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BIOL 2301 Human Anatomy & Physiology I - 2103_lecture23_0421
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00:00 I want to remind you, you , we were talking about on
00:06 Um We were talking about the about and the type of cells that were
00:11 for hearing. Do you guys remember cell type that is called? You
00:16 remember a hair cell? All I'm so sorry. I've got to
00:28 really idiotic about it. It's called cells, right? And the reason
00:32 pointing this out is because what we're start today is gonna be with hair
00:37 . All right now. I know doing a mp for humans, so
00:41 gonna we're gonna keep it really, simple here. Hair cells are a
00:46 . A receptor, right? We've about So basically it bends back and
00:50 . So when you're hearing, what doing is you're moving fluid inside the
00:54 , right? And the hair cells back and forth, and you're detecting
00:57 movement in that cochlear Alright, Have you ever tried to catch a
01:02 by your hands? You know? anyone ever no one's ever tried
01:06 I mean like you're out in the , you feel like a bear,
01:09 like sitting over the water. No person, you two, you're
01:13 yeah, I've done that. But if you try to catch a
01:16 it's like you can't catch a fish it always knows when you're about to
01:20 it, right? The region is they have an organ called a lateral
01:24 . A lateral line is basically a of hair cells that sit along the
01:28 of their body and when they feel movement of water, they swim
01:34 Alright, that's a hair cell. other place we find hair cells in
01:37 is here inside the vestibule. So remember we said that we have
01:43 vestibular, this uh we have the apparatus we have the cochlear to and
01:48 they form that inner ear. And the coakley is for hearing the vestibular
01:54 is for equilibrium or balance. All . And so the two structures that
02:03 inside, like I said, I'm all over the place today that are
02:08 this region are called the uh called it's the vestibule. There's two structures
02:13 the homosexual. And then we have semicircular canals. Now in this picture
02:17 here, I love this because it quite clearly what these things do.
02:23 , so you guys recognize this? if you lived here long enough,
02:27 people are like yeah uh if you've to six flags, whatever san Antonio
02:32 is it? Yes to texas. there used to be an astral
02:37 there is no longer an astral It's very sad, right? But
02:40 that? What's that called? Dungeon ? Right, it takes you up
02:45 30 stories and it gets up to top and it goes beep beep beep
02:50 you think on the third beep you're go. But it kind of sits
02:52 for a second and you're like oh broken. Then you drop however many
02:57 it is and you fall at the that gravity allows you to fall and
03:02 it gets to the bottom and it you and then it's like, oh
03:05 , I'm going to die. And at the bottom like, whoa,
03:08 didn't die. Right? So that's drop. What's this? Mhm.
03:18 better answer to this. Or we're have a really long day. It's
03:21 car. What's this person doing? ? Driving slow or driving fast?
03:28 do you think fast? Look at hair. All right. I wish
03:34 was just a picture of me because , you know, yeah, Dr
03:36 drives fast. Yeah, It's driving . So what we're doing when we're
03:40 fast is we have, sorry, acceleration. So the dungeon drop is
03:47 acceleration, horizontal acceleration is going to exemplified by the car here. Anyone
03:52 besides me like to drive fast? Yeah, you can, you can
03:57 it. This is a safe right? Yeah. You know,
04:00 out of my way. Traffic. all suck. Right? All
04:05 And then there's this one ever done . They have one at the Natural
04:09 Museum. They have won a chemo and if you've ever been to spring
04:12 , any place, they usually bring down on the back of a truck
04:15 they say, hey, come get this thing. It's a human gyroscope
04:18 you can see 123 rings. And they do is they strap you in
04:21 bad boy And then they start spinning of those rings, One ring is
04:25 this direction, one ring is in direction, one is in this
04:29 And so you can imagine what's going with your head and your body at
04:32 point, right? It's like and just throw up everywhere. It's
04:37 Alright. And these three things represent structures that deal with the question of
04:43 because what we are doing when we're with equilibrium is weird telling our brains
04:50 is the position of our head and sort of acceleration is going on?
04:55 . And this is all being detected these hair cells that we saw in
04:59 ear. They're just a different type they're looking at a different type of
05:04 or motion. So the structures of vestibular apparatus include the vestibule,
05:10 Which is near psycho clia. The structures in there called the nutritionist
05:14 These are called collectively odorless organs. called total with organs because they have
05:19 lifts. All right. And what doing is they're looking at the position
05:23 the head during static equilibrium. In words, when your head is sitting
05:27 and you're moving in one plane or plane. Alright. So we're looking
05:32 linear acceleration. Alright. So, drop, driving fast. All
05:40 The semicircular canal on the other there's three of them and they sit
05:44 three planes just like you see here the human gyroscope, you have one
05:51 the in the Y, one in X. And then one in the
05:54 . Plane. And so what they , they have fluid in them and
05:57 hair cells. And they're looking at movement of fluid in each of these
06:01 different planes and asking the question of is my angular acceleration, acceleration?
06:09 ? So that's how you can you see it in that, it's like
06:12 way am I going? Well, three of them are going to be
06:14 of messed up. All right. , we're gonna start with the semicircular
06:20 . So, we understand angular acceleration now. The picture that they're showing
06:25 here. This is a real simple is when someone says no or you
06:30 no to somebody, what do you ? You go No and thats
06:33 you're basically rotating around the axis of spine, right? That's no.
06:39 , so that's when you're semi circular . Can you feel if you do
06:42 , can you feel your head You're supposed to say no, I
06:47 feel it. But yes, you . That's another angular movement. All
06:54 now, I'm dizzy. So, canals, as I said, are
06:59 to be at three different angles. there's one, there's two there's
07:02 You can kind of see here those different angles again, three dimensional
07:06 or two dimensional picture. Three dimensional . Alright, if you look at
07:11 canals at the base of each of canals. So there's a bony
07:16 remember you said inside there's a member this structure inside the membership structure,
07:19 the base of that, of that , is this rounded off region called
07:25 ambulance. Now, this is where got to caution you. All
07:29 When we talk about equilibrium, there several words, several structures that all
07:35 with a. We have ambulatory pula . It's very easy to confuse the
07:40 . So, when you're studying just make you make sure you assign
07:43 right word to the right structure. , so, we're gonna start
07:48 We have this this region that's kind expanded. That's called the ambulance.
07:53 , inside the membrane this region there's whole bunch of fluid. And inside
07:57 expanded region we have a speed The speed bump is basically this gelatinous
08:03 called a cupola. The cupola sits the middle of the angular and impedes
08:08 flow of the fluid. Just like speed bump, impede your flow in
08:12 parking lot. Have you noticed That's what the speed bump does?
08:17 do you just ignore it? Like do. I just ignore him.
08:22 why we have shocks. All Now, if you look here.
08:28 , here's the cupola, and if look at the base of the cupola
08:32 in that gelatinous goo. Are these cells? So the hair cells are
08:38 inside the cupola. So, if bend the cupola which sits like a
08:44 bump or a fin inside the If I bend the cupola one way
08:47 bend the couple of the other the hair cells in the cupola are
08:51 to detect the bending and they're gonna along with it and it's gonna send
08:56 signal, a constant signal. So constantly sending a signal to the brain
09:01 we're in a static equilibrium. But I turn my head one way towards
09:05 Tennessee liam, I increase the rates the action potentials. And if I've
09:10 my head the other way, it down the rate of action potentials.
09:16 it's that rate of action potentials that central nervous system goes, Oh,
09:21 means you're turning towards or away from penicillin. All right. So one
09:26 the things I want to point out is that you have no odorless because
09:31 not odorless organs. But we're going get to the hotel. It's in
09:34 a second. I'm so, you , the cupola has hair cells in
09:38 inside the ambulatory. And when you your head, you're going to move
09:44 as a result of inertia, that is gonna move inside the semicircular canal
09:49 it's gonna push a couple of one or the other and the rate of
09:53 of those hair cells is ultimately going give rise to the sensation of movement
10:01 , it's telling your brain which way turning your head, All right,
10:06 . That's angular movement. The easy to think of is no, or
10:11 , but think about getting in that little human gyroscope and feeling how nauseous
10:16 get. Or for those of you like riding roller coasters. You know
10:20 ? Why don't we like protocols? me sick. It's kind of
10:24 But basically, I'm getting angular motion I go up and down and change
10:29 . Go around turns fast. that's angular acceleration. All right.
10:38 hotel with organs. Remember deal with or vertical movement. Alright,
10:45 structurally, they're very, very You got a bunch of hair
10:48 They're jammed in this gel like structure gel like structure we call a macula
10:54 then embedded in the macula to give mass. Are these odorless odorless are
11:00 calcium carbonate crystals? You can think like this. I know you guys
11:04 young. So this is not as as it was way back when it's
11:07 getting jell o with fruit in All right. You know, you
11:12 , grandmother never made. How about schools do the schools have like the
11:18 ? There are the grapes inside the . No, I never did
11:22 See Luby's did that when I was up. Right. And you're a
11:26 kid. It's like parents are so because you're eating fruit embedded in sugar
11:33 . Right? And that's what this those there's the odorless, right?
11:37 Odalis sharp. They're here. You see the gel. There's the health
11:39 cells. Or excuse me, the cells jammed in that. So now
11:44 mass when I begin movement as a of the inertia. When I begin
11:50 , that mass wants to stay All right. If you can't visualize
11:54 , think about being in a car hitting the accelerator so that you can
11:58 0 to 60 as fast as you . All right. What happens when
12:02 press on the accelerator? What happens your body? It goes backwards.
12:06 presses into the the chair, doesn't ? Right. That's inertia.
12:11 And so the idea is your body to stay back there, but you're
12:15 . So you feel it pressing you . That's what's going on with the
12:19 and odorless provide mass. And so you begin accelerating, it kind of
12:23 well, I'm sitting back here and it pulls the macula backwards. The
12:27 cells as a result bend with the . And then eventually as you
12:32 as you uh your acceleration starts matching . Your velocity starts matching matching the
12:39 whatever. Basically, that's when it back into play, you no longer
12:42 that nursery. You're now moving at rate that you're supposed to be moving
12:46 . Okay, so that's that's kind how this stuff moves. Now,
12:51 of these hair cells whether you're looking the semicircular canals or you're looking at
12:56 of the two ovulate organs, you're to have these vestibular nerve branches associated
13:01 each of these cells. So each these cells that are being bent or
13:05 signals. And again remember this is rate of sending a signal. And
13:08 when you bend towards the penicillium you the rate and when you move away
13:13 the penicillium you slow down. All , so what do we have
13:21 So I said there's two structures that U. two reconnaissance. Actually the
13:25 . Trickle has stereo Celia sitting in vertical position. So when I say
13:30 hair cells are in the vertical Which way is the hair is
13:33 Are they pointing this way? Are pointing that way? Good. All
13:38 . So when they bend, which are they going to bend?
13:42 You see that? So which way I moving When my fingers are going
13:45 way, horizontal movement. Alright, the U. Trickled attacks horizontal
13:54 The saxons on the other hand have hair cells in the horizontal position.
13:59 , so they're going this way. when you go down an elevator or
14:04 up an elevator, you're bending the cells in the vertical plane. So
14:09 detecting vertical acceleration. All right and the same rule applies bending towards penicillium
14:16 towards gives you stronger deep polarization away deep polarization. That's how your brain
14:22 which direction you're accelerating. Alright, It's just basically describes. So imagine
14:30 your head erect, right? You're in the car, press on the
14:33 . My friend had a back back the day when the Mustang first was
14:39 . My mustangs first came out in 60s. Then during the 70s there
14:43 really Crappy cars as mustangs. And in the 80s they revitalized. The
14:49 just shows you how old I So, one of my friends got
14:52 mustang and it was like, mustang. It was a mustang
14:56 So it was even better, And he wanted to see if it
15:00 went as fast as they said they . So we remember being in the
15:03 with him and he said all you just watch the road for
15:05 And he looked at his watch and pressed on the gas and he was
15:09 to see tell me when we get 60. And he was like one
15:12 . He's like, yeah, we're 60. Was like, it's only
15:14 seconds. It's supposed to be six something. It was But anyway,
15:19 that was what we're doing. We're , right? So I can feel
15:22 All right, So my head is . I'm feeling acceleration. All
15:27 So that's what that's what we're doing regard to the cuticle when you get
15:31 dungeon drop or get in an elevator you feel yourself being pressed downward or
15:35 pulled upward as a result of being that elevator or if you like the
15:39 drop if you like that free fall , that's that's actually the hair cells
15:43 being built no bent towards the So you remember what the penicillium
15:57 It's like the long uh stiffer stare silly at the front end. And
16:02 what you see when you look at hair cells is that the hair cells
16:05 kind of like a flying V. you see with ducks. Right?
16:09 the one in the front is the , all the stereo cilia kind of
16:12 up along those lines. And you go back and look at that picture
16:16 I said. This is a colorized or view of the hair cell,
16:21 know from from Tuesday. All So if the cell is constantly be
16:26 , it's is concentrated deep polarization It fires and then it goes into
16:30 , fires, it goes into Alright, So that's that would be
16:32 cell at rest. It normally fires a regular rate. All right.
16:36 so what we're saying is is when have acceleration when you bend that hair
16:43 when you bend the penicillium or the cilia towards the penicillium than that rate
16:49 firing increases. Um Yeah. Yeah. So in this particular case
16:57 bending away from so you're bending away the penicillium. So, would your
17:01 me less or more opposite towards the is the tallest one. So,
17:06 you're moving away from the penicillium, fire at a slower rate. And
17:10 your body feels like it's accelerating backwards opposed to forwards. All right now
17:17 is also a good place for me kind of interrupt and say right so
17:21 guys at one point in your life learned about vectors? Right. You
17:25 vectors? All right. You may remember him real well but you
17:29 Vector was a character in Despicable That's not what we're talking about.
17:35 what did vector say as the Why was he called vector? I
17:39 crime with both direction and magnitude. . That's all the vector is.
17:46 basically looking at something and saying what is it going and how fast or
17:51 hard or how big. Alright. all the vector is. Alright so
17:56 vector has both direction and magnitude. if you think about horizontal acceleration,
18:01 have direction which would be forward. ? Presuming I'm going this direction.
18:06 so I'm moving in the X. or the X axis. Right.
18:12 I've got a certain speed or certain . Now let's put me in an
18:19 . Do I have movement in the still? Yes. Right. Do
18:24 have movement in the white plains? . So when I'm in an airplane
18:30 would be stimulating both the U trickle in the horizontal play as well as
18:36 sack you'il moving in the vertical Would I be moving in an angular
18:41 as well. What do you Yes. Right. So, when
18:45 start tilting upwards, my head is upwards so my semicircular canals would be
18:51 . All right. So, really detection of equilibrium, the detection of
18:55 is all three of these things working . All right. But that's a
19:01 question to ask on the exam, it? Alright. So, what
19:04 want to do is we want to keep it simple for ourselves when I'm
19:07 horizontal acceleration, which structure on the you trickle? Right? It says
19:14 there, you trickle horizontal plane. it's even highlighted in blue for you
19:19 I'm moving in the vertical plane, I'm in an elevator which structure
19:26 Alright. And then when I'm dealing angular movement, which structures, It's
19:31 plural. It's the semi circular Easy enough. Alright. But structurally
19:37 mean, So, how they detect very, very similar. It's just
19:41 the hair cells, right. And direction they're being bent. Alright.
19:46 either moving towards a penicillium so, accelerating forward or I'm moving away from
19:50 Tennessee liam. So, I'm accelerating and that's how I can detect
19:55 All right. The difference between the structures of the stimulus apparatus and the
20:03 has to do with these other Right? The semicircular canals had an
20:08 A and a cupola, the hotel organs have odorless. These calcium carbonate
20:14 that provide mass. And they sit in this gel structure called the
20:19 not a cop killer. All That's equilibrium in a nutshell. It's
20:26 straightforward. I thought there might have a pun there, but there
20:31 All right. And so what we do is I want you to kind
20:34 think about what we've looked at so in terms of vision. We had
20:39 receptor that detected electromagnetic radiation and converted type of energy into action potentials.
20:48 ? And then we looked at Hearing. What type of receptors did
20:51 have started with an M. McCann receptors? What are we detecting movement
21:00 fluid inside the cochlea. Then we've at equilibrium. What kind of
21:07 Mechanical receptors. All right. And looking at the movement of the macular
21:12 the cupola. Right? To detect . The hard one is the
21:17 Because it's like sound waves are not things. Yes, but you're moving
21:22 . All right. And so, we're going to now go into the
21:25 two types of the special senses. , those are the first three special
21:28 . There's five of them. The . The fourth one. Excuse
21:32 And the fifth one is Olfaction. gas station. Olfaction is the simple
21:37 is what do we use? It's smelling. So we're doing is we're
21:42 the chemicals that are in the Alright. And go station is what
21:50 . And what are we tasting chemicals our mouth. Right. It's actually
21:56 chemicals in our saliva. So we're with chemo receptors now. Alright,
22:02 we had we had visual reception, is dealing with electromagnetic radiation. We
22:08 two types of mechanic receptors. Now looking at two types of chemicals that
22:12 like to see if I actually do up chemo reception. Alright, so
22:16 sense of smell, it's fairly right? It's we're looking for chemicals
22:21 what type of chemicals? Well, want to see it in our
22:25 Have you noticed that people have a smell to them? You can actually
22:29 them ladies, you will be able identify your Children by their smell.
22:34 will point this out also now, I think it's just interesting women,
22:38 have a sense of smell that is million times greater than the men in
22:43 room, on average. Right? has been proven by experimentation. And
22:50 know this just by anecdote because we in the house, my wife and
22:53 smell that and I'm like, I know what you're smelling. All
23:00 We also use smell to identify Now, obviously I'm showing you something
23:04 a stinky fish, stinky fish. go, I'm not going to eat
23:07 . Why dangerous, Right? But all sorts of types of things that
23:13 can smell that are dangerous. So, we're using the sense of
23:17 to kind of understand our environment around . Now, when we talk about
23:21 olfaction. Remember we have really, weak olfactory system relative to other
23:27 we can think about dogs. For , dogs can smell all sorts of
23:31 . I mean, the claim is some dogs can actually smell cancer,
23:36 . I mean, have you ever those shows where it's like they take
23:38 dogs and they walk them around a , the dog starts and then they
23:42 and look and say, oh you've got a tumor. You
23:45 it's like, I don't know how works. I guess a tumor smells
23:49 necrotic tissue or something. I don't . But somehow it's magic and they
23:53 figure it out. All right, can't smell tumors at least. I
23:59 think we can. Who knows? right. So where we're gonna be
24:05 we're talking about the olfactory system as in the nasal cavity, but we're
24:10 just anywhere in the nasal cavity, in the highest position, the most
24:15 position of the nasal cavity. Think walking through your day, you're sitting
24:19 , you're walking around and you smell little bit of barbecue. What do
24:22 do? You start pulling in the a little bit deeper, right?
24:27 basically breathe in deep and really what doing is when you normally breathe their
24:32 sits low in the nasal cavity, where the movement is occurring because you're
24:36 trying to breathe, right? But a couple of those molecules hit the
24:40 epithelium theory and you're like, I food, I smell something wonderful and
24:44 . And so you go and so pull that air upwards and it passes
24:49 the nasal concha concha concha, And it causes it to spin or
24:54 terminate. And then what it does that means more air is circulating and
24:59 pulled up and over the olfactory epithelium any molecules that happen to be in
25:03 air are going to be able to in contact where the receptor cells are
25:08 . And there's three cells that you to be aware of when you think
25:11 the olfactory epithelium. So, we're right up here. So we're
25:14 this out, right? So there the ETh Boyd bone. So this
25:18 called the crib inform plate. Here's your nasal cavity. And so
25:22 things that we're looking at are going be the cells that are on the
25:25 or the top most superior portion of nasal cavity. The the olfactory receptor
25:33 are your cells that actually detect the that you are smelling. That's
25:40 And you can see this is a of neurons. In fact it is
25:43 of the only two bipolar neurons that really kind of talked about in the
25:48 . The first bipolar neuron was where the eye And what was it
25:53 The bipolar self very, very, difficult. You know, very complex
25:59 uh nomenclature that they have for This is the second one here.
26:03 can see the cell body you can here is the dendrites over there?
26:06 the axon right remember when we can out bipolar cell, we look at
26:11 cell body and we just count the of extensions. So there's two.
26:15 one. There's two. So, is a bipolar cell, a type
26:19 bipolar cell. It's an eighth parent , its sole job to detect the
26:24 that make up an odor. Alright around them we have supporting cells.
26:29 purpose of the supporting cells to create . We need mucus because the mucus
26:35 two things. It helps to protect environment, but it also creates this
26:40 that kind of holds on and grabs the old factory. Um Or excuse
26:44 , the odorant that you're going to detecting. All right. The third
26:49 of cell and they're trying to show here, the darker purple one is
26:52 a basil cell. Alright, basil are a type of neural stem cell
26:59 now, Truthfully, what it can is it can actually become a support
27:03 or it can become an olfactory receptor . And there's about every 40 to
27:09 days. This is one of those where a neuron gets replaced.
27:13 So about every two months. You , you're going to replace damaged
27:20 And so there's this constant rate of or creating new cells from the basal
27:26 . All right now, what's also the air. Not shown in the
27:30 . But there are other structures within nasal cavity that are like pits that
27:36 called olfactory glands. And so they're producing mucus. All right.
27:42 here's that olfactory receptor cell. All . And so you can see here's
27:46 body. Here's the axons. Axons converging from different olfactory receptor cells.
27:52 what they do is as they converge form a nerve. And that nerve
27:57 the olfactory nerve. And remember what said is when you look, I'm
28:01 go back a slide, right? can see the kind of toothbrush appearance
28:07 of this structure. So, this the olfactory bulb. It's right there
28:11 out from the olfactory bulb is where can see all these little tiny nerve
28:16 . Those are the olfactory nerves. bulb is not the olfactory nerve,
28:20 the fibers that look like the bristles a toothbrush that are the olfactory
28:26 Now where we're gonna focus is gonna down here. All right. And
28:31 here's your dendrite dendrite then it spreads and it kind of lines and and
28:35 sits on the surface of the And it's here these old factory hairs
28:41 what they're called kinda makes it look a green onion. Right. That
28:44 be the bulb of the green Those are the hairs out of the
28:46 of the green onion. That's the of the green onion. Right?
28:50 little tiny hairs is where you're going find the actual receptors that detect the
28:56 . So each one of these cells only produce one type of receptor,
29:02 ? That detects one type of Alright, so it's not like you
29:06 50 different receptors on olfactory receptor cells goes, oh I'm detecting strawberry and
29:11 in this. It's just they detect strawberry if strawberry was an odor
29:15 Or or a chemical. So that's what we have here. So each
29:20 these cells are are specific to the that they detect. So we have
29:25 upon thousands of these that detect unique structures. All right. So each
29:34 Detects one. The street component of odor. An odor is not one
29:40 an odor is a bunch of different in different or varying concentrations that give
29:47 to that unique smell. Alright, this thing is only detecting one of
29:53 tiny components. Now, each of fibers that are traveling up and forming
30:01 olfactory nerves are are penetrating through the reform plate and they go into this
30:08 bulb and if you take a slice the olfactory bulb, what you'll see
30:11 that there's this arrangement of nerve fibers look like a bunch of globes or
30:17 . All right. And that's what trying to show here. Alright.
30:19 ball. It's called a glamorous Alright. And there's thousands of
30:23 And really what they represent is they where similar sell send their axons.
30:32 , I'm just going to pretend for moment. Let's pretend these three receptor
30:38 detect a chemical that we're just going call the chemical. What do you
30:44 ? Cherry Cherry sound good? So cherry chemical. Alright, so these
30:49 represent cherry. And I'm going to these three right here detect the chemical
30:53 is line because sonic is easy to about right? Cherry lime ade.
30:59 ? So what we have here is you smell that cherry limeade, the
31:03 chemicals bind to these types of receptors and they stimulate that particular glam
31:08 A realist. And when that glamorous becomes activated, it's gonna send its
31:13 upward and say guess what? You're ? You're detecting cherry. And then
31:18 here these are only detecting lime. so when they activate they'll activate the
31:22 list. That glamorous sends the information to the central nervous system and says
31:26 detecting lime. And then your brain I got cherry being detected. Got
31:29 being detected. So, I'm detecting lines and then you become happy because
31:35 limeade is awesome. All right. these fibers are called mitral cells there
31:43 the other half there's also tufted cells there but they make up that half
31:48 that glimmer realist. So the glow list is the first place where information
31:52 processed. So what you're gonna be here is you're now going to start
31:57 decisions about what information needs to be forward? So obviously we're gonna go
32:02 the cortex, the purpose of going the cortex is determined what it is
32:06 you're actually smelling. How would you what things smell like? Right.
32:12 you ever smelled? Oh, I know, I'm gonna make up something
32:16 . Have you ever smelled a Yes. So you know what
32:23 kumquats smell like, right? For who have never smelled kumquat, Do
32:27 know what it smells like? but if I told you it smells
32:32 citrus, Can you can imagine what smells like? Why? Because you
32:36 citrus before, haven't you? So understanding of what the world smells like
32:42 a result of your experience. And so what you do is you
32:47 smell memory. And so when you something new. So for example,
32:52 know the smell of a fresh right? Do you also know the
32:56 of strawberry Quik? It's artificial It's kind of like fresh strawberry but
33:02 quite right. It has that unique to it. It's artificial strawberry,
33:09 you'd be able to recognize it because has a similar chemical makeup. All
33:16 . That information is stored in the information is all sent also sent through
33:20 hypothalamus and amygdala. Remember that's the system, what's the purpose of the
33:23 system? You guys remember emotion. . If you smell chocolate, how
33:31 that make you feel happy? The same thing. That's what's going
33:38 there. Look, I'm out of when you talk a lot. The
33:43 guys. I hope these are the that work. Good news. I've
34:02 at least four. So All So you go to the olympics system
34:11 add that emotional aspect to the sense smell. Notice we don't project information
34:17 to the thalamus. It's one of rare instances where that does not happen
34:26 . Characteristics, characteristics of an Alright. So, the thing that
34:29 smelling remember is a compilation of many tiny molecules. So there's lots and
34:35 of molecules. Alright. So those that make up of an odor are
34:40 an odorant. All right. Now at this picture up here. This
34:43 an actual job. All right. do you think these people are
34:49 Mhm. Sniffing what colors? take a look. What do we
34:55 ? That's that That men with hairy and we have a bunch of women
35:01 armpits. So, what are we ? Water smelling body or testing
35:10 Why do you think all the Why do you think all the smells
35:12 women Because they like body odor? , not. No, No.
35:19 I mean these are good thoughts. . But why? Because their sense
35:24 smell is stronger than men. That's that's remember at the beginning
35:29 you're a million times and when I a million times. What that means
35:32 is they take this odorant and this how they did the experiment.
35:35 They take the odorant they put in . They have both men and women
35:39 . And then what they do is they do a 10 fold dilution and
35:42 keep doing 10 fold dilution. So men stop smelling deodorants, like I
35:47 smell anything. Women are like I smell it and then they keep diluting
35:50 until a woman or the women would , I can't smell it any
35:54 So, when I say a that's delusion by 10 x 10 x
35:59 . That's six delusions. So, literally a million times different. All
36:05 . Now, in order for an to be able to be detected,
36:09 has to have a certain characteristic. seen this, you've done this to
36:13 , right? When you said I like you when you're a little
36:16 you do a picture of him. put a little stink lines. Because
36:19 of the stink lines represent is the moving away from the object. That's
36:27 we call volatility. All right. we think volatile would think explosive,
36:32 ? But volatile simply means something that's vaporized. If I were to take
36:37 and put it on the table on desk. After a couple of minutes
36:42 be able to start smelling it further further away from this point, because
36:45 that perfume evaporates. It starts moving the air around it. All
36:52 Just like the stink off the stink off the of the image. The
36:58 thing that in order it needs to in order for you to smell
37:01 It needs to be sufficiently water Doesn't need to be 100% water soluble
37:06 . And the reason for that is your mucus mucus is a combination of
37:11 things. It's water plus protein. proteins are a series of proteins called
37:18 . Alright, mucous mu since there's whole bunch of different ones.
37:22 But really what you're trying to do you're trying to get in through that
37:25 kind of protective barrier that's also kind sticky. And so if an odorant
37:30 dissolve in water, it can move the mucus and get to the olfactory
37:34 yourself. So, those are two . All right. Now, you
37:39 imagine. And please don't do this I asked you to could you smell
37:43 desk? And would you pick up odor? What do you think?
37:47 not asking to do? It could gross. Would you pick up an
37:51 probably do you think that the odor the odor of the plastic? Yes
37:57 no, No. What do you it is? The nasty stuff that
38:02 stuck to the surface of the Alright. Because the plastic itself is
38:08 volatile. All right. What it is all the sweat and the bacteria
38:13 all the horrible nasty things that have left on this desk. I'm so
38:17 you guys are touching this now. . Everyone's like I'm not that are
38:22 here. And so when you smell like oh that's gross, what you're
38:26 is what's on the surface and what volatile and capable of passing through the
38:31 of mucus. All right. So you breathe, like I said,
38:38 you do is your your breath usually really, really low, right?
38:43 then every now and then a little pass its way up and that's when
38:46 body says, oh there is something for me to smell. And that's
38:50 you take that deep breath and that the air up over the nasal con
38:55 causes it to kind of royal move itself. Kind of spin and that
39:01 greater surface area of the of the to allow it to come into more
39:06 with that olfactory epithelium that's sitting up the superior region of the nasal
39:11 All right. And then whatever those sar, they'll diffuse through that
39:16 And what's interesting is near those olfactory cells there's a little tiny proteins that
39:23 can recognize different odorant and basically oh I see you you need to
39:28 over here and it will help them up to the olfactory receptor cells.
39:32 it helps in the odorant coupling with receptor. Which is kind of
39:38 How does it know where it I don't know, it's magic.
39:42 know. Now I throw this up , not for you to memorize the
39:49 . It's very simple. Does it like the other uh G protein coupled
39:53 pathways we looked at? Yeah. all they look exactly the same.
39:57 is why I say you learn it and then when you see a new
40:00 , you're like if I have to the parts, I'll learn the
40:03 right? But you can see here's receptor, there's my G protein look
40:07 an enzyme over there. What does enzyme duo? It makes cyclic
40:12 What a cycle KMP do. It to a channel in this case and
40:15 up the channel allows ions to flow an ion flow into a cell that
40:19 deep polarization when the cell d that creates an action potential. So
40:25 far nothing new that you haven't learned . Alright, now we're not going
40:30 learn all the different parts here. it's like I said, it's it's
40:34 for you to visualize and say, okay. Nothing new under the
40:39 But what we have here, here's odorant notice we don't know what odorant
40:42 is. It's binding to this G . There's G protein we called a
40:47 . Or not. G protein. protein coupled receptor we call it uh
40:51 G protein is going to be specific whatever odorant it is. But it's
40:55 with this G protein that we call O L F O L fro
41:00 Alright. So you see it's All right now you have about 1000
41:06 genes that produce about 1000 different receptors your nose. So you can detect
41:14 1000 different things Actually. Are there than 1000 smells that you can
41:19 Yeah. So, what we're gonna here is that the specificity of these
41:24 can actually be a little bit All right. But once you bind
41:28 , this is what's going to cause deep polarization. Now this is
41:35 So, I don't want you to a lot of time trying to process
41:38 . Alright, I just want this I hope to help you understand why
41:42 just not that our nose doesn't work the absolute. Alright, so let's
41:47 that we have five receptors. And we're gonna keep it simple
41:52 We have the red receptor of the receptor. That's the that's the thing
41:56 detect. And if you want to those, those smells like cherry and
42:01 and blueberry and sour, apple, , whatever. Alright. And what
42:06 here over here is representing is let's there are seven different deodorants that you
42:12 detect and what this is saying and , look, the degree of activity
42:18 a result of this odorant odorant eh to four out of the five of
42:24 receptors. So you see the specificity not really that strong, that kind
42:29 makes sense. In other words I'm to bind bind Ai combined B or
42:33 . I can bind red. I buy an orange I combined blue and
42:36 can bind purple can't bind green at . But when this odorant is there
42:41 gonna bind to each of these things the degree of activation um is going
42:47 be different for when I buy into things. So this is obviously has
42:51 affinity there and so it causes greater . This is less than that,
42:55 more than this and that and so and so forth. So what you
42:59 now is you have variability in terms what it binds. So when the
43:06 binds to these five receptors, your is going to receive a signal from
43:10 life for each of those things. it's gonna have varying degrees of
43:14 And it's that pattern that your brain assigns to the smell that you're
43:21 Right? So if an odor is of utterance, right? And each
43:27 them combined two different receptors with varying of affinity, then I can create
43:35 infinite number of combinations. And so example when I smell strawberry, Strawberry
43:42 not one odorant, let's just make a number, it's 20 odorant and
43:47 20 deodorants have a unique binding ability the number of receptors that it
43:52 it's going to create a unique pattern looks something like this. And so
43:56 that pattern is created in the the nervous system, that's when your brain
44:01 , oh, that's strawberry. And when you do artificial strawberry, the
44:05 is going to look similar to but not exactly the same. And
44:09 when your brain assigns that pattern to strawberry. Yeah, I couldn't hear
44:17 . I'm sorry. Oh, They do. Right. And what
44:22 doing is they're trying to find what your responses to these unique changes,
44:30 ? That's what the chemists do, ? I mean if you want to
44:33 what you can do with a chemistry other than go work back at a
44:37 a college is go work for a company, right? Like frito
44:43 Right? And again, frito Lay dealing with taste more than smell.
44:48 I guarantee you they sit there and , what chemicals can we put into
44:51 Dorito dust? So that it's like these guys crack. Yeah, it's
44:59 , it's the exact same thing. , exact same thing. The difference
45:04 , is the means through which that is is going to your brain.
45:09 I smelling it? Think about How does barbecue make you feel even
45:14 you're a vegetarian you smell and you I want to eat meat. Some
45:19 you are like, no, I . I guarantee you if I splatter
45:22 those salts on top of tofu, be like that's homer. So this
45:33 kind of shows you using a little of color, right? And showing
45:37 how each of the individual cells detect specific odorant and those different odorant go
45:43 specific glamorous eli and then the different liars sending that specific signal to say
45:49 presence of this chemical is here at percentage. And so what you can
45:55 now is now you can leverage and how or how that information is getting
46:02 to the brain. All right. is the dumb example I use every
46:05 . Think of a cherry lime Alright, if you've ever been to
46:08 , how many different types of flavors drinks do they advertise that they can
46:13 ? Have you ever seen this? it like 8? No, it's
46:17 millions upon millions. And they're just math right there saying there's so many
46:21 things we have. This is the number of combinations, right? And
46:25 they have millions of drinks. So let's say you do a cherry
46:27 But that that soda jerk, which what they're called, Accidentally puts puts
46:32 blue coconut in there like Blue So you get like six drops of
46:36 coconut right? When you take a , you're gonna smell cherry right?
46:42 lot of it. You're gonna smell a lot of it and then you
46:46 smell a little bit of blue but your brain will go, you
46:50 , that's not supposed to be It's probably just an anomaly. Maybe
46:53 neurons are firing wrong. So what's at the level of the glamorous
46:56 It may suppress the presence of the coconut and kind of just say,
47:01 , it's not really there. So that modification those mitral cells are
47:07 to refine the smell, sells the signal before they ever get up to
47:11 brain. All right. But you train yourself to actually detect specific
47:17 Think about what an NR file And then in the file is the
47:23 fancy word file means what at the you see file at the end of
47:28 war, does that mean a Right. So in in a file
47:33 a something lover. What kind of what do you think? You know
47:36 to? I'll give you an example I am. I'm an oenophile and
47:41 got my glass with the stem All right. What does a wine
47:47 do? They've got their glass, swirl it. They've got that snooty
47:51 on their face. Ah to protect and current some black oak cherry low
48:10 . That's actually a smell mouse and . All right. But it's the
48:15 sort of thing. Right. What doing is they're they're running that those
48:20 over their nose and they're trying to what is it that I smell and
48:24 they'll taste it and see if they pick those flavors up as well.
48:29 this is the pathway. Remember what said cerebral cortex. That's the identification
48:34 of smell. Alright. We're going the old factory track. We don't
48:38 to the thalamus. We go to limbic system. Hypothalamus is a visceral
48:41 to smell. All right. I'll you an example of visceral reaction to
48:46 . Men's locker room undershirt, under pads. Never been washed all
48:54 Mm Yeah. You can tell who been around the locker room like
49:00 It's like All right. That'd be visceral response. All right, Begala
49:07 the emotional response. That's the the sad and so on and so
49:12 . Calls up memory. All Trying to see what we have in
49:17 of time. Oh good. We plenty of time. Normally I run
49:20 of time because I have so much talking about this stuff. All right
49:23 stations Sense of taste. You're This is an 8 30 class.
49:26 I teach this to the fist fist . The upper level class. It's
49:30 right around lunchtime. So we get talk about things that taste good.
49:35 look at this station. Mm All right. Sense of taste
49:41 chemicals. Chemo receptors were looking at in the oral cavity here. What
49:46 doing is we're going to be dissolving into the saliva. All right.
49:51 what we're doing is we're sampling our and our drink once a year,
49:56 couple of years back. Have you on this campus long enough? You
50:01 we have a couple of red tailed that like to hang out around the
50:04 and if you've been here long enough also know we have a whole bunch
50:06 squirrels, don't we? You know we have red tailed hawks? Because
50:09 got squirrels, they're fat because you feed them and they're slow because you
50:15 feed them. So red tail hawks out here and go let me go
50:17 for the fastest and the slowest squirrel they go down and they grab
50:21 And so one year one of these tailed hawks grabbed a squirrel in front
50:25 the library and everyone's standing around watching red tail hawk just ripping the squirrel
50:31 and everyone's like so cool right? that's what we do when we see
50:37 things, they're cool, right? I was sitting there as an idiot
50:43 and I said how is it now in mind I should know this
50:46 Right? But I was just being idiot. So how is it that
50:49 stupid hawk can enjoy eating this? basically ripped up squirrel bits right?
50:57 like why is it? And my colleague looks at me and she says
51:00 should know the answer to that. because the brain knows what it wants
51:06 terms of nutrients and so the receptors the mouth find those things appealing.
51:13 was like well so think about the you like to eat apart from the
51:17 which have been organized in such a so that you are craving it like
51:23 . All right. But I mean about like you've heard like pregnant women
51:27 ? They have cravings and what they're those cravings are is their brains saying
51:33 know where to find this nutrient. get it for me and that's what
51:38 the requirement is. And so when have that craving for something, it's
51:42 of your body is saying there is there in the food that I need
51:47 I know it's in this food so get it all right now food even
51:52 we can detect what's in the that sense of smell is going to
51:58 the fact or the Augusta Augusta gustatory . All right. So think about
52:04 you have a stopped up nose, mean anyone here besides me suffering from
52:08 right now, it's like your nose all stopped up and you can't breathe
52:11 all if you sound like this And you eat something like soup and
52:16 soup just tastes boring. All you're just like this sucks right?
52:23 you can't breathe, you can't smell when you can't smell you don't add
52:27 dimension because our sense of smell is greater than our sense of taste.
52:32 so that's what provides the dimension to things that we eat. Now the
52:38 system is dependent upon taste buds. right. And so we have these
52:44 on our tongue called papillae. so, if you go look in
52:47 mirror, those little tiny bumps are papillae and there's different types. We're
52:51 see these types, but on the , different types of people have the
52:56 of taste buds. Right? the four different types of propel er
52:59 circum validate the foliate. The fill form which are the most boring but
53:04 most common. And then we have funds to form. All right,
53:09 , it's within the taste buds. so, we're gonna see here these
53:12 buds here, we're gonna look at of the individual ones is where we're
53:15 detecting. So, you can see there, those are the taste
53:18 Those are the taste buds right here the funding for my taste buds,
53:22 a form. Have no taste All right. And it's within these
53:27 buds is where you're going to find actual receptor cells? They're called the
53:30 cells that actually detect taste the All right. So, what are
53:35 different possibilities? We're gonna start with boring one to fill a form?
53:38 right, This is the fill a . When you go look in the
53:40 and go all those little bumps that see for the most part or fill
53:44 form. They're like little tiny fingers your tongue. And what they do
53:47 they help grip food. Think about ice cream cone when you look an
53:52 cream cone. Those little fingers are across the ice cream so that you
53:55 get your ice cream onto your Alright, So that's its purpose.
54:00 they can detect texture, they can food, They do all sorts of
54:03 , but they do not. How's taste buds? And they make up
54:06 grand majority of the papillae on your . Now, if you go look
54:11 the mirror and look closely what you're see is you're gonna see a couple
54:15 things that are scattered here and there look like little tiny bumps. They
54:19 a different shape than the little tiny bumps. All right. They look
54:25 little tiny baby mushrooms. These are , that should be the next
54:31 That's the fungi form. All so they're all over the place,
54:34 just like here and there and Alright. And there's about 300 if
54:37 count them up there, about 300 your tongue. All right.
54:40 these are the ones that you find the surface of your tongue. What
54:44 call the anterior portion of your The posterior portion is kind of behind
54:49 curve where your throat occurs. All . I'm gonna go back over on
54:54 sides of your tongue, way over . This is where you have the
54:58 fully is leaf. They kind of like gills on the side of the
55:01 and you can kind of see Alright, so that would be the
55:06 . Alright, These aren't particularly active your age, but when you're a
55:09 tiny child right under the age of , these are very, very
55:14 So you ever wonder why babies are putting stuff in their mouth. It's
55:19 because that's how they detect the world them. All right. They're learning
55:23 to taste their way through the All right. The last one are
55:29 circum valley and these are the weird . There's about 12 of them.
55:33 make this kind of flying V So they kind of served as the
55:38 between what we would call the anterior and what is the posterior tongue?
55:42 they're fairly big. You can't see if you go, you're not gonna
55:45 able to see them. Maybe if allow someone to if someone lets you
55:49 in their mouth and you use a depressor, you might be able to
55:53 them because they're kind of on that of that turn All right. These
55:59 lots and lots and lots of taste . All right. And they have
56:04 unique kind of structure to them. kind of look like a ring and
56:07 there's depression and that's where all the buds are. And then you have
56:10 possibility that sits kind of out there the front. All right. This
56:14 where the most taste buds are going be located. All right. And
56:18 what this picture is trying to show what it tastes but looks like in
56:21 of structure. It also kind of this oniony look to it. All
56:25 . And so you can see taste is kind of encapsulated. It's kind
56:29 found in its own little area. so these are the cells that are
56:33 be found as part of the taste . The surface is opened up.
56:38 you can see that the cell has with the area where your slide is
56:43 to be even though it might be over on the side. So you
56:46 imagine saliva coming down here. So open on that side. And you
56:51 these little tiny um cilia basically the just kind of goes up and down
56:56 kind of create increased surface area and sitting outside in that little tiny
57:01 So you'll have multiple cells each kind expanding out just a little bit to
57:06 come into contact with the external surface your oral cavity. And then each
57:12 these cells are gonna be associated with nerve fiber. And each of these
57:16 because they're in your mouth and the is a dangerous place. They basically
57:19 going to be replaced rather frequently, every 10 days. Alright. So
57:24 on the nose, about every two Here in the mouth. About every
57:28 days now, if you can't visualize , think about all the horrible things
57:32 put in your mouth. All drink something hot. Burn your
57:36 Ever burn your mouth, right? tastes like metal for a couple of
57:40 , Right? And then after a it's like your taste returns back to
57:43 because you replaced the cells that you . Alright, think about things that
57:47 eat that are rough and hard, Doritos or cheetos or any type of
57:52 , basically. You're you're using stuff grinding and breaking and destroying cells.
57:57 you need to replace them because of type of damage that you do.
58:03 , there is a group of cells here that are called basal cells.
58:06 some support cells in there, but cells that we're gonna be interested in
58:10 the gustatory cells. So, here's bigger cartoon, you can really kind
58:14 see here the kind of the onion shape. So you can think,
58:19 know, factory I have something that like a green onion in the mouth
58:22 something that looks like a regular Alright, so it is a neuro
58:26 cell. I mean, it's derived neural neural tissue. Alright, There
58:30 four basic types. We have the one. The type to the type
58:34 and type four. Alright. The four is the only one that is
58:38 a detecting cell. It's the stem , but all the rest of
58:42 The tech stuff. Type one detects in the form of sodium two are
58:49 G protein coupled receptors. So they a variety of different things and the
58:53 three basically respond to sour. So they do is they are detecting protons
59:01 acids in. So the pathway were cranial nerves. So cranial nerve number
59:11 is the anterior that's the front Cranial nerve number nine does the back
59:16 . All right. And there's and epiglottis, Lord ferenc. So,
59:20 you ever had that taste, it really bad, bad in your throat
59:23 you're like, I got a bad in my throat and you come in
59:27 ? That's cranial nerve number 10. right. You go to the medulla
59:31 the doula to the thalamus. So we have the thalamus from the thalamus
59:34 the gustatory cortex. And that's where basically trying to determine what am I
59:39 and then again back to the hypothalamus system to add you know that's emotional
59:45 that visceral response to what it is you're tasting like when you eat a
59:50 sprout. Do you gag? See that's good. But your Children will
59:58 , it's I think it's a generational like my brother. No, I
60:05 gag on oysters. They're living It's not gonna happen. So the
60:13 to think about this is just really just keep this simple When I was
60:17 school, there were four different types tastes now there are five.
60:22 so we went from 4-5. So you are my age there will be
60:26 or seven and I'll prove that here just a second. All right,
60:29 here's yes sir. Yeah. it's just your ability or your
60:38 Your, you're saying it's not your of taste but your willingness to find
60:44 or joy in unique flavors. It's ratatouille school of thought. You don't
60:51 your attitude, do you? Another homework assignment. Yes. So
60:56 did he teach? What did he ? Remy, his or Emil?
61:01 , Emile was his brother, His was Remy. What what was,
61:04 did he teach him Emil? no, he has a taste.
61:09 he had the lemongrass and he had , he was like the strawberry and
61:13 cheese and you put the street cheese the strawberry cheese has a good
61:16 strawberry has good flavor. But when put them together, you get a
61:19 flavor and it's like, oh, add new dimensions and new flavor.
61:23 was the whole, not the whole of the movie. But it was
61:25 really, really important point. But anyway, so the point is
61:29 that when you're a kid, everything just, you just want the thing
61:32 you're familiar with, right? I want to try new things. I
61:36 I'm dealing this with my teenagers right , they're like, they're in that
61:40 zone of like, so like the day we had some chicken with like
61:45 right? And they're like oh it's artichoke, oh it's green. That's
61:48 first thing. If it's green it's taste bad right? And it was
61:51 , it's hard to choke. It's new thing that I don't want
61:53 But then they started tasting, it's oh new dimensions right? So it
61:57 the taste buds changes that they start these combinations actually give rise to unique
62:04 . Which can be good when you're kid when you first taste beer,
62:08 does beer taste like? Think. , I mean it's like vomit.
62:13 know you're wondering which animal they got from, right? It's like who
62:17 this out, you know? But after a while, you know once
62:20 start drinking beer it's like it's not flavor, it's not the alcohol that
62:25 drinking here. It's actually I'm looking flavor. And so now you're
62:29 well I gotta find this one. like oh this one's good. This
62:31 not so good. Oh there's too hops in this one. There's not
62:34 malt, you know yada yada yada start noticing the unique characteristics. It's
62:41 experiential. Well certainly that's true but I would say is is that it's
62:50 . It's the idea that the foreign not scary is really what it what
62:54 boils down to, right that first you try that living booger. I'll
63:02 that story another time. All I went I went to school in
63:05 Orleans. So you had to have at least once. And alright,
63:12 as the first flavor. Salty. can see here we are literally detecting
63:17 presence of sodium. All right. , when you put salt in your
63:22 , what you're doing is you're detecting presence of sodium. This is what
63:24 type one cells are going to They use a specific type of channel
63:29 enac. So, you can see has a sodium in the middle of
63:33 . Its electrical and sodium channel I is what it stands for. All
63:37 , sour as I said, it's dealing with the presence of assets.
63:41 of all the sour things in your , right? You know like limes
63:45 sour sour patch? Kids are right? Why are sour patch kids
63:51 Do you know what makes them It's citric acid, but not the
63:54 citric acid. What else? It's asset, acidic Yeah, it's simple
64:02 vinegar. Right. And so that's I try to show here is we've
64:05 things that are being pickled. So are gonna be the sour things here
64:09 got citrus citric acid when you're looking sour. What you're doing is you're
64:15 an acid that frees up that proton detect the protons. All right.
64:20 basically what it's doing is acting through potassium channel, basically you block the
64:24 channel. So, the cells stop . So, that's when you Are
64:29 able to detect it. So, is the type three. So,
64:31 one in the three. Those are of simple. The type two are
64:35 complex ones. And this is just show you you don't need to know
64:38 steps. It's just if you want kind of see how it's working.
64:41 that's that's what you're doing. It's um the other ones that deal
64:47 the Type 2s. All right. this is where you're gonna get sweet
64:51 umami. All right. When I started learning umami I called it you
64:55 . So, that's how I remember . Right? Sweet. Real
64:59 What you're looking for is the shape glucose. Alright. And so when
65:04 create these artificial sweeteners, what we're is we're creating a structure chemical structure
65:08 looks like glucose but doesn't actually have not actually glucose. So, you
65:12 break down the sugars and release the . All right. So, it's
65:19 three G protein coupled receptor and through signaling cascade. That's as simple as
65:23 it works you mommy. What you're is you're triggered by the presence of
65:27 acids specifically glutamate is the amino acid these receptors actually identify. Alright against
65:34 g protein coupled receptor. Alright. you mommy, is that sense of
65:40 . Alright. So, the the we show meat meat is made up
65:44 amino acids and glute glutamate is one those amino acids. Have you ever
65:49 monosodium glutamate in your food? What is it? Mono single sodium
65:56 glutamate. What does it do to ? It makes that flavor pop
66:00 The sodium always makes food pop and the gluten makes makes it more
66:05 That's why they use it and it also easy to extract from seaweed.
66:09 it's an easy salt. You don't to mine it, you can just
66:12 harvest it and then we get to bidders. Alright, there's lots of
66:20 . Okay, so I want to what do we have up here?
66:24 does that represent? That's chocolate. what is it what makes chocolate
66:29 Coco. Alright, so that's Coco that? That is a cruciferous vegetable
66:36 sprout. Alright, so good. identified that and what is this right
66:40 here Bir What do these three things in common? They're all bitter?
66:47 , I mean that's why they're on bitter slide. What? So what
66:51 coco brussels spouts and what does beer in common? They all come from
66:59 . What is it in the beer comes from plants that makes big
67:02 Do you know what hops is? lot of people don't know it's a
67:09 . Alright. It's actually it's a , it's a massive vine that grows
67:12 30ft tall and has these flowers on and these little tiny tight flowers is
67:16 you harvest and you use that to beer that kind of that bitter
67:21 Now, really the purpose of the is not just a bitter flavor also
67:25 as a preservative to the beer. for those of you who are beer
67:29 , what is the most hoppy beer you can have? I.
67:33 A. Which is India pale Alright. And the reason it was
67:37 happy was because they figured if I in a whole bunch of hops and
67:41 I'm shipping it from Britain to which means it has to go all
67:45 way around africa and come around. was still a good beer didn't spoil
67:51 of the presence of all that That's where the where it comes
67:56 Right. But we have flour, have dangerous leafy vegetable and we have
68:05 . If you're, when you're a you may have done this recently.
68:08 don't know I did it when I a kid. Have you, did
68:10 like you snuck into the pantry when were a kid and you kind of
68:14 looking for something to eat and you mom's baking chocolate. You will never
68:17 that and go you like grab the . You took that bite and you're
68:25 , no, because it was so cocoa's bitter. What makes cocoa not
68:31 sugar, Put more sugar to make happier. All right. All
68:38 All bitter what these are are Okay, these alkaloids are chemicals that
68:47 produce. Not just plants, but the common theme here that plants
68:52 To tell you that it is Okay, so the brussels sprout is
69:00 because it's trying to tell you don't me, I'm going to kill
69:05 That's why it's like Coco saying, eat me, I'm poisonous. I'm
69:13 to kill you. What happens if give chocolate to a dog? It
69:18 , right? It's an alkaloid. right. Hops is the same
69:23 It's bitter because it's saying you are my reproductive organ. I'm poisonous.
69:27 gonna kill you and we sit there go, you don't kill me.
69:32 know, it's going to kill something maybe, but not me. And
69:35 we've done as our bodies have created receptors to identify different alkaloids so that
69:44 avoid poisonous things. And so we die. But sometimes these poisons things
69:52 other organisms actually kind of taste good us and we exploit it for our
70:01 . But that bitterness is what we're . It's what adds dimension. So
70:06 have about 50-100 different types of bitter . They detect different types of bitterness
70:10 different types of chemicals. And that's we're looking for. Right? There's
70:16 lot of chemicals out there that are to kill things. We talked about
70:20 . Remember capsaicin is what makes peppers . Why do we like spicy
70:25 Because it acts like an opioid, ? But cap station is a chemical
70:31 mammals respond to it. Actually. have those receptors. Birds not a
70:37 . Birds can eat peppers all day and they go around, they eat
70:40 peppers. They pick up the seeds they fly somewhere and they poop and
70:43 drop the seeds and then you have new pepper plant. Right? When
70:46 eat peppers, what do we I don't want to eat anymore.
70:52 we avoid the peppers. Well not meat. Most people people in the
70:59 . So this is just showing you G protein coupled receptors and what they're
71:03 and how they work in these All right now here's the last little
71:08 . This is stuff that you don't to know. This is just for
71:11 . That's for giggle. This is makes biology fun. Alright. See
71:16 even put it here, do not anything on this slide. So we've
71:20 about these five different tastes, really different tastes forever. The fifth one
71:26 it was more recent and what I to show you here is how recent
71:30 that we discovered these particular receptors. we've known for a long time almost
71:36 since the early 1900s where I mean sense of taste right? Like.
71:42 I know it bitter. I know . I know salty. These are
71:44 specific. I know these but it until 2000 that we identified the very
71:50 bitter receptor. It wasn't until 2010 we identified the salty receptor. So
71:58 idea you know that we that you biologists already know everything. We don't
72:02 Jack. I mean the world is incredible amount of knowledge and we only
72:06 a small bit of it. And we're still discovering stuff as we
72:13 . This is an example of All right. So um do you
72:16 like things like cheese? Yeah, . Some people like no, I
72:20 like cheese, I get it But cheese has to it both a
72:28 that's inviting as well as a That's usually inviting. And usually when
72:32 eat cheese we eat lots of it of nachos, right? It's just
72:37 double fist that stuff. Why? , there's evidence that in our mouth
72:44 have fatty receptors, We have fat . And so fatty foods are appealing
72:49 us because one as far as our systems are concerned, that's the fastest
72:55 easiest source of energy for us. ? Sugars seem like you know,
73:00 really good. But it's like it to fat. We're like all over
73:04 . It's like just give it to and it's probably because we have fatty
73:07 that are detecting the presence of the . So maybe in 20 years we're
73:12 have that list and it's gonna And the fatty receptors. You guys
73:15 service. No, I do. mean I'm an addict. I mean
73:20 it right in my vein, you , um we have a receptor in
73:24 mouth car called the car for Alright. And what it does,
73:27 detects carbon dioxide. The purpose of carbon dioxide is because the byproduct of
73:34 when they're consuming during their metabolism is produce carbon dioxide, right? And
73:40 if your food has kind of that to it, it's probably has bacteria
73:45 it that are at a level that probably dangerous to you. So,
73:49 the detect, being able to detect that fizzy nous is probably a way
73:53 you to say spit out what you're now, if you don't think this
73:56 like But what we can also do we can also use it as a
73:59 of pleasure thing. So if you pop rocks or sodas, you
74:02 it's like, oh yeah, carbon . But if you don't believe me
74:05 terms of So you guys know what Dave's is has anyone ever heard of
74:10 Dave's? Yeah, awesome. Pizza . Right. Why what's what's so
74:15 about them? What what is what their claim to fame? You don't
74:18 ? Okay, Pizza Rolls. And on Tuesday it's two for So
74:22 two for one. Pizza Rolls All . They had a couple of the
74:25 here in Houston, but not so anymore. I think that might be
74:28 if you go to college station, all over the place, right?
74:31 pizza rolls are basically just take a . Pizza no sauce. And you
74:34 roll it up and you got piece pizza pepperoni and you know you dip
74:39 in sauce. And what you do you order thousands of pizza rolls because
74:42 know food and you'd go and get sauce up at the salad bar and
74:50 law says is that the end of day, anything in the salad bar
74:53 go into the fridge and then you it up the next day and and
74:55 it back in the salad bar. you know, bacteria can survive in
75:00 types of environments and they can then and double bacteria double. About a
75:03 about 15 doubling, doubling every 15 . So you can imagine if you
75:08 the same pizza sauce or dipping sauce for a while, you can get
75:13 bacteria. I remember once or twice there and getting my sauce on the
75:18 and you put it on your tongue you can feel that it's like I
75:23 we need new sauce and then they'll replace it. I'm not saying don't
75:26 doubleday, doubleday's rocks. Alright, that's just an example of bacteria in
75:32 food. Alright. Last slide. think this last slide. Yeah.
75:35 right. So some of you believe because internet or someone taught you
75:40 And the thing is that it's So this is what I want.
75:43 the idea here is that the, idea that some people have this idea
75:49 different parts of your tongue detect different of flavors, right or sensations.
75:56 you know, this is a lie if you put food in your
75:58 it doesn't change when you roll that around the inside of your mouth,
76:02 ? I mean if you take like soda and put it, it's not
76:05 in the front and sweet in the and it doesn't change as you switch
76:08 around your mouth. All right, stays the same no matter where you
76:12 now. The reason this myth came why people believe this is because of
76:17 first paper that was published as published this in 1901. And he
76:21 says, Hey, if you look the tongue, the tongue has these
76:24 places where you can detect taste. I've identified where they are. And
76:28 what they said. They said, up here in the front, over
76:30 on the sides and back here, in the back. Now, what
76:33 those? That's the funds to form foliage and the circum valley. Our
76:38 are popularly where the taste buds are . But each of those taste buds
76:44 type one, type two, type cells. So each of those taste
76:48 actually detect different dimensions of taste. he published this stuff and he was
76:53 and he wrote his paper in Germany german and someone picked up that paper
76:58 translated it poorly and basically said, , there are different places on the
77:03 that you detect different types of And so if you were in grade
77:08 , you may have had a teacher taught you and said there have these
77:12 sorts of flavors. So now you the truth. So next time someone
77:17 you that bet them a beer or it is, you know, their
77:21 , I don't know. And then kind of come back and you can
77:24 this this is actually the real So that's it for the day when
77:32 come back we're gonna do, I remember some sort of pathway. I
77:37 we're doing motor pathways. Two more . Yeah, Yes. You know
77:47 you have like a reaction
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