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All right. Um, can you see that? Okay. Yeah. Cool. Right. So, um, how everyone I'm Shree. And, um, today I'll be going a bit over some case five for card of students, but a neurology for everyone else. I'll just be going through some urine out to me. CSF brain imaging, New York little cell types and hearing on. We'll have a few SPH throughout as well. Great. So we'll just get right into it. We'll start off with your own, ask me so we'll just start up with the very basics. Um, so can anyone in the chat tell me what this green lobe over here is? Cold? Perfect. Yeah, Frontal. Okay, um, and then the next one here. So this kind of bluish purple lobe here, parietal. Yeah, that's right. Um and then this yellow one here temporal Fine. And then finally the one here in the back and purple. Except it's a cool. Um, And now what about the structure that's tucked under the occipital lobe? Cerebellum on. Then finally this been structure and pink, The brainstem Perfect. So that's just the very basics. Okay, um, now we have a few gyro I and Sulka, so a gyrus is basically sort of a protrusion of the brain. Um, and the sulk. I are sort of the depressions or the crevices in the brain. So the way I remember this is when you're depressed, you sulk. So the cell ky are depressions, so they're quite a few important landmarks in terms of giant cell for that we need to be aware of. So our first one is theseventies told this here, and it runs across between the frontal lobe and the pride's alone. It separates the two main gyra, one being the Precentral gyrus, which contains our motor association cortex on our post central joint gyrus, which contains are sensory cortex. I'll talk a bit more about this when we look at each low. Individually, we then have a fissure or a cell CAS notice electoral or Sylvian fissure. And this just basically separates are frontal and pride too low from or temporal lobe. We've got our pride talks. It'll focus which, as the name suggests, it separates surprise, a low by the occipital lobe. And then finally, we have the sort of imaginary line. It's not really an actual landmark, Um, and it's called a pre occipital notch, and it separates the temporal lobe from the occipital lobe. Okay, so this is sort of just the very basics the basic landmarks we need to be aware of. Okay, so we'll talk a bit more about the euro fulls. Um, so we'll start off with our faults. Very bright. So the fall cerebral, um, is basically right between the left and right hemispheres of the cerebrum, and it's important to different shape between the folks. Three Brian, the corpus callosum. So the corpus callosum is a white matter tract that allows communication between the two hemispheres, whereas the fall cerebral works to separate the two hemispheres. Okay, So fall. So you're Bryce ovaries left and right, hemisphere of the serious cerebrum. Then we've got our country, um, cerebella over here. And that basically just separates us our e Belem for the from the cerebrum. And we've got our fault. Sorry. Balance. Which is just a continuation of the tentorium cerebella. And it'll separate the left and right hemispheres of the cerebellum on. Then finally we have a You're a full. That's not really talked about enough. I've labeled it here, and it's the diaphragm cellie On what it does is it sort of covers the pituitary fossa. Um, and the pituitary fossa is in the salad turkey of the skull. And it's what contains are pituitary gland. So it's really important in sort of covering and roofing d pituitary fossa. Okay, so those are the main sort of girl falls, and we need to be aware of next are meninges. So the meninges are these really big and tough layers that protect our skull? So we start off with our scalp, we then move on to our skull, which is just a bony layer. Then we've got an extra year old space which separates the skull from our your monitor. Now that you're a moderate is made up of two layers, one being the periosteal layer and one being the meningioma. Yeah, meningioma layer. So periosteal layers is more a Z names just more of the bony, um, sort of structure. Where is the meningioma layer contains the actual blood vessels. So together, collectively, they referred to as the your monitor. Then we've got the subdural space, which separates are you're a motor from our our AC tried larger. Um, the actual names have a lot of significance as well. So do Europe is a very thick and tough layer, as opposed to Iraq noid, which is still quite tough. But, um, the reason is called are accurate is because our active means on Spider on what these are occurring matter have are the sort of protrusions or granulations that go into the, um that go into the space between the periosteal and meningea a layer on because of the sort of granulations they kind of look like the legs of the spider, which is why it's referred to us and Iraq. My mantra. Okay, so we've come to the Axiron monitor. We then have the suburb Ackroyd space, which separates the eye or in modern from the PM odor. Now the your mother is one of the only manages that actually follows the grooves, the silk I and the gyre I of the brain. So it's tightly bound to the brain and PM means mother. So that's sort of a good memory to know that PPI is tightly a deer to the brain, and it follows the gyre and sell kind of the brain. So yeah, and then finally we have the brain. So, like I mentioned. Here we have this venous Sinus or the space between the two layers of the dura mater on This is where reabsorption of the three were. Spinal fluid takes place. So the subject, uh, the record modern have these granulations and they protrude into the venous Sinus, which is where your CSF is going to be re absorbed. We'll talk a lot more about this when we talk about the actual flow of CSF is Well, okay, so now that we've covered that, let's talk about the lobes in, um, more detail. So you're gonna notice that with each of the lobes, there's gonna be a sort of trend. Each load has a main function. It has a cortex and an association cortex with it. So if we take the front too low, for example, the main function of the frontal lobe is motor function. Okay, So like we mentioned, Beach got our precentral gyrus here, which is just before the central focus on the precentral gyrus is what complains our primary motor cortex. So the primary water cortex is going to be involved with controlling contralateral laundry movement. So what that means is the right side of our brain is going to control the left side of our bodies movements on then the association cortex is basically involved with fine tuning any input that's received from the motor cortex. So it's going to I'm allowed planning and execution of the movement. We've also got a structured orders. The frontal I feel and the frontal I field is involved with rapid eye movement when were asleep. So basically, when we're asleep, what happens is our move. Our eyes move rapidly and it's sort of an involuntary response on day. Also have some input into voluntary I movement. We then got an area of the front known as the prefrontal cortex, which is really, really important for things like personality, mood behavior. Even memory Power was gonna talk a lot more about the memory aspect of things. But the the prefrontal cortex is basically used for decision making, and just any personality changes a swell. Now we've also got the Broca's area, so Broca's area is responsible for speech. Production on Broca's area is usually located on the dominant side of the brain, so if you're right sided, that's gonna be on the left side on. Most people are right side dominant, which is why it's usually found on the left side. Now, if a lesion occurs in Broca's area, it's referred to as bronchus aphasia. So this is when patients are not able to produce any speech on the way I like to remember. This is broke. A safe Asia leads to broken language. Both of them start with the letter broke of the word broke. Um, so, yeah, a lesion and Broca's area will then cause the patient to be unable to produce any speech like we mentioned. Um, the, uh, frontal lobe is separated from the parietal lobe bi the central cell cas onda it separated from the temporal lobe bi of the lateral or Sylvian fissure. Okay, um, next we have the parietal lobe. So, um, the parietal lobe is a lot of my recording. Hoping recording. Right. Um, the rides, the lobes main function is sensory function. Um, and like we mentioned, it has a somatosensory cortex and an association cortex. So right behind the central focus is our postcentral gyrus, which contains our primary somatosensory cortex. Um, and this is where you have a wariness of somatic sensations. So somatic sensation is anything like pain grows, touch temperature, vibration per perception. All of that. And then our association cortex is basically going to analyze the shape. I'm sorry, not the shape. It's going to analyze where the sensation is coming from, how intense the sensation is. And basically, it's just going to, um, analyze and find, you know, any of the input that's coming into the primary somatosensory cortex. We've also got this area called the posterior association area, which is usually missed out in textbooks. And this area is quite important because it's basically located in the junction between the temporal lobe parietal lobe on, um, occipital lobe. So what that means is it allows for visual, auditory and sensory information to coalesce. Right? So it's located right here in the junction off the three lobes, the boundaries with the price. A low is the central self dest that separates the frontal lobe from the price. A low and the price of occipital self is, which separates the parietal lobe from the occipital lobe. And then finally, the actual Children fissure, which will separate the parietal lobe from the temporal lobe. Perfect. Then we move on to our temporal lobe on the main function of this is August she function or hearing again. We've got our primary auditory cortex, which will receive information about sound. Um, and then the auditory association cortex will then try and analyze where it's coming from on. But, um, how loud it to use things like amplitude frequency pitch cetera. Um, there's also a very important landmark known as Thehuffingtonpost virus, which is tucked right under the superior, um, the superior gyrus of the temporal lobe on do. It's involved with sort of evaluating the sound and analyzing the sound along with the auditory association cortex. So like we mentioned, we have a speech area in the frontal lobe on his bronchus area. We have another speech area known as burning cause area in the temporal lobe, um, as opposed to bronchus area, where because areas mainly involved with comprehending Britain and spoken language so it's more with understanding what people are saying on. So when there is a lesion in this area, it leads to something known as well, because if Asia, where people aren't able to understand what other people are saying on also the patient can produce, was just saying absolutely flu in sentences. But it'll be absolute nonsense. They'll just be saying things that make no sense whatsoever. Okay, So the way I like to remember it is weird because aphasia, what are they saying? So you're unable to comprehend what the person is saying? There's also the primary olfactory cortex, which is found most medially off the temporal locally can actually properly see it in this diagram. It will be here, except it'll be found more immediately on. But it's main involvement is sort of analyzing any sense of smell any old factory input. The temporal lobe is separated from the parietal and frontal lobe by the electoral Sylvian fissure on. Like we mentioned, we have that imaginary line known as a pre occipital notch, which separates the temporal lobe from the occipital lobe. Fine. Um, so now moving on to our final low, which is the occipital lobe, Um, the main function of the occipital lobe is to, um, sort of process any visual information to allow us to see. So we've got our primary visual cortex, which receives any visual information, and then the association cortex, which will analyze and recognize the shape, the color, the sort of object, the movement of the actual object that's being proceed. The occipital lobe is separated from the pride too low by the parietal occipital focus on it separated from the temporal lobe bi the pre occipital much. Okay, so that was just a whistle stop tour of the lobes. There functions and they're sort of landmarks. So we're going to move on to a concept that I don't think is covered really well, in med school, at least I didn't really understand it in first years. So we're gonna talk about the basal ganglia. So the main function of basal ganglia is to refine motor movement, so it's to eliminate any exaggerated, exaggerated or unnecessary movement. Okay, so we have these things on his input nuclei. So that's over here. The cardiac and putamen collected collectively, they're referred to as a straight straight Um, and what happens is they receive information from the cerebral cortex on that goes to the input nuclear family and put nuclear either going to go to our output nuclei which are the bogus palatis and the substantia nigra on from the output nuclei. This will go to various nuclei in the brain stem or the thalamus on from this area, they will go to the effect or organ to sort of refine any motor movement. No, this is especially important when it comes to things like, uh, Parkinson's, where the substantia nigra is, what's implicated. So as you can imagine, if the substantia nigra is implicated, then one of our out but nuclear are implicated, so it won't be able to refine movement as well, Which is why you can see things like tremors in Parkinson's. So in terms of the actual signals that are being transmitted, it's usually going to be an inhibitory signal. So the cereal cortex are going to tell the input nuclei to send out in an inhibitory signal because they are sensing too much movement, and they want to eliminate that movement to try and refine it. So the main sort of areas that send out these inhibitory signals are the globe. Is palatis one of our main out, but nuclear Okay, it's also worth noting that the future man and the gloves palatis So our nuclei here are collect collective you referred to as the lentiform you clears Perfect. Um, so now we'll move on to the arterial supply. I'm sure you guys have seen this diagram so much. So, um, I'm not really going to go through everything. We're mainly just gonna be focusing on the arteries that I've circled. So the anterior middle and posterior cerebral arteries, Um, this diagram is just trying to show roughly the region's that are being supplied by each of the arteries. So if we look at it, we can see that the interior of cerebral artery supplies the frontal lobe bits of the price. A lobe, The middle cerebral artery supplies the majority of the lateral brain posterior cerebral artery, supplying things like the occipital lobe on parts of the Pride PSA lobe. But when it comes to arterial supply, I'm going to sort of cover this in the next light. It's really important to know what limbs day supply, because if they're implicated, if they're damaged or included, and it's important to know what it's important to trace back what our trees being occluded based on the symptoms that the patient presents with. So if we look at our anterior cerebral artery, it's main sort of function is to supply the lower limbs. So if there's an occlusion in this artery, that means our motor and sensory aspects of the lower limbs will be lost. Additionally, you'll have personality changes because if we just go back to the previous slide, we can see that the anterior cerebral artery supplies three frontal lobe. Which campaigns are prefrontal cortex on? We talked about how the prefrontal cortex is really important with things like personality, mood decision making. So, in some cases, if it gets really bad, um, and occlusion in the anterior cerebral artery can also present with personality changes, Then we have the middle cerebral artery. So, um, the middle cerebral artery is kind of a big one here, so it supplies, um, the upper limit the face. It also supplies of basal ganglia. So we mentioned that the basal ganglia is involved with refining movement, and it involves Sorry, it supplies are speech areas as well. So we're Nikas and Broca's area. Uh huh. So you can imagine if this arteries included quite a lot of consequences are going to occur. So first one being there's gonna be a motor and sensory loss in the upper limbs and the face, um, you're going to have, um we're Nikas and broke a safe Asia So what? Because a facial means you're not able to. The patient won't be able to comprehend what you're saying, and you're not gonna be able to comprehend what they're saying. On Broca's area, Broca's aphasia will mean that they aren't able to produce any speech. Now. It's really, really high yield to know that the middle cerebral artery is the most commonly occluded artery of the of all of them. Actually, because if you if we go back to the circle of Willis, we can see that the middle cerebral artery is a direct continuation of the internal carotid artery on the internal carotid artery is quite a big one on, um, the blood flows at quite a high pressure there. So it is quite a common site for clots to just dislodge right into the middle cerebral artery. Okay, on, then, finally, we have our posterior cerebral artery, which is involved with supplying the occipital lobe in the cerebellum. So if this arteries implicated or occluded, then it can lead to things like vision loss. Yeah, fine. Now we have the venous drainage, so it's quite self explanatory. And by the way, this diagram is taken from Meghan um she did an amazing lecture for the second years, so I just kind of took the sonogram because it's really useful and explaining what I'm about to talk about. So if we go back to CSF, we know that the CSF was being reabsorbed in the Venus Sinus between the dura mater. Sorry, the periosteal and meningioma letters of the germ water. So some of the CSF is reabsorbed back into the superior sagittal tighness on and the superior sagittal, imperious, sagittal and straight Sinuses all drain into this confluence of Sinuses. It's also good to know that the great three rule vein is just sort of a continuation of the straight Sinus. So once they drain into the confluence of Sinuses, they're going to drain into the transfer Sinus bile. Actually, so you can't really see it in this diagram. But, um, the transfer Sinus sort of spreads bilaterally across the brain on then the transfer Sinuses going to drain into the sigmoid Sinus, which will then drain into the internal jugular vein. There's not much to this one. Unfortunately, it unfortunately, it is just a case of learning. But I hope that diagram sort of clears up what structure drains into one. And then finally, the CSF, the most dreaded Papa Kable. So CSF, um, is actually really important in our brain. It has a multitude of functions, one being that it allows. Our brain two floats the buoyancy. It prevents the brain from any sort of make a mechanical injuries. It provides chemical stability, and it protects against a ski mia. So in terms of CSF productive production, we have these cells known as, um I've been diamonds cells, and they talk a lot about them when we talked about, in your opinion as well. But these epididymal cells are sort of modified structures found in the cord plexuses, and they produce CSF, and they're mainly found in the lateral and third ventricles. Okay, so floor the sake of this lecture, we're gonna talk about CSF draining from the lateral ventricles. Okay, so we have these epididymal cells forming these cord Texas is that are producing CSF in the lateral ventricle from the last 12. Enjoyable. They're they're going to move into the third ventricle via this intervention killer for a man or from from another one road from the third ventricle. They'll move into the fourth ventricle by the cerebral quit, uh, and then from the fourth ventricle there. They'll either move into the suburb Ackroyd space by the frame in a Majendie or the Spinal Canal by the frame and of Lucia. So I use a sort of ammonic to remember these structures in order. So losing in tennis causes frustration, sometimes losing lateral ventricle in intraventricular. For a man, Penniston third ventricle causes cerebral aqueduct frustration fourth ventricle, sometimes either summer, accurate space or spinal canal. Okay, so once we've got all of the CSF, it's good to know that the CSF is like constantly be generating and constantly being produced. So we need a way for the CS. Have to be re absorbed and taken out of the system. Otherwise, it can lead to things like hydrocodone lists where there's access fluid in the brain, and we don't want that. So what happens is we have those protrusions like we talked about in the meninges of the Iraq run modern on. They stretch into these superior sagittal Sinuses on what they do is they re absorb any excess CSF so that they leave the system and the CSF could be recycled and continue being produced. Okay, so I've got an SBA now, Um, if we could just get a pole launched, please. Three. I think you're noted. Week three. I think your muted Sorry. Hear me now? Okay. I don't know what just happened. I'm sorry. Just for you answer for that. Um, can you see that? But that I think anyway, sorry. I think most people said anyway, so Good. Okay. I'm really sorry. I don't think the, um are the polls working? Yeah, the polls. Lucky. Okay, fine. Perfect. Okay. Um right, so we'll just talk through this one. Um, so this the answer for this one is an anterior cerebral, um, occlusion. And the reason for that is because first, we have paralysis and sensory loss in her legs, so we know that the anterior cerebral artery supplies the lower limbs. Um, her partner says she's been acting quite differently. SARS turn a point towards the fact that there's no blood supply to the prefrontal cortex, which is involved with personality changes and would on. She's also been taking the oral contraceptive pill, which increases your risks of thromboembolism zor clots. So this could have just been a clot that dislodged into her anterior cerebral artery. Perfect. Um, so now we're gonna move onto brain imaging again. This is a really, really high yield topic. I think in our exam, quite a few of these brain images came up and they just ask you to label things. So before that, we'll just familiarize ourselves with planes. So for axial, just make sure that you know that you're always standing and looking at the patient from the feet up words. So from I imagine, if the patient is lying down, you're standing at the feet and looking up at them. So for axial, if you just cut through their head, you're looking up from their feet upwards. So this would be the front or the top of their brain. This would be the back or the bottom. This would be the right side. And this would be the left side. Um, in terms of sagittal is just cut straight through the nose. Um and then coronals is sort of just like that, right through the, um, right to the half the skull. So in terms of that, we'll talk about the differences between Seiki an MRI because they can just ask you, uh, what type of imaging has been used here? So, um, CT is usually used in the cases of trauma. So when you need imaging really quick, because CT is quite quick on it shows things like bleeds really well because it will just sort of be a little brighter. And we'll have, like, a hyperdense area. The way a different shape between cities and MRI is that CT in CT is the bone will appear bright, so it'll appear quite white. You can see her. It's like a white bring of light. Um, the MRI, on the other hand, is better for soft tissue detail. Um, and it's good for looking at things like brain herniations a swell, um, and it's good for looking at the brain and our to me. No, they're two different types of memory as well. There's t one weighted and t two weighted it, um so TNT one you can see that, um, I mainly usually look at the ventricles which contain the CSF so you can see that in t one. The fluid is quite dark, but in t two So these ventricles here they're filled with CSF so you can see the fluid is quite bright on the way I like to remember that is a World War two. So water white into so in P to the water will be bright, whereas in p one, the water will be dark. So, yeah, overall, CT is better for bone injuries or bleeds. And it's good for like, quick things. Quick imaging in patients with trauma when you need a midget really fat really fast. Whereas MRI's better for things like soft tissue detail, they're also quite a few contraindications for Emory. So aside from the fact that they take a really long time to do, they also can be used in people who have any sort of magnetic metals that might be inside them. So things like aneurysm clips. Because, as you can imagine, the Emory is just a huge magnet. So it's just going to rip the like, sort of clip out of them. And so that can obviously be really bad. Um, and you can't use it in patients with claustrophobia, because again, it's like this huge market that brats around you so that can make them really anxious. Um, but yeah, so I'm not really going to go through these slides. But I'd highly recommend looking through each one because they love to ask. Just like, you know, they just like to give you a brain image and then ask you what structure this is what level? What level hasn't been taking that? I'll just point out, though, that this is a p one emery, Because again, the medicals are darker, so the fluid is dark. So that's a key one MRI. Um, but yeah, I've sort of labeled each one's in my each plane a swell, so it will be really useful revision. So again, if the polls work, um, can they be launched, please? Having think you're gonna have to tell me what people say Because I can't see the polls. I think there launched. We'll give it. We'll give it, um, a minute or so and then you can tell me what the majority said. Yeah. I don't know. For some reason, it's not a people voting. Okay, I'm gonna really launch it one more time. Do you a day try to now, everybody? Yeah. Looking cool. Perfect. Thank you. Um, let me know when you want me to send it. You know, the highest response. Yeah, well, we can end it there. Um, okay. So most people have said be on most people would be correct. So, um, this is in fact, an MRI t one reason being that the fluid is darker and this would be the pituitary gland. So if I just go back to the sagittal section, Right. So this is just a bigger version of that picture. The pituitary gland is always right under the optic chiasm around 10 millimeters under on disability. Good for a clinical relevance. Because when you have, um, humor of the pituitary gland known as the pituitary adenoma, it can press on the optic chiasm and lead to visual deficits. Ah, one of them being a bile actual bites area. Bitemporal hemianopia. I don't think you need to know that at your stage, but it's just quite good to know that the pituitary gland comes right under the optic chiasm on this. Can you need to a few clinical implications? Perfect. We'll just move on to bad. So now we're gonna talk about the different cells of the brain, so we'll start off with our oligodendrocyte. So the main function of these are two mile in eight. Excellent in the CNS. Okay, we know that the Schwann cells do this in the pianist in the peripheral nervous system, so there's sometimes referred to as a show on cells of the CNS. Now, Myelination is really important for a multitude of reasons, one of them being that they protect the excellent. So if you remember myelin sheath that sort of just made up of lipids, and so they cover up the axons and they prevent any sort of injury or damage. And even if damage occurs, it's gonna damage the myelin sheath before damages the axon. So it's quite good in terms of protection. It also increases conduction velocity. So if you guys remember, when it comes to myelination in the mile, mile and cheap is sort of a ranged in notes on day. So when an electrical impulses trying to pass through them, they can just jump different lengths of the axon rather than traveling through the whole length of the axon, which is referred to a solitary conduction on. Because of that, it increases thie rate, at which electrical impulses conduct through them. And finally, just for some clinical relevance, there is a condition known as multiple sclerosis, or M s, where these other good undersides are implicated on. But they're no longer able to function properly, and this committee to be generation or demyelinating of the accents. So again, if that mile a nation can't occur than these accidents are no longer being productive, protected, and this can also increase. Sorry can also decrease conduction velocities. Conduction is going to become slower. We then have our astrocyte. So the Astra sides are kind of they play a huge role in the CNS. As you can see, they have a multitude of functions. They're the most numerous type of fetal cells as well. So what they do is if we talk about the second one here, they recycle left over in your transmitter after synaptic transmission. So say, um, we've got, you know, an X in your transmitter and its side ups from the presynaptic to the postsynaptic. And then there's some left in the synaptic plastic. We have enzymes that break down the excess neurotransmitter that's left of the synaptic left so that it doesn't cause any more excitation. But sometimes not all of it is scared away. So what? These astrocyte will do is they'll come and clear away any of the excess neurotransmitter so that it doesn't lead to more excitation occurring. Um, they can clear up. Then you're on and excess potassium islands. They stored glucose from the blood as fuel for the neurons. They can regulate metabolism and homeostasis. So things like regulating the internal environment of the brain. They conform glial cells in response to a nerve injury. So when we talk about nerve injury in the peripheral nerves, a nervous system, what happens is if a nervous cut in the pianists, then there's gonna be something notice, water and degeneration and then regeneration. But in the brain, it's slightly different, so the nerves and the brain don't actually regenerate. Instead, what happens is these astrocyte sit alongside a few other fields. Sells will come along and try and form a scar around the nerve injury so that the nerve injuries only sustain to that one location, and it doesn't sort of spread to other areas. So that's the sort of way in which the brain tackles it. Instead of regenerating, the whole nervous just got a form, a scar to block off the sort of nerve injury from going to any other places in the brain. They also help with the formation of the blood brain barrier, which we know is quite important, especially with the administration of drugs, because the blood brain barrier has these tight junctions that prevent any sort of drug well, it allows a few drugs, such as chloramphenicol, to sort of surpass the blood brain barrier. But most drugs they won't allow to enter the brain because that could be a really toxic to the brain. And then finally, they also controlled breathing. Then we have our microglia, so these are sort of like immune cells of the brain. Um, they almost act like macrophage is. So what they do is when there's when there's injury, they'll come to the area or the location of the infection on. They will try and figure cytozole the infection so that it doesn't spread to the rest of the brain. They also sort of clear away any harmful toxins that the infection has been spreading again so that other parts of the brain aren't implicated. And then finally, there's a process on a synaptic pruning. So what er brain does is it produces a lot of sign ups is more than we actually need. So sign ups is that we don't regularly use will be pruned away, which basically is a fancy term for, like, being killed off and then cleared away. So the microglia help with that process. They just sort of prune any sign ups is that aren't being used regularly. Um, and then finally, we have our up in diamonds cells. So we briefly talked about this when we talk about the flow of CSF. So there are some modified epididymal cells in the court excesses. That's primary function is to produce CSF. But it's important to note that not all epididymal cells pretty CSF. In fact, the majority of them form a thin member Notice that happened, I'ma which alliance the ventricles and they have the cilia that sort of facilitate the movement and the flow of cerebrospinal fluid throughout the ventricular system so that the CSF doesn't just stay stationary in one area. So yeah, there there are a few specialized, modified up and I'm all cells in the cord, plexuses. But not all of them are involved with the production of CSF. Rather, they just form this member notice that happen. Diamond. They can also work as a shock absorber on, but they're good at maintaining homeostasis alongside the Astra sides. Perfect. So another SBA if we can get the polls, launch peas. Okay, thing that's enough time or Northern. Most people have said be be perfect. Yeah, everyone's like doing great. Yeah, So that right answer is exercise. So over here, Peter has gotten into a serious motor vehicle accident. So in, ah, accidents like this, there is a movement. Honest, the coop countercoup movement, which is where the head, um, goes forward and then back really quickly. And then this can cause portion or turning off the nerves. And that can cause them to rupture or pear on. Like we mentioned in the CNS, it's slightly different two in the pianist on the CNS. These nerves aren't going to regenerate, so the exercise is going to come and form a scar around them. It's also important to know that astrocyte aren't the only ones involved in this process. But there are the ones that sort of start this process perfect on. Then, finally we have hearing, so I'm just gonna cover the physiology of hearing and then Pap will take over with the pathophysiology right? So sound basically sound. The way we hear sound is by converting sound waves to electrical impulses that are then sent to the auditory cortex in our camp or low right. So let's just break that down. Firstly, are here is sort of divided into three sections are external year, our middle year and our inner ear. So what happens is the sound is going to travel to the auditory canal on. It's going to vibrate this structure here, not as a tympanic membrane or the ear drum. Um, the ear drum is held under tension by a muscle. Tone is a 12th punny on the eardrum is what separates the external year from the middle ear. Now, in the middle year, we have these small bones. Nose ossicles are malleus, incus and stapes, and there are so the malleus is in contact with the ear drum. So once the eardrum vibrates, that's gonna cause the malleus to vibrate, which will then cause in keys in cussed and stapes to vibrate as well. So then, once we reach the inner ear, which is the Coppelia, we have the stapes. That's connected to a structure known as the oval Window off the coffee a day, and what happens is the stapes will transmit the vibrations to the oval window, which will then transmit it to the rest of the cochlea. Now it's good to note that the middle year is, um, the the main sort of thing surrounding it is a rare as the cochlea in the inner ear is fluid filled. So because of this fluid air barrier, we need something that'll amplify the sound so that the vibration will continue to be transmitted. So we have a phenomenon known as impedance matching. So impedance matching is where the eardrum has such a huge surface area compared to the oval window, which has a really, really small surface area. So this sort of difference in surface area allows for the sound vibrations to be amplified. On this amplification. That means that the sound waves could be transmitted from the middle ear to the inner ear. Um, it's also good to know that are you station to connects the pharynx to the middle year. So when you get sick, what happens is this eustation two can sometimes get clogged up, which is why you're here. Blocks up, um, is also it acts as a pressure equalizer. So when you go on flights or in, like, high altitudes, that drastic pressure change from atmospheric pressure to the pressure in the flight will then cause your ears to pulposus. Well, okay, so now this slide, um, it's it's really I want to break it down so that it's quite simple to understand. Okay, so we'll start off with the sort of structures in our cochlea. Okay, so we've got our basal or membrane. We've got our hair cells or a spirit cilia, and then we've got the tectorius remembering. Okay, in the car. Clear. We have structures known as the Perilymph and the end. Elin's Okay, so the Paralympics are just a fancy sort of structure that have a high sodium concentration, whereas the endolymph have a high potassium concentration. Okay, so the peri limps get their sort of high sodium concentration from the blood and the CSF, and the endolymph skated from instruction on a stronger vascular wrists, which migrates during embryogenesis. So the hair cells that we talked about here the bottom of the cell is immersed in that sodium solution whereas the top of the hair cell is, um, memory standpoint hassium. Now the difference in ion concentrations is around 18 levels, and that's referred to as our end of computer potential. This endoscope, your potential is basically gonna drive potassium from the external environment into the hair cell. Once the potassium moves into the hair cell, it's going to be polarized the hair so on that depolarizations is going to cause uncreative the intracellular calcium concentration. Once intracellular calcium concentration increases. That's going to allow the release of neurotransmitter things on glutamate, which will then allow electrical impulses to be propagated through out the accents throughout the auditory nerves, up to the auditory cortex in our camp or a low on. That's how the sound wave is converted into an electrical impulse so that our brain is able to process it. I don't know if that made much sense. If you want me to repeat it again, I'm happy to just put it down the chat so we know that the end of Coke your potential is important so that potassium can be Dr Driven into the hair cell and allow calcium concentrations to rise and allowing your transmitter release. But there's also another way that these potassium channels open up on the hair cells on. It's by the movement and the vibration of the basal remembering. So what happens is when the sound vibrations reach are oval window of the cochlea. It's going to vibrate the basal or membrane, so it's gonna cause it to move up and down, which means that these hair cells over here going to move up and down as well. So once the hair cells touch the tip toe really membrane, they're gonna be potassium channels on the surface, off the hair cell that will open up. And that's going to allow potassium to move in on. Allow again intracellular calcium to increase, allowing your transmitter release, and then allow the impulses to be propagated along the auditory nerve up to the auditory cortex. Okay, Um, yeah, Okay. Someone asked to repeat it. No worries. Okay, so basically, we have our share cilia or hair cell. Over here, the bottom of the hair cell is immersed in sodium corridor, sodium, constant sodium. Bridge concentration on the top of the hair cell is immersed in potassium. Okay, so this eye on a different station or I own difference is about 80 millivolts, and it's referred to as the end of copy of potential. Now, this endoscopic, your potential is going to allow potassium to move into the hair cell on the influx of potassium into the hair cell is going to be polarizing, which is then going to cause calcium release. The calcium inside the hair cell will build up to a point where it'll allow the neurotransmitter to be released. The main neurotransmitter of the CNS is glutamate. And, um, this neurotransmitter release. Well, don't allow electrical impulses to be propagated along the auditory nerve to the auditory cortex in our camp or lobe on. That's how the sound is gonna be heard. Yeah, just to clarify against our city A and hair cells mean the exact same thing. Okay, right. I hope that made sense. And that just moves us onto the last life. Which is Tony. Toby. So, Tom, therapy is basically, um, the distance along which a, um along which along the basal basal remembering travel depends on the frequency of the sound. No, we are told all the time that the higher up, the basal remembering a sound travels the lower their frequency is, but I never really understood why that was on. The reason, actually, for it is because the basement membrane that's closer to the ear is stiffer as opposed to the basal. Remember, that's further away. So since the business membrane is quite stiff closer to the ear, that means that higher frequency sounds are able to bend or vibrate. That area, where, as lower frequency sounds don't have enough power. So lower frequency sounds will have to travel to the top or further along the basically remembering to the more flexible regions in order to vibrate them. Which is why the lower the frequency of the sound, the further off the basal remember in your travels. Okay, so we have reached our copy. A. We know what happens in the cochlea, and then the sound waves are then going to reach a structured under the superior A liver, a nucleus over here, that so this is mainly responsible for localization of sound, and it's going to compare the input of sound received from the right here in the left ear. Okay, after a disappear older brain nucleus, it's going to travel up the lateral. Um lemniscus and reach the inferior colliculus. The inferior click lie is mainly involved in allowed the loud auditory reflects, which is basically when you hear a loud sound and turn to it. Okay, um, it's also good to know that the superior colliculus is involved with the visual reflex. It doesn't actually have a role in here, but yep, superior, quickly visual, inferior, collect like loud auditory reflex. Once it's past the inferior pellicula it goes, It travels down the medial genuflect nucleus all the way up to the thalamus on both elements. It be just, you know, the auditory cortex wherever it needs on. But that's where our sound is processed. It's also good to note that, um, all the senses passed through the medial geniculate nucleus except for olfactory input. Right. So just to recap what happens is, um, Sound is gonna travel through the superior liver enucleate. It's where sound localization occurs, so the sound is compared between the two years. It then travels up the lateral lemniscus into the inferior colliculus, which is where the loud order to reflex occurs. So if you hear a loud sound, you're gonna turn your head to it, then the sound waves traveled to the medial geniculate nucleus and then up to the thalamus. And then it'll go to the audition quartets where it'll get processed. Perfect. So I hope that was useful. That is the last of my slides. So this is the last SBA. If half you could just put the pole up, we'll give the people a bit more time because it's quite a big one. It's up cool. Have most people answered or 45%? 46? Okay, I think. Okay, that's that's good enough, I think. Right. So what's the majority? Mister? Said options. See? Perfect. You guys are absolutely correct. Um, just to recap again. What happens is it reaches the nerve, which is a superior older break nucleus where sound localization occurs, travels up till actual m diskus to the inferior colliculus I, which is responsible for the loud auditory reflex into the medial geniculate nucleus up to the thalamus, and then the auditory cortex. So perfect. That is the end of my slides. I hope that's been useful. Um, again, if you guys have any questions, you can put it down in the chat. Yeah, We'll have a five minute break a swell. Um, but yeah, I think you guys so much. Stop sharing. No. Yeah. What time do you want to be? Back pounds. Um, so you say at eight. Maybe. Yeah, because it's that that we have time. Yeah. So, um, we'll be back at eight for past presentation. Just get it case. Hi, everyone. I hope you enjoyed the session so far by ST mine. My sides basically in a focus on the pathology of what Sweets already said, So far so far. So I'm gonna covering the runners. Webber's test. The cochlear implant, facial nerve, a lesions memory and then memory lost dementia. The outside ms specifically the marker on before mycology as well. So I'm going to get into it cause it's quite heavy. So three to talk to about hearing so far. So I'm gonna start off with an SBA. So the nasal one of those test it's performed on a patient with impaired hearing on examination. His test is positive for both is on the website. Has sounds heard in the midline. So if we could just launched the polls sure, if you don't know, the next few slides will explain things quite well. I think Just gas cards. We can't see who said what. So uh huh you can honestly get any of the options. Well, I think I'll just leave it there The case the most. It's kind of mixed between and be, um, so I'll explain the answer. Why it's trying to change slighter. Explain why it's actually a so first of all I'll talk about what conductive and censoring urinal hearing losses. So I've made this table so because he conducted here in Los is hearing loss duty issues with the external accused of May Test and the ossicles. So, for example, if we have a blockage that could lead to conductive who lost their sensory neuronal, it has the neuro in the names. So if you just think off nerve damage, that's usually what it's caused by. So conductive usually is caused by stuff like perforated ear drums. So if you have a sudden pressure increase that from course someone's ear drums to first. Well, oh, perforate. Sara's are tightest media's. I know that this was something we had a lot in first year. So this is when this build up of fluid in the middle ear and that could be due to a blockage off the Eustation two. So this is really common in Children, and you might have heard of a device called a gram. It's people might have grown it's in, and that said, to relieve pressure. But there is some debate whether it works, So it's up to you guys to see whether you believe it or not. But there's also auto sclerosis, so this is just basically calcification off the oscal's. So particularly the stapes and the round window. This can lead to conductive hearing loss on. We tend to think that convictable, as opposed to censor in urinal, which is usually permanent so sensory neuronal is usually caused with aging, so high frequencies can't be heard. A swell and we call this price Becuse is we'll hear the word a lot throughout whenever we talk about age related hearing loss. So we just call that press suck use is, um, so usually elderly people. You need to shout when cause they will need to have a higher decibel or higher intensity of sound to hear the same frequency as younger people would. So that's why you might need to raise your voice because of presbycusis is, um you can also have noise induced hearing loss or you just called. And I hate tell. So this is just damage to her cells that can regenerate. Uh, you can also actually lose, um, your hearing due to some drugs you take. So these are called auto toxic drug works. That's congee and said like ibuprofen struck to my sense, um, you know, by side on also, like other chemotherapy people, are drugs like a cyst platin on other diarrhetics that can affect the kidney. A swell. So I've just done a summary off the renascent Webber's test. So what we do in a running nose test is your place a 512 hurt to to in for Fox? And remember the 512 heads on the mastoid process, which you can feel on the back of your ears. Just that bony prominence. And then you'd say, Let me know if you hear the sound and if you could, when you can't hear the sound anymore. So after you trying it, you put it there and they'll say, Stop. Hopefully if you hear it on when they stop hearing it, you move it to the front. So, um, you have the tuning book to the front of the air, and then once they stop hearing that sound, you ask them, Can you hear it? And if they can, you call that a positive test. So a positive test would mean a conduction is better than bone conduction on. This is quite normal in hearing a Z Well, so no, normally conduction is better than bone conduction on I. I like to remember this because normally add travels through the air into our um it can also just around the air condition. Air condition is better than bone conduction on relief, but it could also mean sensory neuronal hearing loss and negative run. A test would mean they actually think that behind the ear is better. So in that case, bone conduction would be better than a conduction, and that would be conductive hearing loss. So with this test, we still don't know whether it's normal hearing or sensory neuronal Felicia. Then we do a Web based test. It, in a weather's test, say they had, um, love a loss of hearing on this side. Then we'll strike the tuning fork, which would be 512 hertz and place it in the middle of their forehead. And then you ask them, Where do you hear is in the center is on our Which side do you hear it? And is it the left or right? So we trying it. And then if it's sensory neuronal hearing loss, it would go to the unaffected. Yes, so if we think after the redness that there's a something wrong with this year, if it's sensory in neuronal, it would go to the opposite side on. If it goes to the side, that's effective. We would say it's conducted hearing loss. However, some people would say that here in the middle, and that usually just means they have a symmetrical here in. So that's that's usually normal or they have hearing loss on both sides. Um, um, A good way to remember it is conducted. Hearing loss is when bone conduction hearing is emphasized. The bone conduction appears louder than if anyone seen the new models. Doctor Strange movie. If you think of the tuning fork in the head, I just like to remain as weather. Is that well, um, so this is an audio um, Grande so you can see that human hearing tends to be between 20 huts to 20 kilohertz. This is not in the grafts. It can see. It goes from hurts to kill hurts without, like a linear progression. So just keep an eye out for that. But infants that can actually hear slightly higher than 20 kilohertz. But after a few years, they as you age, you lose the high frequency sensitivity. So then, as mature, it could actually go down to 15 to 17 kilohertz. Here. I've got a lighted A thing that says Hearing threshold. So this is just the sound level below which a person's here as unable to detect any sound. So for adults, this could be zero decibel, uh, decibels. So decibels. It's just the intensity of sounded so much earlier on. This could be between 0 to 15. Usually, although the threshold classifications with somebody who is hearing impaired would be if it's 25 or below um, Syria. So just keep just run by 20 to 20 kilohertz. So this is, uh, order going to concede that carried out when you basically ask a patient to listen to a sound at a certain threshold and are certain pitch and decibel. And then you just plot the graft a different pictures to see where they are so normal. Hearing you would usually have you be able to hit the soft noise is and you'd be quite consistent throughout. Say they can't hear it. We would increase the decibels until they can. And then you plot at what point they can hear it. So say somebody has mild hearing loss. They can hear it, but we had to increase the decibels here. It would go down the y axis. Um, yeah. So there's basically this is how you'd Portis one with worsening hearing loss would be down here. This is just I put some icons as references, so dog's bark would be here average speech level and be about 60. Uh huh. On a clock would be here pianos and a sore would be down here. So this sort of a quiz, So can anyone tell me what type of hearing loss they think this is? So in this graph, sound cannot properly conduct through the out there or middle year at bone gap so greater than equal to 15 days, but on decibels difference between a conduction and bone conduction. So does anyone know what type of hearing loss this is? I can't see the chat. So three. Could you just read out? Anyone said anything? Yeah, I'll beat up the chat. No one said anything in I do it, uh, Carry on said. This is conductive hearing loss of conduction Darsch olds being 15 desk girls are better than their conduction. So just around the conducted hearing loss, what did I say? In terms of the relationship between Aaron Bone conduction? Can you put that in the child? Is our conduction or bone conduction better? Someone said, Eric, conduction is better. Um, one said bone conduction. It's the upset. So yes. Oh, bone conduction is better in conduct and I can bet that conduction is better in sensory neuronal. But some people could have mixed as well, so you can see they have bad hearing loss in both. I've got another quit. So you guys, that's a common example in that comes up so interpreting these grafts, So can anyone tell me what type of, um, hearing loss? This could be. It's either conductive sensorineural all mixed. Uh, everything. Sensory urinal. Yeah, perfect on the next one. Someone said Mixed. Yep. On define a one is conductive. Eso Just just make a note of these graphs and the general trends. They tend to look quite similar, So I'd say Just remember them as the shape. So, um, we might have heard that loud sounds Concordes deafness. So you have temporary deafness. The loud sounds for an extended period of time to say you stood right next to a speaker. A concert this conclude to temporary deafness on this could last for a whole day. So, you know, some people say, Oh, I can hear the ringing in my ear after they sound next to a loud sound for a while. So that's like a buzzing sensation, and we call that tinnitus on it. Can you can be caused you to have cell damage or even you can even get it. Like I said, do toe too. Toxic drugs. It can also because due to a wax buildup or even auditory nerve lesions, um, so there are many theories as to why, um, loud sounds Concordes. Definite swon that I thought was interesting was that metabolic overactivity in May cause mitochondrion to overproduce freeware, but because that can lead to damage on so you can have tinnitus on. Do you also have pulsatile tinnitus? Tinnitus is the ringing or the buzzing in the air constantly, whereas pulsatile is a sound produced from blood flow through the Yes. So you're here, the blood pulsing through. So he called up post a tile. Tinnitus. Um, treatments would be masking the noise of certain drugs. Come, course interest. So you'd stop giving those drugs as well, so personable, other and said the ones I mentioned earlier a swell could cause that so now we're gonna talk about cochlea implants. So a copy implant is a device that's placed over the air when which can be removed. And this device basically splits the ordinary information into different frequencies. So for those individuals who can't do it themselves, this device on wood due for them, So these are basically, um when we went basically, they used When an individual's hair cells are defective, this's means that it's not conductive hearing loss or 10. It tends to be censoring your own. Also, cochlear implants tend to be used in sensory neuronal hearing loss. So they basically activate sensory neuron directly using a coil that you can see here. So here is an a cochlearia without an implant. And here you can see a coil that passes through and winds around the completely. Yeah, here on this coil passes through the cochlear on disrespect ever would then sort the sounds you here into different frequencies. And Astro said earlier on the father, it sounds on further. A sound travels through a cochlear the different frequency would here, So this, um, this implant would then segregate these pictures. So let's send some further down to have a lower pitch on. Send some less further down the coils here, higher pitch a second, see the center. It doesn't reach the center, so people with cochlear implants might struggle to hear low frequency pictures. So that's just because the cold doesn't reach the student center. The cochlea. Um, so this is this can occur with a hearing loss with it. Age we called presbycusis is on. You could do to damage of the steri scyllo struck stereocilium, which cannot regenerate. No. So I haven't sp a So we, um Now everyone should be a bit more confident with the remains and Webber's, um, so really it is and where this test is performed on a patient, um, with impact hearing on examination, Run a test. It's part. It's positive On the left, it's a negative. On the right here and in the weather's test sound is head on the right here. So what does everyone think it is? I think most people are getting it. So remember, I'll give a clue. So remember conduction conductive hearing loss is when bone conduction is better than at conduction on. But, um after I thought would be a negative test. And okay, sensory neuronal hair loss would lateralize to the unaffected here. That's not a clue. This is a tricky one. I think if you just look at the slide, one more time should be fine. But I leave it there. Think so. It is a 50 50 split, But correct answer is actually see, that's just it. Because if you look at the question a run, a test is positive. So in that case, our conduction is better thing Bone conduction. Oh, I think this is Ah, miss taking the question. I see. I'll correct that. So it is Ah, censoring urinal. So in this case, I'm in a mistake in the question. The in this case a positive test with me and add conduction is better than bone conduction, so that would mean it's sensory urinal. But I'll correct this question, and I upload the slides and put the correct answer right afterwards. But on shout out to the, uh, skis e session on. This is a really good table that I ended up in the Oscars, the cranial nerve session. So if you just follow this, it should be, um, quite clear. So I've got an audiogram question as well. So if you could launch the polls, I think most people have got it. So a patient comes into clinic after noticing there, struggling to hit to normal volume on, they're having to blast the volume up to watch anything. So they request on Audio Gram. You can see it's the higher frequencies that they're struggling to here, here. So, um, I think I tend to pull that. So the correct answer is pressed a Q cysts, which most people got. I'm glad that most people got that so facial nerve palsy. So this is something that might come up quite a few times, so you can see here we have two nuclei. So you have an upper motor neuron here, sit on. Everything coming from the dark green is an upper motor neuron and it does he hear These lighter green ones are lower motor neurons on This is the face of split up into the eyebrow areas on the cheek areas. I'd say, um, so we can have a lesion. Is this could be due to a tumor of the compressions in the facial nerve so you can have it here blocking the upper motor neuron and or here blocking the lower motor neuron. Now, before I go into the table, I'm just going to show you this diagram here. So you take a closer look at this diagram. Um, the forehead here is not just supplied by this lower motor neuron, but it's also do ulcer plied with this upper motor neuron. So even if we had a lesion here, it's still supplied by this lower motor neuron. So that's why here we would have forehead sparing, so let's go through the table. So just follow along with the diagram. So on the affected side, um, affected side for an upper motor neuron would be the opposite side, whereas the the affected side would be on the hips. Electoral side on the Lomotil you were on so in a couple multireligious and you'd get lower muscles of facial expression affected on the in the lower margin and get the pack on the lower muscles. A facial expression affected in an upper motor neuron lesion. You can get very various other symptoms as well. So, um, in a low mutineer and yet incomplete I closure Hyper accuses loss of taste to the anterior tongue. A key thing that a patient my present with would be dry eyes because, um, in the lower motor neuron, we can't contract her eyes off tractor eyes so that inability to shut their eyes with mean that they would develop dry eye syndrome. So that could be a common presentation. Um, we would usually call the lower motor neuron a lesion. Bowels. Palsy. Um, so, yeah, it's going to memory. So this is quite a big top. Yeah, so memory could be split into short term and long term memory. So let's focus on short term memory first. So you have short term memory, which you have, which is, but have been Descents, three memory and working memory. So it's going to go through short term memory first. So sensory memory tends to last two seconds, and it's divided into iconic, which is visual search remembered. I I connect Echo it, which sends to be sound and haptic, which is touch, um, um, So basically, a memory is moved into the working memory when which lasts about their two seconds on deacon store between 5 to 9 items in your working memory. When we think about a memory again, it moves into a working memory. So that tends to be how something moves into working memory. But that's only if you think about the memory again. Um, so creating a memory involves our hippocampus. So this isn't the prefrontal cortex. I think three mentioned this earlier on Do this. Um, focus. Focus is into either sounds. So this goes into the for a logical loops that think of foreign, a logical so phone and sounds or the visual gauge visual spatial sketch card, which is image. It is on the episodic buffer, um, which tends to be when you so see eighth a time with an image. Um So when you repeat, um so when you so when are working Memory is in our short term, it's made a part. Visual is made of our visual skate visual spatial step pad on. This's basically a temporary holding off Visual information you have are episodic buffer, which isn't the relay between long term and the Central executive on you also have on a logical loop. This is just temporary storage on the hassle of order. Information on all three of these are coordinated by thing called a central executive. This basically controls the system, so the Central Executive stores it into our long term memory in the neocortex, which is in this a perceptible a cortex. So, um said that again, the Central executive moves the visual schedules, but vicious business fatal sketchpad, the for a logical loop on the episodic buffer into our long term memory. And then, after enders are long term memory, it can either go into a non declarative, implicit memory or declarative explicit memory. So explicit tends to be our semantic memory. So I'm squinted the next bar so tense about semantic memory. So this is our general knowledge on are episodic tends to be on an absolute events. So things we remember as a moment in a a memory implicit or non declarative tends to be in the cerebellum or the basal ganglia. And this tends to be motive, movements or habits. So it's are procedural memory, so about long term memory a bit more so we have a declared to the non fluoride, which I just talked about. Declarative goes into semantic and episodic and non declared two goes into procedural and basically condition, so our phobias would be an unknown declarative. So I'm going to talk a bit about encoding on memory. Really retrieval. So long term memory is stays in the hippocampus and largely associated with the medial temporal lobe structures. So basically, when you have a stimulus of information through the five senses, say our vision, our hearing are smell are taste Now touch info enters the sensory memory storage for a short period of time, 1 to 2 seconds for our visual, or 2 to 4 seconds for auditory. It is then encoded into a short term memory storage for about 30 seconds, and this could hold on Lee 5 to 9 items like I said earlier. But upon rehearsal. So when you repeat something, you activate certain neurons onda stronger than your arms, and the sign ups has become. You get a thing called synaptic plasticity, so it's basically gets included into a long term memory. That's why revision works. Basically, I'm presented with a trigger. The long term memory storage will send information to short term memory toe. Allow you to respond so anything be when information isn't used. Sign Actiq Pruning occurs, and this information basically gets removed. That's why, uh, if you revise something and then after a long time of not visiting again, that information can be lost again. So that's due to sign up to pruning. So the hippocampus allows come version off. Short term, too long term memories. So remember that for a case I'll talk about in a second. So initially it's stored in the region as episodic memory. However, over time it moves to the neocortex as a semantic memory. So semantic would be like general knowledge is, um, so there's two types of them read that we can think of this recent memory. So memories from recent immense and it also have remote memories of memories from past events on. So remember I said about the hippocampus being involved in memory on short, tempting, long time conversion of memory. So you might have heard of a case off. 10 remodel is and and so basically, he had his hippocampus removed by doctors. This meant on it caused him to go only have working memory in the short term. This meant that his memory only lasted 30 seconds, so he would have anterograde amnesia. I'll talk about that in the next few slides. But Anterograde means, um he can create new memories. Basically, however, while he couldn't form new long term memories, he still had that remote memory as this was stored in the neocortex. So I just got a question here. So if everyone could vote on the pole So on a medical journal, you noticed that I said Gene is a strong respect for Alzheimer's. Which Gene was this referring to? Okay. Can see most people have got this. Don't worry. If you don't know the just guess and it's fine. Okay, I think I'll stop it. That So I think most people went to D, which was indeed, um, the correct answer. So you have the April you 14, which I'll go into in the next three sides. So, um, let's talk about demand. Sure. So dementia just put Giant umbrella is an umbrella term on is basically, um, a bundle of diseases that impair cognitive function. So it could be amnesia, forgetfulness, and that can occur in dementia. So this it's two types of amnesia. There's retrograde. That's the inability to recall long term memories. Are Antara? Grade? So this is the inability to strong new long term memories on the causes of magnesia. Can be temporal lobe surgery hypoxia to the region. I'll go into Kostikov syndrome in a few seconds on. Outside, this disease is the most common cause of dementia. So, um, so outside Ms So before I say that dementia. Just remember, it's a numb brother turn. So it's a chronic issue, and it's carterizing various different impairments or cognitive function, not just memory loss. It could be language issues, orientation issues did real Delirium is well, Uh huh. Okay, so outside murmurs. So this is a really common form of dementia. Alzheimer's. It's just the buildup off Byetta amyloid plaques. I'll talk about these in the next few slides, but on also towel proteins in the brain. And there's basically two think Call me Neurofibrillary Tangles or NF tea is not the currency type. Um, you can also have dementia off the Lewy bodies, so this is just deposited proteins that reduce our neuro transmitter, release off dopamine and also acetylcholine, and it basically causes symptoms that are similar to park in cents on this complete a cognitive decline, but symptoms vary and depend on where the Lewy bodies deposited. You can also have vascular dementia as well, so vascular tend to be small, undetectable hemorrhages. And this concludes to motor issues. I actually has more motor issue is the non sign on Casa Coughs, which I mentioned earlier, So this is actually a reversible form of dementia on. This is because off be one Bittman, like a like off the one victim in absorption. Be one also is called. I mean, so if you get an exam question, it might say be one or thiamine absorption not working. So this is due to chronic alcoholism. So there's a link between alcoholism and lack of B one absorption, and the reason this leads to dementia is because vitamin B one is needed for co coenzyme a production, the links reaction. So without be one, we can't have the links. And hence we can't have the Krebs cycle. Um, this can also occur in Vaniqa is encephalopathy, a swell on disk? Uncalled confusion and loss of coordination, otherwise called ataxia? Um, government has many different things in place to help families and individuals with dementia. So there's memory cafes for people with dementia to talk to it to their family support. There's also financial support for low income people on career allowances and also, like caress, can get financial support as well. So how does the age of the brain relate? Um, age, really to our brain function. So as we age our front lobe contract on. But if it's too much drinking, we would say that's pathologic pathological. But it most people as they age that brand will shrink. Um, especially the frontal lobe. This means that working memory could get in pet, um, hippocampus shrinking shrinks slowed, but then accelerates as you get older. And this means that episodic memories impaired parietal temporal and occipital lobe shrink slower. This actually means we can slightly increase in semantic memory, so on. We send to say all of the forms of memory except semantic decrease and semantic. Like I said, it's general knowledge. So I guess you could say all the people know wise because they have increased general knowledge. You're also could have your ventricles expanding in healthy aging white matter. Anterior regions also decrease, and this can explain the decrease in protesting speeds. Swell. Um, so how does it affect memory retrieval? So I, uh, have a look at these ventricles so this you can see it. They expand. Um, so this side is a normal brain and this is side with outside mistaken city. It's smaller with more dilated ventricle was a swell. So remember, I said to normal aging shows an increase in semantic memory, but a decline in all other forms of memory. So Albany people tend to have a procedure memory a longer as well. So there's two main hypothesis, or aging nervous system causes slowing off neuronal transmission, and hence that can slow processing speed in the White Matter tracks. And that can also be shrinking, like I said earlier of the frontal lobe. And that just affects memory. And hence we can't inhibit irrelevant information, so that can lead to memory loss as well. So something's decrease. Some things increase episodic and working memory decreased. Semantic, procedural and classically conditioned response is either increase or remain the same. Different things can also increase ones memory loss, so you could have risk factors like smoking, diabetes, tease other information and also genetic risks. So people who have familiar with the A p O E four gene the upper gene have a high risk about Sinus. A chronic and cognitive reserve is our brains resist and Stamets, and we can increase that with an active lifestyle, good education, good diet, social stimulated stimulation and also those who have genetics that might protect them. So I'm gonna talk about Alzheimer's and the particles ology behind it. So, um, in the membrane. Well, first, there's two types of all time Mrs Bride sporadic, So this is the most common. So it's late onset, and it's probably due to a combination of familial on environmental factors. But however, some people have familial outside ms that's when they have this dominant a PPO. Before gene inherited that can speed of this disease. So in the membrane, this is just a membrane off the cell in the brain, there's a protein called amyloid prick Curse, a protein that I've just put here. This protein basically helps Neurontin to grow and prepare if it gets broken down. That's normal, actually. So if it gets broken down, normally get used and then recycled over time anyway. So in a normal human, all normal without outside mints would have enzymes called alpha and gum Mr Creek taste, which actually break up our, um, a load precursor protein into a soluble peptide. Um on. Then normal microtubule would be formed, and these would not be tangled. But say someone has a diseased individual with Alzheimer's that be to secretase might not work with that gamma secretase, so this would then lead to nonsteroidal real protein called amyloid beta to bond together and form a beta amyloid plaques. To remember. These plaques are formed, so these plaques then would get between these you're on's, so the urine's would. Then this would affect neuron signaling, cause these plaques would get in between them on it also causes influence patient and effects the surrounding during a swell, so beta amyloid plaques can also activate kindnesses than these phosphorus phosphorylase tower proteins. This basically just causes clumping, um, untangling. So these urines have trouble functioning, and they basically undergo apoptosis, so tangling leads to apoptosis. Um, so an issue with this it would cause the brain to a trophy on the ventricles would then in large. And that's why in the brain, without assignments, they had analyzed ventricles, and this basically affects the normal functioning off the areas of the brain. The's flats can also weaken blood vessel walls and increase the likelihood of hemorrhages in the brain as well. As this progresses, it would present with anterograde episodic memory loss as well. So as it starts in the medial temporal lobe, that's where the the integrated absolute memory would be lost on as it spreads. It can actually lead to semantic memory getting impaired as well. It begins to affect other arrows of the brain so it can spread to other parts of the brain on. Like I said, earlier, risk factors for outside must be smoking, and diabetes is well, there's actually a relatedness between hearing loss that I mentioned earlier on the development off out time Mrs Disease on that could be due to less stimulation off or three pathways. So this is the mental health capacity Act. So when um, health care professional assesses someone with cognitive impairment such a, um, worsening memory loss, they have to consider. Can this person make students about that car? So you can So before we let thumb or don't let them make decisions, But we have to check things principles from the Mental Capacity Act the principal one would be. You can't assume someone likes capacity until they have shown otherwise. Principle to be. You cannot treat someone as if they don't have a question till you have taken steps to help them do so without success. Principal three person is not to be treated, treated, unable just because they make it on my suspicion. So just because they say they don't want treatment, even though it's very beneficial for them, we have to respect that. It's that choice puts before anything you do as a doctor. If you have determined individual lax capacity must be in their best interest on Pitiful five would be. Before you do something to someone, you have to look at other options that provides him with a relatively similar level of care. So, um, we might heard of a marker. So Marker basically is a Montreal cognitive assessment and basically assessing someone's level of cognitive impairment. So this test the cognitive abilities off the individual. And if they have a score off over 26 that's usually normal. If it's around 22 we would consider them had to have mild cognitive impairment on below. 16 would say they might have outside, um, Ms Disease. So finally, I'm just gonna go with some common drugs that you might hear about, um, and topics so you might have a reversible acetylcholinesterase inhibitors so reversible and basically this drug reversibly inhibit acetylcholinesterase. To increase the half life of this, it'll co the sign Actiq left. So you might know that acetylcholine is a common signaling signaling home, and that basically is used in throughout our brain throughout neurons. So does, uh, inhibitor called acetylcholine ashtrays, which breaks down acetylcholinesterase thing, the see No. So people with memory loss might have less accidental curly in anyway, So if you give them something that stops the breakdown of acetylcholinesterase, more acetylcholine present for them to send that signal. If that makes sense, so you have done donepezil so provides a slight improvement in cognitive function. You have gone to me and mild to severe Alzheimer's disease is symptoms you have reversed of the rivastigmine on mild to severe Alzheimer's disease. Symptoms well on D receptor Blockade off the negative Nicosia orange liquid Ellik acetylcholine receptors. So inhibits and MDA receptor is preventing your own a lot death, and it basically inhibits nicotine receptors, which leads to the up regulation off nicotinic receptors. Expression. Enhancing the effects of a sutel colon. So individuals with lacking acetylcholine they can enhance the effect of the season colon that's already there or prevent the breakdown of the CT choline. So would have memantine a more direct to sit in time. Severe Alzheimer's symptoms. So that's just end of my presentation. Uh huh, yeah. So if anyone has any questions, they can put it in the chopped. Uh huh. So she we started the Recording Street