VideoPoints

• ••• • •• • ••••• • •
BIOL 3324 Human Physiology - 3324_lecture08_0923
Help Tour
© Distribution of this video is restricted by its owner
Transcript ×
Auto highlight
Font-size
00:02 All right. So, hopefully now that we've begun class fresh
00:08 Just a brand new day. Nothing's before. This time is what we're
00:12 do is we're going to look at organization or the parts of the brain
00:15 how it protects itself. All That's really the goal. Number
00:18 Goal. Number two is autonomic nervous . All right. So, there
00:21 a couple of ways. The first the brain protects itself is with cerebral
00:25 fluid. All right, cerebral spinal is uh, a a fluid that
00:31 formed by the by the plasma. other words, the brain takes materials
00:38 the plasma and make cerebral spinal It's very similar to plasma, but
00:42 exactly like which we'll see here in a moment, how we make it
00:46 highly regulated. It's done through a called the core oid plexus. All
00:52 . Now, what we're looking at is we're looking at a cut through
00:55 rain. There's there's a lot of and egg stuff that's going on
00:58 All right. So, you just to bear with me at times.
01:01 , here's the chicken and egg Those are the ventricles inside the
01:06 and there's a ventricle right there ventricle here. Inside the ventricles are these
01:10 that contain these highly vascular sized areas epidermal cells are located. This is
01:17 this is called roid plexus. All . And so it's vaporize me and
01:21 blood vessels getting really close and there's be a bunch of exchange between the
01:26 and the interstitial fluid. And then the interstitial fluid. the epidermal cells
01:29 the materials they want and they form uh cerebral spinal fluid. All right
01:36 , why is this a protective Well, what it does it helps
01:40 . And here's the fun little abbreviation brain extra cellular fluid. It helps
01:44 regulate how what the composition of that is through mixing. All right.
01:51 in other words, the materials that the cells of the of the nervous
01:55 are going to be bathed in this cellular fluid and there's going to be
02:00 change. And because we're gonna learn the blood brain barrier here in just
02:03 moment because of that, there needs be a way to actually allow materials
02:08 move in and out to ensure that B. E. C.
02:10 Stays the way it is. All . So, the key thing
02:14 cerebral spinal fluid made by the epidermal found the cord plexus, which we're
02:17 to see in terms of their So, that leads us to the
02:21 structure. The second structure being the . Alright, what are the
02:25 Now, I'm not going to go the evolution of the formation of
02:29 But basically, yeah, I guess am. So, what you have
02:33 when you have the formation of the tube very early on development, it's
02:37 tube that then gets twisted and bent a balloon. Right? And so
02:42 the middle of that tube is something going to get bent and twisted along
02:46 way. That's what the ventricles or a continuation of that tube through the
02:52 neural structure. All right. So just call them cavities. They have
02:57 rough shape. If you look at , you can see it's derived from
03:02 neural canal and uh this is going have some epidermal cells that play a
03:08 in producing the cerebral spinal fluid. there's four of them. So from
03:13 side they kind of look like this you can see when I do that
03:17 that forward view, the anterior you can see there's like two on
03:21 hemisphere And then the other two are located. All right. So two
03:27 ventricles, so we call them the and the right lateral ventricles. So
03:31 the first two they converge and form third ventricle which is the central ventricle
03:38 here and where they converge. This called the inter ventricular for Raymond.
03:42 they basically come in and there's your inter ventricular for Raymond, where now
03:48 have this third ventricle. Now the ventricle is where you're going to see
03:55 this is like in the dying So in that picture that we saw
03:58 , see how they have that little sitting in the middle, right
04:01 that's the bridge of the two halves the thalamus. So you can see
04:05 kind of sits in between the Um And what we have is we
04:09 a structure that then drains out. here you can see it draining out
04:14 that goes to the fourth ventricle that's the cerebral aqueduct. It's a fancy
04:18 , isn't it? Aqueduct? I know why. All right now you're
04:24 into the fourth ventricle. Fourth ventricle between the brain stem and the
04:28 Alright, And it has openings on whole bunch of different sides of
04:32 Alright, has two lateral opening so can see them right there, There's
04:35 two lateral and then actually I guess , the lateral would be a little
04:39 further down and then down in the behind. Over here you have the
04:43 uh opening which is the median apertures lateral apertures media. And so what
04:49 does is that opens up into this underlying um these structures in what we're
04:55 . I don't wanna explain them just because we want to get to the
04:57 slide. But basically you can imagine a spinal cord and surrounding that is
05:04 space where there's gonna be cerebral spinal surrounding that structure and then ultimately around
05:10 brain. Okay, so the apertures for cerebral spinal fluid to go into
05:15 two spaces. Finally what we have we have a central canal that travels
05:20 the way down the center of the cord and at the very bottom of
05:23 cord opens up there. So fluid come back around and into that
05:28 I better just tell you the space called the subarachnoid space when you hear
05:32 word Iraq annoyed. What do you of? Okay, I just want
05:35 make sure we're all on the same . It sounds like spiders.
05:41 So those are the ventricles and this where we're going to form in the
05:47 lateral and that third and the That's where the cerebral spinal fluid is
05:51 to be formed. Okay, switching . All right. There's gonna be
05:55 lot of jumping here because it's like chicken and egg thing. All
05:59 So, I said that's a cerebral fluid plays a role in protecting the
06:04 , but you need to have a in which that cerebral spinal fluid can
06:07 found. Now, if you've ever in a gross lab and played with
06:14 , anyone here ever been in a anatomy lab? Got to play with
06:17 . So, you play with brain of stiff and not particularly interesting.
06:22 grey and icky. And yeah, not what the brain is.
06:26 A brain of fresh brain is like . All right. You ever taken
06:31 warm butter? You take it out bake with and you like take a
06:34 and you push it. You can put the weight of the knife and
06:36 just kind of slices through it, ? That's what brains are like.
06:40 just Yeah. Right. So your is the first way you protect your
06:51 , right? You have a natural . Would you all agree? All
06:54 . So if you all decide to in the wall headfirst, you're
06:58 All right. Not very well protected protected. All right. Now,
07:04 that butter like substance being up against hard substance like bone. What's the
07:10 like substance going to do? So what we need to do is
07:14 need to protect the better like substance the hard substance and that's where the
07:18 come in. All right. three men ng's I'm going to go out
07:25 to enter because it makes most But you're going to see there's an
07:29 that gets formed if you go into . All right. So the outer
07:32 is called the dura matter. Dura matter is very, very
07:36 It's very much like in terms of , it's like freezer bags, like
07:42 gallon freezer bag, ziplock freezer bag talking about. So it's got heavy
07:47 to it, there's two of them they're closely adhered to each other throughout
07:52 of the structure. But when there certain places where those two layers separate
07:59 and in that place that's where we're to form a sinus. So,
08:01 you've ever heard of a dural that's what it's referring to. And
08:05 sinuses like you can see right here this particular example um is basically a
08:11 where blood accumulates and then it serves a way to move blood away from
08:15 brain. So it kind of acts a vein. It will actually empty
08:19 a vein. All right. So duras thick and elastic is the outer
08:25 and it serves as the first line or the first barrier between the bone
08:31 the rest of the nervous system underlying dura which is thick and you can
08:37 of it. It's so thick that does. It's more like drapes as
08:41 to closely adheres. Alright, the layer is the Iraq annoyed matter.
08:45 I should point out there's blood vessels and what not. All right.
08:49 second is the Iraq annoyed matter. matter. Sounds like blood. Thank
08:55 for that. If you don't know has a clock up there. Making
08:59 I quit on time today. All . The Iraq, No matter.
09:04 right now. Here what we have it's another tissue. It's another layer
09:08 . There's tight junctions. Things can't through it. And it's closely adhered
09:12 the dura. All right. But a little bit thinner so it actually
09:17 form around the brain a lot All right. And underlying the retinoid
09:23 is this sub arachnoid space? You see where the name comes from.
09:27 right. So the subarachnoid space name their active. Would matter. Why
09:30 Iraq annoyed matter named the Iraq Noid ? Well, that's where the brain
09:34 live. Brain spiders. Have you a brain spider? Haven't you ever
09:45 in the room and wonder why you in the room? Brain spiders.
09:48 interrupted your train of thought, You're all just sitting here looking at
09:53 like he's got is this Yeah, brain spiders. They're they're all sitting
09:58 scratching their eight legs. Alright. . No, no. The reason
10:03 is because you have these little tiny of connective tissue these tropically that's what
10:08 called and it adheres to the next called the P. A matter.
10:12 so the space underlying where those particular looks like a bunch of spider
10:17 Hence the name or annoyed matter. . But all it does is just
10:22 sure that those two that space doesn't outward beyond what it is. But
10:26 you look in there, I bet could find a brain spider.
10:28 Or at least you can blame the spider. So, this is what
10:33 space is. This yellow space. , this green remembers the dura that
10:37 right? There is Iraq annoyed and the subspace right here is the subarachnoid
10:42 . All right. And you can a little grain lines are supposed to
10:45 the true particularly. All right. the subarachnoid space is filled with cerebral
10:50 fluid? Cerebral spinal fluid remember is from the plasma in the core.
10:57 plexus. All right. And so we're doing is we're making it in
11:01 place, is traveling all the way and it needs to find a way
11:04 exit. All right. So, you'll see is you'll see penetrations of
11:09 Iraq annoyed matter that pushed through the . So, you have a subarachnoid
11:14 that's kind of pushing through underneath the . Annoyed. And these structures allow
11:19 that cerebral spinal fluid to be filtered into the blood. All right.
11:25 , put another way I'm borrowing fluid the blood. I'm surrounding the brain
11:29 this space and then that fluid that borrowed from the blood. I'm returning
11:33 back to the blood just at a location. Okay, So, there's
11:38 a flow that we're gonna be looking here in just a second. That
11:41 hope that makes sense though. All . Now, blood vessels are found
11:47 the dura. Alright. That's where big blood vessels are. And what
11:50 do is they penetrate through into the noid space or the subarachnoid space,
11:54 that's what they're trying to show you . And what we're trying to do
11:57 we're trying to bring blood close to brain. There are Excuse me.
12:01 are small blood vessels in the brain there's always gonna be a barrier between
12:05 blood and the nervous tissue. All . So, what we have here
12:09 we're having these thick barriers and we're the large vessels closer and closer to
12:14 nervous tissue into smaller and smaller Alright. So that's what we're
12:19 And so blood vessels will ultimately move then merge onto the surface where the
12:25 matter is located. So P. Matter they surround the blood vessels as
12:29 dive in and typically they're very, closely associated with the nervous tissue.
12:34 we saw the picture of the cartoon the brain. We saw the sulk
12:38 and viruses right along the surface is the humps and the in the valley's
12:44 . And we said these are landmarks anonymous use. Great. But the
12:48 that you actually have those is because brain grows bigger than the space that
12:53 cranium allows. And so it folds itself and that's why you get all
12:55 bumps and grooves. Alright, The matter moves along the bumps in the
13:00 . It's closely adhered. Think of as like shrink shrink shrink wrapping meninges
13:07 against the brain. All right, , it's a very very very thin
13:12 thinks that's the singular form of the meninges, plural. Men inks
13:17 So, if you see with an on the end, don't panic.
13:20 basically it's just a singular form. left of meninges is just a combination
13:27 the Iraq war and appear together. they just kind of say, oh
13:31 , this right here that select them inch. All right, let them
13:34 angie's those two things together. All . And then just to make things
13:40 more confusing are the tissues? So is the PM matter right here are
13:47 in feet of the astra sites up that like pushing up against it when
13:51 were a kid. Did you ever like the parachute time where you go
13:56 like oh I don't know the tumble and have the parachuting. You get
14:00 put your hands up on against it hold it up and stuff. That's
14:03 this is like. The glia Glia refers to glial cells the limit
14:09 the glial cells and these in feet the astro sites are pushing up against
14:13 pia and they create another barrier between actual neurons and the outside world.
14:22 right so we have is we basically a series of barriers in between these
14:27 structures. All right now, substance inside the CSF right is not being
14:36 to moving back and forth this All right. It doesn't restrict the
14:42 . That's what we're saying. But it is is it is another
14:45 So if you can't pass through a there is going to be some
14:51 Now the central the C. S central fluid the cerebral spinal fluid
14:57 your uh if you were to drain these spaces the subarachnoid space that surrounds
15:02 entire brain and down around the spinal and in the ventricles you drain all
15:06 . You'd come up with about 125 mils of fluid. This is usually
15:10 I look around and see. Do have a soda bottle? Anyone
15:13 Oh you can lift up your water real quick. How big is that
15:17 bottle? 500 ml. Right What is 125 relative to 500 one
15:29 . So hold up your bottle So I want visual image. So
15:33 can imagine almost she actually has some in there that's almost a quarter
15:37 That's about how much cerebral spinal fluid have in your body at any given
15:41 moment. Now How much do we produce? Well it's closer to 500
15:46 . Do I have it up there ? So you are constantly recycling and
15:51 the cerebral spinal fluid so you're making and obviously if you're making it has
15:55 go someplace. And so that's why have this pathway through these granule ations
16:00 through these villa that penetrate that subarachnoid . You know that that's that Iraq
16:05 matter that penetrates through the dura so the fluid can leave out and join
16:09 to the blood. So we're making corduroy plexus. What happens is we
16:14 out from the laterals to the third the third to the fourth from the
16:19 we can either go down the central or we can go out through the
16:22 apertures are out the back through the aperture. But we're getting in that
16:26 space and the flow and the which is a pressure gradient, which
16:32 going to point it out here. pressure grading is driving the fluid towards
16:37 subdural space where the Iraq congratulations are located. All right. So the
16:42 upward and outward and then out and the edges. And so this is
16:47 a granular or so this is a but it's a granule ation in
16:51 So you can imagine the pressure is it this way. So, it's
16:55 one way valve to push cerebral spinal . Start there all the way
16:59 You go back out there and you're your own cerebral spinal fluid four times
17:04 roughly. All right, I have , Bill, I are micro
17:10 graduations or macro structures. What's the between micro structure and macro structure?
17:15 do you think? 11 big small one, you can probably see
17:19 you just cut it up and well that thing that's sticking through,
17:22 a macro structure. The one that have to get a microscope out or
17:25 glass? Like oh that's a micro . So just kind of giving you
17:29 frame of reference. All right how do we get to rebel flannel
17:33 to flow in the right direction? , first off cilia sit there and
17:38 this right, you go that you go away from where I'm making
17:42 . And so you're pushing things how you sit, how you
17:47 how you stand. All that stuff postural, right? The fun ones
17:53 in class, right, Sit up many of you guys set up because
17:56 used to hearing that from your sit up straight, right? But
18:00 way you sit, the way you , the way you move causes the
18:03 of fluid in your body. So another way that does it. And
18:07 as a result of all this there's about a 10 millimeter mercury pressure
18:12 inside this space. It's compartment that the fluid towards those graduations. Anyone
18:19 ever seen um I'm blocking on the . This is what happens when I
18:25 away for a day. Everything gets . Um A epidural never had a
18:32 have an epidural or you've got to in the operating room. Got see
18:35 . Yeah. Right, so an is where they take this massive
18:41 I'm gonna scare all the ladies that is what my job is and what
18:45 do is they come charging at, know what they do is they get
18:48 on the on the table, they on your side, they have you
18:50 of curl up a little bit so you can find what L. Four
18:53 and what they do is they take need when they push it through all
18:57 these meninges and into that uh subarachnoid and that you can kind of feel
19:03 as you go through because it's like said, it's a tough tissue.
19:06 what they do, it's a catheter surround the needle. And then they
19:10 the needle out and then they check there any flow right now? It's
19:14 gonna be like blood work like right , it's just a little bit of
19:18 . Does it form? Okay, , we've got into the right space
19:23 what do all liquids wanna do? want to find the path of least
19:26 ? So, if I put a in that bureau with a you
19:29 with that needle and fluid start flowing . That means I've got the spot
19:33 then they attach whatever it is and they pushed the drugs and everyone's
19:37 Even the anesthesiologist is happy. He's getting sued for she. All
19:45 I know I'm going down tangents All right. So, remember what
19:48 said. Epidermal cells. They're the that produce this. All right.
19:52 , this is just to demonstrate to what's going on. So, what
19:56 have is we have this barrier is blood brain barrier. So, it's
19:59 between all the other tissues of the and the brain. And so,
20:03 I want to bring something into that , I need to have a way
20:07 do so, and that's what these is they bring these blood vessels.
20:11 , here are the capillaries. What doing is we're looking right up
20:13 So, here's the capillaries. This here represents what would be the blood
20:18 barrier. But this is one of places where we don't have it.
20:21 what we can do is fluid that out of the capillaries. The epidermal
20:25 use that. That's what all this is showing you to move these nutrients
20:29 these materials across that barrier to form cerebral spinal fluid here, in the
20:34 ventricles and in the third ventricle. then there's stuff down here at the
20:38 ventricle as well. All right. , the cord plexus, what is
20:42 cells? Some p a matter As a protection and all the blood
20:49 . We got a lot of blood about 10 times greater than the average
20:52 flow throughout the rest of the All right. There's no blood brain
20:58 . Because if you did blood brain sits on the outside of the
21:02 If there was a blood brain you wouldn't be able to get those
21:05 to leak out. And so, , what you have is you have
21:08 leaky capillaries, just like you have else. Where else in your
21:13 This will make a little more sense we talk about the nervous system,
21:16 sympathetic activity tends to uh inhibit the through these areas or inhibit the production
21:22 CSF. You can think about like . And this is just an aside
21:25 we'll get to in a little bit activity is usually goes up when your
21:30 increases it causes vaso dilation which allows to flow faster and harder with greater
21:36 or greater pressure. So you can why would I want to inhibit during
21:40 periods of time? Because I'd make too fast and my brain would probably
21:44 like a balloon. That kind of sense. In other words mambazo dilating
21:49 too much fluid in there. So gonna make more cerebral spinal fluid which
21:53 cause pressure in the brain which is . So sympathetic inhibits during those periods
21:59 everything else is opening up wide. don't need to memorize this. You
22:07 just look at it. It's beautiful it? I have an answer.
22:12 can't promise you the right answer. yes. Mhm. £11. You
22:23 well so it would be very You've heard the term Ortho static shock
22:27 Ortho static pressure right? It's the sort of thing when you lift what's
22:30 first thing you do? Right? take a deep breath but then you
22:34 it right? You know and what do is as you're lifting you're supposed
22:37 release that pressure right? But what doing is you're actually creating massive pressure
22:41 the body. That actually is something is not necessarily good for long periods
22:47 time. Right? And so that's same sort of thing. What you're
22:50 to avoid. It's creating a pressure can cause damage. So that's why
22:53 saying the sympathetic in this particular case causes bazaar constriction. It prevents the
23:00 of blood. Well if you're holding breath. Yeah. So it's basically
23:06 lots of reasons there but mostly that's Ortho static pressure. All right.
23:11 what we're looking at this, I want to show you here's plasma and
23:14 are the different types of salutes that found in it. And you can
23:17 kind of do a compare contrast and can see like for example there's less
23:21 . Not as much protein but everything is more or less the same.
23:26 ? And so I just I just to shoot So it really does look
23:29 lot like plasma, doesn't it? some slight modifications to it.
23:34 That's that's it. I'm not going say. Okay. Which one has
23:37 potassium? I'm not that's not important you. Probably important at some point
23:43 life but not today. I love picture. This is really a very
23:49 micrografx. Alright, what we're looking ? We're looking at a slice through
23:53 tissue. All right. So let's kind of see how well we can
23:59 for ourselves. What do you think stands for? A. D.
24:01 . N. Didn't you write What you think A X. Stands
24:05 ? Exxon good. What do you s stands for? It might be
24:11 . Right. So here's Dendrite Srs Probably Sarka plasma critical. Um No
24:18 couldn't be that. Sorry. That'd wrong tissue. My brain against total
24:22 garbage. Alright. A S What you think that is? Ask your
24:27 ? Good. Um What this is it's trying to show you the dendrites
24:34 the axons and the astrocytes and how everything is. And so, remember
24:41 is space in between these cells. just very very tiny space.
24:47 And so the idea here is just say I want you to think about
24:51 brain being bathed in extra cellular It's not like they're cells where everyone
24:56 all this elbow room and it's like right, we're all comfortable in the
24:59 and we have room. No, basically let's get everything we can and
25:03 it into the small space and everyone's sitting there going okay? At least
25:06 a little bit of molecules of water us. That's what's kind of going
25:11 . All right. So The extra fluid of the brain makes up about
25:16 of the brain volume. All So, what does that mean?
25:20 means it has a high degree of because it's not particularly dense. There's
25:25 fluid in there. Right? But really hard to see that fluid.
25:30 right. The concentration of the Extra cellular florida. The amount that's
25:35 changes over the course of the All right. When you're doing
25:41 Just sleeping watching T. V. doing homework. I don't know.
25:46 going to increase your BcF. Well, basically imagine that's parasympathetic.
25:52 Visa dilation. Generally speaking. So was going to flow into the
25:56 But as I'm moving around and stuff going to be constriction, I'm not
26:00 have I'm basically I'm trying to prevent brain from being stressed or compressed so
26:05 gonna move fluid out quicker. All . So, you can see that
26:10 anywhere through here. If you're a is not just a simple pathway,
26:15 very tortuous. Everything is all jammed there. So, the way that
26:20 talk to each other in the way things move through this tissue is very
26:26 complex. Right? That materials that diffusing through their need to know where
26:33 going. Well, they have to their way to where they're going is
26:36 I'm trying to get at. Right. So, you can imagine
26:40 this uh where was it? The ? Where's my astrocytes? Astrocytes?
26:45 you go? Okay, the blue are the astrocytes. So, you
26:48 imagine the Astros site needs to send across the way and so it has
26:54 pass through that cf So the signals going across that little small space,
27:00 you can see what is the astra doing. It's all around everywhere.
27:03 , it needs to know where is how and to whom? It's communicating
27:08 . The BCS SCF. Remember is contact with the central square of the
27:12 spinal fluid. How right. Remember have the PM matter and we have
27:16 glial mittens. All right. And materials can diffuse between those two
27:22 So if we get an imbalance say potassium because remember what we said over
27:27 , potassium is is low, let's they're gets too much potassium. Well
27:33 All right. It's low there. let's say we get too much potassium
27:37 the E. C. F. , there's a place for it to
27:39 too. There's a natural location that go to so that it can be
27:44 . Because where do the CSF go it's as it's being made? It
27:49 where it starts, it goes in subarachnoid space. And then where does
27:54 go from there? Back to the ? Right. Go through degranulation.
28:01 need to go back and see There we go. Right. I'm
28:06 . I go out and around and eventually I go back to the
28:10 That's the blue stuff. So there's pathway to help me get rid of
28:15 I don't need from the where we're to see here we have this blood
28:20 barrier which prevents the exchange of All right. Yes, sir.
28:30 The waste process used see is the process used. So so remember this
28:40 just gonna be a form of simple . I mean it's not always gonna
28:43 simple diffusion, but you can think terms of as there there's a natural
28:47 equity or or or amount of materials any sort of fluid, Right?
28:53 , if any of them rise or , what we have here is we
28:56 a second compartment. That's what the is allows for that material to move
29:01 its gradient to ensure that we maintain home a static balance. All
29:07 That's really what the idea here Now, why do we have to
29:10 this? Well, we have a brain barrier everywhere else in your
29:13 You don't have a barrier. if you have a build up of
29:17 and just use carbon dioxide is an one, right? If I have
29:20 build up of carbon dioxide, carbon diffuses out of the cell, out
29:23 an interstitial space gets picked up by plasma and off it goes to the
29:27 , Right? But carbon dioxide a example because blood Banbury doesn't stop
29:32 But let's pretend it does. If had a build up of carbon dioxide
29:36 I can't use that as an I'm stuck. So, what the
29:40 does, it serves as a way kind of manage or regulate the environment
29:46 such a way that I still protect brain. So, that kind of
29:50 sense. I hope. Yeah. , it's kind of like there's gonna
29:57 stupid example, All right. It's a partner in crime, lack of
30:03 term. I'm just thinking like a brother that you can blame stuff
30:06 right, You guys. I'm the that gets into all the trouble.
30:10 what can I do is I can off the blame to my brother.
30:15 , no, no, no, . You do this. You'll get
30:18 less trouble because you're younger than you know? So, what I'm
30:21 is I'm always shifting waste and other out this pathway because it ensures that
30:28 stabilized because I don't have another way do so, or at least a
30:32 way to do so. All now, I just kind of jumped
30:37 on the slides here. But let just let me go forward again.
30:41 right, Because this is where I to get to. Is this blood
30:43 barrier? All right. There are few places in the body where there
30:49 an actual barrier between that's tissue and rest of the body. One of
30:53 is the blood or is the brain it's a BBB blood brain barrier.
30:58 when you really had blood brain Okay. And what the blood brain
31:02 is is in essence, a barrier by the astrocytes. The first thing
31:09 astrocytes do. They send out a that causes the capillaries to seal
31:14 All right now throughout your body. capillaries are like, well, just
31:20 your hands for a second. Imagine up marbles and water. All
31:25 And if I scoop up the marbles water, the marbles are gonna stay
31:29 my hand but the water is going leak between my fingers. Right?
31:31 what capital of your life. Their And they allow small things to sneak
31:35 between what the Astra sites did they a signal that says no no no
31:40 not allowed to leak at all. just gonna go ahead and put the
31:42 glue between the fingers. So basically you scoop water stuck there, I
31:47 it's a terrible example but I'm trying use the Cameron. What have we
31:52 ? A similar or is an I know whatever the imagery.
31:57 That's why I'm trying to get out you metaphor. Yeah. That could
32:01 a metaphor and maybe not. All . But the idea is that I
32:05 an environment that I now is I can't pass through it. So
32:10 only way that I can move materials the blood to the brain tissue is
32:15 have to pass through directly pass through epithelium that makes up the capillary
32:21 So that's that India thallium and then have to pass through um the in
32:27 of the astrocytes. In other words I've created here is a physical barrier
32:32 the blood and the brain Now this been official for many reasons. One
32:37 keeps pathogens out. Think of all things that are trying to kill you
32:40 this world. All right? You keep a running total All right.
32:46 shouldn't because there's too many of Everything is trying to kill you?
32:50 is trying to go after you. news. We're keeping it out of
32:53 brain. All right. The only that can pass through these things,
32:57 that's the anatomical barrier, writes a barrier that prevents them. The only
33:02 that can pass through this barrier have follow the physiological rules. What are
33:06 physiological rules? All right. I've to sell cells are made up of
33:12 . So, if I have something lipid soluble, can I prevent it
33:16 getting into the brain? No, just going to work on through.
33:20 , here's a little tip for all . How many pharmacists? Anyone planning
33:23 pharmacy? Excuse Me? No No 1 is going to go to
33:27 . You're missing out. That's big . Top 5%. Okay, If
33:34 prescribing brain drugs or making brain they have to be lipid soluble.
33:40 right. Because anything that's water soluble not going to get past the blood
33:45 barrier. All right. So, an atomic in the sense that it's
33:50 there's actually cells in the way and physiological has to follow rules.
33:55 Here's just the better way to do . And it kind of shows us
33:58 little bit better. So, over , this would be a example of
34:02 normal capital. You see the big gaping hole between the two cells.
34:06 . There's a weakness. What have done over here? Well, we've
34:09 the weakness in terms of the Right, So the initially um is
34:13 longer leaking. Oh by the why don't we just go ahead and
34:15 another barrier of cells around that? anything that wants to get out of
34:19 capital to go into that capital has through the epithelium has to pass through
34:22 astrocytes. And by the way in those two things are the basement
34:26 So there's kind of a screen door between them. So you have to
34:30 small enough to be passed through, you have to be small enough to
34:34 your way through that basement membrane. by the way, when you get
34:37 here um if you're water soluble you to have a transporter that says it's
34:42 to come through that self. And you have to have something that pumps
34:46 out the other side. So guess ? We're regulating whatever goes in.
34:51 goes out of our brains highly That kind of makes sense. Sort
34:56 people are nodding their heads like you to the point I only have 20
35:00 minutes, how am I going to to the autonomic nervous system?
35:05 physiological deals with that water soluble itty or lipid soluble itty issue. If
35:09 lipid soluble not a barrier to water , you have to work your way
35:14 all that stuff. Now there are of the brain that are called circum
35:20 organs that don't, that are outside their regions of brain that don't have
35:25 blood brain barrier. So look at name circum ventricular, what does
35:29 what does that word mean? Circum ventricular, around the ventricles. There
35:36 go. Alright, so don't be when you see these things just
35:40 okay, All right. So these just reaches the brain that have to
35:44 the blood, have to know what's on the blood or putting things directly
35:46 the blood. So, for the , hypothalamus needs to know what sort
35:49 hormones it's getting and so that it decide what sort of hormones it needs
35:52 sin the pineal gland also puts out . Pituitary vomiting. Sitting on the
35:59 the most likely way that you're going ever be poisoned is not by being
36:03 by a rattlesnake or a brown recluse a sea snake or whatever horrible things
36:08 can think of. The most likely is you shove something in your
36:13 Right? So body is sitting there for toxins and other stuff, it
36:19 a toxin. The brain says this bad, we're going to die.
36:22 do I need to do? where did I get it?
36:25 I probably stuck in my body. I better vomit it right back
36:31 You ever wonder why you're sick all time, even if you haven't eaten
36:34 that poisoned you because the body's just it must have come through because hands
36:39 mouth kind of cool. Huh? you ever watched it seems someone who's
36:44 bitten by a rattlesnake or something, what they're vomiting, vomiting,
36:49 No one. What's that? It's not it's not being very helpful
36:56 that point. But Yes sir. . Yeah. So again that's that
37:02 nous. What's the likelihood? So gustatory system and the and the nose
37:08 the whole factories but no system. this is how bad it is.
37:13 telling you I'm not recovered from my . So just to let you know
37:17 had three hours of meetings I traveled like 12 hours. Yeah, welcome
37:22 adulthood. So anyway um So so those things are closely associated.
37:27 so again it's basically saying oh there be toxins in the body. So
37:31 just go ahead and vomit that stuff . It's also a defense mechanism in
37:37 animals. And even in your right? You know, do you
37:40 when you like being vomited on? that like a highlight of your life
37:43 ? Yeah I want a baby throws . You're like oh yeah, trust
37:48 when you become an adult it's just or you have kids you're like you
37:53 you just do it all right. plexus also needs doesn't have the blood
37:58 barrier because you need to be able make the cerebrospinal fluid. All
38:03 20 minutes and s And S. actually a lot easier. As I
38:08 , there's some nuance here but we're make this really, really simple for
38:12 entire length of history. Up until a couple of years ago there are
38:16 divisions whereas a sympathetic and the Now we have a third division which
38:20 compounds and confuse this thing. All , autonomic nervous system deals with the
38:25 that are involuntarily regulated and voluntarily So we're talking about cardiac smooth
38:31 glands like your salivary glands. Anything that secretary in terms of Secretary
38:37 Petroleum's like sweat glands. Examples are the authority of that and I'm nervous
38:43 . Alright, so there is both sympathetic and parasympathetic. They are structures
38:48 are found both in the cns and . Alright, so it's very easy
38:51 just kind of say oh it's only PNS thing because we spend a lot
38:54 time talking over there. But remember are nuclei that are responsible for sending
38:59 signals and receiving the signals. So is a central nervous system component as
39:04 . Typically what we do is we , hey, think about the
39:07 Think about the guts. All Those are the things you can't control
39:11 your stomach growls. Right? It's just it's just gonna do it
39:16 the worst time ever. Right? is an F. Eric system system
39:22 out always always always has two neurons generally speaking, the sympathetic and the
39:27 oppose one another in activities. Not there are some exceptions to the
39:31 We just learned those exceptions, but of the time you can think of
39:34 as a gas pedal, one as break. Now here's the important thing
39:38 makes it confusing. The gas pedal not always the gas pedal, the
39:42 is not always the break, so not say, oh, here's the
39:45 nervous system. It is the gas , air go, it's always the
39:48 pedal, right? It depends on you're looking at. One is acting
39:52 a gas pedal, ones acting as brake. All right, the enteric
39:57 is what confuses everything. So the time we just said is part of
40:01 sympathetic and parasympathetic. What they started is that this is a separate and
40:05 system responsible for controlling digestive activity. right, so it communicates with the
40:12 and communicates with the sympathetic, but can act independently if I take yummy
40:17 and just jam it straight to your . Even bypassing the gustatory system.
40:20 digestive system knows what to do with . It doesn't have to communicate with
40:24 central nervous system to say what I with this. It knows all those
40:29 and all the uh structures that are around the gastric system knows how to
40:36 with food in your belly or lack . All right, so it's an
40:41 system that controls the gi tract. just learning all about this stuff,
40:47 would I would argue that our knowledge the human body or just the body
40:50 general is probably about this much for body of work that's probably like
40:55 We're going to find out all sorts cool stuff throughout your lifetime.
40:58 here's the two neuron chain. You can see how it's divided up
41:03 nervous system out into the peripheral to target cell, which is also in
41:06 peripheral. If we're looking at the nervous system, we'll have that cell
41:11 located in the central nervous system in spinal cord and it would travel out
41:15 our target. Sell directly and innovate target self. You got that That
41:19 sense. That's what we've already We learned that last thursday, what
41:24 doing here is we're taking that cell leaving the central nervous system comes out
41:28 the peripheral and then it innovates a cell. So, that's the two
41:33 chain that I'm referring to. So is found in a ganglia.
41:38 the first cell is called a pre excel. The one that comes out
41:42 the ganglia is called the post ganglion . And that's one that goes to
41:45 target tissue. Yeah. Yeah. picture. Lots of things. All
41:53 . So, the sympathetic nervous the parasympathetic nervous system are organized slightly
41:58 . So, it makes it really to understand which one is coming
42:01 Where? All right. So, you're looking at the sympathetic system,
42:05 can see that that pre ganglia nick exists in the thoracic in the lumbar
42:11 . So basically just think back. right. Makes it really, really
42:17 . So, if it's an it's coming out of a spinal nerve
42:21 then it's traveling to wherever it needs go. So, you can see
42:23 some travel up, some travel But we're covering all the structures like
42:27 the eye all the way down to gun. It's all right. And
42:31 different things that are responsible for regulating of these things. Now, you
42:36 see just outside the spinal cord is very far away. It's just a
42:41 of centimeters. We have this structure a series of ganglia alright, stacked
42:47 each other and they're actually attached to other. This is the sympathetic
42:51 All right. And so, what is this is slightly outside. And
42:54 requires a little bit of anatomy. what it is is you can imagine
42:58 spinal nerve comes out which contains autonomic , sensory fibers right? Coming in
43:04 it has a parent fibers going out are somatic in nature. The autonomic
43:10 branch off that spinal nerve in these structures called Remy communications or community Conte's
43:17 the plural. All right. the rain. My communications is simply
43:23 an in and outdoor. And this is an atomic. So,
43:27 worry about this. But if you imagine spinal cord, right, what
43:32 we do? We form our spinal . All right. Sorry, I
43:36 put my hump there. And then here, Here's my spinal nerve.
43:41 going to be three branches. This right here is going to this large
43:49 that is the ganglion. These two are carrying the somatic fibers that innovate
43:55 back or the structures that you're going in the body. All right.
44:00 , it's this right here these two things. The indoor one goes
44:03 one comes out and their combined together counter that third branch. That's what
44:08 is. All right. So, are what you're going to call the
44:12 vertebral ganglia. What does para Mhm. By nearer. Okay.
44:19 the key thing here because we're going see here in just a second that
44:23 one called pre and it gets confusing and pre. All right.
44:29 they're connected to the trunk. So, here's a reminder. This
44:34 what it's showing you. You can what I just drew here. You
44:37 see here is the venture route. the dorsal root with the big old
44:41 . Here is the spinal nerve. not showing you the spinal nerve splitting
44:44 again. Those are again those are the dorsal remind the ventral ramos.
44:48 don't need to know those. Don't about that. Here is the
44:50 My community counties Raymond community content. can see up there from my community
44:55 . All right now the ramos those community Conte's allows fibers to move in
45:02 move out. I said there's an and there's an outdoor one is
45:04 one is white grey. Is Sorry, I have to double check
45:09 make sure I'm doing is the All right. So the fiber they're
45:13 out of my eliminated so you can the red line and they come in
45:17 the white. Why? It's called violated fibers. When it comes into
45:24 ganglion, it can do one of things. It can synapse with the
45:31 ganglion fiber, which will then go the gray and then continue on to
45:34 destination. It can go up the or you can go down the trunk
45:40 the next level and then do the thing. So you can see it
45:44 . Synapse singer synapse in here. right, so that's number one.
45:49 , I guess that's number two as . Number three is the weird
45:53 All right. Indoor outdoor back which makes it very confusing. So
46:03 can have some fibers that can come through the indoor. They don't send
46:07 . They just keep wandering on and go on to a gangland. That's
46:12 away. That ganglion that's further away the pre vertebral ganglia. Yeah,
46:21 cord pair of a pair of vertebral . Pre vertebral ganglia. That makes
46:28 . Now. Language sucks here because pear look an awful lot alike.
46:33 they mean an awful their sound a close to each other and can mean
46:37 things in some cases. All So, spinal cord pere pre and
46:46 what they should do? They should drawn this over here to make it
46:49 . But back door makes it All right. I'm going to come
46:52 to the picture so that you can what this looks like. All
46:56 Here's a pair of vertebral ganglia. , pair of vertebral. The ones
47:01 are in the trunk are right Okay, so you can see that
47:06 have a superior cervical gang list. , this is something where we've gone
47:11 here. You can see the post fiber going out and innovating things of
47:15 head right here. Innovating upper thoracic here, upper thoracic region. Now
47:22 are down here and we're doing what said where we're innovating at that same
47:27 . Right? So you can see fibers coming out coming out coming
47:30 So it's just staying at the same . So that superior middle in fear
47:34 the upper thoracic ganglia and then everything does some weird stuff. All
47:41 What we're gonna do is we're gonna to that pre vertebral or what is
47:44 the collateral gangly and that's what this . Remember I said. It's kind
47:48 confusing. I promised you this. don't even think I didn't lie to
47:52 . So, again, para para para para para. What do we
47:56 here? You can see here is pre gang ionic fiber. Does it
48:01 there? Know what to do? went through the back door, kept
48:06 going and it goes out here to gangland. That's a distance away.
48:11 is the celiac ganglion. Uh We're have a couple of other. There's
48:15 one. Another one. Superior Mesen inferior Mesen Terex on and so
48:19 The idea here is again, the ganglion fiber doesn't stop in that
48:26 It doesn't stop in the pair of , it moves on to a ganglion
48:32 on nearest the structure that you're looking . And then that's when you're going
48:36 have this fiber, the post cannula is going to go off to where
48:40 goes Sympathetic is the complicated one. right. So, you see the
48:46 go in. I can either synapse up synapse, go down synapse or
48:52 can go in, keep going, to the back door, out the
48:56 door synapse in another gang line some away. That's sympathetic. Parasympathetic is
49:04 butts and brains but brains see that life easy. So all of a
49:14 . Now what do we got? got sympathetic which is thoracic lumbar and
49:20 sure they see too. All Parasympathetic cervical and sacral. All
49:27 That's some brains. They all integrate same locations. All right. You
49:31 see here. Pregame fiber still There are some that originate in the
49:36 stem right? There we go. they go out to the exact same
49:40 where we were looking at that I little bit earlier. You can see
49:44 have ganglia that sit outside. So what they're doing is that gangly is
49:48 right up next to the spinal It's near to the origin where that
49:52 is going. Look at how short fibers are being represented. The ganglia
49:57 the stomach. For the parasympathetic which coming out through cranial nerve number
50:01 Most important cranial nerve you'll ever Just learn Vegas tattooed on your arm
50:05 the caffeine symbol. You know? basically it goes to all the other
50:10 . Then down here in the Let's look at its lower gi and
50:14 the genitals and the a urinary Alright, that would be the
50:19 So that's butts and brains. This just a picture. Not to
50:24 It just shows you these are the . See we said, the central
50:27 system plays a role. It holds cell bodies of these these particular
50:34 Right? So, they're just showing where these nerves come from. All
50:40 . These are the pre ganglion cranial . So they're just saying their cranial
50:44 and they have pre ganglion nerve fibers them. Now the fibers coming out
50:53 the only fibers you're also gonna have going back in. All right.
50:57 , a parent and the parent. looked at the different where they're
51:00 They have to come back in as . And typically these are coming from
51:04 organs inside the body and they tend follow the same tracks as other uh
51:10 fibers. And what they're doing their is to tell the body where there
51:15 be actual visceral pain. Even your appendicitis. Were you fortunate?
51:21 Was it like a nightmare? You out? All right. I was
51:25 summer camp. I kept vomiting and horrible, horrible diarrhea. They finally
51:29 said, well, maybe we should him to the hospital after a
51:32 Yeah. You know this is she care. Go team. All
51:38 I'm watching the time. I see right there. We got four
51:40 All right. And mine rupture. when you had that, where was
51:45 pain? Okay. Yeah, You like, let's see what this
51:51 A touch over here. It's not . What about up here? Not
51:53 , not bad. Holy crap. are you doing to me?
51:57 It's just kind of a centralized All right. You guys watch enough
52:01 and stuff when you have a heart . What do you grab when you
52:03 a heart attack, grab your Right? You don't grab your
52:09 You'd like to think you do. like my heart. No, it's
52:13 , what's going on over here if wondering, I got missed Lots and
52:16 of mosquito bites over the weekend. right. Looks like a druggie.
52:22 . Yeah. You should see my . It's even worse. All
52:26 What we're doing here is we're talking referred pain, referred pain is basically
52:32 the fibers, these Afrin fibers, century fibers going back up, but
52:37 they follow the same tracks. Brain confuses and I don't know the problem
52:42 . I've always had is like, does it confuse because these are going
52:45 specific places? But it basically oh, I'm receiving a signal that
52:49 the same track. So ergo it come from this region. So,
52:54 this little map is kind of showing is like where these types of pain
52:59 of appear in on the surface of body. So, like I
53:02 the heart attack when the heart it you feel it over here,
53:07 When your appendix is sitting over you feel it kind of centrally.
53:11 of these are actually kind of fun you start looking at them are
53:13 really? Yeah, so, ovary make sense, appendix just as
53:19 How about that for the liver? , my liver is killing me.
53:26 not back if the liver pain. right. So, these are this
53:31 just this is what is referred to referred pain. All right. But
53:35 means information is being sent back up the central nervous system with regards to
53:42 autonomic nervous system. Gupta just turned the lights. Oh, enteric
53:47 This basically just says everything we already . It's basically entirely peripheral. There's
53:52 different plexus is basically controls. the digestive system. Alright. There's
53:58 sympathetic. Their post pregame Janek, ganglia nick as well, receiving
54:05 Just understand. All right, I two minutes. I'm gonna stop on
54:11 slide here. All right. I'm to explain this and I'm going to
54:15 there. All right. I'm going use an example to help you understand
54:18 because it's the gas pedal brake You're in a car driving down I
54:23 to Galveston. Would you all It's flat highway. All right.
54:26 1s on the highway, so this really fantasy. Okay. No one's
54:30 the highway. You're going 100 miles hour. You don't have brakes.
54:33 do you stop? Say again? your foot off the gas.
54:40 great. That's exactly the answer. looking for. All right. And
54:43 those files, take your foot off gas pedal. You'll eventually slow down
54:46 from the robot, slow the car . Right now, let's imagine for
54:52 moment. You're a great student. been at the library all night,
54:56 ? You stay till two AM, you parked in BFV? Right.
54:59 parking lot that's I don't know on other side of downtown. Right.
55:04 you're walking there. Alright. And walking alone because while you're brave.
55:09 right. And so here you you're walking across the campus, you're
55:12 a little bit safe. But then start hitting those streets when it starts
55:15 dark and there's no lights and it to be there was the crunchy uh
55:20 lot where you just have the So you can imagine you're crunching along
55:24 that parking lot and you hear the of your feet and then behind
55:28 you hear crunching now you've been in horror movie at least you've seen
55:32 right? Are you supposed to turn ? I knew who you know that's
55:36 the exporter jumps on you, So you're just like, okay,
55:40 hear the crunching of the feet. going to happen? What happens to
55:43 heart rate starts rising? Right? this sympathetic activity, it's rising
55:47 Alright. What's happening in respiratory It's growing up. What about your
55:51 pressure, eyes? Dilate? You're for a way out? All
55:54 But you know, you're gonna be . So what do you start walking
55:56 little faster? And what do you behind you? Is the steps?
56:05 ? Now you're on high alert, , You're just ready. So remember
56:08 or flight? Right? That's Fight or flight. I'm either gonna
56:12 or I'm gonna run right? And things are getting closer, but you
56:15 be cool because you've seen the you know, you don't turn around
56:17 those steps are right behind you and of a sudden you feel a hand
56:20 your shoulder. What do you He faint? Alright, that's that's
56:24 a good defensive mechanism. Yeah. . Turn around, start swinging.
56:30 know, I'm taking you with You know that's that would be the
56:33 response. But what what you You might shriek, you know,
56:38 some high notes guys that like All . And he turned around and it's
56:42 person you've been studying with and I just want to catch up
56:45 I found your car keys. All . Now notice your system is in
56:49 gear, right? You're you're in gear 6th gear, everything is all
56:55 . If you only had a sympathetic , think about slowing it back
56:59 back to home, a static how long would it take be?
57:03 just like writing 100 miles an So you need something to bring you
57:07 into balance and that's what the parasympathetic . It allows your system returned back
57:12 normal quicker and it doesn't matter if parasympathetic is the dominant system or if
57:18 is the dominant system? Right? parasympathetic is dominant sympathetic job is to
57:23 you back into balance if sympathetic is , parasympathetic brings you back into
57:29 That's the premise of the gas and brake and it doesn't matter. So
57:33 I said, for example when you're food, which is the gas
57:37 be the rest and digest system which sympathetic or parasympathetic. Right? So
57:43 when you're pressing the gas to So sympathetic is there to slow the
57:50 process down? Return things back to ? All right. So that's the
57:54 that I'm trying to talk about when get back. We'll deal with all
57:57 other stuff. Um All this simple here. This actually is pretty
58:03 All right. Yeah. Mr Heart transplant. I think they
-
+