| 00:06 | So what I wanna do is I start here today. Um Actually, |
|
| 00:11 | should probably make sure my things working and just make sure we understand signal |
|
| 00:17 | or the visual transaction pathway. it's on. So, I want |
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| 00:25 | to imagine for a moment that there's light. Okay, so the picture |
|
| 00:29 | light but we're gonna pretend there is light up there. So when there's |
|
| 00:33 | light, this receptor is turned on ? Or it's sorry, it's not |
|
| 00:39 | on. What's happening though is that have guana. Late cyclists, cyclists |
|
| 00:44 | constantly making so there's our guan elite constantly making cyclic GMP. I wanna |
|
| 00:51 | cycling GMP. We have lots of GMP inside the cell. We're all |
|
| 00:54 | with that. We have lots of GMP in the south, that means |
|
| 00:57 | have a lot of cyclic GMP to able to buy into these receptors. |
|
| 01:00 | channels. These are the CNG channels allow calcium and sodium to come |
|
| 01:04 | So when that happens, we have of calcium and have a lot of |
|
| 01:07 | in cell is d polarized. All . And that's our natural state in |
|
| 01:11 | darkness. So, we're all good that. Right. That's weird because |
|
| 01:14 | backwards from what we're normally used to when light comes around. What happens |
|
| 01:19 | is that changes the shape of that molecule from the cIS to the transform |
|
| 01:24 | ? When we change the shape of ligand. What we're doing is we're |
|
| 01:27 | changing the shape of the receptor, change the shape of the receptor we |
|
| 01:30 | the G protein. When we activate G protein G proteins now acting on |
|
| 01:34 | different enzyme. That enzyme is phosphorus so far so good. When I |
|
| 01:40 | on foster diasporas, phosphor phosphor jobs take cyclic GMP and desiccated. |
|
| 01:46 | ? In other words, it makes from cyclic GMP to regular GMP. |
|
| 01:50 | , just clips basically breaks the bond you're back down to normal. When |
|
| 01:54 | am doing that. When I'm getting of cyclic GMP, the levels of |
|
| 01:58 | GMP are getting lower. Right? cyclic GMP. Nothing to hold those |
|
| 02:04 | open. Nothing holding those channels No calcium sodium coming into the |
|
| 02:09 | calcium sodium coming into the cell cell polarizes. So, that's when we |
|
| 02:16 | back to this thing right over here I know that I jumped over this |
|
| 02:20 | . You know, as I'm racing the end yesterday. Right, so |
|
| 02:26 | this And this make sense together. heads are nodding the rest you're going |
|
| 02:34 | don't know what he's talking about. I'll figure it out before the |
|
| 02:38 | three heads are nodding. four heads nodding. Okay, all right, |
|
| 02:43 | I need to do I need to this slide again. Okay, so |
|
| 02:46 | I just described is all the stuff going on up here. Right, |
|
| 02:49 | you can see there's assist there's trans are open channels are closed. D |
|
| 02:54 | hyper polarized as a function of the polarization. What I'm doing is I'm |
|
| 02:58 | a neurotransmitter. That neurotransmitter is an neurotransmitter. If its inhibitory it's telling |
|
| 03:04 | cell downstream you're not allowed to do you're supposed to do. It's basically |
|
| 03:08 | on the brake and saying don't go it's pressing on the brake and saying |
|
| 03:13 | go, that's inhibition. That means not releasing the neurotransmitter down here because |
|
| 03:18 | told not to and because I'm not neuro transmitter, I'm not activating the |
|
| 03:23 | cell in the chain which is a cell that cell doesn't fire. So |
|
| 03:27 | perceive darkness, right? So that's going on when it's dark. No |
|
| 03:34 | there go. My brain sees dark the light. We described all those |
|
| 03:41 | . I'm no longer released that So I'm no longer pressing on the |
|
| 03:46 | . If I'm not pressing on the , what do I do I |
|
| 03:51 | right, try this out of You're pressing on the brake when the |
|
| 03:56 | goes from red to green, don't on the accelerator, just take your |
|
| 03:59 | off the brake. Do you Yeah that's what's happening here, is |
|
| 04:04 | I'm removing the brake. So now go and I'm now releasing a |
|
| 04:09 | That neurotransmitter is telling the ganglion cell . So I produce action potentials. |
|
| 04:16 | brain now proceeds or perceives light that's gist of visual transaction. Now pas |
|
| 04:27 | more complicated than that. Alright but our purposes today and not for the |
|
| 04:32 | souls who are going on to optometry and who plan on studying this for |
|
| 04:38 | rest of your life. There's there's types of bipolar cells, there's different |
|
| 04:42 | of ganglion cells and there the whole gets really, really confusing and I |
|
| 04:46 | want to deal with that today. just want to deal with this little |
|
| 04:49 | here so that you can understand the two, step two, step five |
|
| 04:53 | steps. What am I changing in steps now? What I want to |
|
| 05:00 | out also is that the system I described is very binary. Right. |
|
| 05:04 | mean, I'm basically saying it's on it's off. Right. And so |
|
| 05:08 | can imagine with lots and lots of getting from on to off would be |
|
| 05:14 | tiresome or quite difficult to do because would have lots of calcium and lots |
|
| 05:18 | sodium and to you know, get of all that calcium. And so |
|
| 05:22 | have to have pumps in place to kind of remove that. So very |
|
| 05:26 | when you see systems like this, see modulators within these systems, I'm |
|
| 05:29 | show you two modulators that allow us get those that on and off a |
|
| 05:33 | closer. So what we're looking at is in the state of darkness, |
|
| 05:38 | the state of light and what we associated with the guano cyclists as a |
|
| 05:42 | called G cap and the cap what does, it regulates how active the |
|
| 05:47 | the cyclist is. And so it's of its its its ability. So |
|
| 05:52 | kind of like a break that's acting the on the gauntlet cyclists. And |
|
| 05:58 | to apply the brake, what I to have I have I have a |
|
| 06:01 | to have to have a lot of available. So in the dark when |
|
| 06:05 | channels are open I happen to have of calcium inside the cells with lots |
|
| 06:09 | calcium inside the cells. I'm binding to that G. Cap. That |
|
| 06:14 | cap is now putting the brake on late cyclist. So instead of making |
|
| 06:19 | and tons of guano late cyclist, just making enough to keep that channel |
|
| 06:25 | . So when that light signal comes , what do I have? I |
|
| 06:29 | have to remove a lot of cyclic . Right, so I have just |
|
| 06:34 | to keep this open. So when phosphor diaries comes along, it starts |
|
| 06:38 | it very quickly. And let's just just gonna make up numbers. So |
|
| 06:41 | of having 100 molecules to remove, only have two molecules to remove. |
|
| 06:45 | it's a lot easier to get to state where this is closed. And |
|
| 06:49 | I can get my hyper polarization. of course when that channel is closed |
|
| 06:53 | hyper polarized, my calcium levels So what does that mean? I'm |
|
| 06:58 | longer pressing on the brake so I make up a bunch of cyclic GMP |
|
| 07:03 | that this can now become open. I can revert between those two states |
|
| 07:10 | more quickly. That kind of makes . It's like being on a |
|
| 07:15 | being in the middle of the I can balance it a lot quicker |
|
| 07:18 | move back and forth fairly quickly. ? But if I was going from |
|
| 07:21 | end of the seesaw to the other , it takes more time to get |
|
| 07:24 | to to move right, That's what is doing. It's basically bowing us |
|
| 07:30 | balancing us close to on and right there in the middle so that |
|
| 07:34 | shifting like this instead of going like so G cap is an example of |
|
| 07:39 | regulator that modulates how this works. place where we see calcium doing this |
|
| 07:45 | at the level of the channel. , again, I described the channel |
|
| 07:50 | being open and closed. Right cycle binds it. It's open cycle GMP |
|
| 07:57 | removed. Closed. Alright. But have cal module and we talked about |
|
| 08:02 | module in earlier, just as a a defector. And so here what |
|
| 08:08 | is is cal module in when it's up by calcium. What it does |
|
| 08:13 | it modulates the state of openness. , so it's still open. It's |
|
| 08:18 | not as open. Right? Think a door, right? You can |
|
| 08:21 | a door kind of open. Mostly all the way open, right? |
|
| 08:26 | basically blocked open, I guess is way you can do it. And |
|
| 08:28 | what this is doing is basically saying right, I'm gonna modulate how far |
|
| 08:32 | door is open to regulate how much these ions are actually coming in. |
|
| 08:37 | the more calcium that comes in, . More calcium comes in but less |
|
| 08:43 | I have towards binding up cyclic So again, what am I |
|
| 08:49 | I'm getting myself closer to that state open and close a lot faster. |
|
| 08:53 | if cyclo GMP has less affinity to even though I should be able to |
|
| 08:59 | it up further, it's like no no. Just open up just a |
|
| 09:01 | bit so just a little bit of can come in, a little bit |
|
| 09:04 | sodium can come in so that when doors start shutting they don't have to |
|
| 09:09 | through multiple stages of shut. It's and I'm done. So you see |
|
| 09:14 | I've done and I'm modulated. It's a binary system. So these systems |
|
| 09:18 | far more complex. And what I want you to take home from these |
|
| 09:22 | , these two little slides here is calcium serves as a modulator in these |
|
| 09:28 | at the level of the channel and the level of the quantum cyclists to |
|
| 09:33 | how how quick the system responds to . All right. And this isn't |
|
| 09:40 | only place you'll see these in the , they're all over the place. |
|
| 09:43 | I wanted to get to that so you understand that. So one of |
|
| 09:49 | things we talked about um with regard the photo receptor cells. The rods |
|
| 09:54 | cones. Yeah. Go ahead. . No no that's good. Like |
|
| 09:59 | is not binary. Right. And that's on the level of like |
|
| 10:03 | whole cell. What about like a I. Or no. So so |
|
| 10:15 | you would say is that again I'm I can't remember how many exactly. |
|
| 10:19 | think it's like it has four binding . I cannot remember actually how many |
|
| 10:25 | is. Probably says right there but cut it off. Right. And |
|
| 10:28 | the idea is that there's basically four of affinity. So there's a high |
|
| 10:33 | and then the next one the first that binds lowers the affinity and the |
|
| 10:36 | one lowers even further lowers even further finally to the last state it's still |
|
| 10:42 | but the probability of opening that. each individual channel is now responding to |
|
| 10:48 | availability of calcium cal module in and much is actually bound by it. |
|
| 10:54 | is kind of interesting. Right? mean that there's all these systems in |
|
| 10:58 | to kind of control this stuff so you have a greater ability to adjust |
|
| 11:03 | activity. Yeah. Right. So here I was basically saying just think |
|
| 11:16 | it. I mean the way I it is kind of like either you |
|
| 11:19 | a lighter you have dark so that's of an honor and off system. |
|
| 11:24 | . So well this is but what saying is we didn't describe it. |
|
| 11:28 | here now what we've done is we've our binary system of basically the system |
|
| 11:34 | turned off here now it's turned And what are we doing is we're |
|
| 11:38 | the degree of excitement by the availability the calcium. Right? So it's |
|
| 11:44 | easier to move from here to here I don't have to get rid of |
|
| 11:47 | that uh cyclic GMP is really what is. Right, I only have |
|
| 11:52 | couple of molecules in other words, about trying to empty this room. |
|
| 11:55 | are about 120 of us. Probably 80 of you in here right |
|
| 11:58 | Alright. Right. So to get of all of you, each one |
|
| 12:03 | you have to have to leave the . Right? But what if we |
|
| 12:06 | able to get rid of most of before we started telling you to get |
|
| 12:10 | of you? It would be easier get you out of the room. |
|
| 12:14 | would be easy to get you back the room if I'm basically tilting with |
|
| 12:17 | people. Right? It's a terrible , but at least you guys are |
|
| 12:21 | who can recognize numbers. So. , so that's what we're going on |
|
| 12:28 | . Alright, so, dark adaptation to do with really the um ability |
|
| 12:34 | our eyes to see in varying degrees light and it's the result of both |
|
| 12:39 | rods and the cones. So what said is that cones primarily play a |
|
| 12:43 | in day vision, rods play a role in night vision that they are |
|
| 12:49 | rods are very sensitive to two photons cones take are less sensitive. All |
|
| 12:56 | . And that we also have the . The acuity comes from when the |
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| 13:00 | the cones are stimulated there, right in the front and so we have |
|
| 13:03 | of vision, whereas the rods are of distributed on the periphery. So |
|
| 13:07 | kind of give us kind of a idea of what's going on. And |
|
| 13:10 | what this dark adaptation is is basically , look, we're adapted to be |
|
| 13:16 | a nocturnal and diurnal animal. I we're not technically nocturnal but we can |
|
| 13:22 | okay in the dark, not I mean, like I said, |
|
| 13:26 | you wake up in the night and have to go to the restroom or |
|
| 13:28 | , you can manage your way around room because you can kind of see |
|
| 13:33 | and that's a function of the few you get alright, this is what |
|
| 13:38 | referred to as co topic vision. ? So you're these are this is |
|
| 13:43 | dependent vision. So all you need a couple of photons of light and |
|
| 13:45 | enough to excite your eyes to be to see general shapes and general uh |
|
| 13:52 | and things, but it doesn't give a good clear view of what's going |
|
| 13:56 | photo topic. Vision on the other is co independent. So when you |
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| 14:00 | so much light, what happens is over saturate the rods and the rods |
|
| 14:06 | bleached out? And so now you're that point where the cones are being |
|
| 14:11 | and so now your day vision is of taking over. All right, |
|
| 14:15 | think about right now this room is of dark. I'm staring straight into |
|
| 14:19 | bright light, but when you go it's really bright. Right? And |
|
| 14:23 | what you've done is you've basically bleached all your rods And now only your |
|
| 14:26 | are kind of functioning there over the are overwhelmed and so they're basically dealing |
|
| 14:32 | and that's this dark adaptation. so when it's dark, right, |
|
| 14:37 | cones aren't quite so stimulated. Things kind of bleached or not bleached out |
|
| 14:43 | kind of fuzzy, kind of hard tell what things are hard to detect |
|
| 14:47 | because you don't have enough light to able to do that, Right? |
|
| 14:52 | when it's lighter and I know this a terrible example because it's just a |
|
| 14:55 | . It's much better when you turn on and off, colors are |
|
| 15:00 | Right? Why? Because my rods working faux topic sco topic. |
|
| 15:08 | I'm sorry. Yes, cones on left, rods on the right. |
|
| 15:12 | right, now, just to help understand this a little bit better. |
|
| 15:16 | a mythbusters that came out like 10 ago and they asked the question? |
|
| 15:19 | was a dumb question because it's not real question, but it was why |
|
| 15:23 | pirates wear a patch over there? All right. And the the question |
|
| 15:28 | they're asking is did they do it preserve dark adaptation, their ability to |
|
| 15:34 | in the dark. So you can of the other way when my when |
|
| 15:37 | rods are bleached, when I go a dark space, notice it takes |
|
| 15:40 | while for your eyes to get adapted that, to that light and then |
|
| 15:45 | versa. When I go from a space into a dark space, I |
|
| 15:48 | see squat. I probably just said twice and my brain just hiccuped |
|
| 15:52 | Alright, so what they wanna they think that the reason that you |
|
| 15:58 | pirates with the patch other than that a artistic choice is that you could |
|
| 16:03 | one eye up. Should do it way. Cover up one eye and |
|
| 16:06 | it's dark adapted, right? You're out through one eye and you're kind |
|
| 16:10 | viewing your bite. So here you up on dec sunny and stuff like |
|
| 16:14 | . But now you got to go and fight some poor sailor in the |
|
| 16:18 | decks. And so what do you if you went down there? The |
|
| 16:21 | in the lower deck would have the in the fight. So what do |
|
| 16:24 | do? You go downstairs? You up that you have a dark adapted |
|
| 16:29 | Now you can see well. All . And they actually did a huge |
|
| 16:35 | to see if it was true and actually did work now. Did pirates |
|
| 16:39 | do that though? I think that really just a artistic choice. Pirates |
|
| 16:43 | wear patches for that reason. But could Alright, so does faux topic |
|
| 16:50 | sco topic make sense. Does the of dark adaptation? It's basically I'm |
|
| 16:55 | use different types of photo receptors for quantities of light stimulation. That makes |
|
| 17:03 | . Okay, we've already talked about so I'm not gonna waste our time |
|
| 17:07 | what I'm gonna do is I'm gonna into how the ears work and then |
|
| 17:12 | last thing we deal with is we're deal with reflexes and then really how |
|
| 17:16 | the brain map this stuff? All . For all the things that we |
|
| 17:20 | looked at? So if you think it, what are we talked |
|
| 17:22 | We've talked about gas station and What type of things are we detecting |
|
| 17:26 | both those things chemicals? Good. . When we looked at vision, |
|
| 17:31 | were we detecting light, which is form of electromagnetic radiation. And so |
|
| 17:37 | what we're doing is we're shifting gears we're looking at two different receptors that |
|
| 17:40 | mechanical receptors. They're looking at the of things, which is kind of |
|
| 17:46 | because when you think of sound is movement are you listening to movement? |
|
| 17:51 | what you're doing is you're you're moving in the ears and it's that movement |
|
| 17:57 | that fluid that is going to be by the receptors. And so that's |
|
| 18:02 | we're actually detecting. Is that particular . And so this is our actual |
|
| 18:08 | that we're going to be looking at , this hair cell, the hair |
|
| 18:11 | is our mechanic receptor. And what gonna do is these hair cells have |
|
| 18:15 | them, they have these penicillium and can see them here. All |
|
| 18:19 | we have a penicillium on the front then on the back side we have |
|
| 18:22 | stereo cilia. They're all connected to other. And at the end of |
|
| 18:26 | of these, we have a bunch channels. And so when the hairs |
|
| 18:31 | bent one way or the other, gonna open or we're going to close |
|
| 18:33 | channels. Typically when we've been towards , we're opening the channels when we've |
|
| 18:37 | away. We're closing those channels. . And so here you can kind |
|
| 18:41 | see that they look like a bunch asparagus stacked up together. But you |
|
| 18:45 | see if I bend one way they're cause these channels open. They're basically |
|
| 18:51 | the manipulation of those steri silly that those channels open. That's the mechanic |
|
| 18:55 | portion. Alright. And so we're do this for two things for the |
|
| 19:00 | of equilibrium, which is understanding our of our head in space. We're |
|
| 19:04 | be using the vestibular apparatus to do . And the other is audition audition |
|
| 19:09 | we're looking to see what sorts of , What sort of vibrations in the |
|
| 19:15 | we're able to detect. We could say it's under the water, but |
|
| 19:18 | typically are out in air. So, this tells you what your |
|
| 19:25 | is, how you're moving so on so forth. This allows you to |
|
| 19:28 | with people around you. All So, this is trying to show |
|
| 19:33 | that mechanic reception. Alright. when they're not been, there's gonna |
|
| 19:37 | some slightly polarization. But typically what was trying to get at is as |
|
| 19:41 | bending forward, that's gonna open up potassium channels, fluid flows in or |
|
| 19:45 | , potassium flows in. That's gonna the deep polarization, right? Um |
|
| 19:51 | the reason for this is that the are actually backwards, and we'll see |
|
| 19:55 | in just a second. And then they bend out the other way, |
|
| 19:58 | gonna get hyper polarization. And so basically tells the cell to stop |
|
| 20:02 | And so we don't get a Alright, So, bending towards penicillium |
|
| 20:07 | , bending away from the psyllium or penicillium deactivation. So, where are |
|
| 20:14 | spending our time? We're in the ear. Alright. And there's three |
|
| 20:18 | here within this unique uh apparatus that looking at. It's right here. |
|
| 20:25 | right. And what we have is is the temporal bone and inside that |
|
| 20:29 | bone we have this structure that is bony on the inside and then there's |
|
| 20:33 | bunch of membranes on the inside that out the structures and the actual |
|
| 20:41 | All right. So in the bony of our inner ear, we have |
|
| 20:46 | that's called parallel. This is very to the interstitial fluid on the inside |
|
| 20:51 | the member member portions. And that's the red stuff is supposed to try |
|
| 20:55 | show you here relative to the green has in the lymph which is like |
|
| 20:58 | fluid. So when I said it flipped backwards, that's what I |
|
| 21:01 | Is that the concentrations of ions are of flip backwards to what you're used |
|
| 21:06 | thinking. So the three structures were in. We have the cochlear, |
|
| 21:11 | cochlea is the instrument. That is we're going to find the cochlear ducts |
|
| 21:16 | specifically the spiral organ. The spiral is what detects the movement of fluid |
|
| 21:21 | this indolence, That movement being caused sound waves hitting structures to cause it |
|
| 21:26 | move. And that's how we detect . The other two structures are the |
|
| 21:32 | . So this region right here is vestibule. And then you see we |
|
| 21:35 | a series of semi circular canals within vestibule. We have two organs. |
|
| 21:39 | you trickle in the sack, you'll in the semi circular canal we have |
|
| 21:42 | semicircular ducts. These detect motion of head. All right, and they |
|
| 21:48 | so in slightly different ways. So two are used for equilibrium and |
|
| 21:53 | This is used primarily for hearing. right. So what I wanna do |
|
| 21:59 | I want to start in the The vestibule has the you trickle in |
|
| 22:04 | actual And what we are looking at , these you trickles and pools are |
|
| 22:08 | are called organs. All right. have with them. I'm just gonna |
|
| 22:13 | you right now, there's three words are gonna sound very similar to each |
|
| 22:16 | . So you just gotta make sure know where they are. We have |
|
| 22:18 | macula. Macula is like a plate jell o. Alright, a gel |
|
| 22:24 | substance and embedded in this gel like . Are these little tiny crystals called |
|
| 22:29 | ? It's just calcium carbonate. and the reason we have these calcium |
|
| 22:33 | crystals embedded in this gel like substance because it gives the gel like substance |
|
| 22:38 | . All right. When you were high school, did you get jello |
|
| 22:41 | the cafeteria? No, you never jello at the cafeteria. Never |
|
| 22:47 | No, you are a sad, deprived generation. We always had jello |
|
| 22:55 | I remember having jello eating contest. were awesome. You get this thing |
|
| 22:59 | jello and you kind of wiggle a bit and then that was it right |
|
| 23:03 | to make jell o wiggle more is put things in the jello. |
|
| 23:09 | if you have like a great see now we're talking separate, you |
|
| 23:14 | , she has the jello and she the grapes and the fruits and all |
|
| 23:17 | other scary things in the jello and you shake a normal gel and it |
|
| 23:21 | like wiggle wiggle wiggle and then If you have something in the |
|
| 23:24 | you go wiggle wig wig and it sits there and just keep going. |
|
| 23:27 | this incredible amount of inertia. So can imagine calcium carbonate crystals in these |
|
| 23:34 | are going to have incredible inertia. when you start moving, that mass |
|
| 23:40 | that macula to really move now embedded your macula. So this is what |
|
| 23:46 | picture looks like, right? So your carbon calcium carbonate crystals, your |
|
| 23:51 | thing right here, that is your and look what's embedded in the |
|
| 23:57 | What do you got hair cells? their fancy name. Why? Because |
|
| 24:02 | have the penicillin, the stereo So, as you can imagine, |
|
| 24:07 | got these hair cells embedded in Now what's interesting is the way that |
|
| 24:10 | range, you can see that there's reversal line, we're not gonna worry |
|
| 24:13 | reversal lines right now, but it to let you know which side of |
|
| 24:17 | brain is being or which way you're of moving because each side is going |
|
| 24:20 | do the opposite. And so it's it's a way for your brain to |
|
| 24:25 | down kind of movement. But you imagine for a moment that if I |
|
| 24:29 | pulling this way, right? If start moving in that direction, the |
|
| 24:33 | is gonna move in this direction, because of inertia, right? You're |
|
| 24:39 | familiar with that, right? So you're getting a card, you press |
|
| 24:41 | the gas, right? Because you're , you know, you're at the |
|
| 24:45 | sign and you realize you know at red light and it's like, |
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| 24:48 | I'm just gonna go green when it green. I've got to get in |
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| 24:51 | of this person over here because I'm Houston and that's the way it |
|
| 24:54 | Right? So I'm gonna press on gas. What do you do? |
|
| 24:57 | feel yourself pressed back? All So that's basically you're feeling that inertia |
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| 25:03 | body wants to stay back but the is pushing you forward and that's the |
|
| 25:06 | thing is going here. The macula move this way. So you can |
|
| 25:10 | the hair cells are being bent along the macula. So these hair cells |
|
| 25:14 | are on this side would basically close one on that side would open and |
|
| 25:18 | that that combination of movement is what be sent up to the brain to |
|
| 25:22 | you, hey, you're moving in particular direction. Alright. That's kind |
|
| 25:25 | how all this stuff works for these . All right. So, we're |
|
| 25:32 | primarily with linear acceleration. Alright, , I'm gonna make sure you guys |
|
| 25:39 | this stuff because it's been a long that you guys have probably played with |
|
| 25:44 | . Remember vectors? What are vectors and magnitude? If you don't remember |
|
| 25:52 | , you have to go back and Despicable me because who was the villain |
|
| 25:58 | ? And he did crime with magnitude direction. Alright. And those lines |
|
| 26:06 | they always show you show you It's the direction in which I'm going. |
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| 26:09 | its magnitude and the direction magnitude the . All right. So that's what |
|
| 26:13 | want to know is we want to which way are we going? All |
|
| 26:17 | . So the two structures the you and it's actually the yew trickle has |
|
| 26:22 | cells. These stereo Celia pointing So which way is that? Which |
|
| 26:27 | are the health, health hair cells like this? So that means the |
|
| 26:32 | is sitting on top and that means hair cells are gonna be bent this |
|
| 26:36 | . So which way are you going ? Okay, so when you see |
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| 26:41 | trickle think horizontal. Alright. And I'm not gonna ask this question, |
|
| 26:46 | Kenneth Seeley are pointing towards the reverse line. The sack you on the |
|
| 26:50 | hand has hair cells that are pointing . Which is which direction like |
|
| 26:57 | That means the macula sits this So it's detecting vertical motion. |
|
| 27:04 | so top me speeding in my That's the you trickle. Bottom |
|
| 27:10 | You'll that's me going up and down an elevator. All right. Or |
|
| 27:14 | you want to have fun with the dungeon drop. Do you remember |
|
| 27:18 | drops. Okay. They used to used to have astral world. I |
|
| 27:22 | to be able to tell that people Yeah, I remember now it's like |
|
| 27:25 | I have to go all the way to san Antonio go to six |
|
| 27:28 | Whatever fiesta texas. Maybe you've been a dungeon drop. I know where |
|
| 27:34 | is. Go down to chemo go to the aquarium downtown. They |
|
| 27:39 | one at each of those. It's tiny one at the aquarium. All |
|
| 27:44 | , So sexual vertical motion. You horizontal motion. Now this is a |
|
| 27:51 | simplified explanation. I want you to if I'm in an airplane and I |
|
| 27:56 | going, do I have a horizontal ? Yeah, I do have a |
|
| 28:01 | component. Yeah, vectors. So you understand that? It's not |
|
| 28:06 | solely this. You have to consider these things at the same time when |
|
| 28:11 | get to the semicircular canals. On other hand, what we're dealing with |
|
| 28:14 | angular motion. Alright, so think to physics one where you got the |
|
| 28:19 | thing, I don't know if you did the experiments, but you put |
|
| 28:22 | rock on the rope or weight on rope and you spin it and you |
|
| 28:25 | to calculate angular acceleration, blah, blah. Figure out what your velocity |
|
| 28:29 | from all that fun stuff for. haven't taken physics one. You get |
|
| 28:32 | do that. All right. So semicircular canal is looking at angular motion |
|
| 28:39 | three planes. There's three of You have one in the anterior |
|
| 28:43 | You have one in the post airplane then you're gonna have one in the |
|
| 28:47 | what's the other one I have up tonight? Let's just lateral. Thank |
|
| 28:52 | . Just like I always think Y. Z. It's easier. |
|
| 28:55 | . Y. Z. Right? so you can imagine I have this |
|
| 29:00 | and at the end of each loops have these ambulance and continuous structure with |
|
| 29:04 | vestibule. And so fluid is flowing that structure and at the very bottom |
|
| 29:09 | this ambulatory. Alright you see macula to at the bottom of this |
|
| 29:15 | We have a speed bump. And that speed bump fills up the |
|
| 29:20 | area and then you can see it's like a macula, it's basically a |
|
| 29:23 | like flap that sits in the way in that speed bump you're also gonna |
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| 29:27 | a bunch of hair cells. And what it's looking for is the flow |
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| 29:31 | fluid across that speed bump. That bump in the ambulance called a |
|
| 29:36 | So ampule a couple. A macula need to know which one goes |
|
| 29:41 | All right. So when I turned head for example like so I have |
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| 29:46 | on each side, the angular face so so they're opposite lee faced. |
|
| 29:50 | so the fluid flows in the same but they're causing the cupolas to |
|
| 29:56 | And well if I'm turning this way had been this way couple would have |
|
| 29:59 | that way. And so it's the of that bend on each side. |
|
| 30:03 | tells my brain. oh you're turning head immediately or? Oh you're turning |
|
| 30:08 | head laterally. All right, so the flow of the fluid being detected |
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| 30:14 | the bending of the cupola and the cells stuck in that cupola in the |
|
| 30:19 | pula to allow that to happen. now you want to experience this much |
|
| 30:25 | clearly. You can head down to Museum of Fine Arts or you can |
|
| 30:29 | down to um to kema boardwalk or can go to basically any place that |
|
| 30:35 | doing spring break and you're gonna find structures that are human gyroscopes. Have |
|
| 30:39 | seen these three rings? You're nodding head like you've done this. |
|
| 30:44 | Okay, it's just awesome. Do do a couple of shots of |
|
| 30:49 | your favorite beverages you have kept that and clean. They strap you into |
|
| 30:54 | thing and it's basically three axes. start spending you one way in the |
|
| 30:57 | one and they spend the next one then they spend the third one. |
|
| 31:00 | then you're doing this stuff and you'll to experience how your semicircular canals work |
|
| 31:04 | you don't throw up first. Now do have one at the Natural Science |
|
| 31:09 | . I don't think they let you before going in on that one, |
|
| 31:12 | spring break, they'll they don't So All right, so here angular |
|
| 31:19 | . Alright again, taking off in airplane. Which ones are working? |
|
| 31:27 | this one working? Is that angular ? I'm starting to go up up |
|
| 31:32 | this. Yeah. My head tilts its angular acceleration. What about the |
|
| 31:38 | ? Sorry, what about the you ? Is it gonna be uh sending |
|
| 31:43 | ? What about the sack? Is gonna be sending signals? Yeah of |
|
| 31:46 | . All three of them are working three at the same time. But |
|
| 31:50 | I ask you on a task which is responsible for horizontal acceleration? Which |
|
| 31:54 | is it gonna be? You trickle I ask about what about vertical |
|
| 32:00 | Which is it gonna be? And I tell you about angular acceleration, |
|
| 32:03 | it gonna be good? So understanding greater complexity but we're keeping our lives |
|
| 32:09 | . Okay that's equilibrium in a Yeah. Go ahead. I think |
|
| 32:14 | Yeah. Mhm. That's gonna be canals. Alright. Semicircular canals. |
|
| 32:22 | when you nod your heads, Which is it gonna be? If you |
|
| 32:29 | to guess which one is it gonna ? What's my head doing? Look |
|
| 32:36 | my head. Semicircular, it's rotating an axis, isn't it? |
|
| 32:43 | The true answer. Semicircle canals. all three of them. All |
|
| 32:48 | But look at the angle when I my head, my body's you recognize |
|
| 32:55 | you're upside down. How do you that? You're upside down. Do |
|
| 32:58 | think that the locals and sexual are affected. What do you think about |
|
| 33:02 | you think? Semicircular. Of Alright. But on the test we're |
|
| 33:06 | keep it simple. simple. So angles when it's an angle. I'm |
|
| 33:11 | asking if you know its semicircular. I'll say if you're speeding in a |
|
| 33:16 | , right, just picture yourself driving the highway to Galveston's. It's |
|
| 33:20 | Simple. You know, what would be? Okay? You get the |
|
| 33:26 | cords get clipped. It's not a elevator so it doesn't automatically stop start |
|
| 33:33 | sexual. You can ponder that on way down. Yeah. All |
|
| 33:41 | So there's a lot of anatomy with ear that I don't want to spend |
|
| 33:44 | lot of time talking. So just familiar with some of these structures. |
|
| 33:48 | gonna talk about them. But like external ear I'm not going to talk |
|
| 33:51 | just know what the name is. uh For the sake of understanding. |
|
| 33:58 | I don't want to waste our Alright. Just be familiar with it |
|
| 34:02 | so that you can kind of guide way around it. What I want |
|
| 34:05 | get to is I want to talk how sound moves into the ear. |
|
| 34:11 | so what we have is sound waves going to be captured by the |
|
| 34:16 | I want you to look at your ear. Look at how weird it |
|
| 34:20 | . Everyone hides their ears all of sudden let women are just like, |
|
| 34:24 | . Look at an ear. It the weirdest looking structure on your |
|
| 34:29 | I mean it looks like a dried . Why? And the reason is |
|
| 34:36 | it directs sound specifically to the external meeting or the auditory canal. You |
|
| 34:43 | use either of those terms or the auditory. It's actually it's not Matus |
|
| 34:49 | , alright. And what you're doing you're basically directing some so that travels |
|
| 34:53 | the tim panic membrane and then the panic membrane begins to vibrate at the |
|
| 34:57 | frequency as that sound wave that you're you're that is being directed by your |
|
| 35:04 | . Your ear doesn't change the It just changes the direction of it |
|
| 35:09 | that it goes where it needs to . Now. We're going to focus |
|
| 35:12 | in the middle ear. In the ear we have three bones and these |
|
| 35:16 | are called the obstacles. Not to confused with. The O'Dell lifts, |
|
| 35:20 | know, two words with O. the same structure is kind of confusing |
|
| 35:24 | . Little tiny crystals, obstacles. bones were really tiny bones, but |
|
| 35:28 | bones all right. The three bones learned at some point your life that's |
|
| 35:32 | the valley of the Incas and the peas. If you haven't heard of |
|
| 35:34 | those words, you probably heard the , the anvil and the stirrup, |
|
| 35:38 | that's exactly what those three words mean what their job is, is to |
|
| 35:42 | the vibrations from that tIM panic which is going back and forth, |
|
| 35:46 | the frequency of that sound wave hitting . And it causes the bone to |
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| 35:50 | at that same frequency. And then bone amplifies the sound to the next |
|
| 35:56 | which amplifies it to the next one that it causes the next membrane in |
|
| 36:00 | order. Which is called the oval to move back and forth. So |
|
| 36:05 | is an amplifier, same thing that have in your car that makes your |
|
| 36:09 | go boom, boom, boom right to me. I don't like |
|
| 36:13 | All right, So you ever been a concert? You notice? How |
|
| 36:20 | you ever gotten right in front of marshall stack for that concert? You're |
|
| 36:22 | , yes, I've got them right front of marshall stack. You know |
|
| 36:25 | the marshall stack is? Marshall stack that big giant stack of speakers, |
|
| 36:31 | ? And it says marshall marshall marshall marshall stack, Okay. And the |
|
| 36:37 | thing they do, they come out they play that first chord and it's |
|
| 36:40 | wow. And you're like right loud bad for ears. So you have |
|
| 36:47 | reflex to actually cover up your But you also have muscles inside your |
|
| 36:54 | to tune the amplifier, those two are the tensor tympani and the temper |
|
| 37:00 | media. So what they do is wrap around those structures. And so |
|
| 37:03 | that loud sound comes, even though you hide it, those muscles are |
|
| 37:07 | little bit slower than that. And what they do is they tighten up |
|
| 37:10 | they cause those muscles or those bones move with less um Well with less |
|
| 37:17 | , I'll use that word. That's . Alright. We also have a |
|
| 37:21 | , you can see it here, the station tube or the auditory tube |
|
| 37:26 | tube is a tube that opens up the back of your throat and it |
|
| 37:30 | you to collaborate the pressure inside the ear with the external environment. Why |
|
| 37:35 | I need to do that? You ? Here play the drum, everyone |
|
| 37:40 | play the drum. So if you your hand on the back of the |
|
| 37:43 | , does it make the sound that wanted to make? What kind of |
|
| 37:46 | does that make? Muted a And so that's what happens when you |
|
| 37:52 | pressure behind a membrane. So what wanna do is you want to collaborate |
|
| 37:56 | membrane. You know the pressure on side. So it makes the sort |
|
| 38:00 | movement you need to make. In words, if I had higher |
|
| 38:03 | it would have less ability to So this is what allows you to |
|
| 38:08 | that. You're equalizing the pressure and all used to doing this right? |
|
| 38:11 | you ever felt like your pressure inside head is getting a little high. |
|
| 38:14 | what do you do? Pop your right? If that doesn't work, |
|
| 38:18 | can always go pop, here's that . If that doesn't work, go |
|
| 38:22 | a lollipop and suck on it for little bit. In fact, if |
|
| 38:26 | travel a lot and you have you to travel when there's lots of kids |
|
| 38:31 | dumdums with you because you just pass out to the parents because they'll look |
|
| 38:35 | you like you're the king or the of the plane and they'll just be |
|
| 38:39 | , thank you. You know? when you have four kids, you |
|
| 38:43 | about dumb numbers. Yeah. So this is a really good question |
|
| 38:53 | ask. Probably not the best place it. But it's a good question |
|
| 38:56 | ask. So up until about three four years ago, we didn't even |
|
| 39:00 | what tonight this was. I mean were researchers who are still trying to |
|
| 39:03 | out what this is and what it . It's a lower threshold in the |
|
| 39:10 | that are sending the signal to the cortex. So we're gonna see here |
|
| 39:15 | a moment where those those uh neurons located and it's basically they're firing inappropriately |
|
| 39:22 | sending a signal to tell your brain there's a sound being perceived. That's |
|
| 39:26 | it is. Which makes sense after think about it. Okay. |
|
| 39:29 | that kind of makes sense. It's that ringing because it's like, |
|
| 39:32 | I'm stimulating that particular that note. it's not, it's a cell that's |
|
| 39:40 | has been lowered. Yes, Yes. Well, it's yes, |
|
| 39:45 | noise or ringing is another way it's . Huh? Well, like I |
|
| 39:53 | , it's that lowering of that So what causes it to lower the |
|
| 39:57 | ? I don't know the answer to . Yeah. Yeah. So most |
|
| 40:05 | in your body are flattened until there you make them not flattened. So |
|
| 40:09 | you go what you're doing is you're it up and so it makes an |
|
| 40:14 | path. Yeah. I'm glad you asking me like this type of |
|
| 40:19 | That's that's something entirely different. I thought it's another hand. |
|
| 40:25 | Okay, so so far so good structures and what their job is. |
|
| 40:31 | right. So we have this oval and the oval window is opening up |
|
| 40:35 | the cochlear itself. Alright, so we are. You can see the |
|
| 40:39 | or you can see the structure of a is a snail shaped structure. |
|
| 40:44 | literally means snail shell snail shell. right. And so you can see |
|
| 40:49 | is a a slice through it. you can see that it's just kind |
|
| 40:52 | rotating spiraling up like so it's actually tube that goes all the way |
|
| 40:58 | gets to the top and then it on itself and then comes all the |
|
| 41:01 | back down the same direction. And what we're doing when we've expanded this |
|
| 41:06 | , we're looking at the tube that's up and then the tube that's going |
|
| 41:09 | and then the space in between them is that cochlear duct that we're gonna |
|
| 41:13 | interested in. Alright, so this of shows you the two moving up |
|
| 41:17 | and then that top picture you can of see the spiral as it's going |
|
| 41:21 | the way up. And then you say the beige area in between. |
|
| 41:24 | can see how it turns on So, if you were to follow |
|
| 41:27 | all the way forward it goes and it gets right up here and then |
|
| 41:31 | turns back and comes back down the direction. Alright, So, on |
|
| 41:36 | end of that tube you have the window and it goes all the way |
|
| 41:40 | , turns on itself. That's the crema and then comes all the way |
|
| 41:43 | and comes down to another membrane. the round window. So, oval |
|
| 41:47 | round second. All right, These have names to them. All |
|
| 41:54 | So, here's the official one, , vestibular, which means vestibular |
|
| 41:57 | Alright. And then we have the panic duct. So you can see |
|
| 42:02 | I have the vestibular ducked the panicked, ducked. And I have |
|
| 42:05 | membrane that sits at the base of coke or the vestibular duct. And |
|
| 42:10 | a membrane that sits at the roof the tim panic duck. And so |
|
| 42:15 | what defines that member nous region in that forms the cochlear duct. So |
|
| 42:22 | stimulator ducked the stimulator membrane in the is the cochlear duct at the bottom |
|
| 42:27 | the temple or the basil er And then you have the temp panic |
|
| 42:31 | at the bottom. So this one be called Which membrane? The |
|
| 42:36 | Which one is this membrane? It's tim panic, It's basil er |
|
| 42:41 | so you can see it like this this right here would be the |
|
| 42:44 | And that's what you're looking at. the cochlear duct. And this structure |
|
| 42:48 | here is where all the action is place. That's called the organ of |
|
| 42:52 | , named after the guy that discovered . All right, So here we |
|
| 43:00 | . We're focusing on this and inside organ of corti. You can see |
|
| 43:04 | there's another membrane that sits right on top end of that structure. It's |
|
| 43:07 | the tech tutorial membrane. This is of like that stiff diving board. |
|
| 43:12 | a stiffer membrane, right? It straight out. So, you have |
|
| 43:16 | kind of loosey goosey membrane. You another loosey goosey membrane down here and |
|
| 43:20 | the middle. You have this tongue structure that's kind of stiff. The |
|
| 43:23 | tutorial membrane. So the stimulus Bassler membrane, tech tutorial membrane on |
|
| 43:27 | inside and standing up in that base membrane. This is where we're gonna |
|
| 43:33 | the hair cells that are responsible for the movement of fluid inside the cochlear |
|
| 43:39 | . And what ultimately is what's used help us detect sound. So the |
|
| 43:46 | duct has fluid in it. It's with the tim panic duck. So |
|
| 43:51 | has the same fluid and then in middle we have a different fluid. |
|
| 43:54 | that That's that. Cochlear duct, fluid that we're gonna see there. |
|
| 43:59 | the hair cells are arranged in a way. We have one row of |
|
| 44:03 | hair cells and then we have three 123 called the outer hair cells. |
|
| 44:08 | inner hair cells are the cells that the sensory receptor. They're the ones |
|
| 44:12 | play the job of detecting the movement the fluid inside that cochlear duct. |
|
| 44:19 | outer hair cells, on the other , on the other hand, modify |
|
| 44:22 | modulate the degree of movement of that tutorial membrane. So, what we're |
|
| 44:28 | to see is the tech tutorial membrane gonna vibrate more frequently or less frequently |
|
| 44:33 | response to the activity of the outer cells. Because their hair cells, |
|
| 44:38 | hair portion, the penicillium are kind jammed in and stuck in that territorial |
|
| 44:43 | . All right. So, when territorial membrane moves, what you're doing |
|
| 44:47 | you're moving the actual penicillium, stereo , the nerve fibers that are associated |
|
| 44:56 | those hair cells form what is called spiral ganglion and that spiral gangland is |
|
| 45:02 | sending those signals off to the auditory . So, there's all our |
|
| 45:09 | So, how does this all Well, first, let me |
|
| 45:12 | are there any questions I know it be kind of confusing when I'm just |
|
| 45:16 | there throwing things at you. yeah, it's the region that's responsible |
|
| 45:24 | detecting sounds. So, it's just stuff right here. So this whole |
|
| 45:28 | is called the cochlear duct. The duct sits around the organ of corti |
|
| 45:33 | the organ of corti is what actually the detecting and specifically in the organ |
|
| 45:38 | corti. This is how it's This is their only showing you these |
|
| 45:42 | cells. But you can see there's there's another structure and all the individual |
|
| 45:46 | in there actually have names. It's because that's what physiologists and scientists |
|
| 45:52 | We gotta name everything. Put it the box label it, ship |
|
| 45:56 | you know, whatever. Alright, organ accordion, where we're gonna be |
|
| 46:00 | our actions. So what is what sound? We saw what lightwave |
|
| 46:04 | Right? It had both an electromagnetic electrical and a magnetic aspect to |
|
| 46:10 | Right? And so here this is like a rope being snapped. So |
|
| 46:14 | you think of a wave in it's just a wave. It's basically |
|
| 46:18 | compression and rare faction of molecules hitting other. So, like in the |
|
| 46:24 | is what we typically are speaking But you could go underwater, |
|
| 46:28 | And you can make sounds underwater. what you're doing is you're causing the |
|
| 46:31 | molecules to press forward. They run other water molecules and then they fall |
|
| 46:37 | . So you see compression and then they fall away from each other, |
|
| 46:40 | rare faction. All right. And that's what's going on in the air |
|
| 46:44 | I talk loud, What am I ? I'm increasing the intensity. So |
|
| 46:49 | increasing amplitude, decreasing. Got high and low notes and amplitude just tells |
|
| 47:04 | the loudness. So frequency is pitch measured in decibels. That's hurt. |
|
| 47:12 | , some intensity is decibels loudness. . And the truth is, is |
|
| 47:20 | at any given time any particular sound our voices making, you're actually getting |
|
| 47:25 | pitches being laid on top of themselves so you're actually perceiving a lot of |
|
| 47:32 | simultaneously. All right, But let's pretend for a moment that we're going |
|
| 47:35 | just deal with one note at a just to make our lives simple. |
|
| 47:40 | , so what is actually going So these air molecules are compressing, |
|
| 47:46 | off each other. And rare fact creating wavelengths and those frequencies are the |
|
| 47:51 | that we're actually detecting. So, we've done in this little picture, |
|
| 47:57 | little cartoon is we've unwound the cochlear . So much easier to see the |
|
| 48:04 | . So you can see that top the vestibular duct, you can see |
|
| 48:08 | it turns on itself. And then can see how it comes back around |
|
| 48:12 | the uh tim panic duck and ends here at the round window. So |
|
| 48:16 | have oval window, round window, duck, and tim panic duck. |
|
| 48:21 | each sound you hear has a wavelength is an actual distance. And what |
|
| 48:27 | picture does a terrible job of is kind of makes you think that this |
|
| 48:30 | goes up and down multiple times within tube and that's not how it |
|
| 48:35 | You can imagine a wave is gonna in. It's gonna cause the so |
|
| 48:40 | fluid, right? You're gonna create of the fluid. This is why |
|
| 48:43 | need to amplify everything, right? you're saying I've got sound out here |
|
| 48:50 | I've got to make water move with same frequency. So I've got to |
|
| 48:54 | it because it's harder to push water than it is to push air |
|
| 48:58 | right? Why why would it be ? Why do you think? |
|
| 49:05 | Weight density is they're closer together? . I mean have you ever talked |
|
| 49:09 | somebody underwater? Like you know like the summer you're going swimming and you're |
|
| 49:13 | out with your girlfriend and you kind look at them and you do stupid |
|
| 49:16 | . Like say I love you but underwater. And and they look at |
|
| 49:20 | . No, you never did I'm the only idiot. Okay, |
|
| 49:27 | . I'll accept that. Again, gonna my thesis for the semester you |
|
| 49:32 | have lived a deprived life. So I'm doing is I'm creating that same |
|
| 49:39 | , but I've got to push And so that wave is going to |
|
| 49:43 | up and then it's gonna come down some point depending on the wavelength, |
|
| 49:48 | ? It's not gonna go up and onto the plant when it goes up |
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| 49:50 | it comes down, it's gonna hit that looser membrane, that vestibular |
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| 49:56 | And what it's gonna do is it's cause that membrane, wherever that sound |
|
| 50:00 | ? Whatever that length is, is to form, Right? So there's |
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| 50:07 | in the cochlear duct. So, I'm deforming this membrane and there's fluid |
|
| 50:11 | here, what's gonna happen to this here? Let's do it this |
|
| 50:17 | Stand up for a second. I to tell you this is sea |
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| 50:25 | I'm Shamu splash them all right, your arms out like that. |
|
| 50:30 | here's the vestibular membrane. Here's a panic membrane. All this is |
|
| 50:36 | What happens? Put your hand out that. What happened in your other |
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| 50:40 | ? What happens if I push on hand? That hand gonna move? |
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| 50:44 | find out. Did that hand move there? Why? Because the fluid |
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| 50:50 | it move, right? He's all . So put trans out again. |
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| 50:55 | if I push on this, if I push on this he |
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| 51:03 | Yes, exactly. So keep your up. We're gonna do differently now |
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| 51:07 | this like this make a C M. C. Backwards C. |
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| 51:14 | , so look if I'm pushing here there's fluid here, what's going |
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| 51:20 | They move together. You see how doing that now? Okay, now |
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| 51:25 | in between those two things? He's , damn it, right, you |
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| 51:29 | the tech tutorial membrane. The sectorial we said was stiff. So let's |
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| 51:32 | ahead and start moving that vestibular What happens when you're moving the vestibular |
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| 51:37 | ? Right? But what do we ? Sitting on that vestibular memory? |
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| 51:42 | cells. So do it again. see what's going on here is now |
|
| 51:48 | moving the hair cells. You can a seat because those hair cells are |
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| 51:53 | as in response. Because of the membrane causes the fluid in the cochlear |
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| 51:58 | to move. Which causes the basal to move. Which causes the hair |
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| 52:02 | to move. Which are embedded in territorial membrane, which causes them to |
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| 52:07 | back and forth and open and So at the very location where those |
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| 52:12 | cells are located for that particular I am stimulating those hair cells. |
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| 52:19 | now look at the length of the duct, it's long. How many |
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| 52:24 | play keyboards? Right? So at end of the keyboard you have high |
|
| 52:31 | . The other end of the you have low notes. There's your |
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| 52:39 | over here, high notes. High have very, very short frequencies down |
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| 52:47 | is where barry white sounds come Those are the deep low notes. |
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| 52:53 | your body feel all fuzzy. So if I have a high frequency |
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| 53:00 | , it's going to stimulate the cochlear . Or simply the cochlear duct. |
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| 53:05 | organ of corti at the place closest the oval window as I move down |
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| 53:11 | further away, I'm gonna be getting pitches. Much deeper pitches. Just |
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| 53:17 | as you move your finger along the , you have the high notes, |
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| 53:21 | go down to the low notes. so the sounds that we perceive are |
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| 53:27 | function of the frequency of the notes we're hearing stimulating different places on that |
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| 53:35 | of corti. So I'm stimulating hair over here. I'm stimulating hair cells |
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| 53:40 | there. I'm stimulating hair cells over and those neurons are firing in response |
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| 53:45 | that. Okay, well, I go ahead and answer your question. |
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| 53:49 | ahead even. Well, what do think is going on? There's a |
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| 53:55 | question. So there are there notes you can't perceive that are low? |
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| 53:59 | there notes that you can't perceive that high like a dog whistle? |
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| 54:07 | That's right there. Outside of the range represented by that organ of |
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| 54:13 | Right? So if there if the is too high, the vibration doesn't |
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| 54:19 | , that organ accordion doesn't make it if it's too low it just goes |
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| 54:23 | the way around, doesn't stimulate. . Ready. Mhm. You'd miss |
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| 54:34 | miss midrange, right? You can high ranges wherever you cause damage and |
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| 54:39 | ears are really sensitive. People who things in their ears all the |
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| 54:42 | And listening music solely through little tiny . Very, very bad. You're |
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| 54:47 | gonna be deaf when you're old. gonna be sad. Of course, |
|
| 54:51 | listen to everything very very loud. , you know potato potato? All |
|
| 54:58 | , So that that energy, So when I create a wave, |
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| 55:02 | that's energy. Right? And so frequency goes up because the stimulus membrane |
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| 55:06 | go down because basilar membrane to go and so remember there's another tube down |
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| 55:12 | full of fluid. So that fluid gonna be, there's gonna be a |
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| 55:16 | that gets created down there. And this is trying to show you is |
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| 55:19 | is this is that point. So just call it a midrange note instead |
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| 55:22 | it going up and down to be and then down, it hits their |
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| 55:25 | four, it causes that uh that dislocation, but that movement or displacement |
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| 55:32 | what I'm looking for, causes displacement the of the baseler membrane. And |
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| 55:37 | it's gonna do is that that sound continues all the way down to the |
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| 55:40 | window. The purpose of the round is to dissipate that energy because if |
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| 55:46 | was a wall, it would hit and it would echo on back. |
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| 55:49 | then you pick up another sound, not what we want, we want |
|
| 55:54 | to just go away. So it's of like those stress dolls, you |
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| 55:57 | the stress balls, you squeeze them their eyes like that, That's kind |
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| 56:00 | what this is like, it just of absorbs the energy and the energy |
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| 56:04 | away. So, I I really know the answer to this because but |
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| 56:25 | don't Alright, I don't know if they're doing is they're replacing the coakley |
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| 56:30 | or if they're actually basically causing, know, some Right? So, |
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| 56:42 | essence what you'd be doing. So know the answer, how they, |
|
| 56:45 | they okay, go ahead. Okay. So in essence what they're |
|
| 56:56 | is you're getting some sort of device actually vibrates and actually detects the frequency |
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| 57:01 | to what the cochlear does. Internal thing that the vibration, gotcha |
|
| 57:08 | it right. And that would make because trying to you know, replace |
|
| 57:14 | know, actually to innovate the cells would be impossible. Which is what |
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| 57:18 | describing, right? But that was what you were describing. But the |
|
| 57:22 | of of somehow converting that signal would very very difficult. So having something |
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| 57:27 | actually does the reception itself and then for that, that kind of makes |
|
| 57:33 | . Alright. But again, when start dealing with pathologies and stuff like |
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| 57:38 | , like I don't know all malls I know what a cochlear implant is |
|
| 57:42 | never played with one. Alright, do we kind of get a sense |
|
| 57:46 | what's going on here? So it's pressure wave that affects at a specific |
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| 57:50 | based on that wavelength that causes stimulation the cochlear duct at that particular location |
|
| 57:56 | that particular pitch is what we're So when we're dealing with questions |
|
| 58:01 | let me see if I'm going here . So all this is kind of |
|
| 58:05 | same the same thing. This is a little bit more detail. So |
|
| 58:09 | what I said, the outer hair are responsible for modulating really, What |
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| 58:13 | doing is when they get stretched they this protein called Preston and what that |
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| 58:19 | does, it kind of acts as spring and basically pulls the cell to |
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| 58:22 | it compressed tighter. And what it , it pulls on the territorial membrane |
|
| 58:26 | creates flow in that little area where says the inner sulcus. And so |
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| 58:31 | get this flow. So it causes hair cells, the inner hair cells |
|
| 58:34 | wave back and forth. So you greater stimulation of those hair cells. |
|
| 58:39 | that's how you get that really strong . So that's when I say they |
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| 58:44 | because the fluid moving in and of may not be enough to really cause |
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| 58:48 | the Preston and the outer hair cells of pulling on the territorial membrane as |
|
| 58:53 | being stretched as as you get that the territorial or as the base layer |
|
| 58:58 | moves away. It's basically saying oh want to go this way. And |
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| 59:01 | it creates that force to drive the back there. So, that's the |
|
| 59:06 | portion. Alright. And then that gets sent along the auditory fibers to |
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| 59:13 | auditory cortex and let's see what else I have here? Uh Just mentioned |
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| 59:19 | already, The pressure wave round window . That pressure wave gets dissipated. |
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| 59:25 | you're basically moving in one direction all time. All right, so with |
|
| 59:33 | to amplitude, what are we Well amplitude, remember is loudness and |
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| 59:40 | at the same pitch you can have a C. Note. It could |
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| 59:42 | a very very loud C note or a very soft C note. And |
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| 59:45 | what you're doing is you're getting greater at that particular location. And so |
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| 59:53 | result is more action potentials. So action potentials are how we encode strength |
|
| 60:00 | terms of frequency that just tells you you're being stimulated. So once again |
|
| 60:04 | unwound it, you can see here they're actually different thickness and width within |
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| 60:11 | cochlear to and so down here it easier from from uh those deeper sound |
|
| 60:18 | up here it vibrates only in response the low waves but that's really all |
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| 60:23 | is. So wherever I'm stimulating that's I know what frequency, what pitch |
|
| 60:29 | actually detecting and what we're gonna see a little bit is that our temporal |
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| 60:36 | the auditory cortex is organized similarly to this is organized. So that when |
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| 60:41 | look at the temporal lobe it's like notes versus low notes along the |
|
| 60:47 | Oh yeah. So there we go we doing on time. I actually |
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| 60:50 | actually on time for a change. man we're gonna end this on |
|
| 60:55 | This is I just said that so just screwed myself didn't. Alright so |
|
| 61:00 | I wanna do now is I want shift away from these five special senses |
|
| 61:04 | what I wanna do is I just to talk generally about what circuits |
|
| 61:07 | So remember circuit is simply the interconnection different neurons. So it's a network |
|
| 61:12 | neurons. All right. So we local circuits. These local circuits are |
|
| 61:17 | in that specific region. And what doing is they're receiving input and and |
|
| 61:21 | sending output to different other regions. they can be from far away or |
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| 61:25 | can be near. But really a is located in that particular area and |
|
| 61:30 | there's such things as microcircuits which we want to get into. And so |
|
| 61:33 | want to just kind of show you example. There's two examples I want |
|
| 61:36 | show you of local circuits. So we are. What structure is this |
|
| 61:42 | cord? So for every circuit you have an input you're gonna have an |
|
| 61:45 | . You're gonna have a processing So inputs in this case can be |
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| 61:49 | different fibers that can be descending fibers from the higher regions of the of |
|
| 61:55 | brain or from the central nervous right? You can come from different |
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| 62:00 | . It's not showing it here. you can imagine coming from different regions |
|
| 62:04 | the spinal cord and what you're gonna is you're gonna process here at the |
|
| 62:08 | of inter neurons. If I haven't the word interneuron before. What do |
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| 62:12 | think it means between the neuron? . So there you go. So |
|
| 62:15 | between the parents and the parents. right. And so their job is |
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| 62:18 | process this information. They can be , They could be inhibitory in nature |
|
| 62:23 | then the output is going to be sort of motor neuron in this particular |
|
| 62:27 | . All right. So you can I'm taking information in. I'm deciding |
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| 62:31 | do I do with that information. send a signal back out. That |
|
| 62:35 | be an example of the type of circuit. But you also have these |
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| 62:38 | the higher portions of the brain as . So here what you see is |
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| 62:42 | can see I have a sending fibers in. There might be really neurons |
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| 62:47 | in neurons coming from other nearby Those would be examples of inputs. |
|
| 62:53 | , processing would be the inter So you can see inter neurons over |
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| 62:58 | and then the output is gonna be fibers. They're projecting to other parts |
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| 63:02 | the brain or they're projecting down through body. So they can become descending |
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| 63:06 | that go to um to the spinal or ultimately down to motor neurons and |
|
| 63:11 | through the body. Alright, so local circuits. Pretty basic input |
|
| 63:17 | And processing is really what we're trying get at. Reflexes are a prime |
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| 63:25 | of looking at a local circuit. you have all sorts of reflexes. |
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| 63:30 | the spinal cord is primarily involved in basic reflexes but that doesn't mean that |
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| 63:35 | there's not reflexes that occur in higher of your brain. Now this reflex |
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| 63:42 | probably one you're probably pretty familiar Right? And I don't know if |
|
| 63:46 | familiar with this one shining a light and I will cause it to |
|
| 63:50 | So that's another example of a And so what is? It's basically |
|
| 63:55 | . It's always pre programmed. It's , you can't control it and it's |
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| 64:00 | be a muscle or gland to some of specific stimulus. And so if |
|
| 64:04 | not sure what those words are, is some sort of sensory input, |
|
| 64:09 | ? So if you're looking at it's gonna be light. If you're |
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| 64:12 | at smell, it's gonna be chemicals on and so forth. Go |
|
| 64:19 | Pre programmed means it is something that body will always do. We're gonna |
|
| 64:22 | some examples here in just a Alright? Um Pre programmed gonna get |
|
| 64:28 | single time. So if you've ever that knee reflex, You cannot make |
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| 64:33 | stop. I will hit your knee and over again and I will get |
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| 64:36 | same response every single solitary time. , involuntary means you have no conscious |
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| 64:41 | and you can't suppress it. So types of reflex basics these are unlearned |
|
| 64:46 | in responses. If you look at newborn baby and it can actually focus |
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| 64:50 | on you and it's actually focus range about 8", right? And you |
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| 64:53 | at and you give it a big smile. What's that baby gonna do |
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| 64:56 | back to you? No, it's gonna cry. It's gonna look at |
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| 65:02 | and it's gonna smile back. That is an innate basic reflex. |
|
| 65:07 | cannot that it is programmed to do . It's a mimicking program and basically |
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| 65:13 | it makes you go, oh it's cute. We smile and it smiles |
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| 65:16 | and we smile back and over and and over again. Alright, condition |
|
| 65:21 | . This is an acquired reflex. done after practicing learning. We can |
|
| 65:25 | about Pavlov and his dog. You remember good old Pablo and his |
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| 65:29 | Pavlov had a dog. He rang bell fed the dog rang the bell |
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| 65:32 | the dog ring. The bell fed dog ring. The bell didn't feed |
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| 65:36 | dog. What happened? The dog him? No, you're right. |
|
| 65:41 | . The dog salivated because acquired the that when I hear bells, I |
|
| 65:47 | fed and you are just as Right? Think about all those years |
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| 65:53 | being in high school when you heard bell, what does that mean? |
|
| 65:58 | my stuff up, Get up, five minutes to get to the next |
|
| 66:01 | . Right, just an example. , when you see a yellow |
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| 66:06 | what are you supposed to do? up? You've been conditioned. All |
|
| 66:12 | , spinal reflex is very, very . We have five steps to |
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| 66:17 | We have some sort of receptor, ? That receptor sends or detects a |
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| 66:25 | and what it does is gonna send uh symbol or that signal through a |
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| 66:29 | pathway. So it goes into the nervous system where that information is going |
|
| 66:33 | be processed in the integration center. that's what an interneuron serves as an |
|
| 66:40 | center. Once the response has been what needs to be done, that |
|
| 66:44 | is sent along a motor pathway called different pathway. So I'm just I'm |
|
| 66:49 | these words a parent and different. I was using a nice texas accent |
|
| 66:54 | would be different in different right? it gets kind of so A. |
|
| 66:58 | E. A. S. E. Is out and then the |
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| 67:02 | or causes the the response. That's does creates the effect in response to |
|
| 67:08 | . So if it's it's a lateral that means. Is that the receptor |
|
| 67:11 | the effect on the same side. if I step on attack I'm gonna |
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| 67:15 | my foot up right on the same . I'm not gonna lift up the |
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| 67:18 | foot. If I did that that be contra lateral lateral, be |
|
| 67:22 | Right? But an example of contra and I use this as an example |
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| 67:26 | I grab you and pull you towards , you're gonna push away from me |
|
| 67:31 | the other arm. That would be contra lateral reflex. Okay we're gonna |
|
| 67:36 | this here in just a second. mono synaptic versus polish synaptic there's a |
|
| 67:45 | of words on that slide. What you think? Mono synaptic means one |
|
| 67:48 | . So there's no interneuron you don't it So basic I don't even need |
|
| 67:52 | process it. I'm just gonna say this happens, I'm gonna make the |
|
| 67:55 | thing happen. So, an example that would be that knee jerk |
|
| 67:59 | right? There's not even an interneuron process what that means. It's basically |
|
| 68:03 | stretch. I feel extent. I the tendon being stretched. So, |
|
| 68:07 | I'm gonna do is I'm gonna cause muscle to contract polish synaptic just is |
|
| 68:13 | little bit means more complex. It you have more than one synapse. |
|
| 68:17 | , typically, a simple policy synaptic be this, for example, where |
|
| 68:21 | can see I have one interneuron. lighting myself on fire. I don't |
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| 68:25 | that. So, I pulled my away, right in response. Anyone |
|
| 68:29 | done that in the lab Bunsen You've done the Bunsen burner. That's |
|
| 68:33 | worst. Yeah, don't do It's They make you wear safety |
|
| 68:39 | Don't they deprived lives all right. is the withdrawal. It's called the |
|
| 68:45 | reflex. No, they made us it too. We just didn't follow |
|
| 68:48 | rules. All right. But you imagine there could be more than one |
|
| 68:53 | because you may have things where like in a stretch reflex where you're dealing |
|
| 68:59 | only with the muscle that is uh , but you have to cause another |
|
| 69:04 | to relax the the opposing muscle, ? And that's that's kind of what |
|
| 69:09 | is trying to show you, is there is a nice simple reflex where |
|
| 69:13 | can see I'm causing uh mono But then over on the other side |
|
| 69:19 | using poly synaptic. And so we a much more um much more complex |
|
| 69:26 | . And what I'm doing is I'm that antagonistic muscle. All right |
|
| 69:30 | how this happens as a result of muscle spindles. All right. And |
|
| 69:34 | what I want to do and I talk about this and I'm gonna I'm |
|
| 69:37 | reserve muscle spindle and goals you tend here for today. Alright. So |
|
| 69:42 | easy way to think about the muscle fiber is trying to maintain the position |
|
| 69:47 | your muscles for whatever activities that you're to accomplish. Right? So let's |
|
| 69:51 | for a moment that I have a of books and you have a gun |
|
| 69:54 | my head and you say I want to hold your arms out, like |
|
| 69:57 | right, And then what you're gonna is you're gonna drop a book on |
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| 70:01 | of my stack of books. What my hand's gonna naturally do? They're |
|
| 70:04 | go down right? But you put gun to my head and I don't |
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| 70:08 | that to happen. So the reflexes bring my arms right back up into |
|
| 70:11 | original position and it's because of the of the stretch of the muscles being |
|
| 70:17 | as a function of those heavier books in and having to cause the greater |
|
| 70:23 | contraction to maintain my arms in the position. So that's what the stretch |
|
| 70:28 | through the muscle spindle is looking at degree of stretch inside the muscle to |
|
| 70:33 | the position of the muscle for whatever activity happens to be. All |
|
| 70:38 | I'm not gonna ask you about the and the extra fuel and all that |
|
| 70:42 | today is not the day to do . That's more of what I do |
|
| 70:44 | anatomy and I make them cry Alright, so that's that's the first |
|
| 70:50 | . The second one has to do the Golgi tendon and hear what I |
|
| 70:54 | is I have a detector inside the . So muscles are attached to tendons |
|
| 70:58 | are attached to the bone. So I want to move the bone, |
|
| 71:00 | pulling on that that tendon to cause to move. Now again. Let's |
|
| 71:05 | the books out here. I'm holding and you start stacking books on top |
|
| 71:09 | the books again. Gun to my and what am I doing? I'm |
|
| 71:12 | there maintaining maintaining it. But eventually gonna put so much weight on there |
|
| 71:17 | it's actually gonna cause damage. I I could literally tear that tendon |
|
| 71:22 | Have you ever anyone ever torn a while lifting weights Isn't that fun? |
|
| 71:27 | , it's not fun. It's All right. But your brain already |
|
| 71:31 | this. It says I don't want damage this or not. Your |
|
| 71:35 | Your muscles already know that the tendons know this. And so what the |
|
| 71:38 | tendon does is it's looking at the of stretch inside the tendon and it's |
|
| 71:44 | the question how much tension are we here and is it too much? |
|
| 71:48 | when that tension rises too high it says no we're not gonna do that |
|
| 71:52 | . And so it sends an inhibitory back to that muscle and says stop |
|
| 71:58 | . So when you put too much , what do you do? You |
|
| 72:02 | it? So if you've ever carried where you're like, you know you're |
|
| 72:06 | it and you can feel like it's too heavy and all of a sudden |
|
| 72:08 | are you doing? You're like you I'm gonna go put it down |
|
| 72:11 | But if you let's say you couldn't it down quickly, what are you |
|
| 72:14 | do? You're gonna naturally drop because body is protecting itself from damage. |
|
| 72:20 | that's the job of the Golgi Well so what happens is you you're |
|
| 72:32 | saying no I'm not gonna listen to . So the reflex portion is it |
|
| 72:37 | while you're doing? But like if sitting there trying desperately to, you |
|
| 72:41 | like when I did it it was I was trying to get the 200 |
|
| 72:44 | , I think it was a two I might have been trying to go |
|
| 72:46 | than that at that point. This when I was in high school and |
|
| 72:49 | went there and I just I just it. Yeah that was ugly. |
|
| 72:55 | but you can see here they're showing one is inhibitory one is excitatory. |
|
| 73:00 | the muscle itself I'm trying to protect being turned off. Yeah stretch. |
|
| 73:07 | so gold. So the Golgi tendon in the tendon right, protecting the |
|
| 73:13 | protecting you from tearing the muscle away the bone as a result of the |
|
| 73:18 | and the stretch reflex. What I'm to do is maintain the shape of |
|
| 73:22 | bone or the muscle to do the that you're designing it to do. |
|
| 73:25 | holding my hand out like this is function of muscle contraction right? If |
|
| 73:29 | add weight to that my hand is to actually dip down in response to |
|
| 73:34 | weight. But I wanna hold my up here so it has to re |
|
| 73:38 | re decide or re establish what the contraction is in order to maintain that |
|
| 73:45 | . So that's what the muscle spindle doing is looking at how much stretches |
|
| 73:49 | versus what your intensive stretch is supposed be. Oh yeah. So withdrawal |
|
| 73:56 | withdrawal reflex simply was what I was in terms of a contra lateral. |
|
| 74:00 | If you step on attack in this it looks like I stepped on an |
|
| 74:03 | shell, what am I gonna I'm gonna lift my foot up but |
|
| 74:07 | order to lift my foot up, I want to do is keep myself |
|
| 74:09 | falling over, I got to put other side down and so it's just |
|
| 74:13 | you how it's talking to both the muscle as well as the agonist. |
|
| 74:18 | then on the other side doing the , talking to both the antagonists and |
|
| 74:22 | agonist. But one I'm I'm basically this side, I'm basically pulling up |
|
| 74:26 | the other side, I'm pushing down then there's two sets of muscles that |
|
| 74:29 | I'm playing with. But that's what withdrawal is to do that. And |
|
| 74:33 | same thing if I'm pulling on you your you push off, that's not |
|
| 74:36 | you think about. That would be withdrawal reflex as well. In our |
|
| 74:44 | we have central pattern generators. And they do is they basically create rhythmic |
|
| 74:50 | . So what are with rhythmic Things like walking, chewing, breathing |
|
| 74:54 | what they do is this is part as well as voluntary movement. |
|
| 75:00 | And so here what you have is have neurons that are basically working a |
|
| 75:04 | pattern, creating more and more activity that you get this reflection and extension |
|
| 75:12 | pattern. And so like this is you the cat. But just look |
|
| 75:16 | yourself when you walk, what do do? It's I'm flexing and then |
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| 75:20 | extending and I'm flexing and you just of create that pattern over and over |
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| 75:24 | . You don't have to think about so that's the reflexive portion. It's |
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| 75:28 | I'm trying to get over there. gonna flex and extend, flex and |
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| 75:31 | . Alright, so this is gonna found. These CPG s are gonna |
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| 75:35 | found primarily brainstem and and higher. , breathing reflexive right until it fills |
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| 75:43 | . And then what do you You relax the muscles? Do you |
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| 75:46 | to think about breathing, breathe breathe out, breathe in. |
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| 75:53 | You don't do that. You just it. All right. So this |
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| 76:00 | an example of what something like this look like. You do not need |
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| 76:04 | memorize this. Please don't memorize Just wanted to show you how you |
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| 76:07 | see Here is a series of inter . Here's the excitatory, here's another |
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| 76:11 | . And basically what they do is act on each other to turn one |
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| 76:14 | the month and so on. So would be the inhibitory. So see |
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| 76:18 | we go here. I got my potentials that I'm turned off while this |
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| 76:23 | has action potentials and this is turned while I have action potentials and this |
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| 76:26 | turned off so that would be how does it through a pattern like this |
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| 76:32 | a circuit like that about four I'm gonna do it. All |
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| 76:40 | So your brain maps all these types sensory inputs. All right. And |
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| 76:46 | is doing is that it's it's doing to match more or less the kind |
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| 76:52 | information that you're getting in. So example for somatic sensory, I'm gonna |
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| 76:57 | a spatial map. I'm gonna basically my body and say where am I |
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| 77:00 | touched? Alright. If I'm talking visual, it's like where's light coming |
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| 77:05 | ? If I'm looking at auditory what , because cochlear has this range of |
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| 77:10 | I'm gonna look at and pattern that temporal lobe to look a lot like |
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| 77:15 | and same thing. There's chemical maps the olfactory system and as well for |
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| 77:19 | gustatory system. So, if you a mad scientist, all right, |
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| 77:25 | can't do this. But let's pretend could I could take the neurons that |
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| 77:28 | going from one place, let's say the flavor of lime or the smell |
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| 77:31 | lime and the smell of cherry. I could take those neurons and I |
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| 77:35 | switch them. So every time you cherry, you smell lime and every |
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| 77:38 | you smelled lime, you smell Right? Because there's a specific region |
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| 77:42 | the brain that detects the chemicals that lime and that are cherry. And |
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| 77:47 | mapped in your brain. All Now, when we talk about these |
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| 77:53 | , and I'm gonna show you some very, very quickly understand that these |
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| 77:57 | not like set in stone there. like the maps from the you |
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| 78:01 | the 15th century, like this is the coast looks like. And you're |
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| 78:04 | , yeah, maybe right, it's that, you can tell there's the |
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| 78:07 | and the south and there's stuff in . But you couldn't actually tell you |
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| 78:11 | the distance between these two places are . Number of miles or knots? |
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| 78:15 | . So it's the same sort of . Very very fuzzy, very |
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| 78:20 | So the somatic sensory motor cortex, can see what we have here is |
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| 78:24 | pre central gyrus for the motor. I guess this is motor down |
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| 78:27 | So pre central gyrus from the motor centuries in the post central gyrus. |
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| 78:32 | what we have here is showing you map in terms of what is called |
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| 78:35 | motor or somatosensory homunculus. It matches body shape. But does it match |
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| 78:40 | exactly? Right. Does that look a human over here? No but |
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| 78:47 | can see that there's order to So like for example you can see |
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| 78:50 | my full body for the sense of . My feet are down here as |
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| 78:55 | move along, what do I There's my hands and then finally I |
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| 78:58 | to what is that? My can't see from over here. Then I'm |
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| 79:02 | do my head starting up high and down to my chin. And then |
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| 79:06 | I move further down I get into areas of my digestive track. |
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| 79:12 | And you can see that there are that are better represented and less |
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| 79:17 | So if it's better representative, what you think? Am I doing fine |
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| 79:20 | coarse uh sensations? Fine. So you think it's important to know what's |
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| 79:26 | your lips at all times? What you think? Yeah, I saw |
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| 79:31 | . Look, you're thinking about aren't you? You're like, I |
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| 79:33 | know. Yeah, it's kind of . Yeah, I like kissing. |
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| 79:36 | is good. Right? But we oral creatures. We put things in |
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| 79:40 | mouths all the time, Right? not particularly selective about it. Look |
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| 79:45 | little Children, right? Cat, , car keys, legos. More |
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| 79:53 | , right. We're tasting our environment you can imagine, you know, |
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| 79:57 | out in the wilderness is not the century. We're talking before. We |
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| 80:01 | well organized and you're like, I know this berry looks kind of |
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| 80:05 | I don't know. This thing might sharp. It might not be |
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| 80:09 | And so understanding things touching your lips tell you whether or not it's gonna |
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| 80:12 | a danger to your body. So like when you eat a ghost |
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| 80:17 | kind of spicy kinda hot might be . All right. You can see |
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| 80:22 | motor homunculus is more or less the way it matches a pattern. So |
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| 80:26 | know where that information is coming from where it's going to retinoic or retina |
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| 80:33 | , it matches the pattern of the so that the information coming from very |
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| 80:39 | locations your brain already knows. Oh in this portion of my visual |
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| 80:44 | What's interesting is that the cortex also these types of maps for color for |
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| 80:51 | and for other aspects of vision? this is a representative representative of the |
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| 80:58 | of the retina but it doesn't represent the aspects to it. How am |
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| 81:01 | doing since everyone's bailing on me? man. So I guess we'll get |
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| 81:06 | this and then we'll do muscles, are pretty easy as well. But |
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| 81:10 | you guys get get this idea here the maps so far? Okay. |
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| 81:20 | . And the right to know? . No. No. So what |
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| 81:23 | basically trying to show you here is on the left side your left visual |
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| 81:29 | is going to be mapped the same in the right and what they do |
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| 81:33 | they overlap. Which is what gives that that binoculars or that or binocular |
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| 81:39 | . But outside of the crossover. ocular you too. Have a good |
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