Transcript for:
Key Concepts of the Central Nervous System

to the computer. All right. Recording of the lecture has begun. So this is of course the rest of the central nervous system. As you guys recall, the central nervous system is going to be the, sorry, there we go.

Minimize, minimize, resize. This one will just place more. Did this just cover your PowerPoint? Can you guys still see the whole PowerPoint?

Yeah. Okay. Hold on.

You see that? Okay. And nothing's in the way of that first image? Like not my face or anything?

I'm not in the middle of it? No. Okay.

I just want to make sure someone else is coming in. Lisa is waiting. This is all like the new admitting thing.

This is only just my second lecture with new people coming in. All right. So there we go. All right.

So for people who are coming into the meeting, it is being recorded. If you would please mute your microphones during the recording, you can unmute them if you have any questions, but keep it muted. That way any of your background noise doesn't interfere with the recorded lecture.

This is part three and four of the central nervous system. And as you guys recall, the central nervous system is going to be the brain. Okay. So with the brain, the spinal cord, oops, click.

Oh my God. Now my thing's not forwarding. Hold on.

You gotta love technology when it works. If not, I'll just... Can you guys see the next slides?

It's not moving for me. Gosh, darn it. There we go. Sorry.

There we go. All right. You guys see the next slide now? Somebody had to unmute to say that.

Yes. Everybody's like, yeah, sure. You gotta say something.

Okay. So let's go back to some things that we already know. We know that the central nervous system is the brain and the spinal cord.

We had been learning about different parts of the brain. It's composed of the left and right cerebral hemispheres. We know that there's contralateral control with the body. So the right cerebral hemisphere controls the left side of the body.

And then the left cerebral hemisphere controls the right side of the body. We also know that the cerebrum is the site of... The conscious mind, when we look at the cortex, which is that outer gray matter that surrounds the cerebrum, we know that that cerebrum is about 40% of the 83% of the cerebrum's mass, like the brain's mass. So about half of the cerebrum is dedicated to the things that are associated with the cerebral cortex side of the conscious mind. So anything you do on purpose, right?

Anything that you've thought out, carried out, are aware of, awake, alert, et cetera, those are all... things that you do on purpose, right? You have to be conscious, which means awake. The reason why I bring that up is because we're talking about these widespread areas of the brain. And whenever you heard limbic, remember I told you, you think of emotion, emotion, emotion.

And then with the reticular formation, we have this reticular activation system. So it's called the RAS, R-A-S. And that reticular activation system is when your brain is alert and awake and aroused.

And so when a person is asleep, it's a state of subconsciousness. And when you are asleep, the reticular activation system is hampered or it's dampened or inhibited. But sleep is more than just the inhibition or the dampening of the reticular activation system.

Sleep is a full neurological process. And we'll talk more about that in a couple of, well, quite a few slides. Okay, so limbic. Emotion, emotion, emotion. Emotion, emotion, emotion.

Emotion, emotion, emotion. Okay, so the limbic system. When we talked about...

the three association areas that cover large parts of the brain. We had the anterior association area, we had the posterior association area, and we had the limbic. Another name for the anterior association area was the prefrontal cortex.

That is the one that's responsible for your judgment, your personality, you know, like being able to think through the consequences of your actions. That's the limbic system has ability to kind of override what the prefrontal cortex would be in control of. So a person who is under like emotional distress may do something that's out of their character.

At some point in time in your life, you probably said or did something that you regretted because you said it and did it out of anger. So limbic system, limbic system, limbic system. All right.

So again, it says the emotional brain, right? So the affected brain, you're affected by things that are happening. So the amygdaloid body recognizes anger, fearful facial expressions, assesses danger, and helps elicit that fear response. The cingulate gyrus plays a role in expressing emotions through gestures, you know, like you get that kind of stuff, and helps resolve mental conflict.

So all they're showing you is kind of how it reaches like other areas. So you're looking at the, like a hologram, right? So you're looking in the inside of the brain there.

And I'll take my arrow. Oops, I can't take my arrow. Okay.

Yeah. So if you look, it just kind of reaches various parts of the brain. And the hypothalamus, as you guys recall, was the boss.

The hypothalamus is going to respond to emotional distresses. So when you get angry, your blood pressure increases. When you get angry, your respiration increases.

And remember, that's the hypothalamus. Your heart rate even increases. So heart rate, respiration, et cetera.

And then on the prefrontal cortex, so see where I've got my arrow here? That's your prefrontal cortex. So that prefrontal cortex, again, is like the one that's for your judgment, thinking through the consequences of your actions, that type of stuff.

And emotions can override the prefrontal cortex's function or job. All right. So the limbic system also puts emotion to odor. So like when you smell a skunk, you're like, oh my God. that smells so bad.

And then like, you're upset about it. For me, that smell is usually my son who has toxic gas. And whenever he passed gas, I'm like, did you have to do that in here?

Like, seriously, I just get so angry. And then like I said, the hypothalamus relays that. Hypothalamus, again, the boss that it is, it can play a role in psychosomatic illnesses. And I think people may be aware of what psychosomatic, if we broke down the word itself, you know, the soma is your body, right? So somatic is referring to the body and psycho would mean that it's in your head.

So what happens is, is that you guys know the mind is a very powerful thing. And there are people who think that they're having a heart attack and then their body will physically mimic the signs of having a heart attack. So that's psychosomatic.

Isn't that crazy? It's kind of a cool thing, but still it's weird. So again, limbic, emotion, So I already showed you in that picture where they showed the brain as a hologram.

And it says that the limbic system, of course, interacts with that prefrontal lobe. So again, prefrontal lobe, that's your personality. Allows us to react emotionally to things that we consciously understand to be happening.

Makes us consciously aware of emotional richness in our lives. So having emotion is a good thing. We're supposed to exhibit emotions.

But as you know, there are people who are diagnosed with bipolar depression. And what that means for them is that... Their highs are too high and their lows are too low.

And so what we do is we try to medicate them and bring them, you know, in between. The reality is, is that emotions, again, are part of who we are, our personality. So the hippocampus and the mygdaloid body ties memories to our emotion. In the previous lecture, I asked you guys to, you know, kind of think back to your earliest childhood memory.

And when you did that, sorry, I have to look down here and see if someone's coming in. And when you did that, I said that even though I didn't know what the memory was, I guarantee you it was something that made you very happy, or it was something that made you very angry, or it was something that was extremely traumatic. Whatever it was, there was a strong emotion that was tied with it. And that's why you held on to the memory.

So hippocampus plays a role in the memory and those emotions associated with it. All right. So that reticular formation system is far flung.

And all that means is that it reaches, you know, several places within the brain. So hypothalamus, thalamus, cerebral cortex, the cerebellum, spinal cord, so far flung, it reaches many places. And it governs the brain's arousal.

So like I said a few minutes ago, the RAS, reticular activation system, is alert, awake, arouse. And I kind of use alliteration to help you remember that when you get ready to take the test. So reticular activation system, RAS, think of alert, awake. aroused, right?

And when you are awake, you are aware. So awareness, awake, aroused, alert, that. Okay. All of those are A words. So all it says here is that it sends impulses to the cerebral cortex, which is the site of the conscious mind, and it keeps it conscious and alert.

I just like to use the A words because of particular activation system. Anyway, it filters out repetitive, familiar, or weak stimuli. And believe it or not, over 99% of the stimulus that we get is weak.

So it filters that out. It's inhibited by the sleep center. So when I first mentioned it at the very beginning of this lecture, I said that sleep is more than just the inhibition of the reticular activation system.

Sleep is a neurological process, and we'll get into more of that. But anyway, it's also inhibited by alcohol and drugs. All that means is, and you guys know this, is that there are people who have drank so much alcohol that they passed out, right? So they lost consciousness.

And then, of course, there are people who overdose, right? Take, you know, drugs. And even if they don't overdose to the point where, you know, they die, they can take so many drugs that they lose consciousness.

And then if you have severe injury here, you could go into a permanent state of unconsciousness, and that's called a coma. All right. So let's see what else is there.

Since it's about being alert and conscious and sending information to the cerebral cortex, it also plays a role in motor function. So the cerebral cortex, again, if you recall, there's a premotor cortex that's there and there's a primary motor cortex that's there. And it says all it does here is it helps with the movement, right? And then reticular autonomic centers regulate viscera.

So whenever you hear autonomic, think of automatic and things that run. automatically. So the ANS system, so viscera. Vasomotor refers to the vessels.

Cardiac refers, of course, to the heart and respiratory. So vasomotor, cardio and respiratory center. So it plays a role.

All they're doing here is showing you like those arrows. So that's what they mean by far flung. It reaches parts of the cerebrum and the cerebellum. You know what I'm saying? So it reaches, well, sorry, not the cerebrum, but all parts of the cerebrum.

They're not showing any into the cerebellum. but it reaches into the cerebrum where the motor cortex is. And as you guys know, the cerebrum and the cerebellum, which is highlighted here by my arrow, that's the tree of life, the arborvitae, the white matter.

As you guys remember, the pons relays, here's the pons, let me just say my arrow, the pons relays the information between the cerebellum and the cerebral cortex because both of those have motor functions. All right. So then all this is here is kind of a nice little review.

So they list. We already know that the gray matter is going to be non-myelinated fibers mostly. We know that the cerebral cortex is gray matter.

We know that basal nuclei is gray matter. And basal nuclei was additional gray matter that was scattered within the white matter of the brain. We know that the thalamus is the relay center to the cerebral cortex.

Nothing gets to the cerebral cortex without having passing through the thalamus first. So I called the thalamus Gandalf and I was like, you shall not pass. So that's the thalamus.

Then the hypothalamus is the boss. And they just listed a few things here, but this is your body temperature. This is your thirst.

This is your hunger. This is your, you know, visceral response to emotion. So increase of heart rate, rate of breathing. So when I say hypothalamus, I'm saying it's the boss.

It also has endocrine functions because it controls the pituitary gland, which secretes tons of different hormones. which you'll learn about in 2086. And then limbic system, emotion, emotion, emotion. So if you, every time you see limbic or think of limbic, say emotion, emotion, emotion, then you'll start to understand how when you're in a state of emotional distress, it can interfere with the prefrontal cortex. Then you understand emotions and you can smell things that make you feel a certain way.

Like lavender has this calming and relaxing, you know, feel that takes place to it. So again, you think of emotion and then you think of the fact that it has effect. on various parts of the brain because the limbic system reaches several areas.

All right. So when we look at the midbrain, if you guys recall, this is where the corpora quadrumina was, and that was four parts. So there were two superior caniculi and two inferior caniculi.

The two superior caniculi had to do with visual reflex and the two inferior caniculi had to do with auditory. And that's some of the midbrain. So it mentions them, but it didn't tell you what I just said, but you know.

it was there in the previous, wait, does it visual? And yeah, it does. It says that, sorry.

It's too far away for me to see. And I don't have my glasses on. I actually don't know where they are right now. Anyway. And then we have the pons, like I said, and it says the first thing there is like, you know, remember I said, location, location, location.

So the cerebrum and the cerebellum, why? Because the cerebellum is mostly motor control. Yes, I know the cerebellum does other things.

You know, neural imaging proves to us that when we're thinking or emotions are happening and We're going through logical processes that the cerebellum is also lighting up. So it's doing something, but it's mostly movement. And since it's movement and motor, it has to communicate with the cerebral cortex because the cerebral cortex is, again, the site of our primary motor cortex and our premotor cortex. So anything that has to do with movement and various parts of the brain, they have to communicate for each other.

So pons, location, location, location. Now, the reason why I'm reviewing it like this is because... I've said for the exam, you're going to have to know the parts of the brain and their functions.

And so while there may be several other things listed here, I'm highlighting things on purpose because as you recall, I write my own exams. The medulla oblongata, overlapping functions with the hypothalamus, respiratory, and then cardio, and then they said vasomotor. But I put vasomotor and cardiac together, and I just said cardiovascular because vaso is referring to the vessels. Cardiac.

is referring to the heart, and then respiratory. So it has overlapping functions with the hypothalamus, but then it has five functions on its own. Swallowing, which I always forget for some reason, so I do it first now. Swallowing, coughing, hiccuping, sneezing.

And vomiting. So that's gross, but it is what it is. Anyway, so make sure you know those, like on purpose. Let's see what else is there. And then the reticular formation.

This is the one we just talked about. So the reticular activation system. I'm just emphasizing activation because I want to go with awake and aware, alert, aroused.

So I want to use alliteration, a bunch of other words that start with A, right? So that helps you memorize it. And then.

the cerebellum, motor, motor, motor, motor, motor, motor. So it says that, and then it says, you know, some other stuff. Well, no, actually almost everything here is motor. So basically it's motor. When we talk about proprioceptors, we're talking about your ligaments and your tendons and your joints.

Well, that's how we move, right? It's attached to skeletal muscle, which is voluntary. So the cerebellum is, you know, playing a role in your voluntary movement. All right.

Now let's get into some higher functions. And See at the bottom of these ones that are listed where it says sleep and the sleep-wait cycle? It's me going back and emphasizing that the reticular activation system is what keeps you alert or awake or aroused and aware of what's happening. But sleep is more than just, remember, dampening of that system. So we've got language, we've got memory, our brain waves that we're going to look at it, EEGs.

EEGs are electrocephalograms, so electro is referring to electric current. like the head, so cephalic like the head. And we read those waves and I'll explain to you the importance of those waves and what it means.

And then consciousness, again, being awake, aware, aroused, that kind of stuff, and then sleep in itself. So we've already talked about the Wernicke's and the Broca's areas of the brain. The only reason why they're coming up now is because they're part of language and language is a higher brain function. Language is more than just the ability to speak, as you know, because Broca's... is the physical ability to control the tongue and the pharyngeal muscles, the skeletal muscles that are associated with producing language.

And the Wernicke's area is the ability to understand the written and spoken language. So we read, we write, we speak, and all of that is a part of language. So make sure you understand, again, Broca's and Wernicke's, two parts we've already gone over, and they're located on the left cerebral hemisphere for over 90% or about 90% of the population. Now, there are areas on the right.

cerebral hemisphere that are associated with nonverbal communication. So we've seen this picture several times, like in part one and part two, because we're talking about the brain still. That the anterior region that's dashed, and I'll try to outline it with my area, I mean with my arrow, that right there is the Broca's area.

And then back here, the dashed one, that one is the Wernicke's area. Okay. Now, memory.

We already know that there's emotion, right? That's associated with memory. So we have declarative. memory, which is what this lecture is.

So when I'm going over stuff and I say, remember I said this, remember I said that, you are relying on your declarative memory to come up with those names, faces, words, facts, data, the stuff that I'm providing. Procedural memory is a memory of skills. So learning how to play the piano and remembering how to play the piano. Motor memory is like riding a bike. It's true.

What you've heard. Once you learn how to ride a bike, you never forget how. So if you haven't ridden a bike in 10 years, 15 years, or whatever, you will be able to get on that bike and ride it again.

That is the motor memory. And then again, the emotional memory, it ties our memories to emotion. And we know that part already. All right. So we have short-term memory and we have long-term memory.

You're going to find out in this lecture why I do the things that I do. It's a little bit different when I'm lecturing from my home office. versus when I'm lecturing in class.

But your short-term memory just holds, you know, temporary, right? Just holds stuff for a short period of time. And that short-term memory is not going to be very effective when you're taking my exam.

That's going to be over five or six lectures that spanned over two and a half to three weeks, right? Short-term memory. Then you have your long-term memory, and long-term memory is actually limitless, which is awesome, but we've got to find ways to encourage information to move from short-term memory to long-term memory. And then again, you're going to find out why I do what I do during lecture. Your emotional state affects your ability to take short-term memory and convert it into long-term memory.

So it's best if you're alert. Recall, we meet at eight o'clock in the morning and I come in hyper and excited on purpose because if I came into class at eight o'clock in the morning, the way you guys come into class. we would all just fall over.

So I come in one, I like the information that I'm portraying. I love my job and I love to talk and then I get paid to do this. So this is awesome for me, but it's exciting material. It's applicable to our everyday lives. It's going to be used well beyond this classroom and not just to get, you know, to, you know, anatomy two and then get into your programs.

This is like real life. We have people that have, you know, things that are going on with their bodies. You have things that are going on with your bodies, any body. who is alive, has things going on with their body. And this information helps you understand that.

So that's why I'm so excited about it because it applies to life, living things. So it's best if you're motivated, surprised, aroused. So every now and then, as you guys know, I will say something and you'll be like, did she just say, and I do it on purpose. It may not have anything to do with anything that we're talking about, but I just say it just to get your attention. Because again, your emotional state is going to affect your ability to transfer information from short-term to long-term.

and then if you don't know anything about me you know this i am repetitive think about how i drilled muscle contraction into your brain i would come in and i'd say okay class calcium diffuses into the axon terminal what's an axon terminal it's the end of a nerve cell and then what happens acetylcholine is released acetylcholine binds to his receptor causes ion channels to open sodium flows in and potassium flows out That causes an end plate potential, which is localized change in charge that opens up adjacent. And I kept doing it. Like I would stop, they would mention something and I'd go back through it again.

And then I told you that you were going to have to know that information because skeletal muscle principle, right, of the contraction is going to be applied to everything else that happens in the body. Because the nervous system sends information to the effectors and effectors are skeletal muscle, smooth muscle, cardiac muscle and glands. Now, most of you said that in your head as I was saying it, because I've gone over it so many times that it's drilled in your brain. Hey, how about that? This Professor Evans, she might know what she's talking about.

And then we have association, tying new information to old memories. I do this all the time on purpose, but I laugh because I say, so as you recall, and you guys are like, did she say that? Has she said that before?

The reality is, is that if you forget the information, then it's like I've never said it before, right? It's long. It's gone. It's called, you know, it's data that's unretrievable because it's been forgotten.

The reality is, is that you can't possibly remember the things that you've forgotten because they're forgotten. We'll talk more about that too. And then you have automatic memory.

Oh my gosh. You just have a bunch of information that's stored in your long-term memory and it's just there. My husband says that I have this.

I just... bring up stuff apparently from way back whenever. And he just looks at me, he goes, how do you even know that? My husband has some memory loss.

So he's got some issues with his memory and we know why now. But at first I just thought, gosh, you just have the worst memory of anyone. So we were talking, we were at an event and there was someone that we knew.

And I was telling him, I said, hey, you know, we know him. I said, we should go over and speak. My husband was like, I don't know who that is.

I go. Yes, you do. And I give him the whole background story. I'm trying to give him the date, the time, the people who were around us, what the name of the event was.

And he is looking at me like I am absolutely crazy. He literally looked me in my eyes and said, you must've been with somebody else that night. I'm like, dude, I was with you. We went to the event together. Remember?

And I'm going through and he's looking like he has never heard this ever. So I go, okay, well come with me because we're going to go talk. to him.

So I take him with me and I go, Hey, how are you? And he goes, Oh my gosh, it's so good to see you. And I said, hi, so you remember my husband? Yeah, we met at, and he goes, this whole thing that I just tried to remind my husband of.

He goes, yeah, we were at so-and-so's event. We're doing this and doing that. And my husband's like, yeah, man, faking it. He remember nothing, nothing funny, but not funny. So we're aware now that there's some real issues that are going on.

But I used to be like, man, you have the worst memory of anyone, everyone. So I'd watch a movie. He'd be like, we would go to a movie together. And I'd be like, remember that movie we watched? He goes, you must have went with somebody else.

Are you serious? So automatic memory. Apparently, I just have this list of things that I know. I describe the event, the people that were there. I even describe what the guy was wearing.

And he's like, why do you even remember all that? I don't know. It was just there. Anyway.

So we also have memory consolidation, and that's fitting the new facts into categories that are already stored. So you know that we came into this. World not knowing anything right so our brain hadn't fully developed yet And we had to learn as we matured so you look at the stages of development Once a child is born, and then we just start building on it So by the time that you are five years old and you've gone to kindergarten You're learning your ABCs and you're learning your colors and you're learning how to you know see words And you know all that kind of stuff all we do from that point is build on what you've already learned That's why it's so crucial that during early stages that we introduce our children, I don't say students, but, you know, introduce people to things that are going to help them build, right, other things that come along.

So we give them a nice foundation, right, of knowledge and learning. And then we just build onto that. And that's true. That's memory consolidation.

So you shouldn't be surprised at the Hipple Campus. plays a role because we just said that a little while ago, hippocampus allows us to tie emotions to those memories. We have the temporal cortices. So the temporal cortex right on the sides here, thalamus plays a role in that because anything that goes to the cerebral cortex, and it says temporal cortex, anything that goes to the cortex has to pass through the thalamus.

And then that prefrontal cortex is involved in consolidation. But we know that already because we know that the prefrontal cortex can be... influenced by emotion, especially if you're in an emotional rage. All right. So all this picture does is it says, these are the things that we've learned, right?

So you may have never known what the color blue was, right? When you first started life. So you learn maybe at three, maybe at four, maybe at five, I don't know your lives, but you learn the color blue.

So you see the color blue, you've learned that it's the color blue, and then you remember it's the color blue. Then you tie that to other things. which means that when you see other things that are blue, you understand that they're blue.

Okay. Touching things. They're showing you right here that, you know, a person like, you know, got a tack in their hand.

So maybe they accidentally set their hand on a tack that was sitting on the table, but that's a stimulus from the outside. And I promise you that they know how that feels if they should ever get another tack in their hand. Then you also remember what you hear.

So although you guys can't see like, you know, my dogs and everything, if my dog bark, you would know that that's a dog barking. It's what you hear. You would remember the sound of a dog barking because once you heard a dog barking, you would remember. So remember it said on the previous slide, let me just go back to this. So those temporal cortices.

So the temporal lobes in general, and this is test material that I'm speaking right now. The temporal lobes in general are for learning and memory. Temporal lobes are for learning and memory.

The parietal lobes are... basically somatosensory and somatosensory association. So remember, association means understanding. Soma means body.

Sensory means stimulus. So somatosensory, that means any stimulus to the body, right? That's going to be perceived in the parietal lobes. The occipital lobe is where your visual cortex is.

Visual cortex is exactly what it sounds like, your sense of sight. But the visual association cortex is also in the occipital lobe. So on the exam, you have to know the parts of the brains and their function. When we talk about the prefrontal cortex, which is a part of the anterior association area, you need to know that that's where your memory, or not your memory, excuse me, but that's where your personality and your judgment and your perception and thinking through your consequences of your action. So you have to know what the lobes of the brains do.

Does that make sense? And then this would make a little bit more sense to you with this whole idea. So if I'm going to take short-term information, things that I've seen, things that I've heard, things that I've touched, remember, these are the senses, right?

And I'm going to put it into short-term memory. If you look over to the right-hand side, it says right here that we have the short-term storage, right? And then there's this little gray area that goes to this little gray dash box, and it says data permanently lost is gone.

You've forgotten it. And if you've forgotten it, it's like it never happened. And for you guys, my 8 o'clock class, right, sometimes you guys come in.

and you're very sleepy, and you know that you can't remember our first, first lecture, it's really hard for you to retain information if you are asleep when I am presenting it. So sometimes I say stuff, and you guys look at me like I have never, ever said it in life. You're like, she ain't say that. This is her first time saying it. And then if you have done what I've asked you to do and recorded the lectures, you go back and listen to a previous lecture, and you go, oh.

She did say that. I forgot. Because if you've forgotten, it's like it never happened. All right. Now, if you look at that temporary storage, and then we're going to move into short-term memory.

And then look, and even the short-term memory, there's a little gray area that goes back up to... Data permanently lost. But here's the important part. This is what I want to emphasize.

Again, why I do what I do in class. I've been teaching for a very long time. I hope that I present the material in a way that helps you understand it. I apply it to things that make sense, again, and I'm excited about it.

So I do it in a very upbeat manner. So excitement, rehearsal, and then the association of new data with old data. Hold on, someone's trying to come in.

So the association with new data and old data is, again, one of the ways to help transfer that information from short-term memory to long-term memory. So I do that all the time. So I'm repetitive. I'm excited about the delivery of the information.

And I'm always tying new information to the old information. Why? Because your foundation of learning is going to be.

based on things that we've given you already, right? And we just keep adding to your foundation, okay? All right.

So let's see. Oops. I think when I click on my screen, so I admitted someone, and then it won't let me go to the next screen. There we go.

All right. So let's talk about some imbalances. So we already know that the hippocampus is going to play a role with your emotions and memory, right?

So we take a memory and we are easily going to remember it because it's tied to emotion. All it says here is that damage to the temporal lobe, you know, temporal lobes, generally the site for learning and memory, on either side would result in slight memory loss, right? But if it's bilateral, right? So the temporal lobes are on both sides. If it's bilateral, meaning you have damage on both of your temporal lobes.

then you have amnesia because the temporal lobes are responsible for memory. And if you've damaged the center of the brain that's responsible for memory, you can't remember anything. If you've watched any soap opera in your entire life, my mom used to watch soap operas.

So I've watched a few way when I was young, but I remember that it seemed like every soap opera, somebody got amnesia at some time in the soap opera. And when they had amnesia, they were, of course, you know, their memory was lost. People felt so sorry for them so much so that they were going back and living lives that the person could last remember because they forgotten that they were divorced or forgotten that the person tried to kill them or forgotten some, you know, whatever. And then they just went back to, you know, before this thing happened, it's crazy.

Then some people took the memory loss, like on these soap operas, they took the memory loss and they milked it and they just kept faking like they lost their memory, even though their memory had come back because they liked it. the new stuff that they had formed. But the reality is, is that we can see the damage.

We can assess the damage of the brain and we can come to the conclusion that the person has memory loss because we know the area of the brain that's associated with it. And then we can look at it and see that either the neurons in that area are like actually dying off through neural imaging. We can see that it's not functioning. So you really can't fake it like people fake it, right? Like You think about a person with Alzheimer's disease, we are aware of the fact that one of the very sad symptoms of a person with Alzheimer's disease is they become very forgetful.

And then as a result of that, then a whole lot of other things come in because they get scared, they're nervous, they don't know who you are, they're anxious, and then dementia. So it's a whole list of things, but we know that there's actual memory loss. I think it may be this lecture. where I'll show you neural imaging of a brain with a person with Alzheimer's, and you'll understand when I talk about it, what that means. So let's talk about the amnesia again.

So antegrade amnesia means that unfortunately, the old memories are there. So consolidated stuff is there, but new inputs are not associated with the old ones. So they live in the here and now.

That just means that I can have a conversation with you right now, and look what it says. Five minutes later, the person wouldn't remember it. That's the here and now.

This is 51st Date with Adam Sandler and Drew Barrymore. Yeah, that one. Okay. Retrograde amnesia, the memories from the past are gone. Just gone.

Things that you just, you know, from way back when, it's like you didn't exist in that time. And that's, again, very scary for people too. All right. So let's talk about the brainwaves. First thing I'm going to tell you is that they're unique.

Each person's brainwaves are unique to themselves, just like your fingerprints are unique to yourselves. But we do have a classification of waves that everyone exhibits. So everyone has alpha waves and beta waves and delta waves and theta waves.

And we'll talk about what those mean. I tease my eight o'clock classes during this lecture. And I tell people that the eight o'clock class is always on idle.

So you guys are always on alpha waves. That means the two are unique. you know, you're there, but you're almost asleep.

And that's what we see in the first stage of sleep. We see a bunch of alpha waves and I'll talk about those when we get there. So anyway, what we use EEGs for, and again, it's electroencephalogram and cephalogy like your head.

So we record the electrical activity of the brain. I will go ahead and say this to you, and I think most people understand this. You've probably seen some medical show, is that when there's a flat line.

right? It's an indication that the person is gone. So if a person has a flat EEG, that means they have no electrical conduction in the brain, no electrical activity in the brain.

The person is brain dead. Now we can put them on artificial measures, right? So life support, but they're brain dead and people don't come back from being brain dead. You can come back from a coma. As you guys know, we medically induce comas.

People who have gone through very traumatic experiences, you know, on their body or have gone through, you know, like serious injuries throughout several places, we'll put them in a medically induced coma, allowing their body to heal without them having to perceive and understand all of the things that are going on. So we put them in a medically induced coma, which means we give them medicine to put them in a coma, and then we take them out of it, right? So you can come out of a coma. but you can't come out of being brain dead.

And I hope that makes sense. All right. So in this picture right here, this is a person who is getting an EEG.

And then the waves, see down at the bottom where it says alpha, beta, theta, and delta waves. So those are the four classification of waves. We measure them in Hertz. And so a peak is the top part of the wave. Okay.

So now those alpha waves, see where it says idling brain. That's what I was just saying a few minutes ago to you guys. So rev... they're kind of regular and rhythmic, but low amplitude.

Low amplitude means that the peak is not very high, right? So low amplitude wave. And then beta waves are less regular. So they're a little bit more, you know, irregular and they occur when you're mentally alert.

So that means if I did an EEG on you and you're awake, I would expect to see beta waves. But if I see beta waves while you are asleep, I'm concerned. Because those aren't the waves that I should see while you are asleep.

The waves that I should see while you're asleep are going to be the delta waves. They're going to be on the next page. But those are going to be the delta waves. So delta waves, deep sleep. Delta waves, deep sleep.

Alpha, idling. You guys know I like to do stuff to help you remember. And then beta waves, you know, you are awake. Theta waves are what we see in children.

So if we see theta waves in adults, that's an indication that something is wrong neurologically as well. So here are the delta waves. Again, high amplitude, so these are the highest peak ones. And it says that it is, these are the ones that are activated when the RAS, right, reticular activation system, is suppressed, dampened, inhibited, you know, like when you are asleep. So we see these when a person is under anesthesia.

If you think about it, whenever you go into the hospital and you're going to have a surgery, they put you to sleep. The anesthesiologist is there. There's an anesthesiologist nurse. Some of you want to be. anesthesiologist nurse.

So when that person is under there, of course the anesthesiologist and the nurse, they're reading all of these, you know, instrumentations that are going on so that we can confirm that the person is still asleep. The very last thing that we want a person on the operating table to do is wake up. So we want them to wake up after the procedure is over, we want them to wake up after they've had time to heal, but while you're asleep you don't feel pain.

If you wake up during the procedure, you are going to feel pain and there's going to be a lot of trauma. So we want them to stay asleep. All right. So here's a picture of the alpha, beta, theta and delta waves.

So see how the delta waves are really high. That's what they mean when they say that those are high amplitude. And then the alpha waves.

So look like the little brief description afterwards. It's you're awake, but you're relaxed. That's you guys.

Eight o'clock in the morning in class. The beta waves are being awake and alert. theta waves coming in children and delta waves deep sleep. This is a really good slide to help you remember those four waves and what's happening during those.

All right. So you may or may not know someone who has epilepsy. But even if you don't know someone personally that has epilepsy, I think most people are familiar with a seizure. When a person has a seizure, there are lots of things that can happen. And one of the things is that they could lose consciousness.

So all that means is that when a person has a seizure and they do lose consciousness, they don't remember. When they wake up from the seizure, when the seizure ends, they look around and they're trying to figure out. And if they've had one before, they know exactly because they've been in that. situation before, so they know that they seized. But the reality is, is that some of those are very serious, right?

So we used to call the very serious ones grand mal, grand like grande, like big, and mal like malo, bad, Latin words. But now they call them tonic-colonic, sorry, multitasking. Tonic-colonic seizures are the grand mal's.

And then The smaller ones were called petite mal, like so petite, pequeno, small, right? And mal, of course, being bad. So it's a small, bad seizure.

And those now are called absence seizures. Okay. So what else is there? Okay.

So they could lose consciousness, said that already. Epilepsy has nothing to do with their intellect. So a person who has epilepsy, we can see lesions on their brain, but it doesn't affect their intelligence.

1% of the population. has it. Genetic factors can play a role in that. Brain injuries, strokes, infections, tumors can also be a cause of that. I also want to go back and just emphasize two things.

In our general nervous system lecture, when we were talking about the neurotransmitters, I told you guys to remember that GABA, which is gamma, oh my gosh, gamma-aminobutyric acid, so GABA, G-A-B-A, That one is one of the things that we use like in medications like valporic acid. So valporic acid is an active ingredient that's found in anticonvulsants that causes the release of the neurotransmitter GABA. We give it to people who have seizures. Why? Because it's inhibitory.

It's an inhibitory neurotransmitter and epilepsy, you lose consciousness or could lose consciousness, but you have uncontrollable jerking. So uncontrollable movement and inhibition would... prevent you from having that.

If you know someone that has epilepsy, they know that they're about to have a seizure. They have an aura. So this aura is a sensory hallucination.

Now, when they get the aura, they know that the seizure is coming, but they can't do anything to stop it. So the aura, when I say sensory hallucination, it would be like tasting the color blue or hearing the color red. if that doesn't make sense to you, it shouldn't because I can't hear the color red. I can't taste the color blue.

Does that make sense? So those are sensory hallucinations. And then, so they, they perceive those right before they seize.

So the absent seizures, like I said, petite mall, and then tonic clonic seizures are the ones I think I might've said clonic tonic, tonic clonic. I don't know if I said it right the first time I apologize, but tonic clonic seizures are the grand mall. Um, when I was younger, I heard people call these grandma seizures, like grandma, like your grandma, my grandma, grandpa, like that. And I'm like, they're not called grandma seizures. They're called grand mal seizures.

And then people used to call Alzheimer's disease, old timers disease. And I'm like, it's not old timers disease. Although elderly people are the ones that are most likely to get it.

It's Alzheimer's disease. So just some interesting facts about the way people pronounce things. So let's see the petite.

um, sorry, absence seizures, mild seizures. We see them in children. Very hard to diagnose these seizures though, because sometimes it's just a child who, as you guys ready, I'm going to put this in air quotes, looks like they're daydreaming. And I know you guys have all daydreamed at some time. The reason why we say daydream is because you're awake, your eyes are open, but you just kind of drifted off for a second and then you came back.

So that's the, um, the absence seizures. And then Tonic-clonic seizures are the really bad ones, right? So the victim loses consciousness, could break their bones because the convulsions are so violent.

Loss of bowel and loss of bladder. So they, you know, usually, you know, urinate on themselves. And then you guys have probably heard this severe biting of the tongue. So I think most people, again, know that. But anticonvulsants, right, would...

enhance the release of GABA. So gamma immunobutyric acid. And please make sure you remember that. So the control of epilepsy, again, anticonvulsants that are there, they're giving you some really neat things that are happening, but they're saying anticonvulsant drugs.

And I'm being a little bit more specific by telling you that valporic acid is one of the most common active ingredients in anticonvulsant drugs. And what valporic acid does is enhance the release of GABA. I've said it like four times now, so you know what that means. Anyway, there's vagus nerve stimulators, deep brain stimulators. You can get implants.

that go into the nerve, which is kind of interesting, but they go directly into the nerve, into the brain, but they go directly to the brain and they help kind of stabilize the activity. Now, consciousness. Let's talk about the things that we already know that have to do with consciousness.

Cerebral cortex, anything that you do while you're awake, that you are aware of doing, that you did on purpose, that you planned out, that you intended to do, that is the cerebral cortex because the cerebral cortex is the site of the conscious mind. So it says here, your perception of sensation. So remember I told you that when I'm in class, I would find a volunteer and I'd say, may I touch you?

And they'd say, yes. And I'd say, close your eyes. And then I would touch them on their shoulder a certain way, like I'd flick them on their shoulder, poke them on their shoulder, and then I'd maybe rub on their back or something and then ask them, what did I do?

What part of the body did I touch? How did I touch it? Perception of sensation.

But you have to be awake. When you are asleep, You don't know that someone is touching you. When you are asleep, you don't remember what happened.

It's the reason why ignorant, mean, cruel, nasty, psychotic people use rape drugs, right? Date rape drugs. They put pills, roofies, into people's food or drinks or whatever. The person loses consciousness. They aren't aware what's happening and they don't remember what's happening.

Anyway. So, um, I'm sorry, I get a little, I'm title nine. So I get a little amped up about that stuff. Anyway, um, voluntary initiation and control of movement.

So I said, you planned on it. You purposely did it, um, associated with higher mental, um, processes like memory and logic and judgment. It makes sense because you thought about it.

You did it on purpose. So of course there's judgment that's in there. Sometimes we go, you know, under peer pressure and we do things that are against our better judgment. But again, you're conscious, you're aware that you're doing that.

And then it's defined on a continuum that grades the behavior in response to a stimulus. So you can be alert or you can be drowsy or you can be in a stupor or you can be in a coma. So some of you guys come to class and you're like in a stupor. Okay, let's see. Current suppositions on consciousness.

Again, because the cerebral cortex is the site of the conscious mind, it literally says simultaneous activity of large cortical areas. Cortical like cortex. It's superimposed on other neural activities because you're awake and alert and that involves other things that take place. And then it's holistic and totally interconnected. That means there takes so much stuff in order for you to do something in your conscious state.

It's thought about, it's carried out, it's on purpose, it's intended, et cetera. All right. So let's talk about some sleep stuff. Syncope. which is fainting, is not normal.

Just want to put that out there. It's not normal. So slipping into a state of unconsciousness, except when you are actually asleep, whether you were put to sleep medically or you went to sleep, is not normal.

It's not normal. So narcolepsy is going to come up here in a little bit. But anyway, so fainting or syncope is a brief loss of consciousness. Consciousness, if you've ever fainted in your life. you know and realize that when you fainted and came back to, you had no idea how long you'd been out or what happened.

You just wake up like, oh my gosh, what happened? So I fainted. And when I fainted, I tell everybody, I was like, I knew something was about to happen because on the sides, like my peripheral vision, it was like these black curtains coming and they came around, came around in the darkness and I hit the ground.

Okay, give me one second. Someone is trying to come in. All right.

this part of admitting people individually it's cumbersome because like I said it messes up my flow anyway so fainting is not normal and for me like I said it was like this black curtain I saw it happening if there's just nothing I could do it's like the aura that happens when a person's about to have a seizure so blackness just kind of came around from the sides and then shut and I hit the ground and when I hit the ground Um, I must've hit it really hard, but I had already lost consciousness. So I didn't feel it, but it freaked out my kids cause they were with me and they were young when it happened. And then they, when I woke up, my kids are crying and I'm like, what's wrong with y'all? Because I didn't remember anything other than the fact that I blacked out anyway. Um, Most often it's due to inadequate cerebral blood flow, but could be due to low blood pressure.

It could also be due to hypoglycemia, which means if a person hasn't eaten, right, their low blood sugar, that could cause them to faint. And then severe emotional stress can cause a person to faint. If you've ever seen anything on TV where like the police are coming to someone's house to tell them about a tragic thing that happened with their husband or wife or children or, you know, the military comes to.

deliver the message in person of, you know, a woman who's, you know, husband or a man whose wife or, you know, whatever has been killed and, and combat or war or whatever. Um, so they deliver the information. And a lot of times you see them faint.

That's a real thing. Um, so you can lose consciousness because you're under severe emotional stress. And then, um, when you're in a coma, let me just close this. I keep getting alerts on all of my phones and stuff. So when you're in a coma, it's unconsciousness.

It's for an extended period of time. It's not the same as deep sleep though. So when a person is in a coma, we can look at their EEGs and we're not going to see that regular high amplitude delta waves. So again, it's not the same as deep sleep. Oxygen consumption is lowered when a person is in a coma.

All right. See, I let someone in and I lost the ability to control the screen. There we go.

Okay. Now, brain dead, talked about this already. It's irreversible.

You don't come back from it. You have a flat EEG, right? So you have no electrical activity in the brain.

Ethical and legal issues surround the decisions on whether the person is actually dead or alive. It's difficult to make those decisions. So a doctor can come out and tell you that the person is brain dead and you have to make a decision, especially if they were put on life support.

So when they say legal and ethical, it means some states that once you put a person on life support in order for them to remove the life-sustaining instrumentation, you've got to go to court, prove your case, and be granted permission to do so. Ethical issues because people feel like if the person is brain dead, but they're on a machine that's breathing for them, then aren't they really alive? They're living.

And if you do something to stop... them from living, then you actually killed them. So it becomes an ethical issue and it's a difficult decision to make.

I never fault anyone when they take longer, you know, to make this decision. So as you guys know, I lost my cousin to COVID and, you know, I knew a few days into her stay at the hospital, she was there on March 21st. I knew a few days after her stay into the hospital that she probably wasn't going to make it because I was, you know, okay. of course, asking people to get the information from the doctor and relay it to me.

And when I told my cousin, her sister, I was, I'm trying to be sensitive to the fact that everyone's under a lot of emotional stress because we are. But the reality is, is that I was telling her, if you don't make the decision, or you as in the family don't make the decision, then the decision is going to be made for you. Because in this age of coronavirus, we are taking people. off ventilators that we feel don't have an opportunity to recover and trying to put the people on the ventilators that will probably recover.

So they're making decisions for us in that right. And then it took her, you know, the family a few more days to make that decision. Someone's unmuted.

Did they want to ask a question? No. Okay.

Anyway, so ethical and legal and very difficult. It's very difficult. Because even when you hear the doctor tell you that the person's never coming back, it's your loved one. It's a very difficult position to be in. It's why I have so much respect for hospice nurses, because they help make that decision easier.

And they're just wonderful, a wonderful group of people. So if any of you guys want to go into hospice, I think I can say this, but God bless you, because the world needs people like that. All right. So let's talk about sleep.

We already know that when a person is asleep that their reticular activation system is inhibited, right? So reticular activation alert, awake, aroused, right? And aware, that's the reticular activation system. So sleep is a state of partial unconsciousness, right?

The person can be aroused by stimulation, right? So you're sleeping really good and someone comes and says wake up, wake up, wake up. You wake up, that's sleep, so unconscious.

But what I will tell you is this, is that since it's a state of unconsciousness, even though it's partial unconsciousness, people who sleepwalk don't remember it because they are asleep. And people who talk in their sleep, like my husband. don't remember it because they are already asleep. It's funny to me that my husband talks in his sleep.

And then when I try to tell him the next morning about the whole conversation that he held in his sleep, he thinks I'm making it up. So of course, I've taken the time to record him while we're having these conversations. It's just so funny afterwards, but he doesn't remember any of it.

Also now, this is all the rage. where people are going to have their wisdom teeth pulled and family members are recording them while they are coming off of the nitric oxide. So they're like loopy and people are asking them questions and the people are saying the weirdest things and they don't remember any of it. So you record it and you show it to them and they're like, I can't believe I said that.

So that's a new craze type of thing. They didn't have that back in my day. Anyway, so we have two types of sleep.

You're either NREM. which is rapid eye movement sleep, or you're in non-REM. Non-REM is four stages, one, two, three, and four.

And then you go into REM and then you cycle back through again through stages one, two, three, and four. And then you go into REM. When you are in REM, this is where like deep sleep and REM, that's where we get our dreams. REM is our restorative sleep. So if a person has difficulty sleeping, they're not getting enough REM sleep, then they're cranky and they're irritable depressed and moody yeah so it's important that we get REM sleep it's you know like I said the restorative sleep so it says here broken down the four stages so said that already okay so let's go through the stages of sleep now in stage one or two it's that stage one first sorry is that alpha waves that we see where the brain is idling so it says when we look at it we see the slow sleep waves that are there takes about 30 or 40 minutes and we get through the first two stages of sleep in about 30 to 45 minutes.

Let's see, the frequency of the waves declines, but the amplitude increases as we move into deeper sleep because remember, delta waves have the highest amplitude and delta waves are what we see in deep sleep. Let's see, your heart rate, respiratory rate, blood pressure, and even your gastrointestinal activity change. When you are in those first stages of sleep, all of those things decline.

But when you get into deep sleep, this is where your dreams occur. And your dreams, again, are a neurological process. So while you are dreaming, if you are dreaming, you know, when you're running through the woods, then your heart rate is increasing.

If you're dreaming about something or someone who's aesthetically pleasing, then your heart rate is increasing. And then for men, nocturnal emissions happen because they're in that deep sleep and they're dreaming of something sexual. And that's what a nocturnal emission is. wet dreams. See? Stuff that you probably know, just didn't know the physiological or scientific or anatomical names for them.

All right. So after about 90 minutes, you're going to slip into the fourth stage of sleep. And the fourth stage of sleep is again, that deep sleep. So you have temporary paralysis of your skeletal muscles during the sleep, except for your eyes, because REM is called rapid eye movement. Now, Since you have temporary paralysis of your skeletal muscle, let's talk about what I call the paralysis dream.

So paralysis dream is when you are dreaming, but you think you're not. So you think you're awake. So you're asleep, and I'm closing my eyes, I'm going to work it out. So you're asleep, and when you're asleep, your skeletal muscles are inhibited, but you think you're awake. And your mind is powerful.

So if you think you're awake, then you're laying there with your eyes closed. And you're like, I can't. And for me, I'm screaming for my husband to help me because I'm paralyzed.

But I know it's the paralysis dream, but he can't hear me because I'm asleep and I'm not really saying anything. But for me, when I'm in the dream that I'm awake, right, and paralyzed, I realize that I'm in the dream. making me feel like I'm paralyzed and I will myself to wake up.

So I'm always like, wake up, wake up. It's like Uma Thurman when she was in Kill Bill, wiggle your toe, right? Anyway, I'm like, wake up.

And then I come out of the dream like this, breathing heavy, thinking how I was paralyzed and how scared I was. And I turned to my husband and be like, why didn't you wake me up? He's like, what are you talking about? I was screaming for you to wake me up. I was paralyzed.

I need you to wake me up. Sorry, I have a little cough now because I strayed my voice a little bit. Okay, hold on.

All right. So you're temporary paralyzed except for the movements in your eye. Excuse me. And those are going through rapid eye movement because you're in REM. And most dreaming occurs when you're in that deep sleep or in your new REM sleep.

Sorry. So these are the waves. Give me one second here.

These are the waves. Uh-oh. Let me see if Zoom is there. I'm having a choke fest right now. I was going to take myself off camera, but I don't see my option.

There it is. All right, hold on. I'm about to guzzle this water.

Better, better. Hello, hello. Testing, testing. All right.

I have no idea why I'm choking. So I'm going to sound like raspy now and that's awful. And we're just like a third of the way through. So this is going to be bad. All right.

All right. I'm back. Hi.

I'm almost dead, but I'm back. Okay. All right.

Everything's back to normal. Like you can still see the screen and me and all that. Okay. Anyway, so when you're awake, if you see those waves up there, and then you go down to the waves that you see when a person's in REM, they look almost the same. So REM is your rapid eye movement.

And again, skeletal muscles of the eye are working, but everything else is paralyzed. But it looks like you're awake, like your EEG would look like you are awake when you're in REM. So dreaming is real, right?

One of the scariest movies when I was younger was... like the first, um, Freddy Krueger movie, Nightmare on Elm Street. Cause there's like, if you die and you sleep and you die for real, but like, yeah, isn't that neat that the wake and REM, um, waves look similar. Um, let's see, we got our alpha waves for, um, stage one. We got the irregular waves that we see in stage two and stage three, we'll get some of the theta waves, children, delta waves that we, um, see.

And then, um, when you get down to the non-REM sleep, the fourth stage is non-REM. So The fourth stage of non-REM sleep is the deepest sleep before you go into REM and you get a lot of those high amplitude waves. Those are the delta waves. All right. Oh, it also says in this one that this is where your bed wetting occurs.

Oh, and I know you guys know this. You don't have to raise your hand. I can't see you anyway. But some of you may have had a dream when you were probably maybe five or six years old, already potty trained, but wet the bed because you dreamed that you were. using the bathroom, like in the bathroom, it's a real thing.

You don't have to raise your hand if it's happened to you. Okay. Now, how do we regulate our sleep?

We already know that the hypothalamus plays a role in that because the hypothalamus plays a role in the sleep and wake cycle. So the hypothalamus releases orexins and orexins help keep the cortex awake. So if you're releasing an excess amount of orexins, then you could exhibit insomnia, right?

Erexins keep you awake and if I'm releasing a lot of them then I can have insomnia. So what that means is when we begin to realize what's happening chemically in the brain and we're trying to alter the situation, a person who has insomnia could take medication that inhibits the erexins since the erexins keep you awake. See?

Think stuff. All right. Let's see what else. We already know that the reticular activation system is inhibited by sleep because we talked about that already.

Um, let's see hypothalamus with their erections. Um, and we also have the pineal gland, the pineal gland secreting the melatonin and melatonin being part of the sleep cycle. So in this picture right here, there's just showing you how you slip in and out of the stages of sleep. So I told you already one, two, three, four, by the time you have been asleep for about 90 minutes is when you slip into your REM sleep.

And then when you get out of your REM sleep, you go back down through the stages. One, two, three, four, go into REM one, two, three, four. If you sleep, you know, eight hours a night, then you would probably be able to go about four cycles of REM.

Most of you guys at this demographic, college-age students, sleep on average about five and a half hours. So you don't even get eight full hours of sleep. So you probably get maybe two or three cycles of REM, maybe. Okay. Let's see.

So sleep is important. I've already told you that people who don't get enough sleep are cranky. And people who also don't get enough sleep. become depressed.

Let's see what else is there. It's restorative. Let's see, depressed, moody, okay, so restorative was first, moody, depressed, so I said all those things previously when we talked about sleep. And then REM sleep gives the brain opportunity to analyze the events, walk through the emotional events and the problems of the day, and then we eliminate unwanted stuff that was formed, so we sometimes dream to forget.

Your sleep requirements decline with age. So I have a grandbaby who's seven months old. When she first got here, of course, she just slept, you know, all the time.

And then she's staying awake longer now. And then when you're in kindergarten, if you remember, like for me anyway, in kindergarten, naps were part of our day. They took that.

There's no, they don't nap in kindergarten anymore. So they took naps out of kindergarten. But as you get older, your need for sleep declines.

Okay, let's see. Now, let's talk about some disorders. Narcolepsy. Oh, see, there it is, orexin. So narcolepsy is when a person slips into sleep, right?

Just abruptly. My nephew has narcolepsy, and I'm a cruel person. I admit it.

But I tease him about it only because it's just so weird that he literally just slips into sleep. But the way that I teased him about it is that he called me his older brother and his younger brother. So he's the middle brother.

His older brother and his younger brother are both in the military. And I was asking him, you know, early on in his life, what he thinks he might want to do. And he thought about the military.

So he called me up and he was of age at this time, but he called me up and he goes, you know what, auntie? And I said, well, honey, cause he sounded like he was upset. I said, what's wrong, honey?

He said, you know, they're not going to let me join the military, man. And I was like, really? Now y'all know I'm facetious, sarcastic. I'm like, for real?

You mean, why aren't they going to let you join the military? You can tell me. He said, because I got narcolepsy.

I go, can you imagine that? The darn military doesn't want someone who slips into sleep abruptly. Go figure.

They don't want someone handling guns, driving tanks, making decisions about war and safety. Because you slip into sleep. And he was like, well, dang, auntie, when you say it like that. I was like, yeah, when I say it like that. But I told him, I said, it's okay.

He's taking medication for it. It's partially under control. When he was much younger, we're awful. So when he was much younger, I would get all my nieces and nephews. And at that time, actually, my daughter was the only girl.

So I'd get all my nephews and my daughter. And we would be at my mom's house. And we'd go, you know, do something.

And. if we leave the house before we left the, my mom's driveway, because we have this large property, but we, before we left my mom's driveway before we got to the end of the road, he was asleep because you know, one people fall asleep in cars anyway, but he has narcolepsy. And then one time he was telling the story to everybody, you know, we were all just sitting around talking and he's like, everyone used to call my mom abuela.

And he goes, man, abuela's food is just so good. He said, and he just looked at us all. you ever have food that just makes you want to sleep? And my son said, nah, man, that's just you because you got narcolepsy.

And we just all died. So the reality is they slip into sleep and, you know, there's nothing that they can do about it. So we have the erections, right, which are the wake up chemicals. And we think that narcolepsy may be destroying those.

So if they're destroying the signals that keep you awake, then you, of course, slip into sleep. Um, insomnia, as I mentioned before, that would be the opposite, right? Where you can't sleep.

And that may, again, if we use something that blocks the orexins, then that would, you know, inhibit your wake signals and you could go to sleep. So insomnia, either you're not getting quality sleep. So you're not getting the deep sleep, the restorative sleep, um, or you're not getting sleep at all. So insomnia. All right.

So let's move into the meninges of the brain and the meninges of the brain are coverings. And these are the three things that I need you to know. There's a dura mater, there's arachnoid mater, and there's a pia mater. The reason why I say these three things is because of this.

There's going to be several slides that give you a little bit more information, but I'm telling you, this is what I need you to know. The dura mater is tough and durable. Dura mater.

It is the most superficial layer. And you know your terminology, so you already know that that's the one that's on top. The arachnoid mater is like spider webs.

Webs, like arach... like spider. It's gonna be simple. And then the pia mater thin, soft, delicate layer that clings directly to the brain.

So if we're starting from the deep to the most superficial, it would be pia mater, arachnoid mater, and dura mater. If we're going from the most superficial to the deepest, then it would be dura mater, arachnoid mater, and pia mater. That's what you need to know for the exam. And then there's going to be some other stuff in here.

So they have pictures. If you look at the picture, just based on the descriptions that I gave you, See this stuff right here that looks like webbing? That's the arachnoid mater.

See this little thin, delicate part that clings directly to the brain? That's the pia mater. And if you look over here, this thick, I'm trying to do it with my arrow. So this thick part right here, coming around here, this, that is the dura mater. And the dura mater does go into some of the fissures of the brain, like the longitudinal fissure and then the...

transverse fissure as you guys remember the transverse fissure is the one that separates the cerebellum from the cerebrum so it covers the entire brain and spinal cord three layers of these coverings if a person has meningitis it's the inflammation of the meninges and since the meninges are on the brain right three layers but when they're on the brain if they become inflamed then basically what they're doing is they're pushing the brain against itself like asphyxiation inflammation can't go upward and out because of the skull. The skull is bone and it can't go upward. So the inflammation can cause brain damage. A person with meningitis can actually slip into a coma and die.

All right. So dura mater strongest said that already. And these are some of the folds that are there. So the transverse fissure, like I said, separates the cerebellum from the cerebrum.

And so we have the centaurum cerebelli that is the part of the dura mater that folds in between and separates the um cerebellum from the cerebrum. Let's see what else is there. So a nice little picture on the right hand side of this picture, which is also the right hand side because we're looking at the posterior view. This is the parietal lobe being covered by the dura mater and then they're showing the transverse and false a and you don't have to know about them but it's just kind of cool to see them. Arachnoid matter, the middle layer and spider web like and again they show you a picture.

And then pia mater, like I said, very thin and delicate and clings directly to the brain. And then another picture so that you can see all of them. And then I already said this, inflammation of the meninges, meningitis, inflammation of the brain could also be referred to as encephalitis, could be diagnosed by taking a sample of cerebral spinal fluid. So when we take cerebral spinal fluid, that's the CSF.

When we take cerebral spinal fluid, we do a lumbar puncture. Lumbar. punctures are most commonly referred to as spinal taps.

So make sure you know that a lumbar puncture is most commonly referred to as a spinal tap. And when we do a spinal tap, it's so that we can examine the spinal fluid. We can gram stain it. We can do KOH preps or India ink preps.

These are preps that we do to look for fungi. So there's a multitude of things that we can do with cerebral spinal fluid, examining it visually to see if it has... red blood cells.

It could be that it was a traumatic tap when there's blood in the cerebral spinal fluid, but there also could be an underlying condition or issues that are causing the blood in the spinal fluid. Blood shouldn't be in there. So spinal fluid itself is extremely important.

So the brain is bathed in spinal fluid, brain and spinal cord are bathed in spinal fluid, and it keeps the brain afloat. The brainstem... It's just a small stem compared to the size of the brain. Without cerebral spinal fluid and keeping the brain afloat and buoyant, the brain would collapse on the stem because the stem's not strong enough to hold the brain up. So cerebral spinal fluid is extremely important.

All right. Let's see. Choroid plexus.

Just for that, just make sure you know that this is where we're going to get the release of spinal fluid there. So central cerebral spinal fluid is filtered through this plexus. goes through a constant rate.

Circulation of cerebral spinal fluid is like circulation of blood, right? It's got a route that it takes. And that's like on this next picture. Don't have to memorize it, but just so you know that it's circulating.

Cerebral spinal fluid flushes the brain, provides nutrients for the brain, and it cleanses the brain. So it's important. Hydrocephalus is when there is a blockage of the cerebral spinal fluid, so it doesn't drain.

Instead, it accumulates. If you are an adult... then your skull has fused.

And remember we talked about babies having fontanelles because their skull bones haven't fused already. So if it's a baby... there's room for this pressure and their head just begins to swell. But if you're an adult and you get this backup of fluid, there's no place again for the fluid because of the skull.

And unfortunately for an adult that experiences hydrocephalus, they probably are going to have some neurological disruptions because brain damage. Whereas if it's an infant and their skull hasn't fully fused, once we drain the cerebral spinal fluid, they probably will recover. and not have permanent brain damage. So that's, I think all it says there, newborn, adult brain.

Yep, exactly. So treatment of course is to drain it, like I just said. Okay. And so this is a baby with hydrocephalus. All right.

So the blood brain barrier is exactly what it says. There's a barrier between the blood and the brain. That just means that there's some things in the blood that we don't want to get to the brain.

So there's a barrier that's there. A lot of microorganisms. are not able to pass over the barrier, but some of them are.

And the ones that can are the ones that can cause meningitis. So meningitis could be caused by a fungus. It could be caused by a virus. It can be caused by bacteria.

So there's bacterial meningitis, fungal meningitis, and viral meningitis. So again, the barrier kind of prevents things from getting through, but not everything. It doesn't prevent everything. As I said, some bacteria, some fungus, and some viruses can get through, but glucose gets through.

So there's nutrients that get through to the brain, right from the blood to the brain. That's a big deal. Oxygen goes from the blood to the brain. That's a big deal.

So when we say that it's impermeable, it doesn't mean that absolutely nothing can get through. It's just that it's a barrier and a lot of things can't get through. It's tight junctions.

All right. And then it just, these are the accessory cells that we talked about. So remember the astrocytes were the most abundant of the neuroglia cells.

They are the ones that anchor the neuron to its... nutrient and oxygen supply. So the capillaries, and that's how they're doing right now is showing you that again. Let's see, the barrier is selective. So I said that already, some things can get through and some things can't.

So nutrients get through, metabolic waste, proteins, toxins, most drugs are denied, most are denied. Let's see, fat soluble substances though can get through. So anesthetics, the stuff that we use to put people to sleep. It can go through the blood to the brain so the brain can be inhibited and then we can carry out whatever that procedure is. Nicotine diffuses and goes to the brain and alcohol goes to the brain.

It's like fetal alcohol syndrome. A woman who is pregnant could do damage to her fetus, the baby, because of the alcohol. It absorbs and they can be born with brain damage.

Let's see. Blood-brain barrier is absent in our vomiting centers. and the hypothalamus.

And that's because we want to chemically monitor what's happening. Hypothalamus, as you guys know, again, is, I'm sorry, well, it's mainly control of everything, but the boss. But the vomiting centers are important because what if you ingested some food that was spoiled?

Then the toxins get in the blood and send the signal to the brain and let you vomit, more specifically the medulla. If the blood brain barrier was active in the vomiting centers, That means the signal that the food was a toxin and you should vomit, you'd never get that signal. And then the toxins would build up and, you know, it could be deadly.

So vomiting can be helpful. A concussion is temporary alteration in function. A contusion is permanent damage.

Multiple concussions can lead to contusions, right? So permanent damage that's there. Let's see what else is there.

If we prevent blood flow to the brain, you can have a stroke. So cerebral vascular events, vascular again is vessels. And so blood is traveling in the vessels. If the stroke occurs on the left-hand side of the cerebral hemisphere, then the person's going to be paralyzed on the right-hand side of the body.

And if the stroke occurred on the right cerebral hemisphere, then they'll be paralyzed on the left side of their body. Let's see what else is there. Oh, glutamate. Again, one of the neurotransmitters that I told you to hold on to, glutamate is excitatory.

So glutamate acts as an excitotoxin and worsens the condition because it's excitatory. Hemiplegia, like I said, being paralyzed on one side, and it's going to be on the opposite side of where the damage is in the cerebrum. TIAs, transient ischemic attacks. So temporary, it's basically clots.

So you have a small clot and then it just dissolves on its own. When the clot is present, you're going to have that temporary ischemia, and then it leaves once the clot is dissolved. If a person has a true ischemic stroke, you get them to the hospital as quickly as you possibly can, like when the signs of stroke first appear, and then they can be administered the tissue plasminogen activator. And that tissue plasminogen activator is the only...

treatment that's approved by the FDA to help for the treatment of ischemic strokes. What it does is it dissolves the clot so that the delivery of blood to the brain will be renewed, restored, restored. All right.

So Alzheimer's, old timers disease, degenerative disease, so it gets worse, results in dementia. There are some... cases that we already know that are associated with malfolded proteins. So we already know that if a protein has a certain structure to carry out a certain function, that if it's malfolded, misfolded, it's going to malfunction.

Why? Because malformation leads to malfunctioning. Memory loss. So again, we talked about this earlier, but memory loss, short attention span, disorientation, irritable, confused, moodiness, hallucinations, right? Dementia, it's sad.

We also see these beta amyloid proteins that accumulate in the brain so we can physically see those. And then there's this neurofibrillary tangle and it's exactly what it sounds like. The neurons actually kind of like get tangled up and when they get tangled up, it's like a knot.

And if it's a knot, then we're not getting delivery of all the things that are necessary for the neurons to live and they begin to die off. So brain cells begin to actually die. All right. So remember I told you with Alzheimer's disease that I would show you a neural image. I'm going to highlight it.

They're showing you with the arrow, but I'm going to, I could ask you to unmute to ask this question, but okay. So on the left-hand side, we have neural imaging, and this is a normal brain. Over here, this is a person with Alzheimer's disease. And if you look here, if you look here, you should be able to tell me what lobes of the brain those are, you know, cause they're on the side.

So you should be able to tell me what lobes are affected. Well, temporal lobe. Then you should be able to tell me that the temporal lobe generally, right, because there's a lot of things that it does, but generally it's for memory and learning.

So when we don't see any imaging that's taking place, we can come to the conclusion that this person, it's on both sides, so it's bilateral, that this person has severe memory loss. If there is just damage on one side, like some type of brain injury that only occurred on one side, then they would have slight memory loss. But remember I said if it's bilateral on both sides, then it's going to be widespread.

This person has nothing lighting up in their temporal lobes, so memory loss. All right, Parkinson's disease. We know this as well because we talked about it in a previous lecture. Parkinson's disease is associated with the... deterioration of the basal nuclei, gray matter that's responsible for inhibiting unwanted movement or unnecessary movement or preventing antagonistic movement.

So if the gray matter, basal nuclei, is responsible for inhibiting that unwanted, unnecessary movement, and then that gray matter is being destroyed, what do I see? I see this unnecessary, unwanted, and uncontrolled movement. Michael J. Fox has Parkinson's disease. He does a lot of shaking.

Muhammad Ali, before he passed, also had Parkinson's disease, you know, a lot of shaking. So again, that's what you need to know about that. Huntington's disease, and we talked about this one as well.

So basal nuclei, so it leads to the degenerization of the basal nuclei in the cerebral cortex, and they get this wild jerking, flapping. And I already said... I've already told you guys this one.

We've talked about, again, gray matter versus white matter. But just to, again, help you understand what's happening there. The person will die from Huntington's disease. We have treatment, but there's no cure.

Okay. So when we're trying to assess your central nervous system, we can do reflexes. Yeah.

Because a reflex is a rapid, involuntary, predicted response to a stimulus. So we know what should happen every time we do that. The knee jerk reflex is when they take the little rubber mallet and hit you on your patellar tendon and your knee jerks, right? So that's kind of cool. If you have an abnormal response to that, it's an indication that something is wrong.

Could be hydrocephalus, could be some type of intracranial hemorrhages, could be multiple sclerosis. It could be many things. So just doing that little test could help us identify something that's wrong.

We can also do... CT scans, MRIs, PET scans, you guys know this already. We use radioactive, so we would tie, we'll just tag you with a dye and then follow that dye to see what happens.

It helps us visualize specific areas. Cerebral angiography uses x-rays and again, a dye to help find out where the clots may be. And then of course, ultrasounds help us see the blood flow through the vessels, so the arteries of the brain.

That is central nervous system part three. Now part four is all spinal cord, but I'm going to make this so sweet and to the point for you. There are things we already know about the spinal cord because we did a general lecture on the nervous system in chapter 11. We know that the spinal cord has gray matter and white matter. We know that the spinal cord is of course part of the cerebral... excuse me, central nervous system.

So part of the CNS, the really cool thing to remember, the really cool thing, necessary, important thing to remember is that the spinal cord, I'm going to show you a picture of it cut in half so that we can see it. This is a really great pictures, but I want to show you something important. So I'm looking at the spinal cord here and this that I'm highlighting with the arrow, that's the gray matter. This is a spinous process, which you guys know is on the dorsal or the backside. It's the spine.

So then these two right here are called dorsal horns, or sometimes they're called posterior horns. These two up here are called the ventral horns or the anterior horns. And then the ones on the side are the lateral horns. So the ventral horns, the dorsal horns, and the lateral horns of the spinal cord are all gray matter, and they're in the center. or the core.

And then they're surrounded by white matter. What do we know about white matter? Myelinated fibers.

That's important. Now, another thing, just why we're here to make a connection for you. So since this is the spinal cord, these right here that come off the spinal cord, these are called nerves. You know what kind of nerves they are? Ready?

Hold on. Brace yourself. You'll never guess it. In a million years, they're called spinal nerves. The nerves that come off the spinal cord are called spinal nerves.

That's going to be PNS part two lecture. But anyway, so what's important to understand is that the entire nervous system, I told you I could wrap it up in three phrases. I said sensory input.

So sensory input is that stimulus, right? That is being perceived and going up to the brain for integration. Once the brain decides what that stimulus is. And what it wants to do about that stimulus, that's all the integration part, we're going to send a signal down to the effectors.

That's the motor part. So sensory input, integration, motor output. Now, the reason why I'm bringing this up, so notice how I flipped through pretty quickly of those other ones.

Look at why I brought it up. So this is some words, but I want to show it to you in picture. So let's go back.

This is, again, a picture. of the spinal cord. These are the dorsal horns back here. These are the ventral horns here.

And then these are the lateral horns. Look at what I see. I see SS and I'll tell you what it means, somatosensory.

I see VS, that means visceral sensory. So what is sensory? Sensation to the body or sensation to the organs.

So somatosensory is the sensation to your body and visceral sensation is sensation to... Your internal organs. Okay.

Sensory input. Sensory input is associated with the dorsal horns. Okay. Then we have, and by the way, this is like a dorsal root. And then we have the visceral motor and sensory motor, right?

I mean, a somatomotor, sensory motor. So what happens is sensory input from the body or internal organs, and then a motor output through the spinal nerves. So. we have the spinal cord that is gray matter.

And in that gray matter is somatosensory, visceral sensory associated with the dorsal horns. And then I have visceral motor and somatomotor associated with the ventral horn. So dorsal is going to be sensory and ventral is going to be motor. How cool is that? Like test enough cool?

Uh-huh. Test enough cool. And then we're going to learn more about it because we're going to get into the spinal nerves.

And there's like 31 pairs of those. All right. So now we have the gray matter. We have those four parts.

I need you to know that. I'm going to flip back because I want to talk to you about the corda equina. And I want to show it to you in a picture. I think it's, there we go.

So the corda equina is the fact that the end of the spinal cord looks like a horse's tail. So it says here. the inferior end of the spinal cord, right? So the last part of the spinal cord looks like a horse's tail.

So cauda is tail and equina is horse. That's test material because a lot of people were like, wait, a horse tail? Is that true?

Yes, it's true. All right. So now we know the gray parts of the central nervous system, important. I mean of the central system, but of the spinal cord, important. We know the four areas that are in those gray matter, so dorsal horns and the ventral horns.

And then we know that dorsal is sensory. The way that I remember dorsal for sensory is that dorsal has an S in it, whatever it takes to remember. So dorsal has an S, so dorsal is sensory, and ventral is motor. You are going to need to know that. So somatosensory.

Vinceral sensory, and then somatomotor, and then visceral motor. Somatomotor is literally your skeletal muscles moving. Okay. Let's see. So that's everything that's there.

Everything's there. I'm flipping through it because again, it's what I said, it's important and it's like test material. All right.

So what else is there? Dorsal horns. Okay.

Oh, if there's an association area, and we've already talked about this term already. But if there's association area, that means it's taking the sensory information, integrating it and understanding it. And it's, you know, it's in between the motor.

So the association is making sense of what's being sent up afferently. And then the dorsal horns is that part. And then the motor, which are the ventral horns, it's going to, you know, send out a motor response.

Association is the integration, the understanding of those two. So it's in between there. Um, so those are, they said those already showed you in the picture. Okay. And then, oh my gosh, what do we know about white matter?

Hmm. Myelinated fibers moving really fast. What? No way. Um, it says here that the white matter of the spinal cord runs in three directions.

Ascending means it's going up. What? No way. Descending means it's going down.

What? Motor? No way.

And transverse means it's going aside. So from side to side, the commissure fibers, if you guys remember. We had association fibers, which is the white matter on the same side of the cerebrum. Then we had the commissure, which is like the corpus callosum moving from one cerebral hemisphere to the other cerebral hemisphere.

Then we had the projection fibers that were going from lower brain centers to higher brain centers. So this transverse white matter within the spinal cord is going from one side to the other side. It should make sense to you because as you guys know, we are bilateral. We have two sides.

When I say that there's 31 pairs of cranial nerves, it's because there's one that goes to each side, pairs, right? So the transverse are the commissure fibers. What else as far as test the white matter?

We know that it's traveling really fast because it's white matter. Everything that's here showing the spinal nerves, we'll get into that. Again, PNS part two is literally spinal nerves. So you will see this picture again showing you the rootlets that are coming from the ventral end. So the rootlets go into the ventral root, and then there's the dorsal rootlets that go into the dorsal root.

And of course, that information travels from the dorsal horn and ventral horn. But anyway, let's see. So, okay, real important stuff again about this spinal cord stuff. We know that ascending is moving upward.

So that's sensory. We know that descending is moving down, going to the effectors. And we know that the effectors are and always will be.

Skeletal muscle, smooth muscle, cardiac muscle, and glands, right? We also know, because we talked about this already, on the medulla are pyramids. And if information travels along the pyramids, remember the two things that come up on the rise on the medulla oblongata? If information is descending on the pyramids, that means it's going down to the effectors, then it's direct motor. And that's going to come up in here again.

So if someone has damage to their spinal cord, they could be paralyzed, right? If their damage is in the cervical region, which is your neck, and you guys know that, then they would be paralyzed on all four of the appendages, both the arms and the legs, right? So they would be called a quadriplegic. Quad means four. If a person is paralyzed in the thoracic region and lower, then their lower appendages, two legs, would be paralyzed and that would be paraplegic.

So paraplegic and quadriplegic. But as you guys remember from the muscle contraction model, there's two types of paralysis. There's flaccid paralysis, which is the inability to contract. And then there's spastic paralysis. And spastic paralysis means you're in a state of continuous contraction.

and unable to relax. So when a person has paralysis, when we think of paralysis, they're paralyzed. But parathesius is where the person has no sensation. So there are people who cannot move their legs.

but can feel stimulus applied to them. Everybody get that? And then there are some people who lost both. If you've lost both, that means that the dorsal, which is sensory, and the ventral horns were damaged, right?

Because ventral would be the movement and dorsal would be sensory. So that's kind of cool when you, again, you know what I'm saying, think about the spinal cord. All right, so let's see.

Flaccid and spastic, talked about that already. Oh. paraplegic quadriplegic so said that already um quadriplegic cervical area paraplegic yep thoracic area lumbar um and then poliomyelitis um polio is caused by a virus um it's crazy though because it's a virus that is transmitted through a fecal oral route um and so the muscles atrophy death could occur from um paralysis of the respiratory muscle because again muscle right um could be paralyzed you could also go into cardiac arrest because the heart is up muscle, so it could stop working.

Survivors that get the virus and survive could have this post-polio syndrome and could develop neuron loss, so it becomes neurological. You guys remember the ice bucket challenges? That was for ALS or Lou Gehrig's disease, so amyotropic lateral sclerosis. What happens in this disease, so again, Lou Gehrig's disease, if you remember.

It says the destruction of the ventral horns. Well, what do we know about ventral horns? Ventral horns are motor. So a person with Lou Gehrig's disease is going to be paralyzed.

They're going to lose motor function. Let's see destruction, the pyramidal tract. The pyramidal tract, again, was the direct motor.

Anything that's on the pyramids is direct motor. Anything outside of the pyramids is extra pyramidal. The loss of ability to speak.

Remember, the tongue is skeletal muscle, and you control that. The pharynx is skeletal muscle. When you swallow, there's a pharyngeal phase. Then there's an esophageal phase. The pharynx is skeletal muscle.

The esophagus is smooth muscle. If you lose the ability to swallow, and you can also lose the ability to breathe, so then you die. Death typically occurs within five years. So ALS disease.

So they have this drug that interferes with glutamate signaling, and that's the only treatment. So remember, glutamate is... excitatory toxic in this scenario and if you interfere or inhibit it then you kind of try to keep some of the symptoms at bay but death is inevitable because there's no cure all right um let's see so when we look at the motor pathways again things that we already know we know at some point in time that a crossover happened right so when we talked about the medulla and we talked about the pyramids we know that discussion happened a crossover why Because the left cerebral hemisphere controls the right side of my body. The right cerebral hemisphere controls the left side of my body. So, disgustation, a crossover at some point.

The relay center is, again, like it sounds like if you've ever watched a race, a relay. A person takes a baton. They run a certain distance past the baton.

That person runs a certain distance, a relay. So, we have neurons. We have first-order neurons, second-order neurons, and third-order neurons.

And get this. The first-order neurons. get the signal first, and then they pass it on to the second order neurons. And then let me think what could possibly happen. Maybe the second order neurons pass it on to the third.

Oh, gosh, golly. Okay. We know somatotopy because we looked at the homunculi, which means that we know where movement is in relationship to specific areas on the brain.

We know how to delegate movement or how movement is. done through the brain, right? We've mapped it out. And then symmetry, it's paired, right? So I've always said the spinal nerves, there's 31 pairs, cranial nerves are 12 pairs that come off on both sides. So those are just some key points there.

And then this is just the understanding. Ascending means it's going up, first order neurons, then give it to second order neurons, then give it to third order neurons on the way up. And then of course, integration or understanding takes place.

And then the synatotopy, like I said, we already know. where everything's going to be passed through. It does say here that when we are going up through a third pathway, it says it terminates in the cerebellum. What do we know about the cerebellum?

Cerebellum is motor control. What are we talking about here? Ascending pathway so that we can get a motor control.

What? No way. And then one more thing, just to emphasize what we've talked about, about the parts of the brain.

It says a two pathway transmits somatosensory, you know, sensation to. the body, through the sensory cortex, through the thalamus. What? The thalamus.

And as you know, nothing gets to the... cerebral cortex without passing through the thalamus. Yep.

Okay. Let's see what else is there. I don't go through too much of these specifically, but just know ascending means it's sensory and it's going up.

And then they talk about the tracks, which is kind of cool. But anyway, this literally says, if you're going to look at terminology, spinal, like your spinal cord, cerebellar, like cerebellum, cerebellum is movement. It says, hey, guess what?

We use this to coordinate your muscle activity. Okay. And then- Let's go through the descending tracks. I've mentioned it already. So this is just kind of telling you about the ascending ones.

And then for the descending, it says we have two. It's either direct, which means it's going down the pyramids. We know that already. That's also called, pyramidal tracks are also called cortical spinal.

So cortex and spinal cord. And then indirect is anything that's not along the pyramids. Make sure you know that. And then they talk about the pyramidal track.

Then they show you how it travels through the brain, indirectus, extra pyramidal or outside of the pyramids. And then they break it down a little bit further, but I don't test you on this. But it's kind of interesting stuff.

So let's see just again, a little overview of the major descending, which is the motor pathway. So things to remember, ascending is sensory and it's going upward to the brain for integration. Motor is descending, it's going down to the effectors.

and the effectors are and always will be, skeletal muscle, smooth muscle, cardiac muscle, and glands. Additionally, I can say that a sensory is affective, like I'd be an affected, so afferent. And then I can say that motor is efferent, like effectors. So afferent, ascending, sensory, all the same thing.

Descending, efferent, like effectors, and motor. All the same thing. So descending motor efferent, ascending sensory afferent.

Make sure you know, because I can use those interchangeably in the exam questions. So again, just showing you the motor pathways. Now some imbalances. Cerebral palsy, neuromuscular disability. What happens is, is that a lot of times the spinal cord is not developed well and maybe like, you know, outside of the body a little.

Anyway, so. damage could be due to lack of oxygen. Oh, wait, no, I'm sorry. What was I thinking about with that?

Oh, I just had a brain fart about what I, spina bifida is the one with the, okay, so sorry. Cerebral palsy could be just lack of oxygen, could happen when the person was being birthed. And as a result of that, there's going to be, you know, the brain's not getting oxygen.

So spina bifida is the one where the spinal cord is outside the body. Okay, sorry. Anyway, so spasticity, speech development, motor impairment could be there.

They could have seizures, intellectually impaired, not because of the seizures, but just because of the lack of oxygen to the blood. They could be born deaf as well, and they could have visual impairments. Because again, I'm not getting enough oxygen to the brain. And the brain, as you know, has several parts that have several functions. And then this anencephaly, this is where parts of the brain don't develop.

So it's like, you know, unfortunately, they will be vegetables. You've heard of that. So there's no cognition and neural ability.

Um, and a lot of them die soon after birth because it's just not developed enough. It's like being born without parts of your brain. Um, and then spina bifida, um, like I said, it's going to be like outside the part of the spinal cord is going to be outside of the body. It wasn't fully developed properly. Um, so spina bifida oculata is the least serious, um, form of that.

And it's just a few missing vertebrae and there's no neural problems that are associated with that. But spina bifida cystica. is the most severe and the one that's the most common. That's sad. With this one, there is a lot of severity that's associated with it.

So a sac like cyst protrudes from the spine. So you can see it externally. It's like outside of the body, no lie. It could have cerebral spinal fluid in there. It could have parts of the spinal cord and the nerve roots that are in there.

So when you surgically repair that, there's definitely going to be a neurological effect. So mental capacities are going to be diminished with that. We could also see this with a person that has hydrocephalus.

And then this could happen when a mother is pregnant and she's not getting the folic acid. And we talked about this before when at the very beginning when I told you that the brain and the spinal cord came from the neural tube. So you have neural tube birth defects that interfere with the development of the brain and the spinal cord.

And as a result of that, you can get some severe outcomes. All right, so that is the end of the lecture. And I'm going to stop recording and then I will take your.