna be many responses but through

62:34 same pathway. So you get this I dis elongated response in this

62:42 Now I said here it's probably involved higher order thinking. So in these

62:46 networks they're all interconnected with each Like so and so you can imagine

62:51 happening is you can now create right? So this may be going

62:56 a big response after 1234. And maybe it's going through some sort of

63:01 circuit that keeps this thing going all the place. And it's repeating that

63:06 that ultimately becomes an idea or a . Thank you. The Middle

63:22 No, remember. Yeah, it to go remember. Because when we're

63:27 with the synapse, those two cells almost touching. You have a

63:32 Did you ever play the I'm not you game with them? Always.

63:36 . You know, you know what game is? Right? You can't

63:39 mad at me. I'm not touching . It's like this stuff. I'm

63:41 touching you. You can't be Don't be mad at me. You

63:45 get mad. Right? That's what's what neurons are doing. They're playing

63:48 I'm not touching you game right So close that the only interaction they

63:53 is by those chemicals and those chemicals they float away, they get

63:57 So you can't skip over a you have to go through the neuron

64:00 that chemical signaling. Right? So well let's use this one right here

64:06 you can see one there's another here's another cell. So you can't

64:09 go, oh I'm gonna jump over cell because whatever chemical that synapse releases

64:15 never get to that cell. And talking. That could be millimeters,

64:20 ? It won't be able to reach . It has to have that

64:24 that connection between them and what the can't really do is show you how

64:28 that that uh that dendrite is to um tele Andrea they're literally right there

64:35 to each other. Yeah. So happens if you kill this? What

64:45 if that neuron is damaged or dies some, what would happen? So

64:52 would lose this connection? Right, now this cell isn't responsive in

64:57 in this pathway. So this cell here, which is using all three

65:02 really all four pathways would then amplify it's signaling through the others. And

65:08 that original pattern that you're trying to , which would be the 1234 is

65:12 gonna be a 123. But how you make it do what you needed

65:16 do? So you might lose the , right? You might have have

65:21 reorganize how you think think about a , right. If you've known somebody

65:27 had a stroke, they have a time in the same sorts of movements

65:31 they were doing previously. Right? they go to a physical therapist and

65:36 an occupational therapist and the occupational physical retrain how to do simple movements or

65:43 complex movements in the case of an right? And what you're doing is

65:48 going through that process of of really neural plasticity and saying that network that

65:55 formally had no longer exists. We to find a new way for you

66:01 learn this pattern of activity. That's job. All right. I guess

66:09 is the last one because we'll get the spinal circuits. So,

66:12 as I said, the circuits themselves gonna be developed very early on during

66:18 and neonatal growth. And then they're be maintained through that plastic stick.

66:23 plastic nature of the nervous system. , So we're going to reinforce,

66:27 going to break down, we're going make new things. So, these

66:31 are what we are doing to create networks. Right? So everything that

66:37 do is gonna be dependent upon how create those networks and whether or not

66:44 maintained. All right, simple circuits regulate complex behaviors. And what they're

66:52 do is they're gonna produce what we to as reflexes. We're gonna pause

66:56 reflexes and we're gonna come back and with the reflexes. Uh man,

67:00 just kept going there, so take a like a five minute break,

67:04 guess. And then we'll come back try to finish out here. All

67:20 , we're gonna move on. We're talk about reflexes. Um and try

67:24 get through this as like I quick as I can, we're gonna

67:27 from reflexes, spinal cord spinal nerves they kind of all kind of blend

67:32 because when we learn about the most of our reflexes are occurring at

67:38 level of spinal cord. That's not true, but most All right.

67:42 what are the reflex? A reflex definition is a rapid, pre

67:46 right. Involuntary reaction in a muscle gland or to some sort of

67:51 So stimulus is anything sensory input that's to initiate the reflex. Rapid means

67:56 not gonna have a lot of neurons . When we say pre programmed,

68:00 gonna get the same response every time all done this one. Right?

68:04 knee jerk reflex, you go to doctor, put your leg on the

68:06 of the table and you can sit and wax at the at the

68:09 Your leg just jerks right? You do anything about it like you don't

68:13 a choice. It's involuntary meaning you not have a conscious intent to let

68:19 happen. This right here is an of another type. Alright, this

68:23 here would be the suckling reflex. ? You can't see it because it's

68:26 a moving picture. But if you a newborn and put your finger at

68:30 mouth, it will turn its head that finger as if it were a

68:34 so that it would begin suckling. , It knows anything right around

68:38 I'm supposed to latch onto. And that's what it's doing. So the

68:43 cord is primarily responsible for the integration many of these basic reflexes. There

68:48 different types. We have what is basic or what are called conditioned

68:52 Basic reflexes are the ones that are in responses. You are not taught

68:57 . They just happen when you look a baby and smile at the

69:01 The baby naturally smiles back. That a natural reflex of basic reflex.

69:05 is pre programmed to say, I look cute and smile back at you

69:09 you smile at me. Alright. programmed to do that a condition reflects

69:14 what you practice and learn. Think all those years of going to school

69:18 when that bell rings at the end class, what does that mean?

69:21 up my stuff, Get up and , right. If you hear the

69:24 in the middle of the class, begin doing and go, wait a

69:27 . It doesn't seem right. Here's example of a conditioned reflex. You're

69:31 along, you see a yellow What do you do speed up?

69:37 , You've been conditioned. I'm not for that red light. It's gonna

69:41 four seconds. I can get through light right now. You also know

69:45 Pavlov and his dog and so that's that's the classic example of the conditioned

69:50 . Alright. Um This picture is the one most important picture that you're

69:55 see in this unit. Not because the reflex, but it's gonna repeat

69:59 over and over again. All It's a good way to understand.

70:03 only the reflex arc, but also difference between the periphery and the central

70:07 system. Um And how it all together. So, you'll see this

70:11 over and over again. So just of go okay I'm gonna I'm gonna

70:16 this. All right. So the arc is real simple. Alright,

70:19 five parts to it. There's the where the receptor is. Alright,

70:24 this is where the stimulus is detected this particular case. We have a

70:28 . I always say it's an electric because they put lightning bolts right?

70:31 that nail has been penetrated and it's touching some sort of touch receptor.

70:36 right. And then that signal that's by that interaction, then it's going

70:41 travel along what is called the a pathway. Alright, I'm gonna put

70:46 strong accent on the a a ferret if I did a nice texas

70:51 we just call it an affront and sounds a lot like different.

70:56 So it's an a different and then gonna process in what is referred to

71:02 the integration center. All right, the third step. This is processing

71:08 . I've just been jammed or stabbed nail. What do I do?

71:13 , response is when I feel pain this place I move my hand

71:16 Okay well let's tell that area to the hand away. And so you

71:23 the signal down the different pathway to structure that does the job of

71:29 which we call it the effect. it causes the effect. So receptor

71:36 a ferret into the integration center Integration processes or integrates information. Then we

71:43 the signal down the different pathway, out pathway to the effect which causes

71:48 effect. All right. And each these represent where an action potential is

71:54 . Now reflexes could be mono mono means one and then synaptic means

72:04 . How many synapses? One mono here. 1, 2. So

72:10 becomes poly synaptic. Don't let the scare you. Okay so this is

72:17 most simple type of reflex that stretch . The knee jerk reflex is an

72:23 of a mono synaptic. There is neuron between the different neuron and the

72:30 a different different right So I stimulate received that there's a receptor sends a

72:36 . It just goes right on to next neuron and causes the effect.

72:40 is still an integration center. Where when that where that synapses but it's

72:45 is a very very simple reflex. , no other input is being there

72:50 modify polish synaptic. We will typically within their at least one interneuron.

72:57 is an in between neuron. It so in the name. Alright so

73:01 again I'm being an idiot. In lab I put my hand over a

73:05 burner. Don't do that. It and then what's happening? I feel

73:09 heat goes in. I process information move your hand away there goes to

73:14 effect. Er I move my hand from the heat. This synapse while

73:20 seeing here is being very very may actually cause other or there may

73:25 be collaterals that go to other places you burn yourself? What is one

73:28 the things that you usually say? only way you can do that is

73:33 a signal is sent up to the nervous system to the brain,

73:36 So that interneuron allows you to send up. There's also other places where

73:42 may need to send information. So I contract this muscle I need to

73:46 that muscle. So, what we're seeing in here is all the other

73:50 that are taking place here for me move my hand away, because all

73:54 concerned about right now is how do move the hand away? So policy

73:58 have multiple neurons that are integrated into pathway to allow other things to

74:08 Some reflexes are called autonomic reflexes, are called somatic. If it's dealing

74:14 your organs. So think about your grumbling when you smell good food,

74:20 ? That would be something that's affecting organs. It's affecting through the autonomic

74:25 system. We keep using this word and over again, even though we

74:28 talked about it yet. All So that is the autonomic when we're

74:33 about somatic. You're dealing primarily with . Alright, so like again,

74:38 I step on a tack and look foot, that would be a somatic

74:42 , Right? If I like I if I smell food, my stomach

74:47 grumbling, whatever that's autonomic, please confuse autonomic with automatic. All right

75:00 , as I said, we're going move into the spinal cord, we're

75:05 finish up with the spinal nerves. , spinal cord exits via the base

75:11 the skull. Alright, So what going to see is we're going to

75:15 we have the brain, the we have the midbrain and from that

75:18 brain that keeps going down in that of spinal cord, it's encased by

75:23 vertebral column. Remember when we looked the vertebrae we had that um framing

75:30 so we were able to create a through which the spinal cord travels.

75:35 protected by the bones of the It's protected by meninges, all three

75:40 . It's protected by cerebral spinal So just like the other structures that

75:45 when we said protect the central nervous . We weren't excluding the spinal

75:52 When we talked about the vertebrae, talked about there being different vertebrae,

75:55 had cervical, we had thoracic, had lumbar, we had sacral and

75:59 had cox ideal. Alright, the cord is divided along those lines based

76:05 where the spinal nerves are located. right, so the spinal nerves are

76:09 exit out through and in between the at these different locations and so where

76:15 spinal nerves are, you can see kind of look like the little tiny

76:18 legs here. They're basically you can , okay, the first group,

76:23 many would there be? Seven would cervical then, thoracic would be 12

76:30 five, so and so and so . Right. So those nerves are

76:34 to be named spinal nerve number or , one cervical to cervical three.

76:38 and so forth. Just like we when we learned the vertebrae.

76:43 The thing is, we're not there . So that's the spinal cord.

76:50 we take a slice through the spinal , we can see its organization.

76:54 right now, this is not a picture of it. But you can

76:58 this side right here, the dorsal the ventral or the post here in

77:01 anterior sides are a little bit So you can kind of it's a

77:05 bit more squished. You can see there's some grooves, right? So

77:10 the dorsal side we have the dorsal media or posterior medial. Focus on

77:17 anterior ventral side. We have the medial fissure. So this is a

77:23 . It goes deep. The sulcus kind of goes down a little bit

77:27 right, depending on where you make slice of the spinal cord, you're

77:32 to see different shapes to it, it's going to have that same generic

77:36 . All right. The idea of a little bit flat and a little

77:39 elongate, but in areas in different , you're going to see different

77:45 The gray matter is going to be central. The white matter is located

77:50 and there's that central canal that I . That. Is that tube that

77:56 off with the ventricles. So what white matter? Do you remember?

78:02 does white matter? Axons? It's basically pathways. So basically how

78:09 sending signals. And so if we at the white matter here, you

78:13 imagine what we have is we have bunch of axons moving towards you and

78:16 from you. Alright, in and of the out of the screen.

78:20 so there's basically three columns here that call funicular. Alright. That's the

78:26 we use instead of calling it a . It's a funicular. Just pick

78:30 half if you like the left That's great. If you like the

78:33 half, that's fine because it's the and the right is how we kind

78:36 divide things. But what we have up here at the dorsal side or

78:41 posterior side. We call it the or posterior. For Nicholas over here

78:46 the lateral ridiculous. And then down is the ventral or anterior funicula so

78:53 follows all the patterns that we've learned ? Very, very simple. All

78:57 . And these tracks are gonna be or bundles of fibers that are traveling

79:04 with similar origins and or similar All right. I'll elaborate on that

79:12 about two slides. I want to to the gray matter. All

79:16 When you draw gray matter, make life easy draw a nice simple

79:19 So, here's what you do is go, All right. There is

79:24 spinal cord. All right. Here's weird looking butterfly. The gray matter

79:32 divided up in what are called Alright, So, you can see

79:38 have one horn to horn. Three . Right up there. Not so

79:42 to see the horns, but they're still there. Okay, This horn

79:49 the dorsal horn. This horn is lateral horn. This horn is the

79:56 or anterior. This is all post . You can use either term.

80:00 tend to stick with dorsal, dorsal or ventral. All right.

80:06 each of these and you can see gray matter. There's your central

80:10 Gray matter uh covers that central What I wanna do is I just

80:19 to point out what these are. gray matter consists of what type.

80:24 what what is gray matter? Generally , if white matter is axons,

80:29 matter is cell bodies. All So, here what we have are

80:35 cell bodies of sensory neurons. Sorry, that I take that

80:43 Strike that from the record, erase from your brains totally incorrect. Somebody's

80:50 sensory neurons are located way out What we have here are the cell

80:59 of inter neurons. All right. inter neurons are receiving information from sensory

81:09 . So, the information that comes is coming in from that direction.

81:16 , so these are inter neurons. is where the sensory information is deposited

81:23 the central nervous system. In the cord. In the lateral horn.

81:30 going to have the cell bodies of that are motor neurons. In other

81:37 , they leave and they go out a muscle or gland. But these

81:43 the lateral our autonomic if their autonomic means they're going primarily to the smooth

81:51 of the viscera cardiac muscle. Or going to the glands. Their autonomic

81:57 nature. All right. You can't their basically the involuntary muscle. Down

82:05 . In the ventral. What you are the motor neurons of the somatic

82:13 . So they're the ones that deal muscle. Okay, so sensory input

82:18 in via the dorsal horn terminates on neurons in the dorsal horn. Those

82:26 neurons will terminate into the lateral or horns. The lateral horns. Autonomic

82:34 , ventral horn somatic neurons. And are motor. Okay. Century motor

82:46 . It means these are out. , now, we're talking about protections

83:07 by the brown protected by the meninges . All three are there. The

83:10 is that the dura is a single . Instead of two layers, we're

83:15 to see that there's a small space the door and the bone filled with

83:19 . That's called the epidural space epi the dura. Right? We will

83:26 that the meninges extend beyond the length the spinal cord. The spinal cord

83:31 goes to L. two. Your grow faster than your spinal cord

83:36 So your spinal cord shorter than your length. All right. So here's

83:40 spinal cord. Your this so the go down, they cover the spinal

83:44 and they keep traveling down all the to S. two. That's sacred

83:50 . All right, you still have and then sitting over here on the

83:58 . Those little tiny lines are what called articulate ligaments and they kind of

84:02 the entire length down. And that your spinal cord from flopping around while

84:06 move, basically holds it tight to to the structure so that the spinal

84:11 sits in place. So while you still bend and move and stuff like

84:16 , it doesn't bounce around. That's lenticular ligament. This picture here Does

84:23 good job of showing what that spinal does. So here's L.

84:29 That's about where the spinal cord And then you can see that spinal

84:36 continue down and keep leaving along the . There's the line right here that

84:43 you that dura. Look at how dura keeps going past the end of

84:47 spinal cord continues on down all the down. You can see the spinal

84:53 are exiting out where those vertebrae are and they just go by the same

85:00 . The end of the spinal card is called the Conus Miguel Arroz because

85:05 a comb, right? And then spinal nerves keep going down and the

85:10 cords look like a bunch of horse hanging off the back of a

85:14 So it's called the kata Aquafina but see how clever we name things

85:23 what they look like. All There are 31 pairs of spinal cord

85:27 spinal nerves. The exit out via inter vertebral foramen enter between the vertebrae

85:36 . All right. You'll see two . You'll see an enlargement here and

85:41 see an enlargement. It's right up . Okay. That enlargement just represents

85:47 fibers from the limbs from the appendices up. And so it creates a

85:55 of a broader or fatter area. , if you're looking at the spinal

86:00 , you know without all this gunk , what you see of course I

86:04 it out. It looked kind of this like that. And so you

86:12 imagine that there's more fibers coming in the arms would be and more fibers

86:18 the legs would be. That makes . Here we are. Again,

86:28 to the structure. You're gonna see great majesty looks more like a

86:36 What's that called dorsal horn. That that one very good. Alright.

86:49 fibers that are leaving the ventral Alright. So remember those are motor

86:55 and it's the outdoor. And what gonna form is what is called the

87:00 , sorry, it's called the ventral . Alright. On the other

87:05 you have fibers coming in, And that fiber coming in Or those

87:11 those are axons bundled together. It's called the dorsal root. The

87:17 root and eventual route converge and form spinal nerve. So, this,

87:22 ? Here would be the spinal There's your ventral route. There's your

87:26 root. Here's your spinal cord. right. That big fat thing.

87:32 ganglion, What do we say? is having them? Cell bodies.

87:40 ? That's all right. This is we why we play this game.

87:44 right. So, when we are at those fibers, those sensory input

87:50 have to do it over here. it smaller. What we have here

87:57 we have a series of sensory fibers in like so, terminating on those

88:03 neurons. Right? Sorry about the . I'm just gonna make a

88:07 right? So, this is that neurons. So, their cell bodies

88:11 located in that ganglion. All So, the sensory fibers, cell

88:18 in the dorsal root, gangland. , we're going to learn not a

88:22 , but a cadence to help us patterns. We're going to start with

88:25 spinal cord spinal cord. The fibers are coming in and going out are

88:31 in or going out via the Now, the truth is there's actually

88:34 a smaller structure because the roots are little bit thick. So there's little

88:38 structures that are called root. Let's you go spinal cord to root.

88:41 root. Let's to root, convergent form the nerve so far with

88:49 . Let's do it again. Start here at the spinal cord fibers going

88:54 , fibers coming in via the Let's root. Let's are basically the

88:57 tiny versions of the roots. The come together form the nerve spinal

89:05 There's route. Let's root. Let's the root roots come together. There's

89:09 routes come together for me nerve spinal . Alright, spinal nerve contains fibers

89:20 in and going out, right? like a highway. There's not one

89:23 , it's two ways right there all individually. So there's no mixed

89:28 And what you're gonna do for a , you have this very fat,

89:32 short nerve that nerve splits into three . Alright, these branches are called

89:42 ramos. For single. Remy plural Raymond. We have a dorsal

89:50 eventual ramus. Where do you think dorsal ramus is On the back

89:54 Where do you think the venture one front side and then we have this

89:57 one called the Remy communications right? gonna ignore this one as part of

90:03 autonomic nervous system. We will come to it. Alright, so right

90:08 we're not gonna worry about it. can see it sits off over here

90:10 the side. Okay, and we're to deal with that in the next

90:15 . Because if we spend a lot time talking about it, you'll get

90:19 . I want to focus on the to the dorsal and the ventral and

90:23 then I don't even really want to about the dorsal all that much.

90:26 dorsal is simple. All right. , you start off over here,

90:29 the spinal cord, spinal cord goes route. Let's root. Let's too

90:34 . Roots to nerve nerve splits. dorsal ramus, muscles of the

90:41 sensory input of the back. That's simple. Right? So dorsal,

90:49 . That's easy. The ventral ramus the one that is interesting.

90:56 It deals with all the primary nerves your body when you think of a

91:01 other than the ones in the That's where they come from. Is

91:05 the ventral ramus. All right. what they're gonna do is we're going

91:09 see some really kind of weird interaction these Raymond. Where am I communications

91:15 part of the autonomic nervous system. they're they're part of the three

91:18 So, again, we got the cord spinal cord goes to route let's

91:21 . Let's two routes, routes to nerve splits into the dorsal ventral Remy

91:27 well as Remy communications dorsal deals with back muscle and skin. What is

91:32 skin for? Is that sensory or or sensory motor? Century. I

91:39 spider crawling up my back. There's be sensory nerves in my back that

91:43 , hey, time to start doing thing. Right? muscles flexing.

91:51 , So just remember sensory means, motor means affecting. All right,

92:00 venture Ramos is going to branch off a kind of a weird way Now

92:08 we get into this weird way, I want you to see is the

92:12 of your body. Alright. These nerves which go into these different Remy

92:19 going to be organized topographically so that you go into the spinal cord,

92:25 thing that's furthest down from your body going to be more immediately located and

92:31 you move up they're going to move laterally. Think about how you get

92:37 the highway right? When you get the highway, Here's a really good

92:42 right down here at the 288-59 right? You get down to those

92:46 lanes, let's say you're in the far right lane, right on 2

92:53 . Well really it's 59 so you're have lanes that disappear after 2 88

92:59 down to two lanes, you go that horrible crawl, you know,

93:01 know which one I'm talking about. goes like three miles an hour and

93:05 cursing every big truck on the highway all the slow people who are sitting

93:09 their phones right, Because that turn this All right, but if you're

93:12 that left or that total right what's gonna happen is is that that

93:16 lane doesn't stay a right lane much , does it? Another lane will

93:20 and join you. Now you're in middle lane. You travel a little

93:23 further past Louisiana, Two more lanes in and now you're five lanes,

93:27 basically one lane from the left, , and you travel a bit further

93:32 in front of lakewood. And now have like six lanes right? And

93:37 you get over back to 6 10 it like shrinks back down to three

93:41 right? And so what I'm trying show you here is like these fibers

93:46 being pushed because more fibers are coming and they're maintaining their position inside the

93:53 cord, right? These are not that just kind of go wherever.

93:57 just jam them in there. There's organization to it, which makes it

94:03 to understand this material as we move when we start looking at the white

94:06 in its organization. All right. that's just kind of what it's showing

94:11 is that there are nerves that are , that go more medial and as

94:14 go up, they stay uh they on the lateral side. Also,

94:22 nerds are named for where they're That also means the body is divided

94:29 where those nerves go and go to where they come from. And so

94:33 we have is there's an actual We call the derma tone, where

94:37 sensory information is found and we call the Maya tome where that spinal nerve

94:42 and innovates a muscle, Right? again, it's easily mapped. I

94:48 for example that um a nerve traveling L. one is going to represent

94:54 area. It's never gonna represent this . So if you have that like

94:58 tingle or you lose sensation in a of your body, they know,

95:05 know physician with the order. You know. Oh that would be The

95:10 that's innovated by c. 5 All right, so there's a map

95:16 you can actually create to your body's of cool that ramus. So this

95:23 what you see here. See little . Those are the ramus is that's

95:27 ventral ramus or the anterior ramus. . In this case the cervical

95:35 So you can see C12 Yada Yada . So over in here we have

95:40 spinal cord, spinal cords are going have fibers that go in and come

95:45 via the route. Let's root. form roots. Don't do the

95:51 You're gonna lose it. Alright, cord cord to its roots. It's

95:56 roots. Roots to nerve nerve splits form ramos dorsal, ventral, rami

96:04 dorsal for the back skin and muscle ramus is where we're focused and this

96:09 what it does. It looks like in Houston. I was just going

96:16 . Now, the purpose of a . And I'm just showing you this

96:20 . There's an easier way to learn . The purpose of the plexus is

96:23 ensure that a nerve or information going and from a location can get there

96:30 say between here and your home there's massive accident on your normal route.

96:38 there another way to get to your ? Yeah. You're not stuck on

96:42 . Right thank goodness. Right now not an efficient route. Probably a

96:49 you don't prefer but there is a and that's kind of what these plexus

96:54 . Are there not entirely like that you're not gonna get the full

96:58 But basically information coming out of the can then be sent down. It's

97:04 know one track or another. And you end up with is you may

97:07 larger nerves by combining different Remy to the name nerves of the body.

97:16 for example information from your forum will two different Remy to send information up

97:23 the spinal cord. Right? So ensures that if damage occurs. Say

97:30 At least I got information going through . three. That makes sense.

97:35 there's multiple pathways to the same place form these larger structures like.

97:45 Oh it looks like this and you to first dissect it out and figure

97:49 out and play with it right? that's in essence how they identified all

97:54 . All right. Yeah. Well they're all yellow and beige and very

98:00 but its position what they're innovating and they what what they what sort of

98:06 is detective when you stimulate them. right now, I'm showing you this

98:12 because your book uses these pictures. . Which kind of looks like the

98:19 maps from new york, you So if you don't know how to

98:22 a subway map, you might be little screwed. But you know,

98:26 think these are easier to understand Trying to look at a picture like

98:29 and go, oh all right. it's it's easier of course if you

98:35 a cadaver and you're able to tease things out because you'll know what you're

98:38 for and where they go where they from. But I want to understand

98:42 this is not one fiber. Each these represents hundreds if not thousands of

98:47 traveling in the same direction. And gonna be divergence as you move further

98:52 further down because you're gonna be innovating different parts, right? You're not

98:56 sending one nerve fiber down to innovate the skin on the back of your

99:00 . There's gonna be multiple nerves in , right? And they're converging together

99:04 a larger nerve structure which then converges other stuff to form a larger nerve

99:09 and so on and so on and on. All right. So we're

99:14 be looking at these plexus. There's of them that you need to

99:18 Okay, there's some sub plex is we don't ever focus on. But

99:21 are the four major ones. What's is that those ventral Remy in the

99:28 region don't use plexus. Is and reason is because we're gonna form what

99:33 called the intercostal nerves enter means in costal ribs. In between the rib

99:42 . See it's you see how easy is. If you if you take

99:46 the magic and the mystique it becomes little bit easier. Alright. And

99:52 the thoracic nerves are the intercostal There's a portion of T. One

99:58 that is going to form part of brachial plexus. And we're not gonna

100:01 not gonna sit there. And which does is formed by which things?

100:04 don't do that. I'm not gonna you. C. Two and

100:07 Three form what? That's that's not to be the case here. All

100:11 . But here you can see the me basically look you can come out

100:16 ? So there's one you can't see dorsal I mean, I guess right

100:20 there is the dorsal. Alright. there's a split. This remains the

100:25 my communications and that interior ramos just coming around and that is an intercostal

100:32 . So what do those innovate? the upper ones, right up in

100:38 , the tickle points, right? up here in the upper cavity then

100:44 work your way down. That's gonna the anterior chest and you work your

100:47 down. That's finally down into the . Alright. And really it's again

100:52 and the skin, That's what you're with When you deal with the

100:58 these four plexus is The Easiest one a cervical plexus. Alright. The

101:04 plexus are just gonna be c. through c. five and a little

101:07 of T. one. All They're going to create the nerves that

101:12 with the superficial neck. What does mean near the surface? Alright.

101:18 we're gonna talk about the muscles. its muscles of the hyoid, the

101:23 at the surface of the neck and the lower portions of the head.

101:29 are the muscles you need or not muscles these are the nerves you need

101:33 know. So, I've divided it or your book is divided up into

101:37 parts. The cutaneous branch and the branch. Cutaneous meal deals with the

101:43 . So what they're talking about here sensory input. So cutaneous is sensory

101:50 deals with muscles and movement. so here you can see them.

101:56 just gonna point them out just on on the map. I'm not gonna

101:59 you a picture of a plexus. just gonna ask you for if I

102:03 you anything, it's like here's the plexus, What does the occipital nerve

102:08 ? Well it innovates the occipital Where's your occipital scalp. There you

102:14 . That are magic. A regular oracles, your ears. So skin

102:23 the external auditory meters. So that's hole through your ear. That's your

102:29 canal, cervical, the anterior portion your neck. So that would be

102:34 post ear portion. So my anterior be right up here. Sucre,

102:41 , vehicular, above the clavicle the skin of the shoulder. Do

102:46 see how this is? Pretty All right. Now again, you're

102:50 some point you're going to take a of anatomy where it's gonna be a

102:53 more difficult than this. But right , this is where we want to

102:57 muscular branch. We're dealing with the nerve. So, I'm just trying

103:00 show you where they where they So, it's, you know,

103:03 occipital cervical. I'm not going to it out for you, but when

103:06 talking about the muscular branch, here's muscular nerve. They're super close

103:10 They misspelled it. And then the nerve. All right, muscular

103:14 that's the muscles of your throat. , right in there. Right.

103:20 then the frantic nerve innovates the What allows you to regulate your

103:28 Alright. Important nerve to know How we doing on time? Is

103:33 time? Damn it. Well, least we got We only have three

103:37 . Yes, I got a lot . We're gonna finish tomorrow. I

103:44 it. All right. You guys have fun at the lab.

103:50 I slowed down down there at the there. That was the problem.

103:57 do not do

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