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BIOL 4315 & 6315 Neuroscience Mon-Wed 1-2.30 PM - Neuroscience Lecture 14 CNS II
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00:03 Hey, Welcome Back to Lecture 14 Neuroscience. And today we will cover
00:12 central nervous system. So it's going be CNS two. And your quiz
00:18 Friday is going to cover four 10, 11, 12,
00:26 14, 5 lectures. Sorry. through 15, 10 through 14.
00:33 I would say that if you study the quiz and you're expecting maybe 10
00:38 that proportionately about, you know, talked about neural transmission about four hours
00:47 , four C N S two. it might be twice as many questions
00:52 neural transmission as on C N Ok. And I uh think that
00:59 you have followed the material as I and you have reviewed the material.
01:06 you need to in the videos and the notes, then you should be
01:10 prepared to take the quiz, try get as many points as you can
01:14 once again, this is your self . Uh and uh you can approve
01:20 your grades from the exams using these basically in your final grades. So
01:26 yourselves and take the quiz. I hope everyone scores really well and has
01:33 good spring break after that. And when we get back, we'll have
01:39 three more lectures, I believe. then you'll have your midterm exams.
01:47 when you get back a lot of you have studied for the quiz,
01:52 may review for the exam again and the new material uh with more dedication
02:02 . OK. So last time we here when we started talking about uh
02:09 of the brain and we talked about three Arachnoid and PM or the gentle
02:18 . Uh Of course, uh you production of cerebral spinal fluid in the
02:24 . And that is another way in the brain is kind of a cushion
02:30 it is surrounded by this fluid, almost gelatinous like cerebrospinal fluid that gets
02:36 in the chloro Plax and circulates through ventricular system which involves the lateral
02:44 the third ventricle and all the way the spinal cord into the spinal
02:52 It gets circulated through the subarachnoid It gets reproduced and refreshed every
02:58 But this is the spinal fluid that essentially be necessary for the brain to
03:04 the nutrients. Uh If there is production of cerebral spinal fluid, especially
03:11 a developmental condition called hydrocephalus, there be an impact on the overall structure
03:18 the brain tissue but also the surrounding , the skull in the developing newborns
03:26 is soft. The skull plates have fused, your brain will increase with
03:30 after you're born, and the skull will grow around that increasing brain tissue
03:37 the skull blades will not fuse for first, maybe even the first two
03:42 of life properly. And the size the head will still keep growing.
03:48 therefore, if you have abnormal production cerebrospinal fluids that are gonna make these
03:54 very large, and these ventricles are start pushing on the brain tissue,
03:59 brain tissue is gonna start pushing on skull on the bone, uh producing
04:05 abnormally shaped head structures. And so way that you uh uh correct for
04:12 is you drain the ex accessory or fluid by inserting a tube and quite
04:18 draining that into the cavity as a is growing up, especially if it
04:24 a chronic problem. Uh that is persistent problem. So it's something that
04:30 happen during the development. Something that is rare but also can happen following
04:35 brain injuries or even a shaken baby . When uh young babies get shaken
04:41 hard, that can lead potentially to production of CS F and even
04:48 So let's talk a little bit more the development in the first stage of
04:52 development is we have three types of that uh are basic primordial tissues.
05:00 , mesoderm and ectoderm. Uh endoderm a tissue that will end up in
05:10 into lining of internal organs and viscera to skeleton bones and muscles and ectoderm
05:17 nervous system and skin. So, the developmental uh or pluripotency perspective,
05:25 nervous skin nervous system cells or neurons most pop uh similar to skin
05:33 And you have this neural plate at and this neural plate needs to fold
05:38 neural tube. And this process by the plate falls into a tube is
05:44 neural tube formation or the process of . And so you have this neural
05:51 right here, uh neural plate and neural group formation and neural fold
05:59 Then finally, you have neural tube neural crust and you have the SOMA
06:05 it which becomes the jubal column and and skeletal muscles. But this is
06:12 nervous tissue here and essentially the rudimentary the very first uh form that this
06:22 . This flat structure on the plate into a three dimensional folded neural
06:30 Uh in general, this process think of how many cells have to come
06:35 and there's a code and they have form into a tube and that tube
06:40 to form and fuse properly between the and self communication. And for the
06:45 part, I call this brain self because there's a code and there's environment
06:53 the cells are self assembling into this into this tube. Uh For the
06:59 part, this code is robust and are not that many developmental disorders that
07:05 associated with these processes. However, can be rare instances, one in
07:11 or a few 1000 where you have disorders and some of those can associated
07:18 the process of neuralation. And if neuralation process is somehow abnormal in the
07:25 regions of the neural tube, that cause a condition called spin Abita where
07:31 have the lower portion of the spinal , uh forming into abnormal shape and
07:37 often extruding outside of the vertebra and being protected. And that can be
07:42 surgically if it is detected early enough the just depends on many different
07:48 However, there might be more severe which are also more rare where the
07:54 stroll part of the neural tube doesn't properly. And if you have a
08:00 dysfunctions here, these are specifically related neural tube formation. You may have
08:06 lack of cerebral hemispheres or cerebral It could be unsustainable condition called
08:16 When you can see this process here how from this flat two dimensional
08:21 you have this really nice three dimensional formation of neural tube. After
08:30 you have a process of differentiation. means that different parts of this neural
08:35 become different parts and differentiate into specific organs or structures within the brain.
08:43 the neural tube is divided into the cephalon or forebrain in blue mesencephalon or
08:51 in red and rhombencephalon or hind And these are called the primary
08:57 So after this very uh simple tube of a formation. You have more
09:04 differentiation, a more structural difference appearing allows us to separate. Now,
09:10 tube into three primary vesicles and those vesicles keep differentiating into the secondary vesicles
09:19 the pros becomes the forebrain. Uh , the forebrain becomes the telos
09:26 the di and salo and the di along will further differentiate, the topo
09:32 will further differentiate. And here you have optic vesicles. They have an
09:37 ST optic vesicles on the cut edge the optic cup. This will be
09:42 formation of the retina. Uh midbrain keep differentiating further and hind brain from
09:50 secondary vesicle. So or the forebrain developing into the two cerebral hemispheres and
10:03 of the structures that are associated with two cerebral hemispheres. The midbrain differentiates
10:12 the structure that is called corporal quadri on the dorsal side. Uh it's
10:19 of superior colli on top and inferior at the bottom. There are specialized
10:25 , super Colli for visual and infe for hearing information processing. So to
10:36 obviously becomes cerebral cortex, the cerebral gets further differentiated into different lobes that
10:44 now know and study later in in this hour, you have these
10:49 ventricles, two lateral ventricles, the and the right one and two.
10:54 the third ventricle here, the diencephalon differentiates the thalamus and top superior and
11:02 to it, the hypothalamus and the cerebral hemispheres will be interconnected with major
11:10 bundles. So the white matter the two hemispheres which we have lateralization
11:16 the brain function that we saw the area is so dominant in the left
11:21 . It doesn't mean that that information that left hemisphere is not communicated to
11:26 right hemisphere and even tuned with the functions and lateralization of functions that may
11:32 present in the right hemisphere that is through the major fiber bundle. The
11:39 callosum. The other important part which learned today is that all of the
11:44 that sensory eventually reaches the cortex before reaches the cortex that goes into the
11:50 in particular into the thalamus. So of the hearing touch, uh information
11:57 visual information factor information with an exception certain pathway in these fibers, all
12:04 that sense of information goes into the before it goes into the cortex.
12:09 so there are major white matter fiber or projections. Those are the myelinated
12:16 that come out of the thalamus and information into the cortex. Then from
12:21 cortex, you also have reciprocal communicating that information back into the
12:29 And these major fiber bundle that is here between thalamus's cortex is report to
12:34 the internal capsule where you have a of communication between thalamus, thalamic cortical
12:40 cortic cortex. The thalamus or cortico communication. Once again, this indicates
12:46 optic cup and in the front you the formation of the olfactory bulb.
12:52 , encephalon, diencephalon, thalamus, hypothalamus, mesencephalon, midbrain,
13:00 I brain and yellow. You have cord. So for midbrain, you
13:05 differentiation and detect and for you have and hypothalamus, you can see that
13:15 evolve is also a part of the so un on development. Then the
13:24 brain you'll have differentiation into your bow the. So this another name detects
13:32 over the back of your head. is where you have that corporate that
13:38 was telling you about. Then we and say bowel and they come back
13:46 and going into the spinal cord in . And this is a caricature of
13:51 ventricul structure left, right, uh and into the spinal canal, supplying
14:01 spinal cord with a spinal fluid. we learn the surface of the human
14:08 and many advanced species uh animal species which are grooms and ridges, gyri
14:16 that increases the surface area that also the three dimensional complexity, architectural organization
14:22 the cell in three dimensions, which for the ability of complex processes,
14:30 that we have intellectual ability as well motor output that we can perform.
14:36 is the seat of reasoning. And we know those cerebral hemispheres, once
14:41 develop, they divide into lobes, parietal, frontal temporal lobe, and
14:49 these lobes, there are even further into very specific areas that are responsible
14:56 very specific functions. So occipital lobe concerned with visual information processing and there
15:04 many, many different Areas that you subdivide occipital lobe into 15,
15:10 17 areas that will be responsible for the visual information. And typically from
15:18 areas, the more it advances through areas and binds the information with other
15:24 . The more complex an article is processing of the sensor information that we're
15:30 . This is the ventricles in three shown very nicely within the brain
15:35 The two ventricles left, right, , 4th and spinal canal. Look
15:41 some of the similarities and also very differences between the right er rodent and
15:48 brain. But some of the major that we're discussing uh very nicely uh
15:54 here such as phon midbrain posa Uh these actually could appear as labeling
16:02 on the quiz or the exam. it doesn't hurt you to know these
16:08 structures and understand some of the basic that they're responsible for cerebral cortex.
16:16 central nervous system, Neocortex, in can be found only in mammals.
16:23 is sort of the greatest uh the invention in neuronal cell circuits. Neocortex
16:32 comprised of six different layers, 123456 the most superficial layer one which is
16:40 to the skull to the deepest cortical , sticks. And there's a certain
16:46 of cells organization of inputs and outputs this Neocortex. And I remember when
16:52 talked about hippocampus, that hippocampus is to as archy cortex, which is
16:59 cortex. When we said that hippocampus viewed predominantly as a three dominant layer
17:07 , three layers rather than six layers you have in the cortex. And
17:13 have have six layers in human We have six layers in the rodent
17:18 and mammal cortices in general, there going to be some similarities between the
17:24 , the circuits organization and the function lower order species and also human brains
17:32 human organization and function of the And for example, uh if we
17:41 that Neocortex is a six layer it's the latest and the greatest is
17:47 seat of uh cognition and intellectual Uh This is all a part of
17:55 evolution, that's what's the latest and greatest. And maybe someday it's gonna
17:59 a seven layer structure and maybe someday gonna become an eight layer structure.
18:04 all depends on the environment we live the tools and technologies we invent and
18:10 ourselves with because the development of the , although it's pretty well programmed to
18:16 rigid, what I call the self , it's also plastic and can be
18:21 . So in any development, you nature and nurture aspects the genes and
18:26 the environment that you're exposed to during development. And we can change the
18:31 structure and the brain connectivity during early due to the processes of plasticity.
18:37 so think about it, a three structure is a three layer house.
18:40 you're an architect, interior designer, have three stories to work with,
18:45 can only put so many doors, can only put so many stairways going
18:49 and down those three floors. you're the same architect, but you
18:54 six story house to work with, has six layers. Now, maybe
18:59 can blend the second and the third together, make it one big floor
19:04 of this two, you have a more ability, you can put more
19:07 , you can put more stairways, going up and down, the complexity
19:13 as you add these layers. And maybe hippocampus one day will become a
19:17 structure and it no longer will be Neocortex. It will be a uh
19:23 cortex. It will now be a and some similarities that you see between
19:28 and of course some differences. So is the alligator brain. It's a
19:31 small brain has huge factory bulbs in front. It tells you the gators
19:37 around and find their food mostly through . Of course, they, they
19:41 vision, they can see above water the ground and also below. But
19:47 rely a lot on the South's sense smell as they're looking for food,
19:54 animals and different a a aquatic animals have all sorts of different ways of
20:01 food. Some of them will be by smell, others by vision.
20:06 ones by touch, they even have . Uh black drum actually, which
20:11 prominent here on the Gulf coast or uh drum often referred to has these
20:19 who touches the food and finds the . But the about the mammals and
20:23 this case, alligators have huge ol bulbs. Rats have big ol factory
20:29 relatively to the size of their overall . But that tells you that rat
20:33 does something else to find food. that's actually whisking around rats have these
20:39 and whisker pad. Part of their exploration and finding food and mates is
20:44 whisking around. OK. Alligators don't that. So they rely a lot
20:50 on the sense of smell. So lot more of their brain total mass
20:55 be dedicated to factor, evolves to to finding the smell or following the
21:01 of smell. Uh If you take little plug of the alligator brain and
21:07 a rat brain, you will find parameter cells. We saw these excitatory
21:12 cells in the hippocampus. They're typically cells that project in between the layers
21:17 in between different parts of the cortex different parts of the brain. And
21:22 find these parameter cells in the you'll find them in the rat and
21:25 find them in the human and they'll simular structure and they'll have similar channels
21:31 receptors that they're expressing and they'll have functions too. And as far as
21:36 example, patterns of action potentials are be very simulant parameter, cortical cells
21:41 alligator and in human believe it or . So, there are some certain
21:46 similarities in the structure. There's certain in the rules of neural transmission,
21:54 of information, summation, synoptic summation information that can be found in low
22:02 species, mammals and can be also in humans. This is a coronal
22:08 , a cross section through the brain the hippocampus structure here and the and
22:13 rodent located here. And this is missile stain. So if you're call
22:17 stain is really good at identifying the side of architecture because it stains all
22:24 the cells. So this stain in cortex will expose all of the cells
22:29 the cortex. And as you do stain, you will see these darker
22:35 , these darker bands indicate densities, densities, more or more tightly packed
22:43 that are located. And because this exposed like that there was a division
22:51 in six layers. So it's a a structure that can be very well
22:55 with the missile stain. If you with a gold gold G stain gets
23:01 up by a fraction of neurons, it's really good to reveal the dendritic
23:06 exon anatomy and morphology of these So you can understand the circuits and
23:12 connectivity. Uh finally, the new that you're learning today is called the
23:18 stain. The weir stain is specific axons. And when axonal stains were
23:25 , they revealed that there is a of connectivity that is happening instead of
23:31 in this laminar fashion, it's happening in this column of fashion. And
23:38 , we refer to the anatomy and structure of the new cortex is both
23:44 and Collyer. It has an organization six layers and across these six
23:51 you have columns and these columns can very small micro columns, 50 to
23:57 micrometers in diameter to very large hyper . We called it could be one
24:04 or even larger like one centimeter in depending on different parts of the
24:10 And those micro columns of these columns essentially local processing networks. They are
24:19 of neurons that have similar properties. comprised of neurons that process and are
24:27 to the same or similar stimulus. a column in the visual cortex will
24:33 responsive to bars of light visual A column in the auditory cortex will
24:39 responsible to sound to auditory stimulus. there's organization very fine columns, micro
24:47 to larger columns, hyper columns, columns may process very similar type of
24:54 . So in the occipital lobe, , one micro column will process orientation
24:59 light bars, adjacent micro column may this very same a very simular type
25:05 information, also orientation of light So we'll look at that when we
25:10 the visual system, if you take little plug of the cortex across the
25:17 from occipital parol frontal temporal lobes, notice that they all have this laminar
25:23 columnist structure of six layers. There's variability in the thickness of the cortex
25:30 can be observed. So you can that here in these portions of the
25:36 and primary motor cortices are a little thicker in size the layers, but
25:41 overall organization and connectivity, it's going be very similar. There is what
25:48 call canonical organization, a canonical circus you will find across the cortex.
25:58 Now this is organization of inputs and structure depends on function and of course
26:06 depends on structure also. So the are uh intertwined inseparably. And if
26:13 recall, it was doctor Cain and broad that used a lot of missile
26:20 and a lot of human brains and and was able to identify these cyto
26:27 distinct areas, structurally distinct areas which turned out to be functionally different.
26:34 , structure and function again are inevitably uh together. Now, this is
26:43 interesting slide that I like to talk for a minute because I like to
26:48 simulate your brain and think about uh particular concept. You have a
26:58 a braid and the brain and you three colors here, red, purple
27:07 green. And these colors, these under the colors represent how much of
27:15 brain space that animal dedicates to primary information processing. So in this
27:25 this much of the rodent brain is with primary visual information processing, with
27:35 auditory, with primary sensory motor or amount of sensor information. The other
27:43 to understand where primary is is it's basic primary visual information. An
27:55 of that, that I like to is what do I see?
28:01 rodent brain is very much concerned with do I see? What do I
28:08 ? But not, what does it ? What I see? So now
28:14 , when, when we see we see an object, we hear
28:20 , any, any stimulus, we something there. Usually what we do
28:27 association, we associate it. So see somebody in uh red shirt and
28:36 think that's probably a U H student far away. But what I'm seeing
28:44 a person in a red shirt. know, what do I see a
28:49 in a red shirt? But we associate it with campus being on campus
28:57 shirt, U H student. That's sense, right? This is
29:03 So you compare, you associate that . So there's association areas if you
29:10 now on the same campus, uh an older gentleman with long white beard
29:19 a red cloak. And you would this doesn't really associate with U H
29:29 from far away, right? And check the calendar and it's close to
29:35 time in December and it's like, , it must be Santa Claus.
29:40 , so you have this comparative what learned, what you see, what
29:45 smell again. You associate with Cookies. Yes. Cookies. You
29:50 , you, you, you, first is what it is and then
29:54 does it mean? Cookies. You know, yummy, some other
29:59 . Not good. Get away. know. So first of all,
30:05 have a lot of brain space relatively the overall brain volume that is dedicated
30:11 primary information processing in these low for . So they're, they're concerned more
30:17 what do I see there? Like personal chart, that personal red
30:21 Now this is very basic processing, at each station, so I said
30:26 visual information can be processed by 15, 17 different areas depending on
30:32 the task is for visual information processing each area. First of all,
30:37 have the primary visual area and when study the visual system, we'll get
30:43 all the way to the circuit to primary visual area. And you'll see
30:46 that this primary visual area area what we form is a primal sketch
30:51 the world which is pretty cool, it's like a cartoon sketch with color
30:56 some motion and not much beyond And that's where we stop because if
31:01 want to go into the secondary that's where there's gonna be more complexity
31:06 that visual information processing tertiary coordinator 4th 5th, 6th station for processing
31:13 information, it is gonna get more more and more complex. So apart
31:20 each sense, like visual having an with visual stimuli that you've learned auditory
31:26 auditory. Oh this is I know you know, or any sensor information
31:32 its own association area. But we actually associate multiple sensors. It's
31:41 binding, right? Multimodal, meaning mode is sniffing, another mode is
31:49 to music. So you can be in aromatherapy room, smelling pleasant smells
31:55 listening to very calm music and it associate. So you will bind these
32:03 together and it will probably help you in this environment, right? And
32:10 , when you walk in the gym you're gonna hear really loud music and
32:15 dropping weights, you know, you're associate it with a different environment.
32:19 all of these senses, you're gonna together, you walk in the
32:23 you're gonna smell sweat, you're gonna hear music, you're gonna hear,
32:29 people breathing, running, you all of these association areas. And
32:34 we spend a lot of time and dedicate a lot of our brain space
32:40 four association areas for association of individual , understanding what that stimulus is and
32:48 for binding, what I hear and I smell together. We multitask all
32:53 time. Right now. I'm looking you and I'm talking, I'm listening
32:56 myself, I'm waving my hands can smell and there's no smells here but
33:03 know, classroom just regular. Um this is where magic happens. Magic
33:12 the human brains happens when we we learn things and we bind different
33:20 and we do that based on the and the connectivity of the brain and
33:25 slight different, slightly different variations. we have a chemical variation of structural
33:31 in our brains and organs. That's makes us unique. That's what makes
33:36 think differently. That's what makes us very smart at uh music, science
33:45 , the brain space is limited. not like a after you become
33:50 it's like phrenologist, then you should able to keep lifting and keep growing
33:54 a muscle. You can, can that, but you can change the
33:59 but's still fine on it. So something very interesting to, to think
34:04 that. We have these association areas that's where a lot of our
34:09 original thoughts, comparative thinking will come associating multiple senses together and our
34:19 motor responses will be also accordingly uh by that. OK. Let's start
34:26 at the structures in the brain. have the spinal cord, the brain
34:30 , the diencephalon, cerebral hemispheres and of the nuclei that we're going to
34:34 . So the spinal cord receives and sensor information from skin joints, muscles
34:40 limbs and trunk, controls movement of and trunk. So everything below the
34:49 head all of the sensor information of comes into the spinal cord and it
34:57 through the spinal cord and is divided sacro lumber, thoracic and cervical and
35:03 cervical regions. And then it goes the brain stem here. Ok.
35:09 , brain stem is sensor information from muscles of the head, motor control
35:14 head muscles. So that means that stem you learn today has its own
35:20 . We learned about spinal nerves. didn't talk about the nerve endings that
35:24 information would talk about the dorsal roan , the sensory nerves, we talked
35:30 the motor neurons, the out the uh neuromuscular junction right now. So
35:37 is everything from here down. That that when you move your face,
35:42 you move your tongue, when you , when you smile, this is
35:46 spinal cord, these are specialized nerves are found in brain stem called the
35:52 nerves. Uh brain stem also has which by definition again is a collection
35:58 cells that have the same properties. properties responsible for the same with simular
36:04 or processing of the same with simular information or dictating a motor output commanded
36:11 . So brain stem contains nuclei that levels of arousal and awareness. Uh
36:19 some of the vital autonomic functions. will come back and talk about cranial
36:25 that some of them are sensory mode some of them perform both functions.
36:30 long is responsible for breathing heart rate some of the digestive properties as
36:38 So that means that injury to Malaga render you unconscious injury to Malaga to
36:46 nuclei. Malaga can interfere with breathing heart rate. With these vinyl bodily
36:54 that keep us alive. Plans is you have number three connectivity and attachment
37:03 the uh cerebellum and a lot of information that gets initiated in basal
37:10 So this is one of the nuclei cortical nuclei, basal ganglia that is
37:15 in motor command initiation. Uh cerebellum is attached to the pawns where there's
37:23 lot of connectivity between cerebellum and So, cerebral cerebellum or cerebella,
37:30 connectivity and cerebellum is responsible for adjustment force and range of movement learning motor
37:42 . Again, when we talked about hippocampus, we said the hippocampus was
37:46 for semantic memory. And we what is semantic memory? Semantic memory
37:54 names, facts, stories. storytelling memory, if you may hopefully
38:04 correct stories, uh or not also stories, but you still have to
38:11 them. And cerebella is responsible for we call procedural memory, procedural memory
38:19 how to ride a bicycle. five years from now, you,
38:24 will forget the nernst equation that semantic unless you stick in neuroscience or you
38:32 some related field or something with ionic in the cells, but you will
38:38 back on the bicycle. Five years , you'll wobble around and you'll go
38:43 Ners equation. You'll have to probably online, open a book or your
38:49 . If you're gonna save the notes five years from this class and like
38:52 so much, you gotta check the and see the ND equation,
38:58 But you're gonna have to remind you forgot it. But it's very
39:03 unless you have traumatic brain injury or like that. Unless you have the
39:07 in the motor nerves and, and , and the physical muscles joins
39:13 Uh You're not gonna forget how to a bicycle. You're not gonna forget
39:18 to rid, hit a racket. may not be as good five years
39:23 . You know, if you get , you may have arthritis, but
39:26 not how you're gonna, you're gonna it, but you're gonna forget your
39:29 address And their phone number five or years later if you're not going over
39:36 every day. So these memories procedural are very strongly ingrained. There's also
39:45 in this finite brain space that I'm about. Some of us become experts
39:52 science. Others are piano concert others are athletes and that's because their
40:03 space, their cerebella circuits, their memory is really, really advanced and
40:10 over other connectivity in the brain. is also rare to have a
40:17 you know, who is the president the United States. He's also an
40:21 , he's also an MD and phd he's a world champion in swimming.
40:28 who is that? No, it's , no, it's a rare,
40:31 not saying that that's not possible. I'm not saying that if you're good
40:36 academics or science is a and good AAA athletics that the, the two
40:41 co exist. I'm just saying that finite. You know, it's
40:46 How much of the brain space is and all of it is talent.
40:50 takes talent to learn music and to your fingers fast, takes talent to
40:57 the ball and the ball, the cord, it takes, it takes
41:00 coordination and that happens a lot between cortex and the cerebellum. In these
41:07 . Midbrain, you will have sensory motor functions and we'll look at midbrain
41:12 more, including eye movement coordination and and auditory reflexes. In a particular
41:18 is thalamus where information before it goes the cortex enters into the thalamus.
41:25 we'll study that in a second, is different. It's responsible for involuntary
41:32 functions. It's in than the endocrine regulation. So it's a part of
41:37 neuro endocrine system as we call, can influence a hormone, influence hormonal
41:43 , it can influence visceral functions. has very loose blood brain barrier.
41:50 that reason, it's a very good for temperature and some of the toxic
41:55 that may be entering into the And because it is linked to the
41:59 system and essentially has a systemic effect can influence a hormonal release that will
42:04 a systemic effect on the whole body the cerebral hemispheres. We're discussing cerebral
42:11 in different locations within the cerebral cortex are related to different sensory systems.
42:18 also talk about basal ganglia and you know it hippocampus, which we already
42:23 on also amygdala, which is a interesting kind of uh emotional homeostatic uh
42:32 facial emotion recognition se center for facial in particular. So when you think
42:43 simple things that you're doing, and is, we would say,
42:48 it's a simple thing, playing you're waiting for the ball and then
42:51 gonna hit the ball again. You miss the ball if you're not so
42:55 . If you're really good, you just hit it so well that the
43:00 is gonna lose the match. Uh all of the different areas of the
43:05 and how much energy, how much the engagement of different parts of the
43:09 depends on what you're performing. So you're on this side of the
43:13 you're looking at the ball coming at and you're watching the ball with your
43:19 , with your visual system, your cortex is starting to think, how
43:24 I approach and hit this ball? have homeostasis control and the motion uh
43:30 Amygdala, you have motivation and or homeostatic control by hypothalamus. Once the
43:37 crossed over, now you have motor initiation here in recall that is by
43:43 ganglia, you have the command that out of the motor cortex. Two
43:50 below it says move your hand. . And you have uh here uh
43:59 which is thinking, where's my body relation? Where's my hand in relation
44:05 the body? Where's my body in to the ground and to the
44:09 this is called proprioception. So, is responsible for proprioception, cerebellum.
44:16 the behavior is initiated, many adjustments be made. So, cerebellum,
44:21 lot of times is referred to as management for these motor commands or these
44:25 patterns that get initiated by basal ganglia motor cortex. They are communicated to
44:32 through the cerebra cerebella connectivity and cerebellum adjust it. Remember that cortex is
44:40 cerebellum, isil lateral, but there be many adjustments. I use example
44:45 racket ball because there are four the front side, back walls and
44:50 the ceiling too that the ball can . And this rubber ball has a
44:54 of friction. And if you put spin, it's quite unpredictable if the
44:58 is going to jump forward off the exactly in front of or the opposite
45:05 . And so sometimes a person may to strike the ball waiting for it
45:10 deflect off the wall and drop in of them, but the ball doesn't
45:15 and travels along the wall and hits back wall. Now you initiated this
45:21 the with the, with the to hit with a front hand, the
45:24 is behind you, you have to around and hit it with a back
45:28 . And so once you initiated this lot of this kind of a adjustments
45:33 fine tuning of these movements for these will be coordinated between the cortex and
45:40 cerebellum. Ok. More anatomy visual you can see here it says area
45:50 , 18, 19. So here just points to three areas. There's
45:54 more areas of process visual information, somatosensory cortex. Here in the yellow
46:01 motor cortex area and primary motor cortex in red, this is prefrontal cortex
46:08 in in pink the intra temporal this is the auditory cortex and this
46:13 a part of the temporal lobe that be processing auditory information. This is
46:18 gustatory cortex. So you have to parts of the cortex inside these layers
46:25 vain nations who will find gustatory Ok. Diencephalon, diencephalon is thalamus
46:36 hypothalamus. Oam. It's a collection many different nuclei. And so there
46:41 a nucleus that processes visual information. called lateral geniculate nucleus. All of
46:48 outputs, most of the outputs from retina will go to lateral geniculate nucleus
46:53 from Laar nucleus is gonna go to cortex. There's a nucleus that processes
46:59 amount of sensor information. So V L metro posterior lateral nucleus takes all
47:04 the information from spinal cord sensor information to V P L and from this
47:11 in the thalamus, it goes into somatosensory cortex. Auditory information is gonna
47:17 from the ears, brain stem, gonna go into medial geniculate nucleus and
47:23 geniculate nucleus. It's gonna go into primary auditory cortex. So all of
47:28 sensor information, OK. Touch all the information, vision, hearing that
47:35 talking about here. They have their distinct station on the thalamus or
47:40 And for a long time, it thought that these nuclei or thalamus in
47:46 , it just serves a passive And in fact, the cells and
47:49 nuclei are called the relay cells. they just kind of a button,
47:54 relay the information. Uh and, uh that is not the case that
48:01 nuclei actually can be gating and modulating signals. What does that mean gating
48:08 modulating the signals? You're getting a of sensory inputs, think about
48:12 When you're shopping in the store, music is playing. So somebody's talking
48:18 the announcer, somebody's child is uh behind you. You're pushing a cart
48:25 it's vibrating your hands. You're looking your favorite mayonnaise. All of these
48:31 is multiple senses and you need to on finding your mayonnaise. You cannot
48:38 on the child or the announcer, need to get your mail and get
48:43 of here. So what do you ? You're gonna focus it and this
48:48 a conscious focusing. This is another is you're studying in a busy room
48:53 people are talking. Can you block the noise without headphones that focus in
49:01 studying material? Yes, you So part of that, you filter
49:06 information sensor information you modulate, you in on something you gate it.
49:12 if uh the thalamus will be allowing to gate that information, thalamus will
49:18 all of that information to cortex, will communicate information back into thalamus.
49:24 so between thalamus gating and modulating and the cortex and cortex is saying,
49:29 , please focus on the mayo on mayo and the thalamus. Now you're
49:35 to gate and modulate and kind of select almost for a certain sensory stimuli
49:42 order for you to, to get in life uh surrounding these different
49:49 you have reticular nucleus, which is formation here. It's a very interesting
49:55 which is really a sheet of inhibitor neurons. So, inhibitory Hinton neurons
50:01 within the sheet that has a strong influence onto the activity within the
50:09 Ok. So uh now, hypothalamus here nicely is responsible for autonomic involuntary
50:19 functions. Endocrine glands like this uh functions, uh body temperature regulation,
50:28 , water intake, sexual activity, , slow growth such as and hormonal
50:34 growth during growing process. Super plasmatic is responsible for circadian rhythm control,
50:43 is your master biological clock. It your sleep and wake cycles or your
50:53 or diurnal day and night cycles. ? You will probably looking at the
50:59 and you're like, how many things he gonna ask us in the
51:04 And I will, I will say I will leave more detailed questions to
51:11 transmission because we spend more time, more basic general questions, maybe labeling
51:17 or simple questions on the C N . Um And with the exception of
51:25 nerves. So I'll, I'll tell some of the cranial nerves that I
51:28 you to know for this, for quiz. Because then it's gonna be
51:31 nice review for the exam. You not have to study that much for
51:35 exam, just review it more. . So I may ask you like
51:40 identify thalamus or I may ask you contains many sensory nuclei, true or
51:48 . But I may not ask you D E. These are the uh
51:54 functions, body temperature, appetite, intake, all of the above,
51:58 of the above, you know. I can't get into that detail,
52:01 we will have a little bit more on labeling and functions of certain structures
52:07 on the exam because we will actually keep talking about some of these
52:12 These are great labeling uh diagrams. They ask you to identify uh for
52:19 anatomy perspective, you should know the structures, the cerebral hemispheres, the
52:25 , the brain stem, the pawns the uh the bellum, thalamus,
52:35 , uh corpus callosum uh hippocampus here because we love hippocampus and amygdala here
52:46 . Yeah. So just some of things actually, you may have learned
52:50 high school, some of these things may have learned in, in the
52:54 courses. Um I know that my is uh learning a lot of this
53:00 um in, in, in her school. Right. Right. Now
53:04 uh she's a sophomore. So maybe of this is familiar. But uh
53:11 in the cerebellum, you have also hemispheres, the left and the right
53:17 verus in the middle. If you off the cerebellums on the dorsal
53:22 you expose these cerebella pls. This where cerebellum is attached to a lot
53:27 fibers into cortex. And cerebellum will running through these p in the adjacent
53:34 brain stem areas. This also exposes midbrain corporal quadri gemini, the superior
53:42 and the inferior colli and in the and you have the body.
53:51 the other thing that brainstem contains and very important are the cranial nerves and
53:57 are 12 cranial nerves. And I'm gonna ask you to know all
54:01 I'm gonna ask you to know six I'll tell you why and I'll tell
54:05 why. It's not gonna be so for you to remember six cranial
54:09 So 12 cranial nerves. Number two optic nerve where's number one, it's
54:16 , it's not here because what you here is we removed the talon and
54:22 have the diencephalon and the brain stem , the stalk of the brain lab
54:29 the has been removed and the factor and the olfactory nerve, which is
54:36 nerve one is olfactory nerve is not this picture is being removed. Cranial
54:41 two is optic right here. And want you to know number one back
54:48 nerve. I want you to know two optic nerve, I want you
54:53 know number three ocular motor nerve and tell you why I want you to
54:57 these three nerves. First of optic nerve is coming out of the
55:03 and we will study the visual So you have the left and the
55:07 optic nerve and where the two some of the fibers from each eye
55:13 over, it's called the optics. after the fibers cross over this portion
55:19 becomes optic tracked. And so it's longer optic chiasm is here and here
55:26 becomes optic tracked. So that's cranial two optic nerve, there's basically two
55:33 and right who cross over kias and they become the track three oculomotor.
55:42 of all, what do you think does? Ocular motor moves the eyes
55:50 good motor component for the ocular, the eyes, the movement of the
55:56 of the eyes. So I want to know that because it says what
56:00 does. And that's an important And some of the nerves say what
56:04 do if you know a little bit , for example, it will come
56:10 it. But some of the others what they do. The next cranial
56:15 I want you to know is trigeminal , which is five. The reason
56:19 it's the largest, you should be to identify, it doesn't say what
56:25 does, but it's a three part three fibro bundle nerve, trigeminal
56:32 So you should be able to say is trigeminal, this is trigeminal should
56:36 able to distinguish these two large nerves optic. First of all, the
56:42 and second of all, there are that cross over trigeminal nerves of big
56:48 that commodity out of the area. , number four, strog nerve for
56:58 is number five, abducent is number . Faal intermediate is number seven,
57:08 cochlea is another nerve. I want to know because what do you think
57:11 does? Vestibular cochlea, vestibular apparatus auditory. So cochlea vestibule and
57:20 Number eight, Glossop. Number I don't need you to know
57:26 but you can glossal tongue, phal is something to do with the tongue
57:32 ph function Davis nerve, you should number 10 because that's what we stimulated
57:40 discover acetylcholine. Then we finally have accessory nerve here. # 11 and
57:48 nerve number 12, it took. at some point when I took this
58:02 , I I had to take the anatomy, not I wanted to take
58:06 human anatomy and physiology. When I an undergraduate, it was divided into
58:11 head and neck and the body So it was really cool because we
58:18 one semester of just head and neck all of the anatomy in our
58:23 Uh And I took this course uh most of you are junior and senior
58:29 . In our case, we were to have a human cadaver and our
58:36 , part of them were in the and part of them were in the
58:42 . And in my case, we to know all 12 cranial nerves,
58:46 of their functions with a sensory or . And we would come on,
58:51 would have the cadaver, which I dissecting actually for several years, uh
58:59 cadavers. But I did that for while and there would be like a
59:03 tin with a red flag and there be a little type, put like
59:08 string with a yellow flag on these . And it would ask us the
59:13 , which nerve is it? Or nerve is responsible for this function of
59:17 function of that function. So what asking you to know is, is
59:22 lot less. But I think it's valuable. Now, when we had
59:25 learn all of the 12 cranial we always had problem remembering the order
59:32 these nerves and their names. So started to look for some pneumonic and
59:36 we were sitting a little study group the 90s, like 93. I
59:42 we came up with this new Bugs bunny says, oh,
59:47 oh, to touch and feel very vegetables. Ah, so it's so
59:56 , but it's stuck with me since . And what does it mean?
60:01 o is, the first letter indicates first letter in the name of the
60:07 . So, O olfactory o optic ocular motor t trochlea, te
60:14 a abducent of facial d vestibular g vagas uh accessory and hypoglossal. You
60:22 make your own pneumonic if you want , I'm not asking you to memorize
60:26 of these 12 neurons. You you can make your own off up
60:33 try and CV V uh whatever you , you can make up your
60:39 This thing stuck with me for so and if it sticks with you,
60:43 I'm sorry. But uh uh now I want you to know is I
60:49 you to know factory optic ocular 13 geno this studio you were
61:01 in Vegas. The other thing that have to know is which ones of
61:06 nerve are sensory, which ones are and some of them are both sensory
61:11 motor. So that same stormy night the 93 we were sitting in and
61:18 said, OK, another pneumonic bugs says so, so much money.
61:23 my brother says, bugs bunny makes . And what it is here is
61:30 first letter S sensory M is motor is both so, so, so
61:36 sensory m, ocular motor nerve both eight sensory 10 Vegas, both
61:51 . So again, you can just S S M M M B N
61:57 B B M N if you can that order. But I actually remember
62:03 so, so much money. But brother says bugs, money makes more
62:08 this is where we're gonna end So for the quiz, you will
62:13 responsible for the material that we covered through today. Like as I
62:20 I will try to select more detailed on neural transmission and more general
62:26 either identification questions or two false questions this uh C N S section because
62:33 review some of this and we'll continue about C N S and finish it
62:37 after the spring break. OK. good luck studying, good luck on
62:41 exam and stay safe on the
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