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BIOL 2301 Human Anatomy & Physiology I - 2301_lecture16_1020
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00:01 No. All right, guys, enjoy the Yeah. Um is we're
00:17 to uh lower the volume. What gonna do today is we're going to
00:25 at the different types of protection uh the central nervous system has. All
00:32 , it's uh were 1st 1st just kind of generally speaking, what
00:37 the nervous system in general? That's take about a minute and a
00:40 So hopefully, you know me with gonna look at the different structures that
00:47 there to protect the first half, is the central nervous and then there
00:55 uh kind of go through all And I think it's very uh basketball
01:03 just a partisan. Alright, our starting point, as I
01:09 just kind of like, all well, what is the nervous system
01:11 , and the thing I want to of impress upon you first off and
01:17 with the nervous system, is that that we're gonna talk about is heavily
01:21 , meaning that the system will work themselves. So, we're talking about
01:27 that says, let's say we're looking something involved in motor activity, that's
01:33 the only part of the brain or of the nervous system is involved in
01:38 whole bunch of stuff. But the is that our brains can't really fathom
01:43 , very complex systems very well. what we like to do is we
01:47 to take complexes and break them down some very, very simple organizing principle
01:54 help us better understand what it is we're looking at that kind of makes
01:58 . And so whenever we're looking at stuff, just understand that first and
02:02 and then this is the first thing we're looking at here is what we're
02:05 . All right, nervous, it's incredible complex. It consists of all
02:10 nervous tissue that's located uh internally in structures of the cranium and then down
02:15 the uh the vertebrae, you there's structure in there and then we
02:20 the nerves throughout the body. And does this all relate to each
02:23 And so the people will start looking this and let's break it down into
02:29 where we uh you know, control versus areas where we submit or send
02:36 . That's our first kind of area organization. It's where we're dividing it
02:41 into two parts. And so the nervous system is your brain and your
02:47 that means everything else has to be nervous system. Now, when we
02:52 everything else, what is that? else? Well, these are the
02:55 and the ganglia we have we'll get game a little bit here, but
03:00 are found within. So if you're at this picture here, you can
03:04 say, okay, the big thing top and then the little stick that
03:07 down alright, that central nervous everything outside of that is peripheral to
03:13 central nervous system is responsible processing So that means your spinal cord is
03:19 for processing information, The nerves and ganglia are there to organize incentive
03:28 So the idea is, you if you put your hand on a
03:31 stove, it picks up that the that changing the stimuli and then send
03:37 signal up to the central nervous system says, what do we do about
03:41 ? And so the nurses, I a plan put your handle. And
03:46 that would be what system is responsible . It. Takes the information in
03:51 then send that information out. So kind of the way we're gonna be
03:56 at stuff. So we're gonna focus on the central nervous system and understand
04:00 and then we'll dive out into the and maybe come back in over and
04:05 again. But it will be easy see where it was. Like I'll
04:08 , okay, now we're moving back this area. Alright. So there
04:12 some organizational principles that anatomy issues in of looking at the nervous system,
04:19 also how the nervous system organizes Alright. So there is what we
04:24 to the hierarchy organization. And that we have upper and lower levels.
04:29 lower levels are simply those relay those where we really messages up to higher
04:34 . So, if I'm talking about which is central and peripheral, what
04:39 you think peripheral? Right. All . And so what I'm doing is
04:43 mason starting in the lower areas due the higher the higher areas referred to
04:48 central nervous system. All right. so But we also have information that
04:54 travel between points. And so when when you're moving up to the higher
05:01 of the central nervous system, we're talking higher is the brain. And
05:05 lower are the structures below the Now the brain is actually pretty
05:10 And so really what we're talking we're talking about a structure called the
05:14 , the cerebral is the brain When you think of brain. That's
05:18 you're looking at. The cerebral. and so there are things below that
05:22 are considered lower order relative to the . There will be also a structural
05:31 functional pattern of organization, which means neuron similar functions are going to be
05:35 in the same place. And that make sense. I mean, we
05:38 kind of like doing that ourselves, ? You put all your underwear,
05:42 drawer, you put all your shirts drawer and if you don't do that
05:48 , you're stranger than most. so, it's kind of the same
05:53 , neurons that in the work together gonna be caught together. That's really
05:58 it says. 3rd. There's a organization. All right. And what
06:04 going to see is that this is we refer to some matter Toby some
06:07 really body. So it matches or the body. We'll see this quite
06:15 as we're moving through the special But just to give you give you
06:21 idea if you look at the region governs the motor area. Alright.
06:26 see that the organization that there's actually map what we call the homunculus.
06:32 . It looks like a human that can see that. That's the so
06:37 feet are located interior lee, followed the needs, followed by the
06:41 followed by the body and then followed the upper limbs and so on.
06:46 like my body followed that planet fall my feet up to my uh to
06:51 shoulders. And so this organization that us understand and helps your brain understand
07:00 information is going to going. And the last thing I wanna point out
07:06 is that the central nervous system is constantly going through organizational change. Which
07:14 what we refer to plasticity. And so here like for example when
07:20 are studying right? Or when you're a movement alright. For those who
07:26 or played four or play a musical , you're learning to control muscle,
07:33 brain is reorganizing itself in such a so that it can repeat the actions
07:40 way that you want to repeat Alright? And this is also true
07:45 negative things. So like if you at your phone all the time and
07:48 never do anything else, it's reorganizing brain and helping you to better understand
07:54 environment. Alright. So their internal influences that are constantly causing changes to
08:02 structure of the. Now when we changes doesn't mean like completely flipping things
08:09 these other principles are true. Well not gonna replace neurons that are
08:14 One thing something else what you're doing you're you're basically influencing how the synapses
08:20 how the neurons are. There we . Alright. Another form of organization
08:31 has to do with gray and white . You probably gray matter and white
08:34 for those two terms. What? so what they mean? Brain matter
08:39 is areas in the brain or in central nervous is that are responsible for
08:48 . In other words, gray matter the cell bodies of neurons and their
08:54 close association. Alright. White matter the other hand, represents axons.
09:01 . So I should say with great that also includes the dendrites.
09:06 Well, white matter is the Axons typically have my elements of what
09:11 gonna see here is that white represents cattiness of those my that those violent
09:17 of yellow inter side creating a kind a lighter appearance. And so there's
09:22 organization that you can see that is consistent throughout the nervous system itself.
09:30 right, so, I'm just looking here. So here you can see
09:33 your brand new spinal cord, this gonna be the lower regions of the
09:37 cord as you move up. You see that they've done uh cuts uh
09:42 example, here's the medulla, here's brain stem, um a little bit
09:46 up and you can see that there's organizing principle that's kind of conserved.
09:50 the way you can think about if you start down here, this
09:52 the most simple sort of organization. we have in gray matter is centrally
09:57 near the internal region of the, know, it's not perfectly centralized,
10:02 looks like a butterfly. Um and that's kind of how you'll see it
10:06 . But that butterfly has surrounded it the most part, a lot of
10:11 matter. And so what you can is that there's processing in those areas
10:15 there's gray matter and that white matter now tracks of axons that are traveling
10:21 and down the final four, you everywhere matter. And if they're traveling
10:28 then they're traveling up into these different . And if you see here in
10:31 medulla and right here in the that brain matter still internally located.
10:38 after you get up into the this is where most of the processing
10:43 place. There's not enough space on internal side for all the gray matter
10:48 need. And so now what we've is we've taken great matter and we
10:51 it on the outside. So you gray matter internally located white matter and
10:56 matter again. And just to kind see, you can see it.
10:59 here these pockets right there, those the internal pockets of gray matter and
11:03 stuff right here on the outside. the outer gray matter. And you
11:07 see in these regions that white And so those represent tracks that are
11:12 between different parts of the as well traveling down through the brain stem and
11:18 the spinal cord. So our brain specifically located and our black matters.
11:28 what we can do is when we gray matter and white matter, just
11:31 what their jobs are. Gray matter , where the cell bodies and the
11:36 are. So we're dealing with neural . White matter is the signals coming
11:43 those cells going up to other Alright, that's what they represent.
11:52 that out of the way we're gonna coming back and forth between that gray
11:55 and white matter. We're gonna see all those different areas do.
11:59 What I want to do today is really want to kind of talk about
12:02 we protect important. And were you in the native kids with commercials don't
12:10 drugs. So we're just trying to your how do you guys as kids
12:16 to wear helmets when you ride your ? We did my generation did
12:21 It was my generation to make you do it. Well, I guess
12:26 know why. Alright, well what do we protect our brains and we
12:33 in a whole bunch of different All right. So we learned already
12:38 bone. Alright. Bone is one we protect our brains. We actually
12:42 our own helmet, right? But tissue didn't have itself. It's not
12:51 I should bring in. Alright, that's all protected by by bone.
12:59 bone is hard and nervous issue is very soft and I can't remember I
13:06 it to you previously, but just case I did brain tissue, nervous
13:11 is like warm, but All And what I mean that you never
13:17 you know, don't don't think about that you just took out of the
13:20 . That's are you can push It's more like that that bar of
13:24 is being held in position structure because wrapper around it if you put your
13:30 on it, push right into That's how the brain tissue, it's
13:34 very soft. There's a lot of in it because of all that all
13:38 own. And so it's very very . Very very delicate issue. And
13:43 what we need to do, we to not only protect from the external
13:47 , but from also the structures that body actually has. And so we're
13:52 see we're gonna see that there's a of of of you know, tissue
13:58 kind of these structures, Common energies sit there and first protect against the
14:04 brain or that the actual brain themselves . And then what we're also going
14:08 see is that we're gonna kind of up the brain surrounded with a very
14:15 compressible fluid that helps kind of holding place and kind of kind of keeps
14:20 further away from the hard structures of bone. And then the other thing
14:26 need to protect from are the things are circulating in our body and so
14:30 that are circulating in our body are and bacteria long. Hopefully not
14:35 But you know, things that shouldn't in that brain tissue because again,
14:39 all very brains are important. All . Let me just ask a simple
14:44 . I know that had a had beer or sticks. Right. Have
14:51 noticed that it might have a little of effect on the way of your
14:55 and maybe your cognitive abilities and stuff that. So, we've done
15:01 We've taken a chemical and we put into the brain tissue and it kind
15:05 mocks things up, doesn't it? it does make me stronger and better
15:13 there she feel So when we agree there might be things in the blood
15:18 could affect the way the brain Alright. So you want to protect
15:25 brain into that as well. We to control the environment that's surrounded in
15:32 they want to make sure it has right water salt balance, right?
15:36 values that are there right, chemicals can take place. So all these
15:42 are gonna be playing a role in . All right. And so,
15:46 starting point is Alright. Which are the protective membranes. Then what we're
15:53 do is we're gonna look at the spinal fluid, which is that layer
15:55 fluid that I mentioned. And then , we're gonna be looking at what
15:59 called the blood brain barrier, typically BBB. That's better business bureau blood
16:05 barrier. And it's not the only in the body that has this particular
16:10 that separates the issue from the rest the body, but it's the one
16:13 most well known. Alright, very help protect against that um those things
16:21 might be found in the blood that cause problems with the way that your
16:24 actually works. Alright. So, men in jeez, these are these
16:29 membranes form of the word is we usually talk about them collectively.
16:35 don't talk about the individual. All . And they have names. We
16:39 them the matter now. The way said that I did it from the
16:44 out rather than from the outside. normally, what you'd be doing if
16:47 be kind of going this direction. ? So this right here, that
16:52 purple represents the dura matter. This purple. What we decided is that
16:59 . Okay, we're going what What guys are just still Alright the lighter
17:07 is what is the arachnoid matter. then there's a little brown layer down
17:12 kind of goes up and down like very very thin is the piano now
17:17 I flip them around. Well, reason I flip it is because it's
17:21 for me to remember the pneumonic. know it's a pad, right?
17:26 it helps protect. So that helps . So I go oh yeah,
17:30 protected. But if you want to it the and go the other
17:35 that's fine. Whatever works for Alright. But no, that's the
17:40 . He ends with the matter. ? What's the matter with you?
17:47 . So what we're gonna do is gonna start on the inside them.
17:53 the reason I want to start on inside is to help you work with
17:55 P. A. D. Do mind? Right. So the innermost
18:00 is the PM moderate. And the mater sits here and it's in close
18:05 with the brain tissue itself. All . It's it's when we look at
18:12 we're gonna see that has these bulges valleys are and is the proper way
18:19 say it. But so you have basically follows in close association with those
18:29 . And then when you get down spinal cord, you don't have quite
18:32 same fun because you're still it's like for having a very very thin layer
18:36 plastic around the issue. And so clearly creates this divide between the nervous
18:42 and the surrounding environment. Now this tissue. Or I'm sorry this this
18:49 or this Monique is highly, highly this membrane serves as a barrier.
18:56 in order to get blood vessels they have to come in this first
19:00 with that matter when they slowly get as smaller and smaller blood vessels.
19:07 , so when you look at you'll see that it's highly vascular.
19:15 on, There we go. The next structure of is called the
19:21 right. Now, when you hear , what more do you think of
19:26 ? Alright, so there's a reason called that. Right? So remember
19:30 lavender one is the arachnoid matter and can see that there is a space
19:36 the arachnoid matter and the P. . Matter. That little space is
19:40 the sub space. And this is the arachnoid matter gets its name,
19:45 ? Because when you look at it like there's a bunch of spider webs
19:48 that area. And really what it is basically a bunch of particularly that
19:52 bound to uh matter from the arachnoid and holds those two pieces separate from
19:59 other. And the reason is holding separates really actually keeping them from
20:05 Because that's that's space is still the spinal fluid flow that we're looking at
20:11 just a moment. All right the way I remember what this is
20:18 is the space where the brain You have brains papers? I do
20:26 . When you walk into a room your life, why don't come in
20:31 . Yeah. You guys are You don't do that. Right,
20:35 , a couple times. Yeah, done. You don't do that.
20:39 . Just me. Alright, I into a room like or go to
20:43 refrigerator in your life anyway, that's I remember, cause that's where all
20:53 spider webs are and like I it's built uh three response.
20:58 we're gonna learn in a minute that cerebral spinal fluid is taken from the
21:03 . In other words, to make real final fluid, we're gonna draw
21:06 from the blood, water and other and that's gonna make the cerebral spinal
21:11 and it's going to fill this space this cerebral spinal fluid is in
21:15 And we're constantly making it. And if I'm constantly making it, I
21:18 to constantly return it back to the . That kind of makes sense,
21:23 ? So it's like because the three the kind of like a C.
21:29 , if I put water in the , if I don't have a way
21:31 exit, why don't think it's gonna over the edges and it's gonna flow
21:35 house cause bad things to happen, ? So we need to have some
21:39 of drink. And so part of arachnoid matter is going to penetrate through
21:47 dura matter. And these little structures villa and this bill i is the
21:54 point from which that's that fluid is to exit out and return back to
22:00 blood. I'll point them out when look at a picture when we're talking
22:04 this picture does not show it. right. But they exist.
22:13 Now the last one this outer layer notice that the thickness is very very
22:17 here. Kind of thin there. then we get to the big one
22:21 very very thin. The dura matter actually two separate membrane that is pressed
22:27 . It's kind of like a ziplock of freezer ziploc bag that playing with
22:33 big one, kind of thick? to move. And in fact,
22:36 you if you go and play with it kind of has the same feeling
22:44 the dura matter. It has this of the same amount of thickness.
22:48 doesn't stretch all that much. Doesn't can't manipulate really well, it doesn't
22:53 wrapping around stuff, it's just too to do. So that's kind of
22:56 dura matter does. So we have two layers. One layer is nearest
23:00 bone, one layer is nearest the . Right? So we have names
23:07 those two layers. One nears the carry. All right. Harry.
23:13 other one is meaning it is next the it's um It's part of those
23:20 so you can make pancakes together like and go like this and then there
23:26 areas where these two layers separate and these spaces like that. So you
23:35 see these two spaces in between that . It's not the subdural space,
23:41 a dural sinus. Alright? So you hear that dural sinus, dural
23:49 serve as venus. What venus sinuses an area where the blood flecks as
23:58 joining up with blood fest. there are very specific locations. So
24:03 can think of it as the dural serves as the way that blood first
24:09 to leave the brain. So we're gonna do blood vessels here with the
24:13 the blood vessels work generally, you have to write this down is you
24:17 from arteries, the smaller arteries from arteries. Capillaries, capillaries is where
24:23 the exchange between the petitions and then blood enters into small veins and then
24:32 a larger veins eventually returned back to heart. And so what these sinuses
24:37 is that point where we're getting into bigger vein. Alright, so this
24:42 just the structure where this happens. so the dural sinus serves as
24:53 It's also the space where you like I said, you didn't see
25:01 very early on in development actually, first thing what you'll see is you'll
25:09 the formation of nervous tissue and when tissue forms it forms in such a
25:13 that creates a tube of hollow All vertebrates followed this organizational pattern of
25:22 . So it doesn't matter if you a fish doesn't matter if you are
25:27 human, this is the same pattern development. So we all have this
25:32 structure that we begin as and then we do is we form a nervous
25:38 in that too. And then that tissue get organized to look like the
25:42 that we're familiar with. And if went back and looked at that first
25:45 where I showed you the brain and cord, you look and you see
25:49 the bottom of the spinal cord, a little tiny canals called the central
25:53 . And that central canal is preserved the length of the spinal cord.
25:56 then you go to the brain stem you'll still see some remnants of that
26:03 canal is still there. And when get up into the brain, you
26:07 see here there's a central canal, see that going for. Are these
26:12 structures that are called ventricles, just of the same to this is because
26:17 brain was twisted and turned. You bigger spaces and you now having bigger
26:24 that are filled with fluid. And here where it's real final flow that
26:27 made. So the ventricles are where central uh, is where the cerebral
26:33 fluid is made. And there are of them real easy. 1st 2
26:40 the left and right lateral ventricles, third one is the third ventricle and
26:47 fourth one is, they're really left right and their lateral, you can
26:53 them here, right. You can here they are. There's two laterals
26:57 here's one lateral, there's one behind and then here in between them that's
27:01 third. So there it is really looking there is the fourth. There's
27:05 fourth. Now here, when in structures are specialized cells, this specialized
27:13 cell is a type of glial Remember when we learned about back?
27:19 . So this is one of And the purpose of the glial cells
27:21 , the cell is to take material the blood and move it into the
27:28 to make the so they're gonna be in these areas and they're localized in
27:34 very specific areas. Now the connection the two lateral ventricles into the third
27:42 have a name. It's called the ventricular, what is it? It's
27:47 whole feet and you can see the when I think between the ventricle
27:52 that's what it's called. Alright, you can see it mark there and
27:57 can see it's this structure right That's the inter ventricular. Alright,
28:03 you get to the third ventricle, path between the third ventricle the fourth
28:08 has a chance here. All the what is pathway for water,
28:19 That's that's all it is. And it's basically saying, look I'm in
28:22 in the when you get down the veg. Cool. Now what we're
28:25 do is we're gonna open up the that you're making in the ventricle into
28:33 . Alright remember we said spinal So there's a couple of openings.
28:38 have two lateral openings there called apertures lateral apertures. And then we have
28:45 median aperture. Alright. Um So picture doesn't do a really good job
28:50 showing it I guess I'll wait till the next picture but basically it's gonna
28:54 like these two little things that are of hanging off to the side and
28:58 there's one that sits uh in the over here and again. This doesn't
29:02 a good job of showing again. just continue with those vegetables. They
29:07 downward, they form that central This one does a better job.
29:11 here it's staying right out the that would be the median aperture.
29:21 right about there and then the two are gonna be off to the side
29:25 this one shows you the hole where lateral. But you can see here
29:30 the lateral, the lateral ventricle opening the third ventricle ventricle, there's 1/4
29:37 , then your apertures and then you're and then all these things on the
29:43 that's showing you the subarachnoid space. how completely wrapped around are around the
29:51 nervous system. The care that is or cerebellum or brain stem or spinal
29:58 and wrapped around the entire thing creates barrier between the within the and between
30:06 nervous tissue and bone tissue. The blue up here whenever you see dark
30:13 . You should be thinking, this the oxy blood. Generally speaking anatomy
30:19 are drawn in dark blue. Now is a dural sinus and there's dural
30:25 . You can see there's penetrations right in there, right, there
30:30 Those are the only two. These the ville I or regulations that have
30:36 remains based on side where that space penetrating as a function of the matter
30:44 up through the zero. And so cerebral spinal fluid we're making in the
30:49 travels around and then it's pushed out those congratulations into that dural sinus.
30:58 we borrow from the blood and we turned back and that will be the
31:04 flow. So, CSF is how usually see it because we're too lazy
31:11 write spinal fluid. CSF is gonna circulating all the time. You're making
31:18 constantly all day long. It has functions and one we've been describing already
31:23 this protection but also serves as a to raise up and hold the brain
31:29 the right position. It has buoyancy buoyancy and it creates an environmental stability
31:36 blood and the fluid that surrounds the . This would be the extra
31:43 right? And typically you'll see it to the brain or for short.
31:50 right. So, it's it's really not interstitial fluid. Right? It
31:56 sit between the neurons it surrounds in very particular location. So, you
32:02 think of it like this. Here's blood vessel here, cerebral spinal
32:08 here's bright extra cellular fluid. They're . So anything I want to move
32:14 a blood vessel, it can come , but there's actually kind of a
32:20 . And so there is some communication taking place between the and the But
32:27 not like they're mixing. They're near each other. So, that's an
32:34 thing. The pitch. And this when we talk about environmental stability,
32:38 we're referring to. And look I actually expand on these ideas.
32:46 . Um See CSF has the same as the brain tissue itself.
32:53 what that means is if I had swimming pool full of uh and I
32:58 a brain that the brain in the of a swimming pool, it would
33:02 there and float, I could take brain and push it down into the
33:07 . Let it go. And it stay where I could cool.
33:11 And so, what that means is your brain is being held in position
33:17 extralegal final fluid. It basically lifts and holds the brain off the floor
33:22 the cranium. So, that is actually wrestling on that hard month.
33:28 ? So, it means your your your central nervous system in general
33:33 away from the bone and it's kept from The other thing that means is
33:39 I'm being lifted up. That means not using out of the Alright,
33:45 your brain tissue has mass and mass going to follow the uh the pull
33:51 gravity. And so that to ensure no, no, no. You're
33:55 just gonna set up otherwise. Mm serves as a liquid cushion. All
34:03 . Um, Anyone here dumb enough a kid to run into a
34:07 Yeah. Yeah. Or play Yeah. I'm not talking about organized
34:15 . Like you and your friends get and you know, you know.
34:19 , exactly that but it's like probably other up. I mean ladies,
34:23 know you're not as finally um organized are you know what I mean?
34:30 can tell you stories, right? close friends, good friends with Although
34:50 I know you guys leave the protective , right? So like when you
34:57 two guys football make you cry and know two guys and their heads against
35:08 other. It's like two guns. ? And what do we do?
35:14 we gonna have congestion? But we comedies. No, we do that
35:32 . You got a helmet now, it the best moment? Oh it
35:39 on the situation anyway, so we a shock absorb when you your head
35:55 something right? The brain has It still wants to move forward.
36:03 . It wants to go in the you're already. What happens is is
36:08 influence is non compressible. Alright. in and of itself doesn't like to
36:15 and so it does it basically helps hold the brain in position even though
36:20 wants to go forward. So that's we say serves as a shock
36:26 Lastly, in terms of the environmental we're gonna have materials that you're going
36:32 build up you want to get rid . And so the best thing to
36:36 , I mean what you're normally gonna , you gonna take materials waste,
36:39 gonna move into the bloodstream. Sometimes build up stuff and if you want
36:43 balance things absolutely ensure the E. . F. Stays constant. You
36:50 a way to shovel things off into , so it's just a nearby liquid
36:55 which the fear that you don't need be shuttled and then blood. Now
37:02 is not the normal man. It's it's a it's a protective mechanism.
37:07 just following the simple laws of physics terms of moving down concentration because CSF
37:14 brain tissue are in close acquisition. only thing separating the brainy cf and
37:20 CSF. Yeah. So you can things very easily back and why easier
37:30 than the other? Well it's because this basically protects the nervous tissue from
37:40 fluctuations. Um You don't obviously don't anything on the charge here through the
37:47 see the differences between the plasma of blood and CSF. And so remember
37:53 we're doing, we're making CSF from . We're using the to say I
37:59 to take this, and I want put it over here into it.
38:02 , the areas inside the ventricles where is going to take place are called
38:06 corduroy plexi video. So, you see here's the lateral ventricle, there's
38:13 ventricle, there's 1/4 ventricle cord flexes each one. So, this is
38:17 an area where the capillaries that have pushed in the brain coming very,
38:25 close contact with these cells. There no in these locations. All
38:34 So, I want free exchange the so that he had wrapping from the
38:41 . What they're gonna do is they're actively pump in sodium whenever you move
38:46 water naturally follow when water goes. things are going to use that as
38:51 automatic indicator of the direction they need go. Alright, so, there's
38:56 whole bunch of stuff. These are areas where you can kind of
39:00 how do I do it? I'm pulling materials. There are certain things
39:03 I can't pull So proteins are too , so, they stay on the
39:06 , they don't come into the but pretty much everything else looks
39:10 very similar. The difference, I is gonna be potassium, and so
39:15 basically not moving. And so now CSF. And so you're putting it
39:23 and then there's gonna be other things can be added to it as you
39:26 along. So, once you get subarachnoid space, anything that you picked
39:30 along the way that's where you'll see accumulations. So to give you a
39:35 , I'm not gonna ask you how you make, but you make about
39:39 , mils of CSF Or? That's how much is actually in that
39:46 . Alright, but you make about miles per day now to give you
39:50 sense of what that looks like. is where I get to. All
40:01 . Alright. So how much is ? You guys know we're talking scientific
40:09 . So how much mills 500 This is how much as full?
40:26 how much you make in a day CSF. How much is a 125
40:34 course. So that's how much you . So you replace your C.
40:39 . S. C. S. . Daily or not? Right?
40:45 this is your sense of how active . Alright, They're constantly making the
40:51 . So what that means if I'm something I'm pushing the old out of
40:55 way. Right. And so this where we're gonna start seeing that flow
40:59 top of that. The andino cells cilia on their surfaces. And that
41:04 is when you go away you go you go it's basically pushing the CSF
41:09 and then of course that means we more pressure. That pressure is pushing
41:13 fluid away and eventually the point of pressure is going to be in these
41:18 asians and bill. I and so is the point where that CSF
41:23 So over the course of the day this four times or in essence you're
41:29 making it. So it's not like make a new batch. So all
41:34 flow is going from lateral to 3rd to fourth. Out through the
41:38 or down through the central canal into subarachnoid space. Subarachnoid space is just
41:43 the the the flow. In other the pressure gradient and it's leading to
41:47 granule ations. If you were to in there and measure It's gonna be
41:55 of mercury in terms of pressure. what does that mean? That's above
41:59 ? Um You here working in? , Okay. Did you ever see
42:06 uh now black? That's a Alright. Anyone anyone or? So
42:21 an epidural is is this is an being applied directly to the CSF so
42:27 you can numb large portions of your and still be alert and awake.
42:32 ? So they usually do this for and delivery. The pain is
42:37 I'm gonna do an epidural. there's nothing to get this Neil um
42:44 you get past the size is big ? And what they do is they
42:48 through the layer of these of the right? And they're going in that's
42:57 right? And what they have to is you have to ask the question
43:01 the question, am I in the place. And so they basically right
43:06 here in the lumbar region about And so they have been over this
43:10 on the table on the table and they do is they kind of feel
43:17 and you go down into that and what you do is you have to
43:22 my there you pull out the needle place and then you watch and you
43:28 any will come out only if there's pressure there and from out you're not
43:35 right place. Stick the needle back in particular usually unless you have
43:49 Alright anyway, that pressure is the pressure. Alright? So if you
43:54 to measure what's the pressure inside That's about how much pressure there
44:00 All right. And so you're moving , your daily activity helps change cause
44:05 pressure plus the also helped drive the of this material. And just so
44:12 you can see the pictures. Just same picture kind of blown up so
44:16 can kind of see the different So here's the lateral ventricle. Corey
44:20 , their third ventricle, their fourth . You're going out here's median
44:26 there's lateral apertures on the side and all this light. Okay. Could
44:35 aqua marine. What's that turquoise? , we're going turquoise. All that
44:42 represents the space surrounding the entire brain in the entire spinal chord structures.
44:51 it goes all the way around and here it is on the superior surface
44:55 the brain and there where you're gonna the granule. Ations in the bill
45:00 and penetrate through the matter right through dura matter matter. That makes up
45:07 wall. It penetrates through its dural , not subdural space, which you'll
45:15 in the picture, two different So protecting the brain so far we
45:26 um underneath that, what do we ? The and within the context of
45:33 we have. So all these are very physical structures that affect the
45:42 The blood brain barrier is a physical just like structure we've been talking
45:48 So it's an anatomical but it's also for the first time at physiological
46:00 What we're looking at here is we're at a blood vessel, this is
46:03 catholic. Alright, capillaries Normally throughout rest of your body. There are
46:09 different types of vocabulary but the grand of capillaries are ourselves that are closely
46:15 with each other but they have these tight junctions. Alright, so to
46:22 this, I want you to picture bucket full of water and marbles.
46:27 and let's say put your hands and out. Got a whole bunch of
46:34 up this water going through your in between your hands, marbles will
46:41 in the big things stay in your . But all the little tiny
46:44 all the molecules of water droplets are gonna sneak through that's kind of how
46:50 work all the big things in the don't leak out of the blood
46:54 but all the little tiny things, and salt, like small molecules like
47:01 , anything smaller than a molecule. I know you're going I don't know
47:05 looks like, but it's a really small all those can leak
47:10 And so this is how we get between our tissues and the blood.
47:15 right, So we're using the cap got fairly leaky to allow that to
47:21 in the brain. We don't want weakness. And so what's gonna happen
47:26 is we're going to modify those leaky junctions into tight, tight junctions.
47:34 . And the reason we do this because we want to ensure that the
47:39 that are being delivered to the brain exactly what the brain wants to meet
47:44 now to illustrate this how important it to maintain the environment. Small stories
47:54 occurred a couple of rooms. long time ago. Um and I
48:01 a long time ago because it feels a long time you guys remember when
48:05 we came out, you guys were really young. How old were
48:08 Like 12? The original way? it was PS three I think came
48:17 the we and then it was like one, they all came out at
48:21 same time. It was a big because PS whatever was PS two or
48:25 three and Xbox one, I mean was like they were like dude get
48:29 , who was gonna sell the most at christmas All right? And then
48:34 showed up on the scene. No expected this and they're like, probably
48:40 we're gonna charge $100 less and no could find them anywhere. They're like
48:45 biggest they're like whatever year that was , what is right? Every year
48:54 gonna be that one thing no one ever find. It's like the most
48:57 thing, christmas, right? to get a hold of the weed
49:01 like a big deal. And so was a radio station in California that
49:07 having a context. All right. it's like, you know those those
49:11 when you see Mr Beast those Mr B. It's like, you
49:14 , last person take a hand off target card. You know, the
49:18 person to take their toe off the gets a million dollars. I don't
49:22 , whatever, whatever. Mr Beast my kids watching. Never. Um
49:30 , so, they had this All right. We're gonna have a
49:33 to see who can hold their the whoever the longest will get the
49:39 All right. So, they're you know, like eight contestants and
49:43 they do is to get everyone to water and they're required to drink of
49:47 in like 10 15 minutes. And after that was like, let's see
49:50 gonna be able to hold it the . And one of the contestants was
49:55 petite woman. About four ft right? Probably like £7. He
49:59 the same amount of water as probably set six ft eight fat guy.
50:03 know that was there. And after couple of minutes she killed over and
50:08 convulsing, stopped breathing and basically her stopped, right? And all she
50:13 was water. So why did this ? Because when water goes in the
50:19 it's just trying to find where there's water. There's no barriers where water
50:26 . And so you're talking about someone has a very finite volume of fluid
50:30 your body and you add all this water. Pure water goes in and
50:35 all your Saudis everywhere including your brain the respiratory center of the brain and
50:41 part of the brain that regulates your are those two areas and they're behind
50:47 blood brain areas. They're protected from things that are in your blood.
50:52 water is not one of those items the blundering. So basically she diluted
51:00 the environment of the brain which caused breathing to become erratic and unmanageable.
51:06 he couldn't create action potentials right? then so she stopped breathing and her
51:13 stopped because of the same reason it like it started I mean your heart
51:17 beat without signals from the central nervous , but I can't do really,
51:21 good. And being those two she ended up drowning in her own
51:30 . Huh were we? No she dead. Sorry. Yeah. So
51:36 died. Right. So you know another warning is doing this contest.
51:41 a warning to tell you how your works, right? So you can't
51:45 in water. But your brain is to protect you against things like
51:51 So for example if you get something in your body tossed in there is
51:57 barrier to prevent that toxin from getting your brain. Except there are certain
52:01 that that toxin right? Certain That's what we want to talk about
52:06 . So anatomically there's a barrier that gonna talk about that barrier here and
52:11 we're gonna look at physiologically. so an atomic. Alright first off
52:17 said we have our capillary junction. happens is after sides of the brain
52:23 around and with their extensions. Alright these footpaths they wrap themselves around the
52:31 and they actually send the signal you the digestion you have that you're not
52:36 a job of maintaining and making type want you to make them tight.
52:40 so what happens is they basically seal the tight junctions. Alright. So
52:45 a material leave the blood now you live around the cells, it has
52:50 go through the cells. Right? in order for material to actually get
52:54 the brain has to be able to receptors located on the surface of the
52:59 of helium to be able to get the capillaries and then you have to
53:03 another type of channel to allow to other side of another type of
53:09 Alright, so now the cells are as actual barrier the capillary. But
53:14 top of that you now have a of astrocytes. Alright. And so
53:20 astrocytes has to have the right channels the right carriers in the right
53:26 So what you now have is you this real barrier and so you can
53:30 what we have here and this is this picture is trying to show is
53:33 I've got my uh I've got my in the that's just Cavalleri, I
53:42 have outside of that, I have basil which is like a screen
53:46 say anything, got something, catch . And then outside that the purple
53:52 the astra side and then we have other sites that helped coordinate things.
53:55 are called parasites and cells that are to but they don't really play any
54:00 in the blood brain barrier. Is capillary cells and astrocytes. That so
54:07 now have literally invisible barriers. I'm get through, I have to pass
54:12 or uh through the and I have pass through that after side. And
54:17 I don't have the right channel or right receptor of the right carrier on
54:21 cells I'm not getting. So the sites in the helium decide what gets
54:27 the end, whatever go out. , Regardless is ideology molecules. Remember
54:35 under two different categories based you're either soluble or your lipid. So,
54:42 this really serves as a barrier to things that are going to be found
54:45 the blood. Things found in the are water soluble. Alright, live
54:51 substances are not stopped. In other , the platinum membranes are not barriers
55:00 so limit side of the substance that its way to foot can pass on
55:04 just fine. Alright, so, really kind of stopping these molecules that
55:10 be normally in the blood were less about limits. 13. Alright,
55:19 , here's a simple question. Let's your design drug if you want to
55:23 the brain, what characteristics you desperately to have livid ability? That's
55:31 That's all you have to ask. , so the drugs that you take
55:36 have to work on frames issue have particular it's water soluble. You've created
55:44 physiological barrier to. Right? we're gonna have the blood brain barrier
55:55 located at the cerebral blood vessels. won't be a similar type of barrier
56:02 plexus. Why? Because we need hold materials from the blood. So
56:08 don't want that barrier there. You material to be able to move back
56:11 forth. All right, So, just a series of tight junctions instead
56:16 having all the other things in the and again those tight junctions are
56:23 Alright, But then there are other of the brain or you need to
56:28 your environment. All right. we're gonna learn about role in regulating
56:36 the uh well, it's it's a regulator in the body, right?
56:43 regulates a whole bunch of different hormones regulates under. And third regulates all
56:47 of. Alright, so what it to know, need to know what's
56:51 on in your body your body to . So, you don't have a
56:54 brain barrier at the hypothalamus because it to know what materials it needs to
57:02 . All right. Same thing with pineal gland. The pineal gland sends
57:05 hormones. Um Corey plexus as I at Permeable. Um The interesting one
57:12 the vomiting center. All right. , I was just in my this
57:19 I asked has anyone here ever been by a poisonous or venomous animal?
57:30 , head boxed in your monster. , looking at is different.
57:39 I actually had someone in my other but I was asked a question because
57:42 never know there had been bitten by water marks, that's what they
57:49 ordering. And I said, well was one of the responses that your
57:53 did when you got this says? , I got violently ill. I
57:58 thrown up, you know like why? Well what do your body
58:05 ? It doesn't expect you to get by poisonous or venomous reptile,
58:11 Typically it's gonna say, you there's a toxin flooding in my blood
58:16 likely wrapped that got into my I hate something, right? Because
58:22 face it, we some pretty weird . We are omnivorous organism. Everything
58:30 to do. Watch watch a what does the child do, picks
58:37 everything, anything. And so the likely route for a toxin to get
58:45 your body is through. So if vomiting center they're picking up approximately life
58:54 them from a venomous then what's it do? How did this get
59:01 What is the most likely thing that did? Let's eat something bad.
59:06 I'm going to try to get rid whatever is in my gut, still
59:12 so that it's not gonna be Oh, there you go. So
59:22 center needs to test the blood to that how we doing, we're doing
59:33 good coming down towards again. so this kind of shows you a
59:40 bit better of what what it is we're just kind of describing here.
59:44 , so lip is um primarily our do whatever they want to. All
59:52 , they're not gonna be uh prevented move between environments. What are lipid
60:00 substances? So you can think for , gasses, for example, steroids
60:09 filling drugs but generally speaking um they move back and forth with whatever sort
60:16 degree freedom that they want, you have receptors that combined the substances and
60:22 them. Um But they have a freedom than water cycle. So with
60:31 to water soluble so you're gonna use me to trans carrier mediated transport.
60:39 ? And so you know, all molecule we talked about, what do
60:41 do find it? Right. I my shape moving in the south.
60:46 there's a channel or another molecule that's the same type of in the other
60:51 . And so that's basically how you the receptor mediated. This is gonna
60:55 through the process of Transito sis So can see here I picked it
60:59 put it in the vestibule, use vesicles transport to the other side then
61:03 hopefully have something on the other side can do the same thing. Pick
61:07 that moving transport. So these are kind of a different men, we
61:14 about this so carrie needed. These the small molecules receptor media be larger
61:26 . That's right. So any questions the protection right now remember this is
61:36 the central nervous system. So this gonna be true not only for the
61:40 and then we sit there and focus the brain is also true for the
61:42 cord, all those structures exist well protected by protected by the so
61:58 All right, last little bit. I promise you will live anatomy.
62:07 wonder Simon Snyder is to just go these structures and being able to identify
62:15 . But remember, it's not a portion of the test any time.
62:18 gonna be maybe one question like which of these arteries? All right.
62:22 , we're looking at is I want just point out here the major arteries
62:26 concern for us. There are a bunch of arteries and again, when
62:28 see a picture like this, they're try to label everything because they're just
62:31 to save. Alright, And that's our goal here. Don't get distracted
62:35 all the things. Just try to the things that we're looking right?
62:39 , if you look at the what we've done is I've done here
62:41 we divide this into two halves and to posterior segment. This is from
62:46 interior view. So, you're looking into the right, so your spinal
62:51 will be here and you're looking at bottom portion. Alright, So here's
62:56 dividing site. So this is anterior post here. And the interior
63:01 blood is arriving from the heart up the carotid arteries and they go to
63:07 internal carotid and so that's what this represented. So, you can imagine
63:10 internal products are going into our Alright. And so they're gonna be
63:17 things that provide the blood primarily to interior half. And what they do
63:22 they branch they branch into the middle artery and then they branch into the
63:29 cerebral artery. So there's the middle then up here that would be the
63:33 cerebral artery. And what we'll see that we're now providing anterior portion as
63:40 as the middle of this room with to the post here. Alright.
63:47 getting to the circle of Willis here just a second. All right in
63:49 post airier, what we have is have two vertebral arteries. Now the
63:54 vertebral arteries you can imagine are running the Yeah, yeah. Remember what
64:02 told you a couple days ago when looking at these names, they're gonna
64:07 you exactly where there's nothing like super that the are gonna be moving along
64:15 vertical. Alright. And what they is they join together and they form
64:20 is called the artist Now from our right now it doesn't look like the
64:25 . Remember you're looking at it from interior side. So if you put
64:28 like this that basal artery is found the face of the right. And
64:35 the baseler artery is gonna form the here. So here's the basal
64:40 It forms the posterior cerebral artery which gonna be the posterior portion of the
64:46 . It forms the ponting arteries. so the ponting arteries look like little
64:55 and they are providing blood to the stem around the ponds and then we
65:01 the superior um and the inferior anterior cerebellum artist. So here's the anterior
65:08 . If you have an anterior inferior means you have a posterior inferior about
65:11 focusing here. So here's the basilar right here is the anterior inferior cerebellum
65:18 then on the top side of the . This is where you have the
65:25 sarah Beller. So the next will where they are. You know,
65:34 just being able to orient yourself yourself little bit around it. So like
65:39 said one of the assignments homework tonight you kind of look at this,
65:45 now blood is gonna be collected through dural sinuses, Neurosciences converge and ultimately
65:51 gonna exit via the jugular veins. it's referred to as the internal jugular
65:57 that's not being shown in the In fact really in terms of this
66:06 may see a picture like this and what's this one artery. But the
66:10 thing is that I'll probably just say portion of brain the service. So
66:17 kind of pulls out a picture. ? So what I'm doing here is
66:22 just showing you how the cerebral receives blood for the most part the major
66:27 . Right? So we said we the anterior cerebral artery and look at
66:32 serving the anterior portion of the we that fat, middle cerebral artery is
66:38 the middle portions. And then out we have that posterior cerebral artery and
66:45 doing the post ear portions, the of You can get a sense of
66:50 blood I want to deal with the of Willis. I'm gonna teach this
67:01 as if it is most important as we all have Truth is only 8%
67:08 a service. But it's a cool . So that's why. So the
67:14 of Willis is simply a series of , right? That supply the anterior
67:19 posterior portion. So you can see , it creates this kind of
67:23 You see how it goes all the around continuous circle. This ensures that
67:28 and one of these arteries is damaged of course log that blood can find
67:33 way to different parts of the right? Kind of like if I
67:41 the proportion of I 10, can get around Houston? Are there are
67:45 circles around Houston and allow me to to where you? Yeah, but
67:49 kind of like like 16. It's oh a or the grand parkway and
67:54 . The next circle we're gonna Um move around. So the thing
68:03 allows us or creates a circle right is that it's called the anterior
68:09 And what it does, it basically both those anterior um cerebral arteries two
68:15 . So, if some damage I still am able to get around
68:20 . That's really all this is so . So good. That easy.
68:29 does every argument last. I want remind you because what we're gonna do
68:40 is we're gonna start moving away from engineering. So I have two slides
68:48 and then we're done. All So first off remember there are two
68:52 types of cells. We have neurons then we have all the little
68:56 And so what is the neuron? excitable cells. All right. The
69:02 cell is one of the most common of cells that we're going to see
69:08 . It's a multipolar neuron you can here. Why is Right? I
69:13 shape wise chief, Right? It a single axon. That single axon
69:21 just like what we've seen here. when we're looking at the central nervous
69:25 , we're in the person we're learning neurons were looking at this structure.
69:29 can see the dendrites, we can the axon is a really clear
69:32 It's a lot harder to see But we do we still have an
69:36 , right? The axon is going be sending a portion of the we
69:40 a series of dendrites. It just that the dendrites form this kind of
69:44 to shape and this thing is throughout entire prefrontal cortex. So this is
69:50 thing that a major world new understanding things, what I'm saying,
69:56 And the things that you know, the thoughts that you might have.
70:01 , and your memory, right? those things are a result of how
70:08 different cells are clumped together the they play a major role in
70:18 So when we come back, what gonna do is we're gonna talk about
70:24 we're going to remember that when we about these different remember that we're just
70:31 the boxes very often we're looking at . So just gotta keep that money
70:45 three have a great Yeah. Yeah. By the end of the
70:57 it should be about 82 or 83
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