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BIOL 2301 Human Anatomy & Physiology I - BIOL2301_lecture18_1026
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00:01 All right y'all. So today we're week away from the third exam.
00:11 . Not yay, yay, OK. I like yeas. All
00:18 . And what we're gonna do is gonna cover two basic areas today.
00:22 going to look at spinal nerves and organizations. So we're going to be
00:25 our time for half the class and peripheral nervous system. After we deal
00:29 the spinal nerves, we're gonna jump into the central nervous system and we're
00:33 to, I would say we're gonna our way up through the brain stem
00:37 upward, but instead we're kind of the cerebrum first and then we'll do
00:40 brain stem. Um And then when come back, uh after uh the
00:46 , then we're gonna finish out the of the uh central nervous system.
00:49 so what we're looking at here is slice through the uh the spinal cord
00:54 you can see off on the far , you see the spinal nerves uh
00:58 way off on the edges, right it says left and right.
01:02 And so what we're going to be is we're gonna be looking at these
01:06 and what they form and how they're . OK. So the organization here
01:11 a cadence is the best way to about this. And, and if
01:14 think about, ok, well, spinal nerves are derived from or arise
01:19 the spinal cord, what are the that actually form and give rise to
01:23 ? All right. And so if look at this, you can
01:25 I've got this, this group of fibers that are coming out here
01:29 a group of fibers coming out here we call these the roots. And
01:33 , there's actually even a smaller It's a root lit. So it'd
01:37 a rootlet that is forming the And so one of the first things
01:41 we can do is we can start say, OK, we have the
01:44 cord and from the spinal cord, get rootlets and from the rootlets,
01:48 get roots. All right. And are two roots. We have the
01:52 root and the dorsal root, the root is on the front side,
01:56 dorsal root is on the backside. , if you remember the last thing
02:01 were talking about when uh on uh , I gotta remember what day it
02:05 on Tuesday, we were describing the arc. Do you remember the reflex
02:09 ? Do you remember your reflex This is where it starts going.
02:13 You mean I've got to carry things class to class. Yes, I
02:17 . All right. And I this is the picture that is most
02:21 for you to understand moving forward. you all kind of looked at me
02:24 , oh goodness, really? And said yes in my brain, this
02:27 all going on in my brain, out there for real. And here
02:30 have this structure where we have central system and once you get outside
02:35 that's peripheral nervous system. And if think about it, OK, way
02:39 here, that would be where our and our receptor is located,
02:45 Or you could be on this side you want to, depending on how
02:47 want to paint it out. All . So you can imagine, I
02:50 an e uh uh a receptor, receptor takes information sends it in.
02:55 did we call that? A right? And so a Ferran fiber
03:01 carrying sensory input. And what it is it comes along the spinal nerve
03:06 it enters the dorsal root. And then it goes into the central
03:13 system where you're gonna have your inter , that's your processing center, the
03:17 center. And then when you come , we remember we said we had
03:21 three areas in the gray matter. had the lateral horn, we had
03:25 ventral horn and then we have the horn, right? So that would
03:29 the, which one, the thing looks like a horn, which,
03:34 one is it lateral, ventral or , dorsal, dorsal. It sees
03:38 side. So dorsal, it you could call it the posterior
03:42 e either one works right. So have the dorsal and so it comes
03:45 through the dorsal horn horn, it itself or synapses with the inter
03:51 The inner neuron comes down and depending it's autonomic or if it's somatic,
03:55 gonna originate, the cell body will here in the lateral horn or in
04:00 ventral horn. And then what it is that fiber comes out and then
04:04 . And that fiber is an efferent . It is what we refer to
04:07 a motor neuron. Ok. So that same picture that we looked at
04:12 reflex is here again. All And so what we see is we
04:18 up here, we have the dorsal . The dorsal root is where you're
04:22 to find the Afer fiber. The fiber is a sensory fiber. It
04:27 carrying sensory input into the central nervous . So the dorsal horn is like
04:33 indoor into a kitchen at a And then the ventral horn is like
04:38 or the ventral root is like the . This is where the motor neuron
04:42 exiting. And so together they are together along the spinal nerve, but
04:49 are branching. So the organization is cord, I got my rootlets,
04:56 rootlets form the roots and the roots to form spinal nerves do you see
05:04 ? And I'm gonna keep doing I'm gonna keep adding one thing to
05:06 end of this little train that we're . All right. So dorsal cord
05:10 sorry, it's the dorsal cord, cord to rootlets, rootlets to
05:14 root to the um spinal nerve. when we have the roots, dorsal
05:20 ventral, dorsal is sensory, ventral motor, weird thing about the dorsal
05:26 it stand out from the other. you look at the picture and you
05:29 see, I've already highlighted on the , what stands out dorsal root
05:35 big old bump. All right. sensory nerves are weird. See if
05:40 can draw this. They are Uh There's my big blacks. All
05:48 . So a sensory nerve looks like the neuron has its cell body sitting
05:55 to the side and over here, would be the receiving side and then
05:58 there that would be the sending side we're looking at that side. So
06:03 cell bodies are all located in that root ganglia, right? And then
06:09 I'm going into the central nervous that would be my inter neuron and
06:13 my motor neuron looks like that. this would be the dorsal root ganglia
06:21 that dorsal root ganglia. All That's what you're seeing up there.
06:28 right. So notice these are the of neurons that we're used to
06:32 This one's weird looking. So that's you're gonna see in the dorsal
06:37 All right. Now, the spinal which are arising from the dorsal root
06:44 the ventral route convergence coming together. in our little picture up here where
06:50 giving you two views, this is superior view. And so you can
06:54 there is the ventral route, there the dorsal root and they're coming together
06:58 they're forming this big fat thick That big fat thick thing is the
07:02 nerve. If you look carefully at big bump, that's right there,
07:06 would be the dorsal ganglia. But you're doing is you're coming together.
07:10 so now you have your spinal This is just a different view from
07:14 of the, the ventral side, it's not a real good picture because
07:18 really itsy bitsy, teeny tiny. you can see I'm getting a spinal
07:22 and what happens is that spinal nerve into three branches. All right,
07:27 branches are referred to collectively as the . All right. So I've got
07:33 uh spinal cord, spinal cord becomes , rootlet becomes root, root,
07:37 spinal nerves, spinal nerve splits becomes . Three rami. The first rami
07:42 a dorsal ramus. All right, gonna see that the names are gonna
07:46 coming up over and over, ventral, yada yada yad dorsal
07:50 This is the only time we're gonna them. You don't have to worry
07:53 it. After this. They form nerves that innervate the muscles and the
07:57 of your back. That kind of sense, doesn't it? They're on
08:01 dorsal side, easy, easy, . So think about all those muscles
08:05 your back. That's where those nerves coming from. They help you maintain
08:09 , balance, they allow you to creepy crawly things moving up your spine
08:14 not really your spine but your Ok. The second one I want
08:19 mention here is the Rami communic which is a pair of ramses.
08:24 not the proper way to say the . It's a pair of Rami.
08:26 are not gonna talk about them until second and last lecture of the
08:30 Not of the unit of the All right, they're part of the
08:34 nervous system. All right. But are a branch to allow fibers to
08:38 , which are part of the autonomic system to be separated, to do
08:41 things. All right. So we're gonna bother with them other than to
08:46 that the branch is we have a branch. We have the Rami communic
08:49 which belongs to the autonomic nervous And then we have the big one
08:53 the middle, the important one, one that we're focusing on right
08:56 which is the ventral ramus. All , the ventral ramus is this big
09:02 part right here. The one that like it should be a spinal
09:06 All right. But remember we so we started with our cord,
09:11 , cordless, became rootlets, rootlets the root root, became the spinal
09:18 , spinal nerve branch and became the . All right. So we're focusing
09:23 on the ventral ramus. All the ventral ramus is what is responsible
09:30 innovating basically everything else in your All right, apart from the autonomic
09:35 system, which we're not talking about . All right, they're gonna form
09:41 structures which are like highway systems where nerve fibers are gonna start mixing and
09:49 form these structures called plexi. All . Plexus is singular. Plexi is
09:54 plural. But before we talk about plexi, let's talk about the exception
09:58 the rule. All right, there's exception. Yes. Unfortunately, there
10:03 . Oh, wait, oh, gonna first talk about spinal nerves in
10:07 . I guess we're not talking about exception that we're just talking about nerves
10:09 general. All right. So first spinal nerves, they're organized topographically.
10:14 other words, the wires in your are not disorganized, they're organized.
10:18 talked about this before. And so can expect if I have nerves that
10:22 part of my upper limb, they be all in that region, leaving
10:26 spinal cord from that, from a that is upper relative to a region
10:31 is lower. All right. So can see here, there's this organization
10:36 the body. All right, we two. We mentioned this as regard
10:39 the spinal cord, there are two , one that's called the cervical
10:43 One that's called the lumbar enlargement. what this is is basically the,
10:47 , the spinal nerve where you have information going in and out of the
10:51 . So you're gonna have the region the spinal cord a little bit
10:54 So the upper limbs are gonna be uh innervated through fibers that are leaving
11:00 the cervical enlargement for the lower limbs gonna be coming from the lumbar
11:05 That's a real basic thing. The thing is that because of this
11:11 we can map your body. All , we know for example,
11:16 oh if you are feeling information from particular area, we know which nerve
11:21 responsible for that. The good news , we're not gonna learn all the
11:24 nerves which innervate different parts. We that to the graduate programs. They'll
11:29 you what you need to know in for you to progress through your graduate
11:33 . All right. But what you to understand is we have what is
11:36 a dermatome, which is that it's showing you the skin and the
11:41 that are being provided by that region the spinal cord. That's what the
11:45 coding is. It's just telling oh for example, this region of
11:49 hip, the, the skin that's innervated, there comes from fibers that
11:53 L one that's just what that's, the example. And then this over
11:58 is showing you the myotome, the shows you where the nerve fibers are
12:04 , what muscles they innervate. So muscle derma skin and the tome refers
12:10 the topography. And so that's what seeing here is look, we can
12:14 and tell you which nerves are where and what they're innervating and which
12:17 are being innervated. All right. you need to be sure that you
12:21 the term, the dermatome deals with information. The myotome deals with muscle
12:29 information, information that comes in versus that goes out and you got to
12:34 remembering that sensory is in motor is . All right. That's the key
12:40 here. All right, the nerve , what is it? I want
12:47 to think about how you got, you don't live on campus, I
12:49 you to think about how you got the university today. All right.
12:53 about all that fun little traffic that drove through yay traffic and think about
12:57 would happen if there was a 40 pile up in front of you between
13:01 house and here? Ok. How you get to the university? Are
13:04 stuck on that one track or is an alternate route? There's an alternate
13:10 good and you should always have at one or two alternate routes in your
13:14 to say, ok, if I to this point and things are
13:17 how do I get around this. right, the way your body is
13:20 is very similar to how you have routes to different locations. All
13:26 In other words, what the body is, hey, I can't put
13:30 my nerves in one basket. I just send all the fibers that are
13:33 to a specific location via one I want to be able to mix
13:38 match and so different parts of the are going to be uh sending fibers
13:43 and from those two locations via different . And part of the, I
13:49 take my sip here. I hate I pick this up and I just
13:53 around with it for like two All right. So part of what's
13:57 on is, is right outside that rama, what's gonna happen is you
14:02 seeing the crisscrossing of fibers and the of fibers so that you can form
14:06 name nerves of the body that are to a very specific location. But
14:10 fibers themselves are arising from different rami different location and I just want to
14:16 out. All right. So you need to know this. I'm just
14:18 it to you. So here's the nerve, the fren nerve is what
14:21 you to breathe in and out. other words, it causes the thoracic
14:25 to expand and contract. All But look at where the fibers originate
14:29 . So we have fibers coming from five, that form the phrenic
14:32 We have fibers from C four that in form the phrenic nerve. We
14:36 fibers from C three that come and the Fren nerve. So if I
14:39 to damage, say this branch, I still have fibers that are able
14:45 go to and from the thors? mean, from the fren nerve.
14:50 . And that's the idea here is don't wanna, if I damage,
14:54 say C four, that doesn't destroy ability to survive. It hinders,
15:00 causes problems, but it doesn't completely hinder or not hinder, completely kill
15:07 . All right. So that's the here. Bew behind plexus is that
15:12 allows for fibers to cross themselves and form the name nerves to ensure that
15:17 are more than one pathway between those locations of the central nervous system.
15:22 the thing that's being innervated. All . Now, what we're gonna end
15:29 with at the far end of any are the name nerves of the
15:32 All right. And the last thing point out is there are four main
15:36 . This is when you go take anatomy classes are the four you
15:39 All right. There are more than four, but these are the big
15:43 . Ok. Now, here's my . All right. So the one
15:49 where we don't see a plexus is the thoracic region. All right.
15:53 we're talking about the thoracic nerves and they're gonna do. So remember thoracic
15:57 refers to the spinal nerve nerve leaving thoracic region. And what they do
16:01 they form what are called the intercostal . All right, they're going
16:06 going between the ribs. Hence the the, in between the nerve or
16:11 between the rib nerve. That's the , right? Intercostal. All
16:16 Now, here again, we're dealing the uh the uh anterior ramus,
16:22 anterior ramus or eventual ramus is, , is just going. But instead
16:26 crisscrossing, like we're gonna see in these other places, they just keep
16:29 straight and they go in between the nerves, they do two things,
16:33 invert innervate both the muscle and the uh the skin. All right.
16:38 they're playing an important role not only sensory. And I say up
16:42 they iterate the inner costal. So also playing a role in the contractions
16:48 the, of the muscles inside uh thoracic cage. All right. So
16:53 do we have here? Basically? There's, there's a couple of
16:57 So, sensor information from the skin the axilla to the medial surface of
17:01 arm. All right. So what's region kind of right in here?
17:05 right. And then you just work way down, look oh the anterior
17:08 lateral chest walls. So we're moving and finally, oh down to the
17:12 muscles. So they're just coming around they're innervating so that you can feel
17:17 as well as innervating the muscles of thoracic cage. That's the idea.
17:23 right. So they're the easy just intercostal muscles, they form from
17:27 thoracic nerves, basically straightforward. T also plays a role in the brachial
17:33 . But truthfully, I'm not gonna you, OK, what nerves give
17:37 to this? I'm, that's just , especially in a lecture class.
17:42 I'm gonna show you a picture so you can see like what you see
17:45 here. And then we're gonna show kind of a, a stick map
17:50 the pre of the plexus and then , we'll kind of show you the
17:54 that are important. All right, are being inner innervated here. So
17:58 right here is the Cervico brachial All right. So there's two plexuses
18:04 represented here. Plexi. All We have the cervical plexus. All
18:09 . Which part of the body is cervical plexus responsible for, do you
18:13 just by based on where it's Neck? Right? So it's,
18:18 says upper region. So it's your and ba basically the back of your
18:21 and then you have the brachioplexus which sits down a little bit lower and
18:26 can see where those fibers going. , they're going down to the
18:30 All right. So you can kind see what we're doing here is just
18:33 very simple organization. We're just gonna our way down our body here is
18:36 neck region. Now we're gonna deal the arms and then we do the
18:40 muscles or the uh or the intercostal . That would be the thoracic.
18:44 then when we do lumbar and they're gonna be working down the back
18:47 the fronts of the legs. All . So this is just a visual
18:53 showing you those, those uh All right. So this right here
19:00 what we would refer to as a map. Um If you've ever been
19:04 like New York or Washington DC, they have a subway system, they
19:07 you maps like this, say this how you get around the city and
19:10 doesn't look like the city at It's just bas basically a bunch of
19:13 to tell you how to get to various regions. You follow the red
19:17 , the blue line and so on so forth. All right. So
19:20 job is not to memorize this. right. This is to help you
19:24 relationship. All right. And so is this showing you? Well,
19:28 dots represent where the Ramus is and the lines represent the fibers that are
19:34 off of that Ramus and forming specific . So like for example,
19:39 we can see part of C one part of C two come together and
19:43 form what is called the muscular All right, that's, that's how
19:48 read this map. All right. this is gonna be the back of
19:52 neck. All right, primarily C to C four, C five is
19:58 involved, right? We're gonna be with superficial neck structures. This
20:06 so what does superficial mean on the ? So we're talking about skin,
20:10 we're also talking about muscles attached to hyoid. You guys remember where your
20:14 is right on your trachea, right, the surface of the neck
20:19 the lower portions of the head. right back in here. All
20:24 So this shows you here that we a cutaneous branch and a muscular
20:31 Cutaneous means on the surface. So it's on the surface, what are
20:37 dealing with? Centura, motor, , good muscular branch? Well,
20:43 tells you what are you dealing with or motor? OK. Now,
20:49 isn't all that helpful to you, I if you like this better come
20:53 to this map, I like this better. OK. Oh No,
20:56 don't. It's not there. It actually this. All right. Let's
21:01 through this cutaneous. Look at the of the nerves. All right,
21:05 gonna see these big names and you're be freaking out. All right,
21:08 freak out. We have the occipital . All right. Remember where was
21:11 occipital bone? Good. So where you think it innervates right back
21:17 It's the skin on the back of head. That's easy. All
21:21 auricular nerve. Do you remember what oracle is? We had another name
21:25 it called the pena. So, is the auricular nerve innervate? Do
21:29 think the ear good? That's your ? All right. So, basically
21:35 skin back here and your ear? right. The cervical nerve.
21:41 we've been talking about the cervical This is a cervical plexus.
21:45 what is that? That's the back your neck and then supraclavicular supra is
21:53 clavicle there. So, what are in there? I don't even need
21:58 map it. The name tells you it does. This is very,
22:02 common. So if you ever I, I don't know, it's
22:05 scary word. Think about what the means. Pause for about a second
22:09 you'll be able to understand what it . All right, when we're dealing
22:12 the muscular nerves, we're talking about muscles of the throat that so that
22:15 be the muscular nerve and the front diaphragm to regulate breathing. So that's
22:20 breathing portion with, along with the muscles. All right, brachial plexus
22:28 the most complex. All right. end, it is the most complex
22:32 the four that we're looking at. is the scariest. All right.
22:36 what we started with, we started the co the spinal cord, spinal
22:40 with Tullis rootlets to root, root Rami. We had the dorsal ventral
22:44 Ramon communic cans, but we're talking the Rami, the rami formed these
22:48 . All right. And so with brachial plexus, we're gonna see that
22:52 branch is these rami, these ventral they come together and they form what
22:57 called the trunks. And so these circles are representing where that trunk is
23:01 . So there's three trunk, there's superior trunk. If there's a superior
23:05 , there means there's an inferior I told you there's three. So
23:07 means there's one in the middle, would be the middle trunk. All
23:10 , then the trunk divides each one them divides and one is in the
23:16 and one is in the back. we call it the anterior division and
23:20 call it the posterior division of the , inferior or middle trunk. So
23:25 have the remi the remi forms a , the trunk forms a huh
23:31 Yeah, that's all right. So that's what we got here.
23:36 that's what these little uh triangle or triangles with the little squares are trying
23:39 show you. So here's the there's the posterior, anterior,
23:43 anterior, posterior, all right. trying to show you on the map
23:47 then what we do is we're gonna cords. And so what we're gonna
23:51 is we're gonna combine things together to the cords. So you can see
23:55 here, I've got anterior and anterior together forming a lateral cord. All
24:00 . Then what do I have is have a posterior to posterior coming together
24:03 actually three posteriors coming together to form the posterior cord and then the medial
24:09 is all by its lonesome. It's the anterior um division of the uh
24:15 uh trunk. All right. So do we have here? We got
24:19 , trunks form divisions. D uh are the splits, the splits come
24:22 in different combinations to form chords. then it's the cords themselves that form
24:27 nerves. So what we have here like that. All right. It's
24:34 of weird and spooky and scary and and oh yuck. All right.
24:38 news. It's hard to see this a single screen. What I want
24:44 to understand is just the order in those things are being divided.
24:47 ma'am. Can I say the relationships ? Oh, so yeah. So
24:55 s themselves are gonna come together and cords. All right now in the
25:00 of your upper arm. All you have an artery. All
25:04 That artery is the structure around which cords are, are found, which
25:10 why we have a lateral cord, posterior cord and a medial cord.
25:14 one is lateral to that artery, is medial to the artery, one
25:18 posterior to that artery. That's where names come from. All right.
25:22 you see this picture? No. right. Could you see it if
25:25 showed you that? No, because a two dimensions you need three
25:28 That's kind of go in there and things. All right. So this
25:31 not about you identifying, it's about what is the order of organization.
25:36 right. Now, this picture tells what we're gonna do is we're gonna
25:42 12345 nerves. OK? And so can see a picture like this where
25:49 don't know if this is more helpful you or not. You know,
25:51 look at this and I see lots words and it scares me because it's
25:55 and lines go everywhere. All this to me is a little bit
25:58 , but it's still not the easiest . So what is the easiest thing
26:03 my mind? Not this, Because yes, I can see those
26:08 and we're gonna learn those nerves, five nerves are important for you to
26:12 . But I think this makes it . Ok. So here we can
26:19 see what those nerves are actually After you go from those trunks through
26:24 divisions through the cords, you're gonna the axillary nerve. All right.
26:29 the axillary nerve? Well, it's the deltoid muscle and the skin of
26:33 axillary region. All right. That's easy. Ok. Well, what
26:37 do we have? Well, we the muscular cutaneous nerve. What a
26:40 name for a nerve. It innervates and skin. Great. Thanks.
26:45 , very helpless. All right. is that located? Well, musculars
26:48 is gonna be the lateral forearm. . So that's an easy thing to
26:53 of see. All right, then have the radial nerve. It's named
26:57 it runs along the length of the . Where does it go?
27:00 it goes down to your hand, . You can see here here's radial
27:04 , its upper arm and it goes the middle. But really what you're
27:07 here is your, it's the skin this region. But really you're getting
27:11 to your fingers here, you falling on your arm, you're woke up
27:15 your arm, just doesn't respond. you're like, yeah, so that
27:20 kind of show you when you press what happen, the ulnar nerve,
27:23 gonna be the outer regions of your , right? And then the median
27:28 , it's the f it's the actual of your palm. So you can
27:32 ulnar medial or median nerve and radial are all coming down to your
27:37 The purple thing is not labeled Why? Well, because I didn't
27:40 it was important enough, but it what is called the medial muscular cutaneous
27:45 and we're not gonna do that. . No, it's again, nomenclature
27:50 based on, well, where is going? That's all they're doing
27:53 What, what are we looking What are we here? All
27:56 So this, I think is helpful this particular case. All right.
28:04 that, is that a little bit ? Yeah, you can learn your
28:07 nerves. All right. Yeah. . Lumbar plexus. Back to our
28:14 map. You can see the different . All right. So this is
28:17 be located in the anterior pelvis. your pelvis? Elvis hips,
28:26 It's this region, it's the region we call the bikini zone. No
28:32 . All right. So we're talking that come through that region. All
28:38 . Not particularly complex, but there divisions in it. So there is
28:42 trunks, there are no cords. we do is we have division.
28:45 an anterior and posterior division. All . I'm gonna go ahead and flip
28:50 now because I think it's just easier way. So these are gonna be
28:54 innervating the anterior aspects of the lower . All right. And you can
28:59 in the picture here's the anterior aspect the lower limbs, right? You
29:03 see that anterior two nerves of There are a lot more nerves.
29:08 can see there are a lot more . All right. Two that I
29:11 are important to you. The femoral name because it follows the femur.
29:17 . And the ator, I don't why it's called the operator. I
29:21 looked it up. All right. in essence, you can see
29:24 what am I doing? Femoral nerve the anterior medial side of the thigh
29:29 the anterior medial side of the front the leg or the lower leg.
29:36 right. You can see here, also wraps around and does a portion
29:40 the posterior side. So, medial side. So you can just
29:44 it's the inside and then the operator the inside of the thigh.
29:49 medial thigh, all right. So skin and muscle. All right.
29:56 easy. Look at the muscle, the name of the muscle? Vastus
30:03 ? What does it mean? big, middle, large?
30:08 Just showing it. All right. lumbar is anterior. So what do
30:18 think sacral is posterior? Yeah, it's, they make it sound when
30:25 read the stuff and you see these as being far more scary and complex
30:29 it is. Now, truthfully, you go to medical school, for
30:32 of you who are going to medical , you will have to learn all
30:35 these muscles and all of these nerves anatomy and you'll probably only use it
30:41 in your life like when you take anatomy exam. All right. Unless
30:46 go into like for example, um or something. All right. The
30:51 of y'all will just like, I got it, vomit it out
30:54 the test, do it on the . Move on. All right.
30:58 plexus. All right. So it's the same region, but now it's
31:02 anterior pelvis, it's posterior pelvis. that doesn't mean buttocks, it means
31:07 region, but it's going backwards, comes through and it goes around the
31:11 All right. Again, we have in anterior and the posterior.
31:16 what we say is the anterior division a role in muscles that flex,
31:20 the posterior division deals with muscles that . All right. So that is
31:25 of the kind of the kind of cool things about this. All
31:28 But again, I think looking at is a little bit easier, the
31:32 nerves that we're gonna be interested in the tibial nerve and the common fibular
31:37 . So, again, named for bone over which they travel.
31:41 these two nerves arise from a much larger nerve. It's one of the
31:45 nerves in the body, which is we're mentioning it. It's called the
31:49 nerve. All right. You somebody who has sciatica, have you
31:54 , it's horrible, horrible, horrible pain that is derived from the sciatic
32:00 . Um If you've ever gotten a massage in the buttocks and you kind
32:03 get that sensation of like this is the best feeling ever. It's because
32:08 rubbing the sciatic nerve and basically it , it melts your body. Uh
32:13 who's ever had to stretch, you , done the four stretch, you
32:16 , like push your leg back, your leg up like this and
32:21 You ever done that? I'm looking for the athletes. Yeah, it's
32:24 it just stretches everything in your lower and it stretches your buttocks and uh
32:30 what you're doing is you're squeezing on nerve and it's just like heaven.
32:34 right. It's the deep massage of muscle or that nerve is just
32:39 But when it goes wrong, I , you can't sit, you can't
32:42 , you can't lie down. It the worst thing anyone who's ever had
32:46 will tell you just kill me. right. So we start off with
32:51 big giant nerve, the sciatic nerve it splits in the tibial and the
32:54 fibular. What does the tibial nerve ? Well, tibial nerve is gonna
32:59 the anterior port or sorry, the portion of the back of the
33:03 So lower portions of where your calf it goes down and does the plantar
33:09 of the foot. So basically what stepping on and on the back
33:14 when you're talking about the common fibular , we're now on the lateral
33:18 So you can see here la lateral limb and then on the, on
33:23 lower portion of the lower limb all the lateral portion and the top of
33:27 foot. So that's skin and Alright. So is that map easy
33:34 understand? Yeah, kind of sort . All right. So,
33:43 that's kind of what I'm gonna ask is what does the tibial nerve
33:46 What does the fibular nerve do? does the muscular nerve do? Does
33:49 con continue, you know, that of thing? It's just gonna keep
33:51 as simple as I can. I'm gonna say, what is this formed
33:55 like S one through S3 I, not, I'm not concerned about that
34:00 much. All right. So that us through the spinal nerves. So
34:07 look at the organization again. All , we start with the spinal
34:10 Spinal cord forms the root. Let's , lets two root root two
34:18 right, spinal nerve, spinal nerve into the dorsal, ventral and Raymi
34:25 , ventral is what we're interested Those form. The plexuses within the
34:29 . We're gonna have all sorts of organization but the most complex organization is
34:33 be trunk or sorry, co uh , trunk to division, division to
34:40 . Two of them just have One of them didn't have any of
34:42 stuff. Ok. And that's how get to your nerves. All
34:51 we have the intercostal nerves, intercostal are just ventral or anterior A I
34:57 just keep going not too terrible or it terrible? Terrible? Ok.
35:05 OK to admit it, it's terrible , but maybe in, you
35:08 in the afternoon it might not be terrible. Horizon, correct. So
35:19 question is, is do I need know which, which spinal nerve or
35:23 ? Yeah, which spinal nerve gives to which Plexus? I'm less interested
35:26 that and more interested in what's it for? OK. The part of
35:33 reason they go over all, I , why that stuff is discussed why
35:37 brought up is there's a lot of aspects that are involved in this.
35:41 I'm not si, again, I'm trying to steer absolutely clear of
35:45 developmental with you guys because it just Exactly. Yeah. So the idea
35:50 is, what is this Plexus? arises from it? How is it
35:55 in a real superficial way? Notice not going like, tell me all
36:00 branches. I wanna know all the . No, I don't, I
36:04 want those two. All right. think that's, I think that's
36:08 right? I mean, five nerves of 12 nerves, out of
36:12 another two nerves, another five nerves four nerves. So I think that's
36:18 . Ok, let's get back to central nervous system. Maybe they'll feel
36:25 little bit more comfortable than the maybe. Yeah. Hey, um
36:30 , when we come back, what gonna do is we're gonna talk about
36:32 nerves. Do you guys know anything cranial nerves? How many cranial nerves
36:35 there? So, I saw a , how, how many you wanna
36:39 ? 12. Yeah, there's there's 12 cranial nerves. You know
36:43 they're called cranial nerve. Number one cranial nerve number. They all have
36:47 name. But that's one of the that we learn. It is one
36:50 12. All right, then we're gonna learn the names and we're gonna
36:53 what they do. And when we what they do, that explains the
36:56 or if you look at the name explains what they do, either way
36:59 one through 12 is less helpful, it shows you the organization.
37:04 So what we wanna do here is wanna look at the structures of the
37:08 . And so what we're gonna do we're gonna do brainstem and we're gonna
37:11 Cerebrum today. All right. So , we're gonna start there, even
37:16 if we started with the spinal the next thing that's in, in
37:19 should be the brain stem. But , for some reason, your book
37:22 . No, no, no, gonna do this and then we're gonna
37:24 over that and then we're gonna work way down. I think part of
37:26 reason they do that is because of cranial nerves. They wanna kind of
37:30 cranial nerves as near as they can the spinal nerves. But that's
37:33 I think the organization is not the . All right, I'm just following
37:36 book. All right. So here's cerebrum. When you think of the
37:41 or when you think of the this is what you're thinking of.
37:43 right, if you play any sort video game or any sort of thing
37:48 talks about brain, this is what show you, right? That's a
37:52 . It's just a portion of the because the brain has all these parts
37:55 it. But the cerebrum you can it has a unique characteristic to
38:00 It has these bumps and folds and . And the reason it has these
38:03 bumps and folds is because the skull and the brain grows faster than the
38:08 does. And so it starts folding itself and creates this kind of unique
38:13 which is well preserved across all of . All right. So if we
38:18 out your brain, we're not gonna that. But if we cut out
38:20 brain, your brain would look like brain and my brain would look like
38:23 else's brain. Very, very And so we have these, these
38:28 features that anatomist use to help identify regions of the brain. And so
38:34 bump the ridge portion, the thing you're seeing here that is referred to
38:38 a Gyrus, plural as gyri. I'll, I'll keep saying probably till
38:42 day I die. Gyrus is just reasons, right? And then in
38:47 them. So where you go down the valley, that valley region,
38:51 depression is what is referred to as sulcus. All right. So you'll
38:56 sulcus and then a Gyrus sulcus and gyrus. And then if you have
38:59 really, really deep valley, a groove, we refer to that as
39:03 fissure. And so we're you here , there's what is called the lateral
39:07 . You can see the lateral fissure then there's a longitudinal fissure. And
39:11 you were to get a pair of or if you got your fingers and
39:14 of pulled apart, you'd see it in deep, but then at the
39:17 it does end and it comes back again. So it's not like it's
39:20 a cut all the way through. just kind of looks like that.
39:24 right. So these structures are used anatomist to help us understand what we're
39:30 at within the brain and you'll see in just a moment. All
39:34 And this is kind of part of right here is we have four major
39:39 of the brain. All right. we have the cerebrum. This is
39:43 we're looking at is the cerebrum. there is a structure that is deep
39:48 the brain right there that is referred as the diencephalon. The diencephalon is
39:54 of what the brain sits on top the and surrounds. All right.
39:58 if you were, if you're, you're looking at all the structures of
40:00 central nervous system and think of it an ice cream cone, it's like
40:03 first scoop. And then what you've is you've taken a second scoop and
40:07 kind of covered that first scoop with . And then we have the brain
40:11 which sits at the base of the . So it'd be uh cerebrum,
40:18 brain stem and then out here in back that is the cerebellum. All
40:23 . And we'll get to all these and what they do. But just
40:26 put them aside, what we've done these are all developmentally derived. So
40:31 remember, I told you, you started off developmentally as a tube,
40:35 ? And then what happened as organisms more and more organized, they started
40:39 things to the end of the And so the cerebrum is the most
40:44 addition. And when you look at vertebrates, it's like uh primitive organisms
40:49 lizards and amphibians. They have structures are similar to the brain stem and
40:54 to the cerebellum and similar to the . I mean, I say
40:58 I mean, they don't look like there, but structurally, they,
41:02 do the same thing but their cerebrum not quite so developed. But as
41:06 move further on into the birds and mammals and, and other types of
41:11 , you see the cerebrum being more more organized. So this kind of
41:15 an organization that is well preserved in vertebrates. And that's what I was
41:19 to say is I want to stay from the developmental stuff because it gets
41:22 confusing and scary. All right. the cerebrum has two hemispheres. And
41:28 if you're looking at from the anterior , you can see the two
41:32 there's one on the left, one the right, that's pretty straightforward.
41:35 then if you look inside each of hemispheres, if you consider just that
41:38 hemisphere, each of those hemispheres has lobes. When I sat in your
41:43 , we just said it was four , you know, so one just
41:47 up magically. And actually, that's true. It's just that we start
41:51 things much more clearly as we go and start understanding things. All
41:55 So the four lobes that are simple the frontal parietal, occipital and
42:00 And you already know where those are you've learned the bones over which they
42:03 . So the frontal lobe would be then the parietal would be and then
42:08 occipital would be and then the temporal be there. Great. And then
42:13 have this weird one, the all right, the insula is deep
42:19 in between. So here's the frontal , here is the temporal lobe.
42:22 if you spread apart with a pair calipers and look down deep, that
42:25 the insula. So it sits underneath frontal lobe and behind the temporal
42:31 how very very frustrating, right. let's talk about how we define what
42:37 things are. All right. So is where we're going to jump into
42:40 anatomy. Again, it's a very , heavy day. So this is
42:44 anterior lobe, right. So the lobe is the is the anterior part
42:48 the brain. It's divided from the by this very large central sulcus.
42:54 is what we call that division. an easy thing to identify and it
42:58 everything in front of that is going be frontal, everything behind that central
43:01 is going to be the parietal And then we use that longitudinal fissure
43:08 a boundary between the temporal lobe and frontal lobe. So going back to
43:13 picture, you can see it much clearly. I said la longitudinal,
43:19 meant lateral longitudinal would be in the . OK. All right.
43:26 this gyrus right here next to the sul sulcus, it's called the precentral
43:35 . OK. What do you think one behind it's called if this one's
43:39 , what do you think that one post? That's postcentral gyrus.
43:42 so why we point this out is see this is one of those gyrus
43:47 that we learn what it does a bit later. OK? Plays an
43:51 role in movement. Now, the frontal lobe has a basic function
43:58 a generalized function. All right. motor activity. So movement, motor
44:05 includes speech. All right, you're your mouth is the speech portion.
44:11 plays an important role in thinking in decision making, in planning things
44:21 right now, you're planning your Are you planning your weekend or are
44:26 just listening to me? You're just to me, see you. Gold
44:29 , gold star, gold star. right, I should do that.
44:35 should just come in and just give . Would that make you guys
44:38 It would, yeah, see there's about stickers that make everyone happy.
44:42 right. So when I think it's frontal lobe, all right, I
44:48 , therefore, I am right now about the frontal lobe, what's working
44:53 frontal lobe, the frontal lobe is dealing with the frontal lobe.
44:57 right, moving backwards to the parietal . Remember this is gonna be the
45:02 on the side or not side but here on the top. All
45:07 we have that central. So we have right here. That would
45:11 the postcentral gyrus. All right, plays an important role in understanding things
45:16 we are touching. All right, lobe in general plays an important role
45:22 sensory processing. All right. what is it? Well, we've
45:29 defined the central circus where it divides parietal from the frontal. Back
45:34 we have this large gyrus that goes , that would be called the parietal
45:39 gyrus, not a particularly hard And then what we do is while
45:44 lateral fissure only goes back a little , what we do is we just
45:48 a dotted line and we just keep it to the parietal occipital sulcus.
45:52 we use that as the dividing line the parietal and the temporal. So
45:56 how we define what the parietal is on. We have the occipital
46:01 you can see occipital lobe back We can use the prial occipital sulcus
46:05 separate it from the prial lobe as as from the lobe, the occipital
46:09 . Primary job is visual processing and memory. OK. Visual processing.
46:16 I time out for a second? put this on the exam, do
46:19 store this in memory, not gonna asked on the exam, about 80%
46:23 your brain is responsible for visual All right. But the first
46:28 So, so we're gonna talk about when we get to the eye.
46:32 there's like these uh regions of the , they're called V one V two
46:36 three V four. There's 20 vs each of these are a different level
46:40 visual processing. The first seven or of them are in the occipital
46:45 So that's why visual processing and then goes off to different areas.
46:52 but occipital visual processing, easy way remember this. All right. This
46:58 not true, but it's an easy to remember it. My eyes are
47:03 and they project to the back of brain. How's that? That's not
47:08 they work. But is that an way to do that? Occipital
47:13 OK. Temporal lobes, all We have the la lateral fissure right
47:20 the prial occipital. So temporal lobe is an easy one. What do
47:24 think it plays an important role in ? Right also plays a role in
47:29 processing. Um oh yeah, olfaction well. So what we're dealing with
47:35 primarily sensory input. These are specifically special senses, but the key one
47:41 to walk away from it is It's easy. All right. And
47:45 we have the insula, that's the that's deep. All right. This
47:49 gonna be uh memory and Gus Do you guys know Gus Station?
47:55 . Taste. All right. So can see here that we have that
48:00 have five special senses and they're all here. We just didn't mention the
48:06 one. All right. So we vision, we have hearing,
48:12 We have smell, right? So three. We have taste, which
48:17 in slow, whichever way you wanna to it inside. And then the
48:20 one is the weird one. It's your ability to stand up, you
48:26 , close your eyes, touch your , that sort of thing.
48:29 proprioception is another word for it. is another way that you'll sometimes hear
48:35 and that would be temporal lobe. goes with the ear. All
48:42 we said the cerebrum has gray matter it has white matter. So with
48:47 to the white matter, we're forming , we mentioned the tracts in the
48:53 cord, the tracks of the spinal , we refer to them as being
48:58 ascending or descending. Ok. So basically either going up from the spinal
49:04 to the cerebrum or we're going from cere cerebrum down to the spinal
49:08 Here, we have the three tracks are basically saying I'm going between different
49:13 of the central nervous system. First of tract is commercial. So a
49:22 tract is basically saying, hey, wanna cross between two points that are
49:28 same across the hemispheres. So I've something processing over here. I'm gonna
49:34 that information and have it processed over . That would be a commissural
49:38 All right. Oh, hey, I have an association tract. All
49:43 , an association track is where I'm . And it's really hard to see
49:47 this picture because they decide to The color yellow is stupid on a
49:51 where you have the picture basically yellow . But you can see here,
49:54 got these little tiny arcs. So going from Gyrus to Gyrus. So
49:58 basically going, oh I'm processing information here. I need to send it
50:01 information over, send that information over . Those would be arcuate fibers.
50:06 a type of an association track and we have long fibers traveling between two
50:14 . These are called um longitudinal Um Just longitudinal fibers should be
50:22 All right. So here I'm sending information between two zones. So you
50:28 see here just as a as an , if I'm sending information from the
50:32 lobe up here to the frontal lobe back again, what do you think
50:34 trying to do? Trying to think what I'm looking at? Right?
50:40 , do you recognize this? Does make sense, that sort of
50:43 All right. And then we have fibers. That's what the green fibers
50:48 coming down here. So what these , these are things going from the
50:52 to other parts of the central nervous . So that would be a projection
50:57 . I'm projecting between the cerebrum and cerebellum. I'm projecting between the cerebrum
51:02 the brain stem. Does that make going from the brain stem to the
51:07 ? So they go both directions? right. So this is what all
51:10 white matter represents. It's just points two parts of gray matter. Did
51:19 guys grow up watching Pinky in the ? Yeah. Do you remember the
51:23 song? No? OK. Just it down, youtube it later.
51:28 brain song from Pinky in the I don't think it'll help you,
51:33 maybe it'll make you happy. I know. Yeah. All right,
51:40 has three parts to it. we're going backwards again. We went
51:43 to the cerebrum. Now we're going and we're gonna go 123 up towards
51:47 cerebrum from the spinal cord to the . The region nearest the spinal cord
51:51 called the mela langa or the mela short. So you'll frequently when we're
51:56 the uh in the brain, we're gonna just call it the medulla.
51:59 above the medulla is the ponds above ponds, is the midbrain and the
52:04 sits underneath the diencephalon So this would the diencephalon, midbrain ponds,
52:10 spinal cord. All right. uh very, very generic things.
52:18 This is uh taking information from the was part of the diencephalon and also
52:24 allowing you to control visceral uh visceral . So, we're talking heart
52:30 respiratory rate, that sort of Um We're gonna come back and go
52:34 more details. We're gonna dissect these boys too. Um, the ponds
52:39 serves as a way for signals to between the cerebrum and the cerebellum.
52:45 right. It actually has nuclei within as well. We're gonna dissect that
52:49 in a couple of slides here and finally, the midbrain, this is
52:52 superior region. Uh It helps you control head and eye movement in response
52:57 sounds. All right. Go to tennis match. Watch everybody. What
53:01 they all do? Watch the watch the ball, watch the ball
53:06 you're walking across campus and someone hey, what do you do?
53:10 turn around because your name is, . Right. Yeah. OK.
53:15 right. Scary anatomy part. All . Again, don't be scared by
53:20 anatomy. This is uh what we're at is. So the medulla has
53:25 length to it. All right. if your brain stem is this
53:28 the Mandula is like this long and you can slice it in different places
53:31 you'll see different things in each of individual slices. So, what I'm
53:35 to do is trying to give you picture type stuff in this particular,
53:39 think the first thing of interest is and this is the pyramid right here
53:44 because it has a pyramidal shape and where most of the pyramid tracks are
53:48 . And the pyramid tracks are basically neurons that originate in the gray matter
53:52 have a pyramidal shape as well. right. So that's why it's called
53:56 pyramids. And so this is mostly fibers traveling down, going to leave
54:03 go control your muscles. All many of them are going to
54:09 Many of those motor fibers are We call that a Decca station because
54:13 have to make complicated words, Instead of just saying they crisscross,
54:18 Decca. All right, next to pyramids are the olives. Why are
54:24 called olives? What do you Because they look like olives? It's
54:29 because of the color. OK. right. So here we're gonna see
54:33 inferior olivary nucleus. Uh So when you hear that word nucleus,
54:37 what you should be thinking is, , there's gray matter there. That
54:40 there's processing that's taking place. These gonna be playing an important role of
54:45 uh information off to the cerebellum. this is proprioceptive information. All
54:52 the things that keep you in All right, we have also the
54:57 , you can see them over the inferior cerebellar peduncle that is an
55:02 or surface uh structure. A peduncle something that sh that hangs out and
55:08 projects as a, a structure of that's like if you look at a
55:14 and you see something that kind of outward and holds up the next
55:17 that would be a peduncle. And here, the inferior cerebellar peduncles are
55:23 you it's on the inferior side of cerebellum and it projects to as fibers
55:28 moving from the medulla often into the . All right, it's not the
55:33 . We also have cerebral peduncles that see a little bit later. So
55:37 an inferior one. All right, have a bunch of different types of
55:41 that are part of the autonomic nervous . So we said that the medulla
55:45 an important role in regulating autonomic function heart rate and stuff. And so
55:49 have the vaso motor center, vaso center, vaso blood vessel motor is
55:56 . And since your blood vessels don't around the body, that refers to
55:59 ability to contract and relax to create pressure. All right, the respiratory
56:06 , there's two regions which we'll uh learn a little bit more about in
56:10 uh A and P two. It's dorsal and ventral respiratory groups, the
56:14 that help regulate your breathing. All . Uh There's one that's also gonna
56:21 in the ponds which are responsible for those. There's a center for coughing
56:26 sneezing and salivating. Have you noticed you stop breathing when you get ready
56:29 sneeze? Right. Well, you , it's important. Right. You
56:37 want to be breathing out while you're to breathe in. It doesn't work
56:40 way. And so these are sinners are controlling those different aspects if you
56:44 to, have you ever tried to and breathe at the same time?
56:49 , uh, actually humans are the ones. Most other organisms can because
56:54 trachea goes beyond the pharynx. And they're able to swallow and breathe while
57:01 eating or swallow. Yeah, we . But let's see what other organism
57:08 has the gift of speech. We're . And that's part of the reason
57:14 can have speech is because of where trachea sits so we can choke on
57:19 food, but we can talk to other while we do it.
57:23 yeah. All right. But so just showing you there's things that
57:27 controlling stuff autonomously. All right, mentioning these two here not to point
57:34 out. All right, because you're gonna see them, but we're gonna
57:39 about them in the next unit. this is kind of a pre let
57:43 mention these so that, you we have the nucleus cus and the
57:47 gricius. All right. And what do is they prevent our sys thematic
57:52 to the thalamus, which is part the diencephalon via, via the medial
57:58 . All right. So that's the lemniscus. So these are tracks that
58:02 traveling between the thalamus and these structures are processing. So, information coming
58:08 to the body are gonna be traveling this pathway. We're going to point
58:12 out later and then these are gonna a bunch of cranial nerves are gonna
58:16 located in here. And so you start seeing that they exist and we're
58:20 connect the dots uh after the next . All right, what we have
58:26 is the ponds. We have the and superior cerebellar peduncles. All
58:35 So here is the middle peduncle. is the superior peduncle, cerebellar.
58:42 this is demonstrating to you that in ponds, what are we doing is
58:45 or going into the cerebellum? All . So it's a one of the
58:50 that its job is, is to these fibers to pass on into the
58:54 structure. We mentioned the respiratory center the mela. So here is the
58:58 one. It's not gonna be shown here. I don't think I have
59:00 listed. No, but there is respiratory center that's located in there that
59:05 the medulla. So this is actually uh regulate so that you don't overbreathe
59:10 under breathe. Then we have the olive complex. Again, this is
59:14 to be uh dealing with uh locating . So the idea here is I
59:19 my head in response to sound. this is processing, where is that
59:24 coming from? And finally, we some crane on there of nuclei that
59:28 trying to demonstrate here. But we'll get to these a little bit
59:32 uh in the next lecture. And , we get to the mid
59:39 the midbrain. Now we're further And so what we're doing is we're
59:44 to the cerebrum. And so the thing we're gonna see are peduncles that
59:49 fibers coming from the brain. So these are descending motor tracks. Where
59:53 those descending motor tracks going? Ultimately up. Think about the mela,
59:58 structure in the medulla has the descending tracks, the pyramids. All
60:05 So what they're doing, this is first thing. So here you can
60:10 the peduncle, there's a cerebral So cerebrum, cerebral cerebella,
60:19 OK. Easy to get those I'm just gonna tell you now,
60:24 . So where you have cerebrum? means brain, cerebellar means little
60:30 OK. That's so ser little big brain, little brain. All
60:39 . The substantia Nigra, what do think? Substantia? Nigra means
60:47 black. All right. It's substantia substance. All right. So
60:57 the black substance again. How they the stuff? Cut the brain
61:01 Looked at it and said, This region's darker than the others.
61:04 gonna call it the black substance. , what it is is basically a
61:07 that produces tons and tons of All right. Not melanin for the
61:12 . It's just, it's producing the . It also produces dopamine. All
61:18 , someone explained this to me once just gonna explain it to you the
61:20 way. So it just kind of in your brain like it's stuck in
61:22 brain. This is like a sprinkler of dopamine. This is where the
61:26 in your brain comes from. And like, and it just sends dopamine
61:31 over your brain. That's how I it. OK? It is connected
61:36 the basal nuclei which we're going to about later. I think next
61:41 And so what this does helps with basal nuclei does is that it plays
61:46 important role in coordinating movement. you've probably heard already, we've said
61:51 , movement, movement at least three times so far. And this is
61:55 I start like not liking uh all right. Or really the physiology
62:01 I like to throw things in one . It's like here's a structure.
62:05 This is movement. I'm gonna put in the box. But now what
62:08 doing, we're starting to throw a of structures into the same damn
62:12 And I like that. It's OK you don't like it either, but
62:15 just have to learn. OK? do I organize this? So what
62:18 can see here is there is going be lots of structures that are doing
62:23 things working together and we're gonna just to keep it simple. All
62:27 So the basal nuclei is one of structures that is important for movement and
62:33 getting some of its signals from the stem. All right. So that's
62:38 we've done. We've gone from the peduncle up into the substantia nigra.
62:42 moving now into a region called the or sorry, the tegmentum tectum is
62:46 . All right, the tegmentum plays important role in maintaining your posture.
62:52 right. So the way that you're up now or not sitting up
62:56 right, where your heads are lulled to the sides, the reason you
63:01 fall out of your chair. All , it is because your body is
63:04 to maintain at least a semblance of . There's a lot of communication going
63:09 between the cerebellum and the cerebrum, your muscles what they should be doing
63:15 up with a plan and executing a . And so this is what the
63:19 is gonna be playing an important role two structures of interest. We have
63:24 big round structure which is a gray , but it's not gray, it's
63:29 . So it's the red nucleus, red nuclei is the pair. All
63:34 . So what does it do? coordinations? Great. Another one,
63:38 just throw it in the box. right. And then finally, over
63:42 , we have this region, it's of this generic structure called the reticular
63:48 . We're gonna deal with this in a second. This is your
63:52 you who are falling asleep in class now or have fallen asleep in
63:55 you know, on your way into , that sleep, did you notice
63:59 you kept jerking a little bit that brain desperately trying to stay awake at
64:04 reticular formation trying to keep you All right, here's another way you
64:09 think about this. Have you been on the highway? You know,
64:12 you're just cruising along, you're happy your 65 whatever. And then two
64:15 giant trucks come on either side of , right? And now your
64:19 car starts shaking. Do you, you become pretty awake at that
64:24 Right. Are you like white knuckling ? Please don't let me uh in
64:27 brain. You're kind of like what's happen to me? I'm gonna,
64:29 , I'm gonna go underneath it. you? No, am I the
64:32 one that does that? It's like , the, the semi is gonna
64:35 me under. Ok. Yeah, why I drive fast. I wanna
64:39 away. So I, all So that alertness, right? You
64:44 , of, of danger and stuff gonna be a particular formation. All
64:51 , two other structures now we're moving the tectum. All right. So
64:56 is this region that sits right around aqueduct. I remember we said that
65:03 leaving downward between the third, the ventricle is called the uh uh cerebral
65:09 , right? So the region surrounding is the peri aqueduct. So,
65:15 aqueductal gray matter. All right. next to the, the aqueduct,
65:20 what it means. All right. this plays a role in modulating your
65:24 and then finally, that tectum. here we have two structures, the
65:29 and the inferior colliculus. So the ones on top, the inferior ones
65:33 the bottom, the superior one plays role in visual reflexes. Again,
65:37 movement. So when you see something by and your head moves, but
65:40 don't, you just kind of do , that would be the superior colliculus
65:43 the inferior colliculus is turning your head in response. Now, notice,
65:48 we already say that there's a region plays a role in processing this
65:52 Yeah, we said it was a olive and the inferior olive. So
65:56 again, this is one of those where it's like it's not just one
65:59 . There are multiple structures that are in this, but the colliculus is
66:04 the dots between the movement of your and the movement of the sound or
66:10 movement of the, of the visual . OK. So that's what the
66:17 is. Now, I point all things out for a reason. All
66:21 , and we're gonna, when we into the stuff in the last
66:25 that's this is where we're gonna connect dots. We're gonna connect these regions
66:29 the brain to the tracks that that they form in the spinal
66:35 OK. So that's why we're mentioning now is so that you have a
66:38 in which you can then deal with subject. At the end, our
66:43 little slide for the day. the worst picture that you'll ever find
66:49 anything anywhere ever. OK. This the reticular formation. No textbook does
66:54 good job of this. So the formation sits within the midst of the
66:59 stem. So we looked at it , you can say, oh
67:02 look, there's reticular formation. But you go down, it's,
67:05 it's just everywhere. This is reticular , reticular formation. It's, it's
67:10 sits within the center of the structures the brain stem. And so when
67:13 look at pictures in the book, basically like the look, oh
67:16 there's arrows and look at the They just go everywhere. All
67:20 That's because they do, they send throughout the entire cerebrum. But it
67:26 this uh this region that sits central these structures. And again, here's
67:32 picture of mela highlighting the reticular All right. So what does it
67:38 ? Well, it's maintains your cortical and enhances its excitability. It's the
67:43 that helps you kind of respond to world around you by keeping you aware
67:48 things going on. And then when get alerted, basically keeping you on
67:52 alert. All right. So it multiple functions. It's gonna be because
67:57 goes through these different structures. It's play a role in different things.
68:00 again, we've talked about some autonomic . So, respiration, cardiovascular
68:05 um digestion uh thing. So this vomiting center. So, you
68:10 vomiting is MC tuition. Do you what that word means? That's
68:14 So MC tuition is a fancy word saying when to go to the
68:18 uh sexual uh activity, sexual sexual arousal, um there's gonna be
68:25 of the forebrain. So this is level of alertness, right?
68:29 you know, right now I'm seeing three or four people who are just
68:32 fading like fast, you know, if I went up and slammed my
68:36 on their desk, I guarantee that be like, all right. So
68:40 wake, sleep, wake centers in brain are fighting, there's two different
68:43 and that's gonna be part of Um your eye movement we've talked about
68:47 pain modulation we mentioned and there's some function that's being controlled through this.
68:53 right. So the reticular formation is of like, how do I send
68:56 information up to and back from the to help maintain the normal functions,
69:03 to day functions of the body? us today. Yeah, it was
69:07 stretching. All right. When we back, we'll finish this out.
69:12 we have an exam on Thursday. you haven't signed up, you've got
69:15 drags in terms of when to take exam. No, no,
69:19 no. Yeah. Next Thursday. today is Thursday. Yeah, I
69:23 the same one.
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