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BIOL 3324 Human Physiology - BIOL3324_Lecture10
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00:08 No, I got excited about So, um, I was harassing
00:15 all with stuff. All right. think we're up and running. We'll
00:24 if you can hear me online. ahead and give a thumbs up.
00:29 getting thumbs ups. Not yet. right, let's see. Okay,
00:36 are coming. All right. So, um, here we are
00:39 again, Another beautiful day. It's fall here in Houston. Enjoy it
00:43 a couple of days, because then gonna come back to summer.
00:47 Because we don't know better. yeah? So what we're gonna do
00:52 , we're gonna have a little bit fun. Um, I think we're
00:55 talk about no, see scepters and we'll talk a little bit about
00:58 reception. And we'll kind of skim that because we come back to it
01:01 a little bit later in this and then we're gonna talk about vision
01:04 how vision works. And then we do some equilibrium. It's supposed to
01:07 at the end of the lecture, we'll see if that actually gets
01:10 Because the way I way I talked no se Reception is just a fancy
01:15 for paying recognition. And really, we're looking at here in this picture
01:21 just kind of ah, overall view it. We're not gonna dive real
01:25 just because it is kind of and we've got plenty of other things
01:28 look at. But they're different types no see scepters, meaning that no
01:33 , sectors are the actual receptors. could be mechanical receptors. They could
01:37 thermal receptors. They could be chemical . Could be Paula model. Meaning
01:42 detect a whole bunch of different things . And so you can see if
01:46 not familiar with those words. Mechanical pressure. Thermal would be different
01:51 Um, Chemical is basically responding to the presence of certain agents and then
01:58 pollen model means all the different things once. Um, and the thing
02:03 , is that these receptors can be or modulated by the virtue of
02:09 Acting are having chemicals act on All right. So you can imagine
02:14 have a certain threshold to get and then chemical comes like this would
02:18 the neuro modulate. Come on. it brings the resting membrane potential up
02:23 to that threshold or or above the so that that receptor is more
02:29 Um, or is actually becoming too, by that chemical. All
02:34 , so, uh, this allows again if you're not sure what pain
02:38 . I mentioned this last week. is what its weakness. Leaving your
02:43 . I said that. I What else studies pain? Is your
02:46 telling you? Stop doing what you're because you're killing you yourself, and
02:50 actually closer to the truth. Pain just an indicator that something is damaging
02:55 tissue. Now, does it not mean that it's damaging permanently?
02:59 It just means that whatever you're doing be bad for you. And that
03:05 mean running or exercising, even though painful. Just means that you're actually
03:09 your muscles beyond what they're normally used , which actually leads to strengthen the
03:13 . All right, that's what nos does. Um, there are different
03:19 of fibers that no see sectors could found. Um, and so it's
03:24 fat fibers, too thin fibers you see up here. We got a
03:27 delta and C fibers. And we're just keeping this simple. A
03:33 and a deltas are both my elated . So when you hear the word
03:36 , you should think in terms of , slow transmission fast. Alright,
03:41 the fiber, the fat of the . So the A betas are large
03:45 fat. A deltas are small, a bait of fibers are faster than
03:50 delta, even though both are my . All right, so you're dealing
03:53 both factors simultaneously, all right, C fibers are boring and small.
03:59 other words, they have no and they're very, very tiny.
04:02 smaller even then, the deltas, so these are very, very slow
04:07 , but the type of information they is very specific now. A beta
04:12 are typically in other areas, but do carry some noxious stimuli, and
04:17 see the little picture graph down But it says non options mechanical
04:21 you know, tickling is, is the case that they're showing here is
04:25 feather. It's like, Oh, is not painful. But if you've
04:28 been tickled long enough, it's painful it, So it is kind of
04:33 . Alright is basically a recognition of specific type of stimulus So there is
04:38 notes. Deception there, but not it's not like the major carrier of
04:42 see septics stimulus. So you could use these kind of pictures to kind
04:45 help you, uh, the A . They carry specific mechanical, so
04:50 would be like touch or cold? is specific. There you can see
04:54 the picture it says, Ah, or chemical, but not for the
04:58 . So different sources, you they're just drawing different things here.
05:03 , the C fibers, some mechanical some heat and cold stimulus. But
05:06 gonna make this simple for you to this. Have you ever been hit
05:09 something really, really hard, like baseball or basketball or soccer ball?
05:14 right in the face? Right, know, And so when you get
05:19 by that, that ball, it's you get that sharp pain immediately?
05:24 . So that would be carried by kind of fiber do you think?
05:27 immediate pain, right? It's It be one of be probably the A
05:32 , right? So it's very It's like, Wow, I just
05:35 hit and e. I mean, feel the pain before you even gonna
05:38 to it? But then afterwards you that throbbing pain that kind of
05:43 Afterwards, that would be a C . All right, so it's coming
05:49 the same source, but it's a sort of feeling. And so
05:53 what it's telling you is that something has happened. And then that's
05:58 Sit there telling you Oh yes, damage that has occurred here, you
06:01 , pay attention, pay attention. right, so that's the difference between
06:06 . So just be familiar with what different sizes represent. For the most
06:10 , I don't think I said, don't think I ask you the
06:13 What is the specific type of of information they carry? It's more about
06:19 size that matters. Can't believe I said that in class. Actually,
06:24 doesn't surprise me. I said something that class, but alright,
06:29 alright, analgesics and algae. Asia basically the suppression of pain response analgesics
06:34 the things that do that suppression. is to be different than an
06:39 Alright, an aesthetic is where you the lack of the sensation where,
06:44 , analgesia analgesia is where you're basically allowing the signal to come up and
06:50 this little picture down here below again to memorize. But it kind of
06:53 you see where ah local anesthetic It basically blocks the receptor from from
06:58 , and then you kind of work way up and you'll see that there's
07:01 allergies except up there, the opioids would be the example of the
07:06 So we have what we would um, natural and our natural or
07:11 . These are the things that we produced, so you probably recognize these
07:16 . Thean Dodge. This one's in means made in the body. We
07:19 the endorphins. You've all heard of endorphin. When you exercise, what
07:23 you produce? Endorphins, right and . It's an opiate. So the
07:29 you like to exercise you the first , it's painful. Your body
07:32 Oh, pain and says, I'm take care of it, gives you
07:35 natural endorphins. And then what does body want to do? I want
07:40 of those endorphins, baby. Come , hook me up. So that's
07:45 you keep exercising until you skip a and then you realize sitting on the
07:48 is much more fun. Empty Please exercise. Okay, so that
07:53 be that. You probably haven't heard the Calphalon, but same thing.
07:57 dine orphans, these air again, different sorts of opiates. Now,
08:01 purpose of an opiate you can see in this upper picture up here is
08:05 it inhibits pre synaptic terminals. So is that pre synaptic inhibition that we
08:11 in the last unit right where the is gonna be sent because the stimulus
08:16 there, right? We're recognizing the and that fiber is sending it down
08:21 length of its acts on. But we're inhibiting at that pre synaptic
08:26 no signal is being released. And that information is not sent up to
08:31 central nervous system. And that's why don't perceive the pain. All
08:37 so that's the idea Here. Is the energy six basically blocked the signal
08:41 coming up. And aesthetics just prevent from receiving the signal altogether. So
08:51 the extent. Yes. See this about five fiber response to when you
08:59 your pin keeping second or two give it depends on how are you talking
09:05 hitting it. I mean, are hitting it with a hammer or because
09:09 hitting with a hammer? That's an . It's on a delta.
09:12 If you're, um Oh, I know, basically squeezing it with a
09:19 . Maybe that would be more of C fiber. All right, so
09:23 asking for very specific examples, and probably not great. Another is.
09:28 know how I distinguish it. this is a question. I think
09:32 put on exam before, but I have taken it office. How do
09:35 perceive between something like being hit by and saying being chilled by ice like
09:41 ever touch dry? Anyone here touch . You should. You know,
09:46 you work in a lab, you've our eyes. Probably right. Dry
09:49 burns, doesn't it? So how your body you know the difference between
09:52 and hammer? Anyone else? This not a trick question, not
09:59 I thought I heard over here. to speak about mathematics. May do
10:04 family. Yeah, it's a type receptor. Right. So you have
10:08 ah, thermal receptor that detects the in temperature. And then you have
10:11 mechanic receptor that detects the manipulation of cell, right? And so you
10:17 take a hammer. And it could , But nobody says, Oh,
10:21 type of pain comes from this type receptor air. Go. It's this
10:24 of damage, so that's kind of key thing. So what is the
10:28 question? I hope I answered I know I kind of skirted around
10:31 I don't know the specifics, you ? Why doesn't why? Doesn't know
10:35 a pinky, that your pinky is hurt. You know all that?
10:38 it's a specific fiber going to the . Okay. Uh huh. Moment
10:44 . Energetic have Jesse doesn't have want do with It's a dilation.
10:50 Also again, it has to do blocking the chemical signal that that,
10:55 , sensory neuron is using to send to the to the perceptive centers of
10:59 nervous system. All right, so reason you recognize pain is because that
11:04 is being sent, uh, into central nervous system. Member perception is
11:09 about central nervous system. Okay? so if analgesic blocks that signal from
11:16 , right, In other words, don't release my chemical onto that secondary
11:21 , then no signal is getting up the perceptive centers. So I don't
11:25 the pain. I don't Even though stimulus is there, my central nervous
11:30 is not being alerted, right? like intercepting the note before it gets
11:36 . If that kind of makes follow up question. Then you have
11:45 . Yeah, look, more Ah, high pain, threshold e
11:51 know where that comes from. To real honest. I mean, if
11:53 ever watched so the question is where high pain thresholds come from one it
11:57 be just, you know, I'm put up with it. It could
12:00 that you have lower sensitivity. It be any sorts of things. If
12:05 ever watch people like walk across hot , it's not like they're super if
12:10 feet are still burning. But they either ignoring the pain for you
12:15 they have a higher threshold towards the . That's usually the picture. You
12:20 , it seems like they show these walking across all codes like No,
12:23 do that. That's just bad, wrong. So in different ways,
12:31 have a stimulate fans A lot. , commission well there. There's probably
12:41 aspect to that, right? I , the idea that if I'm,
12:45 know, if I lightly tapped, use a needle because the needles easy
12:48 . Because you can see if I I use a needle, can I
12:51 a cell with the needle? Do think I'm gonna detect that with pain
12:55 ? Have you been poked with a before? Does it hurt?
12:59 so So the answer is yes, would hurt, right? And so
13:03 can imagine I could take a and I can barely touch you with
13:06 . Right? But I could take needle, and I can take a
13:09 start jamming into your arm One of two things, right? So now
13:13 you're dealing with here is you're dealing , uh, magnitude. And so
13:18 could be that summation that they could referring to. And that's really it's
13:22 number of action potentials that are being . Right? So with the the
13:26 needle, I may send, you , the light needle. I might
13:28 sending an exponentially Okay, that's that's pressure. I'm seeing that. I'm
13:34 okay now. It's it's hurting and , as those fibers start firing more
13:39 more and more frequently, that's the sense of it's becoming more and more
13:43 . That would be the additive Okay, you have a question Over
13:49 is Well, now, okay, to board and all that I
13:55 All right, so with regard appropriate , I have two things here that
14:00 gonna mention. I'm going to skip slides, and we're gonna come back
14:04 it again when we at the end the of the unit, because I
14:07 have it in two places, and no point in repeating it twice.
14:10 it's much more fun to talk about than these two things. All
14:13 but action. What appropriate exception is ? Simply your body's ability to judge
14:18 position in space. All right. so, for example, if you
14:22 your eyes, could you touch your with your fingers? The answer should
14:27 Yes, right, Because I know my hands and my arms are
14:31 My nose is relative to each right? Which is why it's a
14:35 good test for D. U. . S because you you haven't impaired
14:40 to maintain that sort of equilibrium. that's why you're touching your face all
14:44 the place when you do that If you drank too much, all
14:47 , so this is basically what appropriate is It's that ability to judge where
14:53 are for your body, and it's , if you've ever. This is
14:56 fun little thing. Have you ever down to Chema or Thio?
15:00 the Natural Science Museum, anyone? you ever seen the human gyroscope
15:06 You know, it's like three rings you could get into right at the
15:10 Science Museum. They do it for little kids, and it's very
15:14 very slow. But if you go to chemo, if you go down
15:16 Galveston during spring, have a bunch tequila and getting one of these
15:21 it's a It's an adventure, all , because you got wondering that goes
15:25 the X playing one that goes in Y plane one that goes to the
15:28 plane and all three of them are . So you're just like just trying
15:32 hold it together, right? You , But you kind of know which
15:37 is up right now. right. you close your eyes and we spun
15:40 around, you kind of go. . I know which position I'm in
15:42 now, so that would be appropriate . Alright. Now, with regard
15:47 your limbs, we have organs that a role in helping you understand that
15:52 is the Golgi tendon in the muscle fiber. And really, what these
15:55 things do with regard appropriate exception is . The degree of muscle stretch that's
16:01 on relative to what you're trying to . All right. And so,
16:05 I said, I'm gonna put a in that right now for today.
16:09 you want to read the next two , you can We're gonna come back
16:12 it, and I'm gonna give examples these things. All right?
16:18 to touch palpate. All right. have you ever been sick? You
16:25 , you wanna feel if your glands gonna palpate the glands pages to
16:33 All right. So that's what these few slides air the stretch reflects,
16:36 the Golgi tendon reflects We're coming back them in about two lectures.
16:42 Might be one lecture after this I'm not certain. So what I
16:46 to do for the majority of today's . I wanna talk about vision,
16:51 right, and then hopefully I'll get with it would like 10 minutes to
16:54 and then we'll deal with the question equilibrium. Which kind of deals?
16:58 exception a little bit alright. But regard to vision. So remember the
17:02 two things we talked about? We about gestational affection. What we're detecting
17:05 those two things, if you have , classify those two things together.
17:10 were we detecting? Chemicals. So use chemo reception, Alright, and
17:17 vision is a unique type of its electromagnetic reception. All right,
17:23 looking at a very distinct band of radiation. You can see there's the
17:29 radiation scale right there and you can there is the visible spectrum right there
17:33 the middle. All right, and can see there's infrared. What can
17:38 . Infrared. I think I already this season to read. Uh
17:42 Snakes, pit vipers. What can in the ultraviolet spectrum? Bees,
17:48 ? So it's not like there's This is the Onley spectrum. And
17:53 knows? There's probably stuff out there can recognize X rays and all other
17:57 you can even see out there. broadcast bands, you guys,
18:01 You're freaking out about. Five Yeah, you know, it's like
18:06 like the end of the world. know? It's like we're gonna open
18:08 the black hole, you know? you seen those? There's a guy
18:11 YouTube. I really like. He's engineer and he is so dang
18:15 If I find this video, I'm post it. So you guys,
18:18 why you shouldn't be afraid of five ? I can't remember what his name
18:21 , but he like he, explode stuff all the time. While
18:24 working on it, she shocks himself just he doesn't have, for the
18:28 of effectiveness, right. But he about five G and how you know
18:32 the wave length is relative to microwaves stuff like that. It's like it's
18:37 nothing anyway. But anyway, so can kind of see there. There's
18:41 that band. What what we're doing we're detecting that small little band
18:45 just understand, You know, you learned at some point in your life
18:48 , you know, life is has wavelength and it has an amplitude.
18:52 wavelength represents the amount of energy, that's actually the best way to think
18:56 , Uh, light is that it's packet of energy. It's not 100%
19:01 for our sakes, it's really especially if you're in biology because you're
19:04 , Okay, here comes a light it's hitting, you know, a
19:08 are that photon is hitting, you , chlorophyll. And so what are
19:11 doing is you're taking the energy of photon and you're transferring the energy of
19:16 and you're kicking out electrons. You that Z pattern you learned in
19:19 too, or by a one you're like, Yeah, I vaguely remember
19:23 was a Z thing and I had remember, and it was like,
19:25 . Yeah. So if you think light as as as energy, it
19:31 things a lot easier. But here's thing is that this amplitude intensity the
19:36 , which represents the amount of is not a wavelength that we're used
19:40 thinking about, like the waves. see, in a notion they don't
19:43 in one plane, they actually exist two planes, and so that picture
19:47 there. I pulled off of of just so that you could kind of
19:51 and you can see the the two direction. I want you to goto
19:55 . I want you to look up so that you could look at
19:58 that because it's a it's a moving , right? And it's it's mesmerizing
20:04 it just kind of does this I can't even do it with my
20:07 because ones up and down, And the other one is side to
20:11 snake wise, and you just sit and you'll just stare for it.
20:13 like watching hypno toad from Futurama. like you're just like, Oh,
20:19 cool. So this is why this is really kind of complicated. So
20:24 you get into physics and you start into its just like okay, you're
20:28 getting into a realm that requires me think harder than I normally do.
20:32 right, so we're gonna be looking that small little spectrum, and so
20:37 purpose of our eye, which is very large structure relative to the actual
20:42 . So we call the I a system or receptor Oregon. There's a
20:46 selling their That's the receptor in the cell has specific molecules that do the
20:53 . Alright, So again, this not an anatomy class even though you
20:56 to know your way around it. this kind of breaks down with the
20:59 , you can see it's kind of , Uh uh, almost spherical 100%
21:04 , but almost spherical structure. It three basic layers to it. All
21:09 , so the whites of your eyes the clear part in the front is
21:12 the square A and the cornea. the white part is the square it
21:16 around. The whole thing is basically type of connective tissue. And then
21:19 the front, you know, there the light goes through, that's your
21:23 , and it's actually living cells. just clear, which is kind of
21:27 . If you think I was wow, you know, they shed
21:30 this stuff that would prevent light from through. All right, so that's
21:34 the outer layer. And then underneath and you can kind of see in
21:38 picture, you know where it kind really begins. It's right here.
21:42 can see if this is your right? There's your cornea white stuff
21:47 there is yours, Clara. You see starting about right there and goes
21:51 the way around and read, and stops right about there. That's that
21:55 or middle layer, which includes the oId. That's the primary portion,
22:00 Sicily. Everybody in the iris. you've heard the word iris. Iris
22:04 muscle right? That allows that determines much light is gonna be passing
22:10 uh, through the eye into the of the eye. But the co
22:15 , that's basically a layer of blood that supply the nutrients to all the
22:18 that are found in this Clara and the inner lot or inner layers as
22:24 . And then you have the silly , which is hard to see since
22:29 just drawn over him. But the everybody's. We'll see your asshole sit
22:34 of right over here, like and what they do is they play
22:39 role in changing the shape of the so that you can focus inward and
22:44 is the process called accommodation, and also produce the fluid that's called the
22:49 fluid that's gonna be found inside So there is liquid in these
22:54 There's a cavity in the front in of the lens, and there's a
22:57 behind. So the one in the has what is called the acquis
23:01 and the one in the back is the vitreous humor. The humor.
23:04 always making the vitreous humor you're kind born with, and it doesn't really
23:08 all that much over time doesn't mean doesn't change. It's just not a
23:13 right. But the layer that we're interested in is the innermost layer,
23:16 sits even further on the inside. you can just think of it is
23:21 layer is connective tissue protective? Then have a middle layer that is,
23:26 , kind of a bloody muscle so blood muscles, and then we
23:30 the retina. The retina is the layer, all right, and so
23:35 neural contains Ah, first, a of pigmented cells and the purpose of
23:40 pigmented cells so that when light comes , it gets absorbed. It doesn't
23:45 around or bounce back out when you deep into your partner's eyes or just
23:51 eyes, for that matter. The . Starbucks, right? You look
23:54 in their eyes. I'd like a film lot. You know, Whatever
23:57 is, I don't drink coffee, I don't know, You know?
23:59 do you see in the center of high? You see the beautiful color
24:02 their eyes, Whatever it is. to blue to green, thio
24:05 There are yellow eyes. Did you that? And yellow eyes were
24:09 I knew somebody yellow eyes. It just like, Are you sure you
24:12 human? But what's what's inside that ? What do you see?
24:18 right? And really, you're actually into their eyes. The difference is
24:23 the light doesn't bounce back out at . It just gets absorbed. And
24:27 you see black. It's kind of looking into a dark closet, kind
24:34 like the depths of your soul. you for laughing. I'm just having
24:39 today. All right, so that's that's what's going on. And so
24:43 that the outer layer, remember, working from the outside in, and
24:47 the most inner layer is where the cells are. We're gonna look at
24:50 individual cells Now that lens focuses light on the reading to a specific
24:58 and so you can see right back in the back of the eye,
25:01 have something that's called the Macula. I want you to think of a
25:05 . All right, so you can if you've never played darts. I'm
25:09 everyone here has, but just in , people at home don't get to
25:12 this picture. Suckers. So that's dartboard. It's circular. Are they
25:20 ? No, that was saying, right, so then you have another
25:24 . And then down here, you a bull's eye. And then there's
25:26 double bull's eye. Right? Does look familiar? Everyone nod. Your
25:30 said, Of course I know Right? So the macula is like
25:34 bull's eye. The center portion is is called the phobia. All
25:39 so this is where light is trying be focused, all right? And
25:43 rest of this this dartboard represents the of your retina because it wraps
25:50 So again, for those who are at home, everyone to cup your
25:54 like this include you guys, That's what your eyes shaped like.
26:00 . It's like this. And so can imagine that's what your retina is
26:03 . It's kind of wrapping around like bowl that you just made your
26:07 So light is coming into the front the bowl. It's being focused at
26:11 center, but the retina still makes all the sides of the Aya's.
26:17 , uh huh. Now let's focus light on that retina. So you
26:23 see in this normal vision, it you there's your focal point that would
26:26 in the macula, the very center it being the phobia. How does
26:30 bend? How do we get like focus on that? Well, basically
26:33 passing through multiple layers and it's being . Refracted is the word we used
26:38 say. Light is being bent, so again, the numbers aren't important
26:42 here in the picture. But you see light has to pass through the
26:45 , which it basically always does, it basically does so straight. But
26:49 hits, a translucent object it causes light to reflect, reflect refract so
26:56 could see the cornea cause it to fracked, the acquis humor, the
27:01 and then the vitreous humor, and of this is causing it to bend
27:05 that phobia. And so this is the light gets focused because of all
27:09 structures that it has to go through the primary one is a cornea,
27:13 all of these other things have a a role as well. So the
27:18 of the lens, remember, it's . It's also living cells, just
27:23 the cornea is. It's just focus light specifically on the retina to allow
27:28 to accommodate either vision or far All right. And this is accomplished
27:35 what we could do is we can the size of the lens,
27:39 or the shape is not really the , the shape, the lens.
27:42 can allow the lens to be squatting , or we can pull on the
27:46 and make the lens longer or more and thinner. Okay, that's really
27:52 goal here. And the muscle that this, as we said, is
27:55 silly eri muscle. And so we're in that middle layer. We're
28:00 come to the retina moment where in middle layer. All right, where
28:03 the blood vessels aren't on the edges that middle layer coming around towards the
28:07 , where the lenses is where those Serie muscles are all right. So
28:11 have a round object with muscles that wrapped around that muscle, and then
28:16 ligaments are attached to the lens and that muscle. And so what you're
28:20 with the mussels, you're always pulling a ligament. All right.
28:25 when the muscles are relaxed, what do is they fall backwards,
28:32 That's what you do when you right? You fall backwards, so
28:35 what they do. They fall but when they fall backwards, remember
28:38 , wrapped around around objects so they back away from the lens. So
28:44 they fall backwards, they pull on ligaments when they're relaxed, which makes
28:48 lens stretch. And so what we is what we call farsighted vision.
28:54 , how do I remember this? you ever eaten a meal that's just
28:58 so much food? And you just of fall into that food? Come
29:01 the end and your eyes just kind unfocused and all you could see your
29:07 that are far away there people in of you doing this? And you're
29:11 , Yeah, yeah, I see . I'm not moving my head,
29:14 , right? So just think that I'm relaxed, I am farsighted.
29:19 right, But when I need to on something good, what do I
29:22 ? Right as I contract the muscle when I'm studying, I need to
29:25 focused. And I'm you know, you ever get like that? I'm
29:31 , I e. So muscles are , everything's tense, right? Because
29:36 matters, right? This very And so the muscles, air
29:39 And so they what they do is they contract, they move forward.
29:42 when they move forward like that, they're contracting this way, they cause
29:47 to relax, which causes the lens , get all fat and thick,
29:52 allows you to see things up So the process of moving between these
29:56 things, right is process of Yeah. Uh huh. No,
30:09 directors Boy. Boy, I'm not picturing breakfast muscles now, which is
30:15 shameful since I actually teach anatomy. huh. Rectus muscles basically are.
30:25 . Well, let me just put way so that we're all speaking English
30:28 so I don't make a mistake. wrapped around the entire No, the
30:32 retina wraps not threaten the core. wraps entirely around. All right.
30:37 basically, from the back to the and then at the front of the
30:42 , where the Salieri muscles air that's basically about three quarters of the
30:47 the anterior portion of the eye about that is, that's where the lens
30:50 located. Does that make sense? I hear rectus. I'm thinking of
30:55 in the stomach, but that's my , not hers or hiss. My
31:03 is putting. People in the classroom laughing at me because I should know
31:07 anatomy since I teach it So that the question. Second one fire.
31:21 magic. It's like they put the under the doctors walking around a little
31:25 come in and they do magic. , I'm not a physician. I
31:31 know the answer that my wife had . It's I think it works on
31:36 cornea, and then they shave. shave it to shape it, but
31:41 quote me on that. Like I , it's far as I'm concerned.
31:44 Els that got fired from Keebler I'm on. I'm gonna get myself in
31:56 . So the iris is different than silly every muscle. All right,
32:02 . There's two muscles there we have sphincter Papillion, the dilator futility.
32:06 right. And so they're referring to pupil, which is that space.
32:10 the pupils. An empty space between muscles. So you have a straight
32:17 and you have a circular muscle. circular muscle. When it contracts,
32:21 makes the pupil smaller, right? dilates when the, uh the straight
32:27 contracts was doing. It's pulling and makes the pupil larger. Alright,
32:32 that's that's the functionality here. All , Now this sphincter that's the round
32:38 dilator. That's the straight one. you could see the pictures here,
32:42 I put this picture up here. that you need to know the
32:45 This is the pupil pupil area Light . If you take a light and
32:49 in someone's eyes, what's it gonna ? I'm gonna get itsy bitsy,
32:53 tiny rights that's a natural reflect and can actually cover one eye. Or
32:57 could basically divide the two eyes like and then, like prevent light from
33:00 in this one, and you can light into the right eye. And
33:03 the only one that's gonna, you know, not dilate, but
33:09 because they work independent of each which is really kind of cool if
33:12 think about it. Oh, they're not tied together, all right.
33:16 in essence, what this does this the amount of, ah, light
33:20 gonna pass into your eyes. So dependent on the availability of light.
33:24 right, Now, the sphincter papillon , uh, innovative para sympathetically.
33:29 dilator is sympathetic, and there's another toe to remember this. All
33:33 so remember sympathetic deals with the fight flight response, right? So when
33:39 present, you know, you don't want to fight. Like if you
33:42 a bear. Do you want to the bear? No. You want
33:46 get the heck out of dodge, want to run, right? And
33:49 what you're doing is you're looking for quickest and fastest way to get out
33:52 . So really, what your eyes is they dilate so that you can
33:55 more clearly even if you have plenty light available. All right, so
34:01 actually a natural response. Natural That's how I remember. It's like
34:05 I if I hear, see a , it's like I've got to get
34:07 of there. So para sympathetic Eat lots of food. What am
34:14 this Just go out All right? throw this slide in here just so
34:20 you can see because people always ask these questions. I do not know
34:23 answer. Hold on. I'll answer question. Say, when you asked
34:26 . The question is like, well, if I have a
34:28 what's going? I am not an , Okay, but it just shows
34:33 where the focal point goes under certain , right? So there's 1/6
34:38 farsightedness, nearsightedness. Remember, our point is the phobia. And so
34:43 happening here is we have miss shape terms of the lens, and so
34:48 improperly focusing the light onto the And that's why the vision is fuzzy
34:54 you're not getting it Focal focused at specific point, you're getting it focused
34:59 where it needs to be. So why you put glasses. You're putting
35:03 refractory lens to get it to focus it needs to go. And I
35:07 I've told this story before. I know. I tell you all the
35:11 . So I've never had to wear until I turned for the high
35:17 But and it was the saddest thing my entire life because my whole
35:21 my brother, is legally blind. , e. He's been wearing coke
35:25 glasses since he was like 10. had 2010 vision my entire life,
35:30 one day I woke up and I read the side of a bottle.
35:33 know, like you know, there's I could do. So finally I
35:36 and got my eyes check and I to see the optometry over at the
35:40 school because it's free, you at certain times of year, they're
35:43 , Come, get your eyes checked like, yes, free. I
35:46 have to pay money, no co and I go in there and she
35:49 , Well, you have a I said, Well, what caused
35:53 ? Do you never, ever, give this answer? It's because you're
36:00 . Yeah, I'm what now? that's why I put this up here
36:08 to remind me I'm old. all right. There was a question
36:14 , this sprinting, trying to see then passed, Do I mechanics.
36:21 but you man, that these big like like I know anything about
36:27 It's It has to do with the of the lens there, squinting primarily
36:31 they can't get there. They're not , right? My wife has to
36:35 reading glasses. She should be wearing all the time, like May.
36:39 , you know, she's in but in essence, she does the
36:43 thing. What's the first thing you when you can't see something you you
36:46 of squint to see if you can the adjustments that you start doing the
36:49 movement, Then you start doing that at the same time trying, and
36:53 it's all uses. It's basically one these reasons right here is you're not
36:57 to get the light focused where it to be focused and what I'm hoping
37:00 do here. And I'm gonna try show you guys I'm sorry I talk
37:04 way. It's just is Yeah, . Um what I'm hoping to show
37:11 here in just a moment is um What's what's actually going on in
37:16 phobia. Why we're trying to focus there. Okay? It's not just
37:19 want your name stuff. There's there's rationale behind all that. So I
37:23 can't answer their question because I'm not with the pathology. And the truth
37:29 , Is a lot of things that guys are really interested in is why
37:32 things work? I can only tell how they work, right? So
37:36 like if you brought me the busted , I just say it's because it
37:39 work. Yeah, victims. A . Astigmatism. Yeah, Don't worry
37:51 that, Z Yeah, apparently If that's what they told me
37:58 is it Onley old people? But like I said my entire
38:02 I have 2010 vision, You 2010 vision is 2010. Vision means
38:07 what you can see it 20 ft what people see clearly. Usually a
38:10 ft. I had incredibly good Now I do not, and I'm
38:17 sad. So when does it No, You can have young people
38:22 astigmatism. I'm sure there are people this class stigmatism back there. And
38:27 like what like 16. Uh Just just go with it for right
38:34 . Say yes until I go to bar. I'm 16. Right.
38:37 right. So let's kind of look the retina. All right,
38:41 like I said, this is the tunic. So you need to think
38:44 terms of I'm going, I'm working the outside in. All right.
38:49 so what we have here? There's layers. I mentioned the pigmented layer
38:52 can see down here on the So notice the picture here.
38:56 It's showing you here is the I . The direction light is coming.
39:00 this is the direction light travels into retina, all right? And so
39:06 can see you know, light is through the lens down to the
39:10 And granted, I can't draw a line like this, but you can
39:13 so light has to pass through multiple layers of neural cells. And then
39:20 here, the outermost layer is the layer. And what this does,
39:26 ensures that when light comes in, doesn't flow through. So we don't
39:30 it coming through. So, doesn't pass through your eye. Nor
39:35 it bounce back out all right? if it bounced out and stimulated another
39:40 cell, well, you wouldn't understand the hell was going on. Have
39:43 ever driven a car late at There's a cat, raccoon,
39:51 Out in the street, you're coming 90 miles an hour gives you that
39:56 like. But the only reason you're to see it is because light is
40:01 out of their eyes, right? don't have that. Nocturnal animals have
40:06 reflective layer. And basically, I what it is is to amplify the
40:11 of light that's bouncing around so they seek more clearly in the dark.
40:16 , so humans don't have that. there's that pigmented layer, all
40:20 And then we have these. This what we call the neural layer.
40:23 is the innermost layer. Now, only do you absorb light there,
40:27 is also where you can produce vitamin . We need vitamin A in our
40:30 because we're going to see that the for the receptor is half a vitamin
40:36 molecules called retinol. All right, is basically if you take two retinol
40:40 Jim together at their tails. That's vitamin A so clear. Vitamin A
40:45 half you get two retina als So this is where we're gonna process
40:49 A. Now, there are five of interest. Three of them are
40:56 cells that are in kind of, , ABC Order. And then two
41:01 these cells sit in between the A CS. Alright, so it's basically
41:05 interruptive. Be interruptive. See? . Sorry. A interrupted. Be
41:11 . See? There's no other All right, so we're gonna work
41:15 the outside. Our sorry from the out, All right, Because our
41:20 interesting sells the photoreceptors self. So the That's the inside of the most
41:24 cell. So the first cell that gonna come across it's called a ganglion
41:30 . All right, so that's what looking at right there. These are
41:32 ganglion cells. All right, so are the cells that receive the signals
41:39 everything that's upstream of it, and sending the signals onto the central nervous
41:44 . All right, so they're like last cell in our pathway. Maybe
41:47 should go. The other direction would better if I go outward inward.
41:50 that's the way I wrote it up . Alright. So back up,
41:54 . Erase the tape a little Leaving early. You guys know
41:58 Are you sure? Just making sure been a long time. All
42:04 so we'll go. Here's our pigmented down the bottom. Sorry,
42:08 At home, it's hard to follow way. So here's our pigmented
42:13 Our first group of cells. Those the photo receptor cells. These are
42:16 light receptor cells. There's two different . They're called the rods and
42:19 Why they called rods and cones. they look like a rod. They
42:23 like a cone. That's it, , See, you are biologists
42:27 You've got it figured out all And what they do is light passes
42:32 all the other cells, and then come into contact with the receptors that
42:35 located there. And that's what we're use to activate these cells, to
42:39 whether or not light is there. they do is they produce a signal
42:45 is going to act on the next of cells. These air called the
42:48 cells. They're called bipolar cells because bipolar cells, right, meaning that
42:54 have that central body and they have acts on one dendrite. Right?
42:58 there literally bipolar cells, two places the body. Where you gonna find
43:03 bipolar cell? One is here. other one is in the olfactory system
43:09 clean ones right now. Bipolar There are fewer of them. So
43:15 just gonna make up numbers right Will you bear with me while I
43:18 up numbers? Alright, What we're say is we're gonna have say,
43:21 , 100 photo receptor cells. Maybe the bipolar cells, we're gonna have
43:26 bipolar cells, so you see what doing. We're converging inward in terms
43:31 the number of cells, right? then the last thing we're going to
43:35 the ganglion cells. And again, fewer ganglion cells. So what we're
43:39 is we're converging on the ganglion So when we talk about receptive
43:43 what we're really talking about here is gonna talk about what the ganglion cells
43:47 information from so in our little model we drew over here, this ganglion
43:51 has a receptive field of 100 photo in this model. In this little
43:58 , I gave. All right photo receptor cells are not very
44:03 so they don't produce action potentials. only produce graded potentials. All
44:07 you get a greater potential, and gonna be enough to send a
44:10 And again, you're releasing Chemical to the bipolar sell, the bipolar cell
44:14 stimulated, and it's a very small , so it's only gonna produce a
44:18 potential. But it's enough to cause of a chemical that chemical acts on
44:22 ganglion cell. The ganglion cell gets . If you stimulated well enough,
44:25 produces the action potential that travels all into the central nervous system so that
44:31 can see what they're trying to do look, it's like, Oh,
44:33 , here are all the actions of ganglion cells and off they're going,
44:37 what they eventually do is they converge they form the optic nerve. From
44:43 , the two other cells is are horizontal cells and the Quran sells the
44:48 cells. What they do is they between the photo receptor cell and the
44:52 cell. And so here you can there's your horizontal cell sitting right in
44:57 , and then the am a Quran , since between the bipolar and the
45:01 cell, and the purpose of these is to modulate signals. All
45:05 So in other words, while the receptor cells were responding specifically to the
45:11 that they're receiving, those signals are modulated as they progress up to the
45:16 cells even before you get to the cortex. So your eyes are already
45:23 information so that your perception of what going on is been modified. All
45:32 . Have you ever seen the picture the man on Mars the face on
45:36 ? No, There's satellite imagery from . When I think it was
45:41 it might have been Viking. I remember which I'm old enough now that
45:45 know things have gone on that I know what's going on right? But
45:48 this picture, and again I apologize those who are at home. But
45:53 like this thing. It's obviously it's hill, right, and it's kind
45:57 like this, but the light is right. So you get this kind
46:00 shadow that's going like this, you , on the hill. And then
46:05 you look at the thing it has shadow here, Shadow there, shadow
46:14 , shadow like that. And of , the you know, they're out
46:21 . You know, we believe people that. And they said, this
46:23 proof that they're aliens out there. civilizations Because they have created large structures
46:29 us to recognize. And the answer no. We process light. And
46:34 when we see something that looks like face, we say it's a
46:39 You know how I know this? , one because I'm I've read all
46:43 stuff about it. Right. But guys ever watched the cartoon about the
46:47 toaster? Yeah, I remember a tester. What a little tester looks
46:51 here is a tester. All It's a toast. All right,
47:04 face. Alright. Testers don't look that. They don't have faces.
47:10 not humans yet. We see that the little steam shovel. Did you
47:16 ever see a little steep show? , get on your Disney plus start
47:19 through some of the old Disney comer Disney cartoons. Same third name,
47:24 anything. Just give it something. something like a face, and your
47:28 says Okay, I believe this is . Hm. And that's kind of
47:33 going on. Is that pre processing place in the eye at these levels
47:38 of these cells. Now, what wanna do is I want to focus
47:41 the photo receptor cells on. Then kind of hopefully move forward.
47:46 like I said, we have we have cones. They respond to
47:50 wavelengths of light. All right, , rods, there's only one type
47:55 rod and they're sensitive to this broad between you do not need to know
47:59 numbers. Please do not memorize the online. Do not memorize the
48:04 Okay, I'm throwing them up there you can see that there's a lot
48:07 overlap. Correct. So basically, have a certain degree of of absorbent
48:14 a broad range of about 200 right? And what you can see
48:18 you look at the little picture up , the look at the black line
48:20 the graph. And so if you at this graph, it shows you
48:24 wavelength at the bottom. But on on the Y axis, what you're
48:28 at here is relative absorbent, which relates to how stimulated is the
48:33 So if you're 100% stimulated, that be one. If you're halfway
48:37 be 50 and obviously zero would be not stimulated at all. And so
48:42 can see if you look at that line, there's this range of stimulation
48:46 40% and down here on the other . Basically, it says about 20%
48:51 , so you're most stimulated. Ah, wavelength of light. Roughly
48:56 500 animal meters hits that rod and can see Where is that? Sit
49:01 the wavelength sits around the green band visible light case Well, so
49:08 Well, the so what here has do with the way that we've named
49:11 cones? Because cones are responsible for ability to see colors. All
49:17 And we have three different cones. have what some people call the
49:21 the green and the red cones which terrible, terrible names and their name
49:24 where their maximum absorbency is located. right, the correct terminology is the
49:31 in the l, which is super , and low frequency which takes away
49:35 color aspect, all right. And reason we're going to see. This
49:39 how do we How do we perceive ? And so what? It basically
49:43 you can look at the range is to 5 54 and 6 50.
49:46 do they have overlapping ranges? Of . So Roger stimulated roughly in the
49:51 range as the other ones are But it's their specific wavelength and how
49:56 respond at their specific in that range their wavelength that give rise to
50:02 And also which ones are being All right, so I want
50:07 Look, ladies, you're gonna have answer this question because guys only know
50:10 colors. What color is his Okay, you guys are gonna say
50:17 because literally we know eight colors, ? What color is it,
50:22 You turn around so he so they see what color is that shirt you're
50:27 with? Pink to pink. Okay, we've got a lot of
50:32 color is this? What I I thought I heard Hunter Green because
50:39 mean, because that's that's you know it is. All right. What
50:42 is his sweatshirt? University University huh? That's an orange. Red
50:51 is red red. Red. normal. I could get a fight
50:54 . It's awesome. It's like, , it's scarlet. No,
50:57 no, no. It's not Cardinal. God, they're sitting
51:00 Going e don't know, Read because don't know colors, right? If
51:06 we had a challenge, If we the room in males and females and
51:09 name the total number of colors that , well, the guys who get
51:13 primaries, you know, the first colors, and then we'd probably say
51:16 and dark so that we could triple right. You can, ladies.
51:22 right, here's the challenge. Named Blues. Go. Fuck ! I
51:28 civilian. I was the first one you lean. Wow, baby,
51:36 ? Sky in to go. Do see these guys? You see where
51:42 guys have you guys heard of? flour, Cornflower blue filth.
51:47 you guys gotta get out more. struggling with our colors here, but
51:51 okay, you guys, the brave that left the house. So that's
51:55 . All right, So anyway, I'm pointing out here is that we
51:58 different cones and different rods in different . I mean, we have rods
52:02 we have cones. They have different to them. All right, we're
52:05 come back to the color in just moment. But I want you to
52:08 first that there's a range that they're being stimulated. That and that they
52:11 variability within the range in the terms the degree of stimulation. All
52:17 What this map is showing or what picture is showing you is the relative
52:22 of rods versus cones. Cones typically almost a 1 to 1 ratio to
52:28 ganglion cell. All right, so cone has basically one ganglion. All
52:34 , so it basically means that the field for those ganglion is basically only
52:39 sell in terms of its reception. when you're dealing with rods, there's
52:44 of rods to a single ganglion so they have much, much
52:48 receptive fields, right? So if can imagine if I have a receptive
52:53 online, picture me with my hands right over here On my right
52:58 I have a single rod cells. got ah, 100 of them across
53:01 the breadth of my arms. But got another rod sell over here.
53:05 I stimulate this rod sell the ganglion , which my feet represent is gonna
53:09 stimulated if I stimulate this rod sell on my left hand. This ganglion
53:15 , which my feet represent is going be stimulated. So it doesn't matter
53:18 the light hits as long as it within this range, that ganglion cell
53:22 going to be there. So I have a high degree of acuity when
53:26 stimulate that ganglion cell, right? other words, it has a broad
53:32 . Remember how we were talking about receptive field on the hand or the
53:35 of the leg last time? It's you have big, receptive fields.
53:39 like I don't know where the stimulations from. It's just in this general
53:44 . That's what's going on with Rods have these very large, receptive
53:48 because they are many of them converging a single cell. And that's what
53:53 is trying to show you. And this if you look at this
53:56 it shows you all right here, me take my red. And I
53:59 the little bowl I showed you. me flatten it out and then let
54:02 measure the number rods in the number cones. So if you look on
54:05 periphery where I start on the I got lots and lots of
54:09 And as I start moving towards my , it flip flops. And my
54:14 flop now has lots and lots of , Ortho cornea, lots and lots
54:18 cones. And then when I go out the other side, it's back
54:21 rods again. Now what this is you is the density of the
54:27 Alright, so I got lots and of cones in the phobia. No
54:32 . And I have lots and lots rods out on the end and very
54:36 cones. And so that means they kind of different purposes. All
54:42 there's lots of rods that converge. few. Basically, cones don't converge
54:49 all. And what this has to with this has to do with
54:53 Now, I'm gonna go over some heads here, But if you are
54:55 video file like me, this is make 100% sense to you. All
54:59 ? Do you guys remember standard death for TV, right? That's the
55:04 TV that you used to watch, ? You guys were probably like to
55:08 this stuff was out, right? talking 480 p. You know,
55:12 numbers represent that's a number of pixels the top of the screen to the
55:16 of the screen, right? And 400. That's that's how many are
55:21 . So if you get a TV the same size and you put 10
55:25 p, that means you're gonna have and 80 pixels from top to
55:29 so the picture becomes much more And this is what HD is
55:33 If you've gone out and have bought four K TV in the same size
55:38 now have based on the name 4000 from top to bottom. So is
55:45 picture clear? Or is it It's clear. And of course,
55:50 you didn't know this, they have for the A K in the 16
55:53 , but they haven't released it out because they want to make their big
55:56 as fast as they can on everything they could do. So just wait
55:59 Christmas or two, and then they'll the I know that you can buy
56:02 , but it's not like mainstream. right, Now, that's what this
56:06 showing you its like. Look, here. You see the fuzzy
56:08 There's your SD full HD. That's it looks like versus the ultra off
56:12 four K. All right, now ? This is actually demonstrating. And
56:16 , if you took a 32 inch and counter the number of pixels,
56:21 density of the pixels is telling you many things there. So think of
56:25 of those pixels as a receptive field your eye. The more receptive fields
56:29 have the clear of the picture. is the receptive field representative off the
56:36 cells for a cone? How many do we have? Per cone?
56:42 one. So you're gonna have really high acuity wherever you have these
56:48 cones. For rod cells, you lots. How clear is the picture
56:55 be when you're looking at something? it's hitting rods is gonna be
56:59 They're gonna be clear. It's gonna fuzzy. All right, Now we're
57:03 have a little bit of fun. want you to look at an
57:05 Look at whatever it is that you in front of you like your note
57:09 or something. I want you to on a word, all right?
57:11 maybe if it's a paragraph or some Is that word clear to you when
57:16 looking straight at it? Alright. moving your eyes from that word,
57:19 want you to kind of take your outward and look around that word.
57:23 it fuzzy without moving your eyes from word? Notice how your eyes say
57:28 don't like the fuzzy. And so got to go look at whatever it
57:30 I'm trying to look at right. you're trying to do is you're trying
57:33 move your vision so that the light focusing it onto the phobia where the
57:39 vision is right. So what you do is you can imagine out here
57:44 the periphery things air fuzzy. If catches my interest because it's moving or
57:49 looks like something that I'm trying to or something like that, what do
57:52 do is I turn my head and my focus where my clearest vision is
57:57 , right? And the easiest way do is just pick up a page
58:01 text and look at it because that's it's like, where I'm reading the
58:03 . One of my eyes do is move the text around. What I'm
58:07 on is not focused. The text looking at is focused. This has
58:11 do with that degree of convergence. right, so if the standard def
58:16 def and ultra death don't help Think about in terms of that,
58:22 , cones are densely packed. They low convergence. So I have low
58:26 field. So I got lots of fields jammed together with rods. I've
58:31 bigger Recep receptive fields. They're not close together. There is some overlapping
58:36 , um, so that's that's But it means I got fuzzier
58:40 Now, the one thing that we Thio No, and I don't mention
58:46 in the end of the next but we use rods primarily in the
58:49 . We use cones primarily in the . We're gonna get to it in
58:52 a moment here. It's gonna be that Scott topic faux topic is.
58:56 right, so I want you to it being dark, right? You
58:59 up in the middle of the You have to pee because whatever.
59:02 old now, that's what I'm just ready. That's coming for you.
59:07 avoid it, right? And you up and there's no light. But
59:11 too lazy to turn on the You know where everything is in
59:14 But you look around the room and see that big pile over in the
59:16 . What is that big pile of in the corner? Probably your
59:19 Because that's where you left it, ? Good. I'm just making sure
59:24 not the only one You don't It could be a monster, because
59:29 you look at it, your cones not stimulated. Right? Rods play
59:34 major role in your night vision where have lack of clarity, right?
59:40 can see shape, but you can't see color quite so well,
59:45 Onley. When it gets bright enough this space does do things become clear
59:50 you could see colors very clearly. , let me see if I can
59:54 in the classroom. Can't promise I , but I'm going to try.
59:59 part of the reason that is difficult show in the classroom like this is
60:03 we have this up here, but notice how the colors became a lot
60:05 muted when I turn those lights That's because you're now dealing with the
60:13 . Can't be quite a stimulated. rods are vastly stimulated because they don't
60:18 a lot of photons to make that . So when you have a chart
60:22 this, this is an easy way do the compare. Contrast. All
60:26 , easy way to compare contrast. come back to this in just a
60:30 . We've dealt with the the shape the feature because their names we dealt
60:36 color vision. Which ones play a in color vision cones we haven't talked
60:40 . Sensitivity rods are more sensitive than are their check mark Security, which
60:46 plays a greater role in acuity Very good. Let's go. Top
60:52 photo op will be with convergence cones less convergence rods have more convergence.
60:59 it's basically the number of rods going that gangling selling, lastly, where
61:03 located Well, phobia versus, the rest of the retina. So
61:10 I want to do is, I to interrupt this. I want to
61:13 with. How do we actually All right, how you know?
61:18 on. My eyes. See? does it work? And it depends
61:22 a bunch of different molecules. And is again signal transaction Cascade. And
61:27 , um, I have this picture here just to kind of show you
61:30 players, and we're just gonna kind walk through. So we have one
61:34 cyclists. It's job is to make p there's an is. All
61:39 So you take GTP, you cleave , you get cycling and bend it
61:42 . You get cyclic GMP. Photo is our actual receptor. Alright,
61:48 basically gonna be the thing that absorbs and so you can see in our
61:52 picture here, I should probably be these things. Alright, So here's
61:56 our photo receptor. Um, this'd , um they're not even showing there's
62:04 with cyclists. Guan Later, Guan little little, little little little little
62:07 little You can is the same Alright, Trans Dussan, That's just
62:11 fancy for r r g protein. was named transducer because of the first
62:15 discovered and transducers light energy into a message again just proving once again biologists
62:21 not original people. Eso it's a . I'll circle that. You can
62:25 it attached to our protein but here is in its active form. So
62:28 can see it right there and then it is again on then we have
62:31 special enzyme here. It's called Fossil Astir Ace. Um, I don't
62:36 which specific fossil diocese races. I've even bothered to look it up,
62:40 its job is to take that cycling that we converted or made early
62:46 and we're going to deci plated into . Alright, so that's where that's
62:50 from and why we care about that because we have a channel called a
62:55 nucleotide gated channel that is activated by GMP. So the amount of cyclic
63:00 you have determines whether or not that is gonna be open or closed.
63:04 right, now, when this channel open, sodium is able to come
63:07 the cell. When sodium comes into cell, what happens to the
63:10 Higher polarizer d polarized de polarized. ? So basically the cell is
63:16 What you mean I've got a system is going to have a cell that
63:23 gonna allow the cell to fire. . When is it gonna be
63:26 All right, here's the thing that everything up. It fires in the
63:32 . Let's screw with your minds for . We'll come back to it.
63:35 right, So this is actually what's on. It's called what is called
63:39 Dark Current. Doesn't that just sound a metal band way? Are the
63:45 current scream from my throat? Now this is the photo receptor
63:54 What? Basically what it's saying is , Look, there is no
63:58 I'm producing cyclic GMP when I'm producing GMP cycling GMP binds to this.
64:03 it buys, his channel causes channel . When the channels open, sodium
64:06 in when sodium comes in my cell polarizes. And when my cell to
64:10 , I'm gonna release a chemical. chemical that I'm releasing is a neurotransmitter
64:15 blocks the activity of the bipolar So this is inhibition. So in
64:22 dark, I don't see anything because telling the bipolar cells that I'm not
64:25 like I'm not detecting light. In , that's the signal all the time
64:29 not detecting line. I'm not detecting . I'm not detecting light. Why
64:32 I do that? Well, because more life than there is dark.
64:36 this takes less energy, so it's a backward system. All right,
64:44 the problem is, and we don't about this all that often is that
64:48 sodium comes in, eventually reach So I have to have a system
64:53 allows me to pump it out. so there is studying potassium, a
64:55 pumps. And so basically what I'm is I'm creating a natural current,
64:59 is why we call it dark So it just allows it to state
65:02 this perpetual state of activation. All , that's what what the dark current
65:09 now. Photo pigment. As I , this is our G protein,
65:12 this is our G protein coupled All right, so it's a seven
65:16 membrane protein. It's already bound to ligand. The linkages doesn't activated unless
65:20 changes its shape. The ligand, I mentioned earlier, is this molecule
65:25 Retinal and has two shapes. It's This 11 cysts is what it naturally
65:29 to this. And so if you here. That little purple thing that
65:34 the 11 since retinol. And if you wanna kind of picture
65:37 you can make your fist that big , uh, circle, right,
65:41 that organic ring, And then you your fingers, the tail. And
65:44 if you put a crook in your like so there you got sis
65:48 And when light comes along, it that 11 carb to twist around its
65:55 . And so it becomes a trans . So it's an all trans versus
66:00 . And so you can imagine Here am inside this space that has limited
66:04 inside it, right when I change shape I changed the relationship with what
66:10 receptor is. And so I changed shape of the receptor. When light
66:15 around and I've moved from this that and that's where the activation comes
66:21 . That's when I detect life. how I detect the light.
66:30 Yes, it's as far as I . I mean, most of the
66:36 that they've done on this are on , so cats are nocturnal. I'm
66:42 guessing. Yeah, I'm not an expert. When you want to talk
66:46 test ease. I'm your man or . Doesn't matter. E can have
66:55 , right? I'm not gonna be expert on everything. I know this
66:59 information about everything. All right? I throw this up here just so
67:05 you understand that there's this cycle that's on, right? So when light
67:08 along, I change the shape to transform. But then what I have
67:10 do is I have tow convert it to the cyst form so it could
67:13 reusable. So there's this process of , of transforming this molecule over and
67:21 . So there's this recycling and this is incredibly complex, and you don't
67:26 to know it. But I like show it to you anyway, just
67:28 it's scary. All right, so here, you got the rod.
67:32 sorry, Rod. Over here you the cone. It basically says,
67:34 , I change the shape. And what I do is I take that
67:37 . I throw it over to the , sell the pigment itself, goes
67:40 like a billion different steps to change back. And then I give it
67:43 chaperone. The chaperone sits there and itself around this says, Please don't
67:46 your shape before you get toe If light comes along, I'm not
67:49 let you go until you get in right place and then it moves it
67:52 over to the original thing says Get in your space and then light comes
67:55 and checks. The whole thing goes over again. And the thing
67:58 is that it's really, really fast . And I say really fast.
68:03 a relative term in cones, but relatively slow in rods. You can
68:11 this yourself, go to a movie . Watch your movie. Of
68:15 Go to the matinee because it's Are they even open now?
68:19 so you can go to your movie 7000 ft apart from everybody Go
68:25 It's dark. Come out in the On what happens? Texas sunlight hits
68:29 eyes. What do you do? right. And you can't see
68:33 Right? But does it take very for your eyes to adjust?
68:37 Do the opposite. Go from an where you got lots and lots of
68:41 go into a dark space. How did it take for your eyes to
68:44 about 10 to 15 minutes. the truth is a measure. Truth
68:48 , 20 minutes to get fully acclimated the dark, all right. It's
68:53 of this process called retinoids cycle. don't need a noble steps. Just
68:58 that I process my retinol, get back to its original shape. So
69:03 takes us back to this process. , So when light comes along,
69:08 it's gonna do is it's gonna change shape of that retinol molecule right when
69:14 retinal molecule goes from the cysts form the transform, what you're gonna do
69:18 you're gonna kick out the transform. at the same time, what you've
69:22 is you now have activated your Um, transducer. When it's
69:27 goes and activates Fossil digester is when Iast races activated. It starts chewing
69:32 all the cycling GMP that you're And when you show up all the
69:35 GMP, you lower the amount of GMP that's inside the cells. Less
69:40 GMP, less cycling GMP to bind our nucleotide gated channels when there's less
69:47 the channel's clothes when the channel's clothes can't come in when sodium can't come
69:52 . I don't do polarize when I do polarize. I don't release my
69:57 . When I don't release my neuro , I'm no longer inhibiting the bipolar
70:01 . The bipolar cell is basically doing exact same thing and saying You've been
70:05 me, Don't Nothing's going on. going on, Nothing's going on
70:08 now you're not telling you nothing is on So I'm gonna go ahead and
70:12 in the same way that the, , the the photo receptor cell
70:17 In other words, I don't need be stimulated. You're keeping me from
70:19 stimulated. So it naturally goes to deep polarization and using the same sort
70:24 methodology. That's how the ganglion cell . So just to kind of give
70:29 a better picture of that, this kind of what it looks like right
70:34 on the left side. That's the . So what is retinol? It's
70:39 its sis form. In the It gets transformed to transform. Sodium
70:44 are open versus sodium channels. Closed is too polarized. Membrane is now
70:49 polarized. When the membrane is deep , I released narrow. The neuro
70:54 is inhibitory That's why it's in So the bipolar cell doesn't fire.
70:58 bipolar cell firing. No signal sent the C. N s Converse.
71:04 I'm preventing the release of neuro I no longer inhibit the bipolar cells
71:09 it starts releasing its neuro transmitter that action potentials in the ganglion cell.
71:17 this is a break that prevents signals being turned on in the dark.
71:22 in the light you take your foot the brake allows the ganglion cell
71:27 That's how the system works. It's than what you would expect. I'm
71:32 by light. There go. I to see you know, your stimulating
71:36 you're no longer inhibiting. That's why get to see it's a positive leaked
71:41 an anti negative. That doesn't Don't mind. Now, let me
71:51 you a little bit if you're not confused. I like to use these
71:57 because you makes you think that there's binary response right. When lights
72:01 I detect the light. When there's light present, I don't get to
72:04 the light. That's very binary, ? But we know that there are
72:08 levels of stimulation. Would you agree me with that that you can see
72:13 semi light you can see in in dark. So on and so
72:18 So on, right. If the was brighter, would the color will
72:21 more vibrant to you? What do think? Yeah, so there's
72:28 So calcium is a molecule That's that this. So this cycle of GNP
72:33 , uh, cyclic nucleotide gated It allows sodium, but it also
72:37 calcium and all right, so there's in there. And there's this molecule
72:43 G cap. You can see it's there next to the guano light.
72:46 , Let me circle it for It's in red, right? So
72:49 this thing in the minds of calcium calcium is available, what happens is
72:55 that this, um, basically, um slows down the production of cycling
73:03 . All right, so even in dark, you're not producing as much
73:06 GNP as you could. So it's putting the brake on a little
73:10 even though you're still moving forward, ? It's like the yellow lights
73:14 So it's like instead of accelerating, just kind of Okay, I'm gonna
73:17 gonna slow down because the cops behind all right now, when the channel
73:25 , calcium can't come in so calcium bind to G cap G cap,
73:30 , we said, is the It's slowing down amount of cycling GMP
73:32 being produced. And so now what is you ramp up the amount of
73:36 GMP. Now let's put this in . I have less cycling GMP.
73:41 fossil diaspora fostered Iast arrays, That grave purple thing over here doesn't
73:48 to work so hard to get rid cycling GMP, right? In a
73:53 where I don't have this, I'm cycle. GNP had given rate what
73:56 doing them slowing down the rate, removing the amount of cycle GNP doesn't
74:01 quite as hard as it would if didn't have the break rd on.
74:07 when I take the break completely off there is light. In other
74:11 when those channels were closed, I produce a ton of cycling GMP,
74:16 that means the system. As soon I remove the signal of light,
74:21 it will automatically go quickly over to other way. That kind of makes
74:26 . It's like putting the gas on that I can flip the state of
74:30 cell quicker brakes to flip the state the sell gas to her flip to
74:38 back. So I'm modulating. Does kind of makes sense? This'll is
74:44 the blank stares come out. I'm to see them. It's all
74:49 You can ask the question. I get it. She did it.
74:54 , I'm not gonna be the person it. What if I just told
74:58 everything I told you was backwards? trying to see if you're paying
75:03 No, I told you correctly. . Here, I'm just gonna
75:09 Is less cycling GMP because of the of the calcium. Where's the calcium
75:13 from? It's coming in, No calcium, no breaks, no
75:23 . Lots of cycling. GMP. what can the cycle of GNP
75:29 It can go on, bind up soon as the system allows it
75:34 It's now gas pedal. Binary systems two speeds on and off. That's
75:49 , but imagine it was your speakers your iPhone, right? There's two
75:56 of your iPhone is on or Would that be fun to listen to
76:00 10 or not at all. No through your batteries, quick. And
76:07 music would sound like crap. All , So what do we do?
76:11 put a volume control. So we a volume control for our channels as
76:16 . The volume control for a channel , uh, cow module in on
76:22 Cal module in does is it allows to, um, modify how much
76:28 GMP can actually bind to the All right, so this is what
76:34 pathway says. It says, all right, I've got psycho GMP
76:38 opening up to CNG channels. I'm gonna make up a number. Let's
76:41 it's four of them. What happens Kalma calcium comes in, it binds
76:45 module and Cal module in basically reduces affinity for that channel for cycling
76:52 All right. What does that First one bind, it's like,
76:56 , but I'm not so interested in second one. I'll take it,
77:00 , you know, whatever. third one, man. So I
77:05 to Okay, I guess. Fourth one, I'm not gonna buy
77:11 one. That's what How module is , right? So if without cow
77:16 basically be like give me four. completely open. So now what I've
77:20 . And now I have graded I'm wide open and I can kind
77:28 decrease how much I'm being open. what this allows the cell to do
77:34 to avoid those two states open versus . It allows me to get to
77:40 that point where the seesaw is right on the edge of opening and
77:44 So I could be kind of open of clothes, kind of open,
77:48 of close. And so now I modulate the state of the cell
77:52 much easier. That kind of makes . So that's just another example of
77:58 modulation. I thought they know I'm gonna give them control. You set
78:03 there, right? I guess I'll there, e I know you guys
78:10 done. No, actually have two , so I'll just get So this
78:15 the scope topic versus the faux All right, this is we've already
78:18 about it, so let me just you. So remember the rods and
78:22 , they're the ones that opening are . Toe light cones respond to higher
78:30 of of photons. You need more toe. Activate that cell. All
78:36 , But once you activate them, activated and they could, and this
78:40 us that clarity of vision. All , so this is what is referred
78:45 as faux topic vision rods. You need a lot. You can literally
78:50 a rod with a single photon, they because of their the degree of
78:57 , of convergence that they have, because they can adapt very, very
79:02 or respond very quickly. But you bleach them out. It takes him
79:05 long time to respond. So they're good at dark light, where it's
79:10 , like so don Early don, right there, dusk or even at
79:14 . They're very, very functional. once you get in the light,
79:18 are right now are Roger bleached out our vision is primarily based on cone
79:26 right now. Alright, because again the degree of activation for those
79:30 so rods or Scott Topic vision and is not a good representation, but
79:36 the closest thing you can get with picture, because all they've done is
79:38 open and closed the f stop. when it's bright out, you have
79:45 topic vision. When it's dark you can still see stuff, but
79:49 not quite as clear. This would SCO topic vision and what that graph
79:53 showing you is kind of where that one takes over the other one,
79:57 two different curves, but they're And again, this is my last
80:01 . And then we're out of Color perception. The colors that we
80:05 are the result of the three different . Okay. And what that means
80:09 that when you see red, you're simply activating the red cones. If
80:15 seeing green, you're not activating just green cone. Remember, all three
80:20 those ranges overlap, right, including the rod. But we believe that
80:25 out. So just think of your cones. So the degree of stimulation
80:30 each of those cones represents the color you can see So you can see
80:36 color wheel up here. Right there your Roy G biv. You remember
80:39 old Roy G biv right in Roy biv, Is there any pink?
80:42 you see pink at all? How colors do you think the human eye
80:46 recognize? I mean, guys can a colors, but that doesn't mean
80:50 don't see more color. We just know the names of them. That's
80:53 I just call him Red. How colors do you think the human eye
80:56 see? You wanna take a What do you think? Give me
81:02 number. It's not like a Question. 500. You wanna go
81:08 or lower? Like the price is . 500. 500. So I
81:12 higher. Do I hear lower? do you think? Probably lower.
81:16 do you think? 200 wants to lower. What do you think?
81:21 huh. Five colors. Well, eight right there. So what do
81:29 think? To 56 point, You guys suck it. Prices,
81:34 . 501 You go five or you win the game. Uh
81:39 We can see close to 2.5 million . Right? And there are some
81:47 who have extra cones, which takes number up to 10 million.
81:55 Now, again, we don't know names of them all because we haven't
81:58 model names, but right. So what happens is this is this
82:03 the thing I want you to focus . Look, look here, if
82:05 color green. All right, So just gonna point out a color.
82:11 . Um, we're just gonna right. You gotta bear with me
82:15 lines. Not gonna be straight. . But, like, right
82:18 so ignore the black line. You where I cross right there? I
82:22 right there, and I cross right . Okay, So what we're looking
82:28 is we're looking at the different Right. So here's the M.
82:32 M is almost 100% maximally stimulated, ? So we'll just say the income
82:36 about 100%. Stimulates m equals All right over here. That's not
82:43 option. So we could ignore that . So does he s Can't even
82:47 it. So the S cone is . And then over here, here's
82:51 l cone. It's We're gonna make the number of 75% right? So
82:57 color green is perceived because the 100% Theis cone is 0% stimulated. The
83:05 cone is 75% stimulate. That's where color green comes from. That's how
83:09 perceive it right. And if you or any of those things where you're
83:15 to just the color just right. know, you're like, you
83:17 pressing the R G Bs and your clicking. Oh, just three more
83:22 or whatever. That's in essence, it is. It's the ratios between
83:26 degree of stimulation between those different cones give us a perception of color.
83:34 why we see that color, what all call pink. I don't think
83:39 pink. It's more of, a light maroon. It's like a
83:45 maroon. Is that Is that Yeah, yeah. What color is
83:50 shirt? Her jacket? The You see? He's red. What
83:55 is your jacket? Okay, we'll with crimson. I like that.
84:00 . Do you see? It's not read. It's a type of
84:05 And that's what this allows us to because your jacket is definitely not the
84:10 color. Red is that jacket right ? Right. But we recognize that
84:15 in the same palette range, so know I've talked along. We're not
84:20 go into equilibrium today because so I'm pause. You guys can leave if
84:24 want to leave, but I'm sure are questions about the transaction pathway that
84:28 just talked about. But there's probably stuff is, well, yeah,
84:32 . Can we distinguish? So the answer that is, I think we're
84:40 to most people who are not color so usually questions how you're color
84:45 You're usually missing a cone. So you're basically saying there's a zero in
84:49 category and that's why we can't perceive . But for the most part,
84:53 males and females can recognize the distinctions those two colors. Like if we
84:58 these two colors side by side, two reds that we're looking at here
85:01 could definitely say, Yeah, there two different reds, but guys have
85:05 names for him. Guys just call red. Women have names for
85:10 and they're better at at knowing what names are. I mean,
85:16 what colors? What is fuchsia? a few shit to me. You
85:24 an answer Is a bright pink. laser there. No, not so
85:31 . It's closer to a purple. . So But guys would be like
85:37 purple, right? Yeah. Can start something empty So So the answer
85:48 that calcium modulation. What allows you do is instead of existing in a
85:53 state of on versus off right. is kind of how we initially described
85:58 . It allows us to put grades between the on and the off
86:01 So your 50% off for 50% on that kind of makes sense. So
86:08 idea here is that instead of being right, I'm just gonna I'm gonna
86:12 speeds to help. Help make this . You're either zero miles an hour
86:18 you're 100 miles an hour. All , so when you modulate, you
86:22 now be 40 miles an hour or miles an hour or 50 miles an
86:26 , depending upon theme, out of that's available. All right, that's
86:31 that does so that it's not just 100% closed. Our I'm 100%
86:37 I'm now a state that exists between two states That allows me to move
86:43 between or open versus more closed. that kind of makes sense to that
86:50 . I help. Yeah, give a thumbs up or thumbs down if
86:55 don't like it. You got Okay. Okay. So the key
87:01 with retinoid cycles first don't have to any of the steps, right?
87:05 number one. So no, because would suck even for me. All
87:11 , so what the retinoid cycle does allows us to recycle our retina.
87:16 . Alright. So when light comes , we take the CIS. The
87:20 form is the inactive haven't seen like . And so when light comes
87:25 it changes it into the transform. is no longer bound to the
87:32 it pops out. Now I've got got something that's not working because it
87:37 to have a cyst form. And what the retinoid cycle does allows me
87:40 take that transform and transform it back the cyst form. Sorry.
87:50 all right, so So the idea I I basically I take it away
87:55 move it back, recycling it by its shape back to its toe to
88:00 state that allows it to be stimulated light because it's that retinol that gets
88:05 by light. It's not the It's the ligand. Ligand is already
88:09 the receptor. It's just not in form that activates the receptor yet so
88:14 I light comes along causes that tail change shape. Now that activates the
88:21 is exactly that is correct. So get the receptor or sorry, The
88:28 is not the light receptor. It's ligand that is the light receptor,
88:33 retina. So together the two things of the different types and this is
88:38 a little bit outside. So the we can have these different wavelength is
88:43 they all have a different option. the option is the the G protein
88:50 receptor, and that retinol binds to , so they're all the same
88:56 But how that receptor is tuned depends which you know how that shaped causes
89:03 change in the shape of the bigger . But we don't need to go
89:06 tow into that. The idea is , oh, it's a paired
89:11 And so when I affect the thing actually detects the light, then the
89:15 half of the pair doesn't work, I have to recycle. That's and
89:20 how it comes about. And where I get the retinol from Vitamin A
89:24 in half? You get two which is kind of cool.
89:30 structure. Mhm. Thank you. actually good at that is correct.
89:42 that's exactly right. So the pupil the hole between the Irish muscle.
89:47 gonna put plural there because there's a and a sphincter muscle. There's two
89:51 there, but that's all. Pupil is literally a space between those two
89:56 . Thank goodness we have a corner there. You could put a finger
89:58 into somebody's eye. And if you got tonight test E. C.
90:03 got tonight test when they come up you and they're like shining light into
90:06 eye. They're literally looking inside that , which is kind of cool if
90:12 think about it. But also kind creepy because, remember, it's
90:18 dark, dark and wait. exactly. It's it's like that that
90:27 well, the red eye is probably reflection off the cornea. I don't
90:31 for certain, so I'm not gonna not gonna speak that, but
90:34 so what you're doing when you get red eye in a picture, it's
90:37 like reflecting back, but it's probably the cornea and not from the actual
90:43 of your eye because because, the pigmented layer doesn't allow light to
90:49 back. So when they come they're doing that. I examine.
90:52 looking into your eye there, literally light into a dark space that absorbs
90:57 light but doesn't mean that you can't what's in there, right? You're
91:00 looking, so it's kind of I have a knife, Freckle.
91:08 know. That's very personal. You freckle too. I have so
91:11 So is, is this anything I to be worried about? No,
91:15 just telling you so that you have else to worry about. Yes,
91:21 are mean to me. All When we come back on Tuesday,
91:25 deal all with the ear, and we'll kind of ripped through stuff.
91:28 other questions? We're good to All right, You guys have a
91:31 day. I will see you later . Thursday. You think we're gonna
91:38 a football game this
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