okay today's lecture is going to focus on the brain and cranial nerves uh I love the brain personally I think the brain is absolutely a fascinating uh organ and the the crazy stuff that goes on with the brain uh is is just fascinating so uh I hope you enjoy it as much as I do uh hopefully I'm going to try to throw in interesting stuff here as we go through the actual lecture um so let's dig right into it shall we so the adult brain weighs approximately 1.4 kilogram so for those of you that don't actually function on the metric system that's approximately 3 pounds uh it's got a volume of about 12200 CC's but CC stands for cubic centimeters um by the way um something important to make note of that the the size it's itself is there really only for for your general knowledge in terms of relative importance of the size of the brain it matters very little because it's not the physical size of the brain that determines your intelligence or an organism's intelligence or a person's intelligence but rather the number of active synapses that exist uh in that brain right so again don't get hung up on the on the actual size of the organ per se by the way we're talking about adult brain here not a child brain um one of the most interesting aspects of the brain is the fact that it responds to stimuli with such great versatility and uh adaptability it's very impressive in the way that it can it's very versatile so it can respond to stimuli the same stimulus in different ways uh it can learn new stimuli uh an incredible amount of different stimuli and how to respond to those different stimuli differently in different situations all depending on the person and the again the situation and environment they're in uh one neuron this one blows me away by the way one neuron can process information from about 100,000 different sources at the same time which again is insane I'm not entirely sure how that is possible but uh but yet it can do it so it's very impressive that way we've got a lot of neurons in the brain about 20 billion right give or take a million who knows uh but a lot of neurons in the brain right because that's what the brain is it's a centralized integration and processing center now the brain while it has this incredible versatility and this incred incredible adaptability and so many connections via neurons that it's its functions are so amazing but yet there are limitations to this organ despite the fact that it is you know has all these abilities it the brain cannot be both immediate and precise and adaptable all at the same time right so it cannot be all three of those at the exact same time it can be immediate and precise and the the the analogy I like to use here is is like learning a new job right many of us work right and so uh when you when you first get a job nothing you do is going to be immediate because you're just learning that job for the most part most of us when we get a new job it's a new experience for us very new experience for us very rarely that somebody get a a new job doing the exact same work they were doing and they really have nothing to learn so you're nothing you're going to be doing is immediate your your work can still be precise so that is your responses by the brand can still be respice or precise respice they still be precise and they can be adaptable but they cannot be immediate as well because that adaptability doesn't allow for immediacy right but if you once you've been at that job for a while you probably know that job in and out you know exactly what you do know exactly what you're doing every step of the way and so the immediacy is there you you can do that job precisely and immediately but the second that something changes from say like a root situation or a typical situation and adaptability must play in now all a sudden that immediacy goes right out the window because you can't again do and do things immediately and adaptably the same way it's also difficult sometimes depending on what it is you're doing to be both precise and adaptable at the same time right because if you don't know how to respond then Precision often becomes difficult so lots of things to consider there still very interesting though still very amazing uh what the brain can do despite its limitations uh this figure in and of itself might be one of the creepier figures in your book I especially do like the fact that there are eyes here for whatever reason um but that's neither here nor there uh this picture is will be more for reference we'll come back to it later uh um on as we go through certain important things okay so the gray matter right uh when we talk about gray matter and again if you think back to the nervous system lecture that we've talked about where the the the actual neurons themselves unmyelinated neurons right so again specifically uh neurons with no myON sheaths around them uh we they appear gray specifically because of the fact that they have these nissle bodies in their in the cell themselves nissle bodies remember again are the ribosomes within those cells and so your average neuron that's not melinated is going to look gray and so any gray matter within the brain typically again we're talking about the external sheets of the cor of the cortex of the cerebral cortex we're talking about all these external sheets here where you see all these these folds on top of the brain right that cover most of the the service of the adult brain as well and this by the way is the cerebrum so those that service of the cerebrum as well as the external service of the cerebellum which is right here so the external sheets of these two portions of the brain are are gry matter right and it's because gry matter houses motor neuron and interneuron cell bodies so these are these are areas where information is going to get processed right it houses dendrites which means information's coming in here it's got axon terminals right so information's going to leave here as well and then unmated axons so we're looking at all these unmyelinated aspects of a neuron which is why gr matter is gray in the first place right so again when you think of gray matter you think no milin whatsoever well that leaves us with white matter and white matter is actually very easy now that we've had this conversation because white matter is entirely melinated axons so in this case I mean you think back to what we know about an axon the function of an axon is to carry a nervous impulse from the cell body all the way to the terminal end of that axon that is to an to another neuron or to an affector of some kind whether that affector be a muscle or whether it be a gland right and so we're talking about melinated axons here which means all white matter is basically a transportation Highway and that's it it's just conveying information from one point to the other So within gray matter or sorry within white matter you should not have any actual processing that occurs right and in this case when we look at the adult human brain uh we see that the white matter is actually deep to the gray matter so it's deep to the cortex cerebral cortex is here this is ultimately what we often associate with with the higher level function of the brain we're going to come back to that talk about that now occasionally within the masses of brain within the masses of white matter you will see these clusters of gray of gray matter and we see them here and here here and here here and again obviously symmetrically on both sides and these clusters are called cereal nuclei right these are clusters of gray matter and from here on out you want to make a note from here on out a nuclei or nucleus no longer means an individual nucleus within an individual neuron now when we talk about nuclei or a nucleus we are talking about a grouping of neuron cell bodies in one specific place so this area right here is a nucleus right and this is a nucleus that makes sense right and so these are specific areas that we see are aggregated neuron cell b so they're basically islands where information processing can occur within the brain now before we actually talk about the brain itself to a to a great extent the function of the brain and all the interesting aspects of the brain we do have to talk a bit about the support protection of the brain that exists around the brain so obviously we've got the skull superficially into the brain right so we've got that skull that hard bony Cranium that provides that rigid support that rigid protection around the outside of the brain but once we get through the skull this is where things become unique and different and what we haven't talked about yet and so these tissues that we call meninges start to become extremely important a meninges is a protective connective tissue membrane uh that is there to both surround and cover protect and partition portions of the brain so it's going to actually surround the entire brain and it's going to divide up the brain into specific portions we're going to show you where that happens and within the spaces that are formed by these layers of menes we see cerebros spinal fluid uh cerebros spinal fluid is um abbreviated CSF so every time you see CSF now you can think back to cerebral spinal fluid this is a cushioning fluid the brain itself actually floats within the skull and so this provides a cushion a barrier so that the brain doesn't slam into the front of your head every time you run into a door for example right so that's another layer of protection that we have besides the menes and then finally we also have that bloodb brain barrier that we've talked about that BBB that I I referred to back again early on in the nervous system lecture and the blood brain barriers is again meant to prevent entry of these harmful things that we ingest so whether it be uh harmful levels of toxins that we ingest that toxin could be a drug it could be a prescription drug it could be a a non-prescription drug it could be uh it could be an actual drug a legal drug per se uh it could be um uh it could be just changes in fundamental ions or hormones or other things that could damage the brain if we allowed them to come into the neuron neurons so this allows us to actually separate that out make sure that those things don't don't affect the function of the brain okay so when we talk about the menis we have to start by understanding the actual ual order of these menes so we're going to start superficial and Run Deep so keep that in mind uh The Superficial most layer is the dura modder now the term the word itself actually matters Dura in Latin means tough and mo in Latin means mother so this term literally means tough mother the duramater is a very strong fibrous very cloudy white layer of tissue it's very very tough to cut uh and so uh it it literally holds up to the name t tough mother now that is The Superficial most layer of menes just deep to that is a space between the Duram Mater and the next layer that we're going to talk about here in a second and that space here is now called the sub Dural space which again that seems to make sense that space is beneath the dura subdural Okay so we've got the dura modern then we've got the subdural space and our next meni is called the arachnoid meny and for those of you who are aware of this term here irach noid refers to spider now this doesn't look like a spider it's called the aroid modder it doesn't look like a spider but it looks like webbing and hence the because it looks like webs it was named after after that appearance and so that's why we we see the term arachnoid referred to here this this is called the arachnoid or the arachnoid modder again deep to the arachnoid Moder is a space and just deep that space just deep to the arachnoid is called the Sub arachnoid sub arachnoid space so there's a space again filled with CSF here called a subarachnoid space and then finally we have the Pam moer okay we see the the use of this term Mo again uh Pia means precious mat means mother so this is precious mother this is a very thin delicate layer we're going to come back to this that literally covers the actual brain itself so it's literally indistinguishable from the brain itself now the idea behind the cranial meninges is that they're there to enclose and protect blood vessels that supply the brain so they're going to they're going to do that in addition to just protecting the brain they're also going to contain and and circulate that cerebral spinal fluid that we've been talking about and in some cases we're going to see that that portions of these cranial meninges are going to form some of the veins that in turn help drain blood from the brain this is a very unique system up there uh in in the skull and so the meninges actually play a part in now draining blood from the brain so we'll show you that here in a few now the Duram Mater itself we're going to break down means each one by one the Duram here is a double layer it's got two layers the The Superficial most layer is called the per oal layer per oal for the surrounding the bone layer right that's what Perry means Perry for perimeter or surrounding and oal for bones this is that layer that's going to directly touch the bone and there's a space between that I'm sorry there just deep to that layer is the second layer of the uh the menies and this one is called the the Duro derer and this one's called the menal layer go Mouse sorry so this menia layer here right we see is that is just one layer deep to the periostal layer there right now in some cases you're going to see the periostal layer and the menia layer split and in between here you see this void or space and inside you're going to see that um that blue fluid that the cursor is if we look at it here it's currently pointing on or I moved it again but here it is right here again this space is called a dural Venus sinuses this is one of those places where the meninges come together and they actually help form uh those veins that help drain blood from the brain now the space that we see directly beneath and I'm going to move my mouse again do we see this thin space here just deep to the menia layer of the duramater this is the sub Dural space that space between the arachnoid modder and the dura moer all right so the arachnoid modder you can just call it the arachnoid as well again lies in immediately internal to the duramater right so it's going to be just deep to the subdural space and so we again we see that periostial layer here and the menal layer here and there's a deral Venus sinus right in between and now here is that layer here and here's that arachnoid modder and notice that this layer often looks like a web hence the term arach now the space just beneath this arachnoid modder here the space where we see the actual webbing is called the sub arachnoid space so just beneath the actual arachnoid modder and these branches that make up the webbing uses one of these terms that we continually reuse and that is the arachnoid Trula this is a delicate web of collagen and elastic fibers that are found with in the subarachnoid space and in some cases this arachnoid layer is actually going to pierce through a break through or erupt through the uh duramater the menul layer the duramat anyway and we're going to get this arachnoid villis the arachnoid villis is a projection that allows cerebral spinal fluid to pass within those Venus sinuses and this allows us to exchange uh some of the fluid of that CSF with the the fluid inside the the veins I.E the deoxygenated blood all right so that was the arachnoid modder we can see the subarachnoid space and then we've got this very delicate layer right here and this deepest most layer of menis is called the pamer Pam precious mother this is the innermost layer it's a very thin delicate layer and tightly adheres to every Contour of the brain so it's indistinguishable from the brain itself unlike the arachnoid where when there are these depressions in the brain the arachnoid will go over that depression rather than following into the valley of that uh sulcus for say I'm going to show you what those are in a bit here so you can see that this this layer while very thin um does actually just surround the entire brain rather than actually adhering and following every Contour of the brain but this is not the case with the with the pomat the pomat will legitimately cover and follow every Contour of the brain okay now we talked about um where the the brain itself act the sorry the the duramater actually separates portions of the brain up and this is a wonderful example here right so we see these flat partti we call SEPTA where the the duramat itself actually extends now uh inferiorly from this top portion here and actually divides up the right hemisphere of the brain from the left hemisphere of the brain in in in a portions of it anyway right that helps provide additional U um protection support of the entire brain overall okay so the ventricles of the brain ventricles are literally spaces these are open spaces or cavities within the brain which sounds weird this is not filled with a tissue it is literally an open space and we see these ventricles here they're they're ghosted out in a kind of a bluish gray color here so we see this is one ventricle this is another ventricle here to the side of it this is a third ventricle here we're going to talk about and then here's that fourth it's the four ventricles of the brain they are continuous with one another think of this like a really odd Cave System inside of uh a mountain where you've got all these different caves connected through each other to each other via tunnels right tunnels here or we see this other tunnel here and we see this other tunnel extending down here into the spinal cord we're going to talk about all those um but the you want to think of the fact that these ventricles are are continuous with one another there's four of them there are two lateral ventricles we see the right lateral ventricle here and the left lateral ventricle here now there are two of them and these are not numbered one and two so it's not like it's left first then right so this isn't one and this isn't two this isn't one and this isn't two there are two of these they're called the lateral ventricle and they're denoted by left or right the the third ventricle is literally called the third ventricle and this is it does kind of look like a weird creepy duck in this picture I'm not sure that it necessarily looks exactly like that in the the way you're going to see it in the brain but that's fine this is the third ventricle it is referred to as the third ventricle and this is located within a region of the brain that we call the Dian sephylon which you haven't learned yet but you will and then finally connecting the third um third to the fourth we're going to pass through this we call cerebral aqueduct in this figure it's also called the mezen phalic aqueduct same thing different names um you'll learn it as the cerebral Aqueduct that's a lot easier to spell is the fourth ventricle here and the cursor's on it right now and as soon as my cursor catches up with me here H there it is is right here now the fourth ventricle lies directly between the cerebellum and the palm and so these are two regions of the brain that we're going to discuss and right between them is this fourth ventricle again these are continuous CSF is Flowing so cerebral spinal fluid is thr flowing through all of these uh ventrical so it's flowing from one to the next very slowly obviously but nonetheless there is exchange there the cerebral spinal fluid is a clear colorless liquid it circulates within the ventricles and with within the subarachnoid space itself it's formed by a choid plexus layer of tissue that lines each ventricle and the corid plexus is itself composed of these cells that we talked about before these are a specific type of gal cell that we call the endal cells right and these actually produce these endal cells actually produce the cerebral spinal fluid from the blood plasma the job of the cerebral spinal fluid uh obviously is to protect the the brain it also B bathes the exposed surfaces of the central nervous system it completely surrounds it and it provides some pretty important functions here it floats the brain so we talked about this before remember how I said the brain basically floats in the skull again it's because of the cerebral spinal fluid brain actually floats in there that provides some protection right from um shaking around too much again within reason um against damage but the other really big function that the cerebral spinal fluid uh serves is this idea of environmental stability and that is that the the actual environment that the brain is literally soaking in is important remember the cerebral spinal fluid is made of things with ions and proteins and hormones and all these things like that and so the idea is that that CSF is maintained at a stable level so that way the brain doesn't suffer from erratic changes in these concentration levels of certain things or heat here's a good example heat um if it gets really hot outside the nice thing about that cerebral spinal fluid is that it it kind of buffers against that change in heat so that your brain doesn't get too terribly hot and overheated um pH again another thing it allows for stability in the pH because again we expect the brain is going to need a stable environment in order to function the broad brain barrier we talked about this before this is that cut off from General circulation so the the actual neurons themselves are cut off from General CC culation so it allows us for a strict regulation of what can and cannot enter the brain right so it prevents exposures of a lot of things like drugs waste waste being things like Ura that we produce uh through normal metabolism uh or waste products from food that we eat or whatever the case may be as well as pardon me as well as variations in levels of normal substances so again those ions those hormones that could adversely affect brain function we don't want that to happen we don't want a fluctuation in an ion per se to really screw up the way our brain functions now if you're a lipid solid soluble material so we're talking about something that is um um hydrophobic right so it's it it doesn't diffuse well in water because it's much more of a uh a lipid based m molecule then then it can just easily pass across the cell membrane of the asite and so it can diffuse straight through the blood vein barrier but water soluble molecules on the other hand things that are hydrophilic things that dissolve very easily in water these on the other hand must be what we call actively transported this is the idea that we must use a pump some kind of active pump to pump this across uh from one side of the the asite to the other and that puts the asites in this positions to act as a gatekeeper it holds the keys to the gates to allow certain things in and deny access to everything else now the bloodb brain barrier by virtue of its function by virtue of what it does is noticeably reduced or missing entirely in three distinct regions of the brain it's not seen in the CH plexus remember the chy plexus makes CSF so if we're going to be pulling substances from the uh like fluids from the blood to help make the CSF we can't have that blood brain barrier in the way keeping us from from doing this job well and efficiently the hypothalamus this is a master regulatory area for our endocrine system we cannot have a bloodb brain barrier in the way keep keeping us from determining what hormones we have to uh secrete and what not to secrete so noticeably reduced or missing in the hypop phalus and then finally the pineal gland pineal gland is really fun it's it's a one that makes for a really easy example to make for those of you that either have kids or you have babysat kids or you have younger children in your family or um you know this well for those of you that don't uh it's actually pretty funny thing when you become a parent or at least uh when you get to spend time around younger kids uh little kids are amazing in the fact that they will just run and run and play and they they have so much energy and then they start to get tired and you can see they get crabby they get tired you can kind of tell they're getting tired and then at some point if they don't get a nap then then they get the second wave of energy that just carries them for a little bit longer after a while there and they they could they function for just a little while ler but at some point and every parent can attest to this it's amazing kids will just pass out they are just going to pass out and what basically whatever position they're in wherever they're at um and it's impressive because sometimes they end up being passed out in these really weird positions like half hanging off a couch upside down in a chair you know my daughter frequently sleeps in these what appears to be in an incredibly uncomfortable position uh in her uh um safety seat in the back seat of my car and yet I couldn't sleep like that but at some point when they just get tired enough that pineal gland in the brain which regulates circadian rhythm regulates our sleep our daytime day night cycle our sleep cycle this PR pineal gland just basically effectively shuts them off because they're so tired their body is saying you're done you need to sleep here's a figure showing the uh asites right which looks kind of like a weird octopus I know or or uh kind of a weird sea creature like the Kraken uh but and you can see how it actually attaches to these capillary networks and helps facilitate that blood brain barrier okay so we need to go through the blood the the blood the regions of the brain right because these are not necessarily as intuitive as we'd like them to be okay so we've got the we've got the cerebrum here and this is this is very easy to see it looks very folded looks like it's got these Hills and then it's got these these Hills by the way are called gy singular being gyrus and then these valleys in between they look like creases um and they're called uh like plural here would be sulai right sulai uh singular would be a sulkus uh that we see this Valley in between here so that's particularly easy to see the Dian saflon exists right here right so we're going to come back to that then we've got the brain stem itself and then finally the cerebellum which literally means little brain the cerebellum a lot looks a lot like a mini version of the cerebrum itself the brain itself has 12 pairs of cranial nerves that we'll discuss later um that operate VAR various different tasks so again we'll come back to that now in an adult brain this is important an adult brain because a child's brain isn't done forming yet so it varies depending on the age of the child and and whatnot um an adult brain has this extremely folded outer surface of the brain and we see all four loes here I should five loes here that are have all these these gyri and sulai kids brains don't look anywhere near like this because they're still developing so it all depends entirely on how old the child is that we're talking about we're going to start here with the cerebrum going over these regions here the cerebrum itself is actually divided into a a left cerebral hemisphere which the uh Mark the pointer is on right now and then the right cerebral Hemisphere and they're separated into these hemispheres by this longitudinal visure seen here in the middle of the brain there are also transverse and lateral fissures that we also see as well there's a transverse fissure that separates the cerebellum from the cerebrum and there's lateral fissures that separate the uh temporal lobe on the the left of the uh left or right side of the brain from um from the the other the the parial lobe that we're going to see there so again I'm going to come back to point that out but you have to have a lateral view of the cerebrum in order to see the the lateral fissure there now each hemisphere has five functional areas that we call loes now when I learned this there was only four and so I'm going to show you the the the relatively new um lobe that has been discovered recently relatively recently anyway so you've got the the frontal lobe here on the right and here on the left got the parial loes here and here you've got the aspal lobe here and here now this one is aspal this is a superior view of the brain so it's actually much larger and it does it does go farther down underneath the brain so I'll show you that here more of it in a second we cannot see the temporal temporal or the insula here so I'm going to move forward for a moment so that I can show you this is the temporal lobe here and then this is a much this is a much better view here of the aital lobe right don't pay attention to the coloring here this is supposed to be for function but temporal lobe aital lobe and since we're here see the sulcus that exists right here or sorry this fissure this is the transverse fissure that exists the last lobe that you have not yet seen this is again this is a relatively new one is this tiny little lobe here just deep to both the frontal lobe and the uh temporal lobe here and that is the enilla right here now the cerebrum is associated with all the very higher level functions of the brain we're talking about conscious thought processes so things that you're aware of consciously uh are going on up here intellectual function functions right the idea of intelligence and whatnot that stems from the actual cerebrum memory storage memory retrieval and Complex Motor patterns are all seen here now there's a central sulcus that exists between what we call the motor and the sensory portions of the cortex and so here that cursor is B basically right on that uh Central sulcus come on catch up with me here there we go uh I just need to get the cursor to catch up here this is that Central sulcus that exists right here and we've got the sensory portion here that is just posterior to that Central sulcus and we've got the primary motor cortex here that is just anterior to that Central sulcus now there are motor and sensory association areas that we just got motor and sensory areas we just got done talking about a little bit we will come more into detail here about in a few in a little bit and we've got these association areas right so areas where we associate certain functions with uh so we're going to come back and talk more about that here in a bit integrative centers these are areas where a great deal of certain type of information is integrated so that decisions can be made based upon the data coming in the stimuli coming in we've got these basil nuclei that deal with subconscious control of muscle skeletal muscle tone or coordination of learned motor patterns so for example um subconscious control of skeleton muscle tone the best way to think about this can be something like the your basic posture everybody's got a basic level of posture and you that posture uh it's often something we don't really think about that much until again somebody brings it up to us or we start thinking about it but most the time we don't we just we do still stand up straight those back muscles have to be being used they're they're being told to do something even though we're not necessarily consciously aware of it so there's a good example of that coordination of learned movement patterns uh this can be things like um how many of you us have have driven before where and this is my f one of my favorite examples where you get in your car and you're destined to say go you're you're you're supposed to go to say work right but for whatever reason you're you're having one of those days where you get in your car you start driving and then you blank out you're you're you're thinking you're all stuck in your head and you're all wrapped up in this conscious thoughts and all a sudden you kind of and this this is where Quotes come in you kind of wake up and you notice why am I at Harper why did I pull into Harper because you you've driven to some place that you did not need to go but that because you were consciously you know thinking about other things you apparently just went to a default place now that Harper Harper in this case can serve really any place that you find yourself ending up at um but obviously you were awake me you were conscious and awake and functioning to do all that driving it's not like you got into an accident it's not like anybody died in that whole process you did a perfectly fine job of of getting yourself to the wrong place that you were going and all those uh coordinated learn movement patterns are the driving you steering the wheel making sure that you're giving just subtle amount of gas and making sure you use the brake when it's appropriate and whatnot couldn't ordination of learn motor patterns now here's the real fun one and I really enjoy this because anytime we talk about emotion here uh everything gets sticky and messy everything gets uh um complicated with emotion and the lyic system deals with the mo emotion and that's found in the cereum again uh the hippocampus which is essential for storing uh essential for learning essential for storing long-term memory is also found in the cerebrum as well so this figure here is my favorite figure of all time because this figure has been used in so many different textbooks uh since about the 1960s and obviously it's been updated and and changed a little bit modified as we learn more and more about the brain but this is hysterical because here on the left highlighted in blue this is the primary so uh the primary motor cortex right so this is this uh whole area here uh this whole gyrus here that you see highlighted in blue up here in the upper figure and this side here is the primary somata sensory cortex right so this is involved in sensation and this again here's that Central sulcus here and this is that orange or rust colored highlighted uh gyrus that you see here motor stat sensory cortex now the reason I like this and I'm going to focus on primary samata of sensory here for a moment because this is the part that's uh uh kind of so often uh thought about so back in the 1930s and 40s and 50s when we had less I shouldn't say we but when when there were less than desirable ethics and morals involved in same medicine uh there were and unfortunately usually the patients that were used were often uh in that time mental patients right patients that were in at that time were called asylums right which obviously AR call mental asylums anymore but that's at that time what they were called now instead of mental health facilities like they are today and so these were patients that could not advocate for themselves for which family may or may not have ever been around at that point anymore and whatnot and so in this case uh uh they would do brain surgery on an individual so they they'd expose a portion of the skull and then they would take these on these little um electrical probes and they would gently or lightly touch certain portions and the patient could actually tell them where they feel this stimulus so for example if a a physician were to place electrical probe here they would feel a a stimulus or sensation on the forearm right that's how the patient would perceive it uh or if they were to touch here that same stimulus would be on the nose or here being somewhere in the LI lips teeth gums or jaw somewhere depending on where it is but the reason I love this figure so much is if you look at the Historical drawings Associated here on the top here so again really huge hand MC Jagger lips apparent ly uh superstall small stomach and so on right but the these are this is the map associated with certain areas on certain gy associated with certain uh stimuli in certain places of the body now conversely on this side over here this is the primary Som primary motor cortex so if you've ever seen that orbits commercial where the the physician is doing brain surgery and the patient has got a laptop on their lap and you see the physician just touching places of the brain and the patient is typing in the search this is what this is this is what that commercial is alluding to that if you place an electrical Probe on some portion of one of these areas like say for example here the arm would move or here the elbow would move or here the forearm some portion of the forearm would move or here the wrist would move a certain way or here the hand would move a certain way right so those electrical stimuli uh apply applied on this particular area of this gyrus would cause that certain area to move okay the Dion seylon here is this uh kind of middle region here we see it Associated between the epithalamus which is the pineal gland that's right here and the thalamus itself which is this region right here the hypothalamus which is this region just below the thalamus hence the term hypothalamus and then finally the mammilary bodies right which are uh not necessarily easily seen here you can see it better on this uh figure down here this is the mar bodies so again we're talking about this General region right here now the epithalamus this is otherwise ter termed pineal gland either term is acceptable I usually use pineal gland uh just because I think it's more common and uh um the this regulates uh the amount of melatonin produced by the brain and thus released out into the body that helps regulate day and night cycles the thalamus there this is this is a major area of sensory uh information uh for processing of sensory information for processing of motor information and for relaying of sensory information or motor information to the appropriate places that they need to go the hypothalamus here this is that it connects directly to the pituitary gland which is right here pituitary gland is the master gland of the endocrine system whereas the hypothalamus is the master con control system right here the hypothalamus is the master control area of the autonomic nervous system and thus then the endocrine system as well which this is often thought of as our homeostasis Center as well as a large source of our emotional behaviors uh finally the mammary bodies are not very big these are pretty small we see them here and just the inferior surface of the well inferior just inferior to say the the thalamus and just a little bit posterior to the hypothalamus and the mammilary bodies are actually a small region of the brain that control feeding reflexes especially early in life right so you know the idea of a um baby suckling or swallowing swallowing is a reflex for adults right so so those kind of feeding reflexes the mezen seylon uh is otherwise referred to as the brain stem or the midbrain so it's got three different names again I'm more inclined to call it the brain stem because this is a whole lot less complicated to consider than the Meson there's a lot of things going on here this is the basic portion of the brain this is basic survival kind of stuff uh as opposed to say um higher level thought processing and emotion and all that other stuff um So within the the the brain stem we find the the cerebral nuclei or sorry not the cerebral nuclei but the nuclei for processing Visual and auditory information so incoming visual uh stimuli incoming auditory information right and it these will in turn generate an involuntary somatic motor response to those so let's say for example that uh you're joking around with a friend and they go to like Pokey in the eye they're not actually going to Pokey in the eye but it's kind of one of those joking things where they're going to act like they're going to poke you in the eye and your knee-jerk reaction is to kind of flinch you know maybe you put your hands up over your eyes as well or at the very least you close your eyes and kind of wise right that is an involuntary somatic motor response to visual information coming in this is the idea that we're talking about here basic survival kind stuff basic protection kind of stuff um the brain stem also allows for the M maintenance of what we consider to be Consciousness so the idea that somebody is in fact conscious is actually controlled in the brain stem the corpora Quadro gemina in your lab menual this is often called the tal plate uh uh is comprised of two pairs of structures two Superior calculi and two inferior calculi each individually is called a calculus right so two Superior calculi two inferior calculi make up the corpora Quadra gemina and these are relay stations for visual and auditory reflex centers right so they're going to relay information both Visual and auditory uh for the reflexes associated with the body the whoa whoa too fast too far the red nucleus is shockingly red and this is going to integrate information uh this is going to Reg integrate information from the cerebrum and cerebellum and it's going to help in uh producing involuntary motor commands to help um maintain posture so again we talked about this the idea of Maintenance of posture in some kind in some ways right so again that red nucleus here is is going to play a role in those actions the substantia means black substantia means substantially so substantially black that is this black colored Nu nucleus that we find in the brain stem and this sends inhibitory information to cerebral nuclei to regulate motor output uh and this is closely tied with the neurotransmitter dopamine so the idea here that we uh it helps us kind of fine tune our skeletal muscle motions so we don't shake a great deal and and that is something that would be typical we shake a lot more because of all this constant influx of of S information from from motor output but the the inhibitory information that's sent from this uh area helps to kind of smooth our skeletal muscle movement so that they're much more fine-tune they're much more stable finally the re pedal uh these carry ascending information as sensory sensory information to the phalus so we've got when we've let's say you put your hand down on a hot surface that pain that you feel the original stimulus goes up from obviously your hand all the way through up your spinal cord through the cerebral podal and into the phalus so that you can register this uh at a conscious level that Hey ow I just put my hand down on a hot p here are the uh the substantia and here is a red nucleus so one substanti here's the other and then here are the two red nuclei here are those uh calculi for the Corporal quadr gemina here are the two Superior calculi and here are the two inferior calculi and all four of them together make up the corpora Quadra gemina or in your lab manual will be called tectal plate uh here's the thalamus and we see the pineal gland here but these are a part of the Dylon these are the cerebral pedals okay now the pawns is this first bump when you look at the actual brain stem this first bump here uh this houses nuclei for sensory and motor cranial nerves 5 through 8 uh it houses specific autonomic respiratory centers um that have to do with controlling the rate and the depth of your breaths or breathing right so so how fast you breathe or how deep those breaths are this is going to be monitored and maintained in the ponds uh it's also going to mod modify activity um of the respiratory Center in the medulla Oblada so actually respiration is actually controlled by both the ponds that I've already showed you here and the medulla aaga here so it's actually a kind of a partnership between these two areas of the brain stem and the ponds actually connects to the cerebellum that is directly behind it so we see this mini brain here the cerebellum right here the cerebellum has two hemispheres the cereum in a lot of ways is a lot like the cerebrum it looks a lot like it it's got gyri which are those pit Hills and the sulai which are The Valleys um it has two hemispheres just like the cerebrum so we see a hemisphere here and another hemisphere here left and right and this space in between is called the vermis this is a connection point between the two hemisphere called called A vermis Now function of cerebellum very important this is the coordination and fine tuning of skeletal muscle movements from learned patterns so these are learned muscle movements right the best analogy I can give to this is uh if you've ever watched somebody who can really dance and really dance well well if you've ever watched them dance it's it's beautiful it's fluid it's graceful it's it's amazing and impressing imp impressive and that is because they can move their body in such an intricately fine way because of the cerebellum the cerebellum has become so good at at learning this this set of skeletal muscle patterns that it knows exactly how to move it just went and they have such fine tune control such subtle movements uh in there so makes it graceful and beautiful uh it's also involved in the in equilibrium so our ability to understand that we are in fact upside down or right side up right uh or balance uh being able to have that stay keep maintain our balance stay upright and and walking upright um again the vermis is that connection point between the two hemispheres and if we do a cross-section of the cerebelum we see that it has got some gray matter around the external side again very much like the cerebrum but inside again very much like the uh cerebrum we've got white matter as well except here the white matter looks for all better purposes a lot like a tree and so the term arborite is used to name this structure this structure is called the arborite arborite literally means uh tree of life and so hopefully that will help you remember the medulla ablan is this portion here it's that last bump there before we get into the actual spinal cord itself this connects directly to the spinal cord it's a relay for sensory information to the thalamus which if you're kind of following up here the the thalamus would go all the way up right about here um we've got a lot of autonomic sensors centers controlled here in the uh medulla magada we've got cardiac for both rate and strength of actual contractions that is controlled here in the medulla of Mada the vasom motor so we're talking about vessel diameter control uh in response to blood pressure that is controlled here respiration again uh controls rate in cooperation with the ponds and then other very unfortunately uncomfortable kinds of things that we have to be able to do coughing sneezing salivating swallowing gagging vomiting these are all actions that are controlled here right in the medulla of Lata it's also it also houses the nuclei for cranial nerves 8 through 12