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BIOL 3324 Human Physiology - 3324_lecture09_0922
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00:04 Alright. I think we're going ahead get started here. I'm gonna stay
00:09 for just one second. So I'm see if this is the mike.
00:13 it is the mic. I will to the front second. But I
00:16 to draw on the slides for a . So um if I can find
00:25 way down to the bottom of the , there we go. Alright,
00:29 well we were talking about last you don't have to look at
00:32 you can look up there if you to what we're talking about on
00:35 we were finishing up with the autonomic system and I was like, oh
00:40 we only have two more slides And and then I opened up to
00:43 prepping for today and I found there like five other slides so we'll continue
00:47 the autonomic nervous system. And then we're gonna do is we're gonna start
00:50 into the sensory reception. We're gonna at looking specifically at the special senses
00:56 then we're gonna jump in the general is that we're gonna jump back to
00:58 special senses on Tuesday. And so standing over here so we can actually
01:02 a little bit of sound. But I want to point out this is
01:05 of the slides I missed on And what I wanted to show you
01:09 this slide was that uh there are different fibers. So we are detecting
01:18 information from the viscera to determine what's on inside the viscera. And so
01:24 often they can detect pain for And these will travel on these sympathetic
01:32 . But because they travel along with types of fibers, what happens is
01:38 that visceral pain is mapped by the from that specific organ to a specific
01:45 of the body. In other it doesn't do what it's supposed to
01:48 . In other words, our body know specifically where this pain is coming
01:52 . We call this referred pain. probably familiar with this. You've probably
01:56 of referred pain. Uh Anyone here watched a movie tv show where someone
02:00 having a heart attack. What what they grabbing when they had a heart
02:04 where they grabbed their chest? they grabbed their arm. It's the
02:09 . So referred pain is probably the of a shared pathway between those different
02:17 which are traveling from the viscera and no see receptors or different fibers traveling
02:24 pain receptors to other parts of the . So the brain perceives the the
02:30 stimuli from coming from an appropriate Is that little map right there just
02:34 of shows you at the bottom like some of these are. Anyone here
02:37 appendicitis. I had appendicitis. Anyone have appendicitis Now you're all fortunate.
02:44 . It's a nasty horrible pain and I had it in sixth grade and
02:49 was at summer camp which was even right? And it was a good
02:53 because my mom thought I was a . And so if I had been
02:56 home, I would have been Um but I want to show here
03:00 it shows you right here, there the referred pain for appendicitis. The
03:06 sits right over there. And what do is they start pal painting,
03:09 like touching, doesn't you know, you show up, like, does
03:11 hurt? No, doesn't hurt, this hurt? And then they touch
03:14 right there, and it's just like if someone had just stabbed you with
03:17 knife multiple times, and you're yeah, yeah, no, this
03:19 this is the worst pain I've ever . But if you kind of look
03:23 the system here is all sorts of areas, like if your ovaries
03:28 that's that makes sense. That's kind where they are. Um But you
03:33 see all these other different areas. if there's visceral uh disruption or noxious
03:39 in the viscera, you're gonna feel in these uh in these different
03:44 Now, there's you can see it says that the pain is,
03:48 know, the stuff is responsive, or chemical stimuli that makes sense,
03:52 ever have a stomach ache from eating hot peppers. Yeah, it's hot
03:57 is a good example, anyone Ghost pepper eater. Ghost pepper,
04:04 favorite. Alright, also these are . So the signals are typically fairly
04:09 . Uh so the thing I actually to do here is I wanted to
04:13 sesame Street with y'all you guys watch Street. Did you ever watch Sesame
04:20 ? So if I start the one of these things is not like
04:24 others, one person, the rest you all need to get on PBS
04:28 start watching Sesame Street. All The reason I bring this up is
04:33 I'm sorry, making you creek your uh the reason I bring this up
04:37 because it's very often when you're when given a situation like this where there
04:42 four things to learn and one of is different than the other three.
04:46 easier to memorize the one thing that's and then apply the other to the
04:50 three as being the kind of collectively same. Right? So rather than
04:56 all four, which takes more energy more effort, this is gonna be
04:59 easier way. And what I want talk about are two different things.
05:02 want to talk about. What are neurotransmitter that the autonomic neuro system
05:05 What are the receptors that they And so there are two primary
05:11 Norepinephrine. And instead of calling you know what Nora ephron is Nor
05:17 You know what that is? All . Do you know what epinephrine
05:21 Okay, if you if you've never that word or if people are nodding
05:25 heads the other name for epinephrine is . Okay, so adrenaline and epinephrine
05:30 the same thing. Nor epinephrine is a small modifications to that molecule to
05:36 this new molecule. Nor nor e . And so they're very very closely
05:40 . Very small. They're close cousins far as molecules are concerned. All
05:45 . And so if you are a that releases norepinephrine, then you are
05:49 neuron that releases a colon ergic um . So we refer to them as
05:56 ergic fibers. Sorry why did I that? Like it's so adrenaline.
06:02 to remember. Right? Adrenaline. epinephrine, Norepinephrine related sow. Nor
06:07 . Is from a geologic fibers. don't know why I said. Uh
06:11 ergic. Maybe I'm just looking at slides wrong. The other, the
06:15 one is the seat of choline. comes from Colin ergic fiber. So
06:19 you release that fiber, your colon . Alright now we're gonna look and
06:25 how do we say which fibers do . So remember we have pre and
06:28 have post gaggle ionic fibers. We fibers of the sympathetic system. We
06:33 fibers of the parasympathetic. So that there are four different fibers. There's
06:37 pre uh there's a sympathetic ganglia Parasympathetic, post or pre ganglion fibers
06:43 . Post parasympathetic, post. Alright we're gonna use this little chart here
06:48 help us understand because if we know one is the weird one. Then
06:51 know the other three. Alright, . And on the next slide we're
06:56 look at the receptors, what receptors what we're gonna do is we're gonna
06:59 down one because the receiving cell from pre ganglion fibers. Which cell?
07:06 pre ganglion IQ. Which is on other side. Post C. Not
07:11 . And then on the post ganglion we are going to our target
07:15 So we're gonna ask the question. receptors are on those receiving cells?
07:20 the post ganglion cell or on the cell. So if we know which
07:24 what your transmitter we're sending we should able to look and see what sort
07:28 of receptor is receiving. All But we're gonna do this simple one
07:34 . When you think of adrenaline, do you think of? Yeah,
07:36 ahead. Oh no more. It's so epinephrine, norepinephrine. There are
07:49 receptors that combined both. But they have other receptors that are specific to
07:55 , other receptors specifics. Nor Alright, so it's gonna be dependent
07:59 the receptor in which they bind. right, we'll see that in the
08:02 slide. That's a good question. . Yes. What I think?
08:09 . Alright. That's you're smarter than am. I don't think that
08:13 But that's right. You you that's a good thing to think about.
08:16 when you hear adrenaline, what do think of fight or flight exercising where
08:22 someone scares you. What goes up right? When you're in a in
08:27 like a fun ride, like a coaster adrenaline right? You are an
08:33 junkie. So you can imagine fight flight those periods of times of sympathetic
08:39 when I'm stimulating something sympathetic. That's I'm probably gonna be seeing that a
08:46 response. Right? So the one that's not like the others is
08:54 All right. So what we say that sympathetic post ganglia nick fibers are
09:00 norepinephrine to act on their target Alright. And the reason I remember
09:05 because sympathetic is fight or flight and acting on the target to respond to
09:11 kind of that adrenaline. Even though not adrenaline, it is norepinephrine.
09:14 how I remember it. If you a better way to remember it,
09:16 fine. All the others are Alright, so parasympathetic is acetylcholine.
09:24 a pre ganglion fiber releases acetylcholine. post ironic fiber releases acetylcholine. The
09:30 that stimulates the post game sonic fiber the acetylcholine from the pre ganglion IQ
09:35 fiber. So you see how it's to memorize the one, The other
09:40 fall into place. Okay, it's a memorization thing. Now, knowing
09:45 that's true, let's take a look the receptors. Alright. The
09:49 Ergic receptors. There are two The two types are referred to as
09:59 nicotine? IQ or muscular nick. you guys have any idea why they're
10:02 nick nick nick nick nick. Hm . Okay good. And what do
10:10 think for musk urine must carry So what happened was is that when
10:17 were researching these very early on, discovered them. And this is what
10:21 works like if you've never done science real. Other than, you
10:24 if you've only done lab science, know like the, you know the
10:27 attached classes, we don't go in with some sort of hypothesis. I
10:33 X is going to do why most the time. It is kind of
10:36 , I'm just trying things out to what happens and then you kind of
10:41 . And so what they did, can imagine is they went under the
10:44 and I looked up there and we got a whole bunch of chemicals
10:46 here. Let's just start seeing what when I dumped chemicals on these
10:50 And what happened was nicotine bound one and mustering bound the other receptor.
10:56 , you already know, right? know what nicotine comes from? You
10:59 where nicotine comes from? Yeah, it's actually a toxin that the tobacco
11:06 produces to protect itself from getting eaten bugs. And the reason is because
11:11 all sorts of nicotine receptors throughout the kingdom. And so it binds to
11:15 receptor, it blocks it. That receptor no longer works. There's another
11:20 for mustering mustering is another chemical. want to have any idea where you
11:24 that comes from muskrats. I like . I mean this is good,
11:32 is even if the answer is It's good to start thinking about where
11:37 names come from, musk urine comes mushrooms. You guys ever eaten a
11:43 toadstool? No. Why don't you bad toast tools? They'll kill
11:50 What they do is they buy into muscular receptors. The mustering in that
11:54 to the receptors. It blocks the . The receptor your body basically shuts
12:01 and then you die. Well, always, but most of all.
12:04 . So we have two types of . We have nicotine and we have
12:08 nick. Alright. So where do see the nicotine receptors? Remember we
12:12 acetylcholine being released from pre ganglion fibers post ironic fibers in the parasympathetic
12:17 And we had pre ganglion nerve fibers the sympathetic system. So when we
12:21 about nicotine nicotine receptors, I was to draw on these and I didn't
12:25 can't stand standing over there is going be both the sympathetic and the parasympathetic
12:31 ganglion cell bodies. Alright, so are on the receiving side of the
12:35 ganglion IQ fibers. So you can over here these are nicotine receptors
12:42 Because they're receiving from the pre Remember we've changed we shifted down one
12:46 then the muscular nick is gonna be on the post? Sorry, on
12:51 parasympathetic post ganglia nick uh fibers. right. I get that right.
13:01 not right because it should just be . This It should be on the
13:07 . See this is why slides are sometimes. Alright, so muscular should
13:14 there there it is on the front my bad. So it's on the
13:17 tissues. So on that parasympathetic fiber the post gangling fiber it's releasing
13:25 It's landing on the target tissue which a muscular receptor. All right.
13:31 last one is sympathetic. This is you're gonna find the energy receptors.
13:35 there's a lot of information up here the energy receptors. There's alpha that
13:38 betas, there's an alpha one and to a beta one. Beta two
13:41 a beta three. Um I don't the beta two listed up here.
13:46 Alpha two is the one that's I'm not gonna ever ask that question
13:50 the test, I promise. And I do you just come and say
13:52 told me you promised and I'll take off the rest of our excitatory.
13:56 the same thing. The idea here that these different types of receptors respond
14:01 different ways to norepinephrine and epinephrine and kind of makes sense. So
14:06 remember we're talking about the sympathetic system I'm running a marathon. Do I
14:09 to digest food? No, but releasing epinephrine and norepinephrine when I'm exercising
14:17 norepinephrine is gonna bind in places to some systems but it's also gonna bind
14:24 other places to activate or excite systems kind of makes sense. So having
14:30 that's inhibitory kind of makes sense. are all meta tropic And you've already
14:36 about these summits are these types of before? Not in my class but
14:40 life in general anyone I think I've anyone here doing pharmacy. No no
14:46 doing pharmacy. Okay. Have you heard of beta blockers? Yeah I
14:51 you've watched enough tv you'll see a for beta blocker. What do you
14:54 ? Beta blockers block data? What receptors. Alright and what do we
15:01 through beta beta blockers? Heart blood . Right. So what we're doing
15:07 we're modulating and regulating the amount of pressure. As you imagine if my
15:11 pressure goes up or really if I my blood pressure goes up and that's
15:15 function of the norepinephrine acting on the epithelial cells of the vasculature. So
15:22 is just you know, something that already know that you're kind of putting
15:25 context. So in in content in at these two charts you'd have one
15:30 these things is not like the other the previous slide. And now you're
15:34 saying which receptors are they binding And we're not gonna care if the
15:38 one alpha two beta one beta three to whatever. I'm not gonna care
15:41 those today but you should be able know which one of these have nicotine
15:45 neck or a drone ergic receptors where are gonna fall. Okay so these
15:53 , What are they? This Is this one is there we
16:00 All right. What else do I ? Should probably actually take my stuff
16:06 there now since I'm not actually gonna anything. Uh So the last rest
16:10 this is just kind of a summary the stuff that we've already talked about
16:13 just kind of putting into context so can really see it because when you
16:17 at this, when you hear for very first time and I remember sitting
16:19 your seats and hearing all these differences the sympathetic and parasympathetic and I just
16:24 anatomically I became overwhelmed. I was like I can't learn this. Have
16:28 ever done that in a class like la la I can't learn this.
16:31 he won't ask it on the You've done that. Okay. Yeah
16:34 done it. I told you I did it right but this kind of
16:37 breaks it down. It's like alright so where do the pre ganglion cell
16:40 where they located the cranial sacral for basically you're back thoracic and lumbar for
16:45 sympathetic. Alright. Where the ganglia ? Remember we talked about the
16:50 Those are located near the spinal Those are those pre vertebral or sorry
16:54 of vertebra and then they also have pre vertebral but with regard to the
16:58 . We said that there near the or in the wall of the organ
17:02 ? I don't know if you remember saying that. I did say it
17:05 . What is the response? Well regard to response, we haven't talked
17:08 this. Parasympathetic systems are very very . So when you get a simple
17:14 a parasympathetic response it's it's acting basically one tissue at a time where sympathetic
17:22 the other hand, is that mass . So remember that example I used
17:26 the end of class last week or Tuesday you're in that parking lot.
17:31 noise behind you. Has your system now. So what's happening? Name
17:36 system that turned on that we I'll start heart, heart rate goes
17:41 . What else happens, pupils What else happened? You're breathing faster
17:48 breathing rate, digestion slows. You don't have to pee actually are
17:56 ready to to just kind of it's of like spraying ink. You know
17:59 a squid. Actually that I mean if you if that's that is one
18:03 the defense mechanisms is defecating and peeing your on your assailant. It's it's
18:08 it's a common way because most creatures surprisingly all right now the reason this
18:15 , this mass activation happens is because sympathetic system is reinforced by the adrenal
18:21 . Alright, the medulla, the gland is a modified sympathetic ganglion.
18:26 the fiber that goes into that causes release of epinephrine and norepinephrine out into
18:31 circulation and so you're not just targeting tissue. You're targeting anything that has
18:36 receptors. And so the idea here in that fight or flight situation,
18:41 want everything activated. Parasympathetic, this more the rest and digest. This
18:46 I'm hanging out. And so turning on and turning that off is kind
18:50 an easy thing. It's not a or death thing. Right? So
18:55 , it's just like I'm getting I'm either gonna fight the bear or
18:59 going to run away screaming. And so turning everything on becomes the
19:05 thing. And then I can turn off as I need it to be
19:08 off. Some other comparisons in terms the fibers, pre gangland fibers.
19:16 mentioned this, the parasympathetic ones. long. They go almost all the
19:20 out to the organ. To that that gangland. The ganglion is on
19:24 near the wall of the organs. that means the post gangland, it
19:27 to be short. Right? And the opposite is true. We went
19:30 to that pair of vertebral gangland, means we have a short fiber.
19:34 then we have these long, post fibers that go out all the way
19:38 the organ. And in terms of nation. Um again, this is
19:43 little chart. You can fill out can say, well, when it
19:47 to my elimination, post gangland fibers lack Myelin, whereas the pre ganglion
19:54 do have Myelin. So you can kind of throw that in there and
19:57 in terms of the actual branches. , if I'm dealing local versus
20:02 you can imagine that I'm going to multiple um uh extensions or what is
20:09 ? What do I have here? branches. And so the idea here
20:12 that post ganglion or the parasympathetic will like 21 tissue. There's not gonna
20:16 a lot of branching to go to systems. Whereas with the sympathetic,
20:20 gonna just go wherever I can send so I can get a widespread
20:24 So even though I'm reinforced by the medulla, I am not solely dependent
20:32 the circulating hormones. I'm actually sending to all these different places. So
20:38 just kind of shows you that kind that ratio. Again, the ratio
20:41 not important. It's just a few lots and finally control where we control
20:48 this. Well, ultimately the hypothalamus the side of control. You go
20:56 a scary movie. Anyone here like movies. Alright, adrenaline junkies,
21:01 ? That's why that's why you like . You like being scared you like
21:04 feeling of like, oh and then like and it's over and over
21:09 This pumping of the adrenaline to your . Now notice the reason that you're
21:14 to go high low is because you suspend your disbelief and watch a movie
21:19 go, this is real. And I can get that response right?
21:23 the good news is that it's not , it's a fake thing. And
21:28 you can modify your responsiveness, So example, I like to look
21:36 like to think of is if if if you came in here and I
21:39 getting in your face and yelling at top of my lungs and giving you
21:42 movement, would you, would your rate start going up? Would you
21:46 fearful for a moment? I'm a guy, aren't I? Yeah,
21:52 , look at me. I'm all . So you wouldn't you? Your
21:56 would be a sympathetic response. But you've watched people in the military,
22:01 you see that like that drill sergeant in that person's face that private during
22:05 training and screaming and yelling, that just sits there and just just has
22:09 deadpan face. Like I'm not here nothing you can do or say will
22:13 me, right? What's going on up at the level of the cortex
22:18 he already knows that that sergeant's not touch him. And so what he's
22:22 is he's disciplined himself not to respond way that you normally would when you
22:28 threatened. So it's a training so can control, you know how you
22:34 the environment. But ultimately your hypothalamus the one that's making the decisions on
22:39 you're going to be sympathetic or Alright, that's what this really tries
22:45 convey to you. That hypothalamus is highest level of control cortex can
22:51 What's going on in the hypothalamus but still the hypothalamus in charge.
22:55 when it comes to sympathetic and parasympathetic so far so good. Let's go
23:03 and talk about something else. Something think is fun. This is what
23:07 the class fun thinking about these types things. So we're gonna do is
23:10 gonna look at sensory receptors and as said, we're gonna do we're gonna
23:13 gonna first dive into the two special Gas station and olfaction first. Then
23:19 gonna go back to the sense of which is not a special sense.
23:22 then we're gonna jump back in on into the sense of sight, you
23:27 , vision and then we'll do the of hearing and the reason I do
23:31 is it just in terms of time divides up a little bit better.
23:34 think really the first one you should talk about is well, probably Gas
23:39 in general, really probably the sense touch and then move in all
23:43 But just so that we are all the same page, what is the
23:45 a receptor is simply something that responds stimulus. So when we talk about
23:50 earlier we were talking about molecules right on cells, but the word receptor
23:55 refer to a cell itself. So refers not only to the molecules on
24:00 cell, it can refer to the cell that has those molecules. And
24:04 to make it even more complicated, can actually look at an organ and
24:07 can be receptor like your eye is receptor or is a receptor.
24:13 the nasal epithelium is a receptor. you have to know what you're talking
24:18 in context but in essence what is receptor, it is something that responds
24:23 a stimulus and results in some sort sensory information up to the C.
24:28 . S. The stimulus that has sort of change in that sensory
24:32 So right now is this room Light to you dark? Can we
24:37 it darker? Yeah, all we do is turn off the lights and
24:40 you would perceive the change in brightness the room so that is a
24:46 So the fact that you're able to the light and detect changes in light
24:51 stimulus as a result of those The last thing is a sensation.
24:55 sensation is a conscious awareness of that information. It may not be right
25:00 right there on the edge all the . Like you're not going right now
25:03 the room going it's bright, it's or it's it's dim, it's
25:06 it's damaged. But if I ask what is the condition in the
25:10 you can actually tell me right. only way that you can have conscious
25:16 of something is if that sensory input up going to the cerebral cortex.
25:20 fact is we have tons and tons receptors but many of these receptors don't
25:25 uh rise to the level of So like right now who can tell
25:29 what your blood osmolarity is? can you detect the radiation that's penetrating
25:35 your body right now? No or it? No, but you do
25:40 receptors for those things. All And the other thing I would say
25:44 is that reality is a function of receptors we have in other words?
25:50 it's our perception of what the world as a result of the receptors that
25:53 have. It doesn't necessarily tell us actually going on around us. So
25:57 example, just to say, you , this is kind of like sounds
26:00 philosophical. There is UV light in room, right? I mean that's
26:07 projected but can you detect it? it doesn't mean that it doesn't
26:12 We just don't have the receptors to it. Right? So what our
26:18 is is a function of what we understand what gets to the cortex.
26:25 just understand that reality is probably far complex than we have any sort of
26:29 of because we just don't have the necessary to detect it. And just
26:33 proof of that, you know, know, bees have can detect in
26:37 range of the ultraviolet, right? know that pit vipers can detect in
26:42 range of infrared and I'm just talking uh the the electromagnetic spectrum,
26:50 Which covers X rays and all sorts other fun stuff. Can you detect
26:55 waves? No, you can't. you don't have receptors for FM or
27:01 . But you can have devices that detect that and convert it into something
27:05 you can then perceive. Alright, receptors are a way that we translate
27:13 transform one form of energy into another of energy that the brain can
27:19 What language does the brain understand? and specifically in the form of action
27:27 . Alright. So what we're doing we're changing electrical code in one way
27:32 not. Electrical code, but the of something in one form and converting
27:36 to another form. Right? So our brains can perceive it,
27:42 So in this particular example right what we have is we have a
27:46 that is tethered to a receptor when membrane moves what it does, it
27:50 up this channel this receptor and that us to go through. And so
27:55 we've done is we've created some sort potential change. So movement, which
27:59 one modality is being converted into a of a potential change that the nervous
28:06 actually understands. So that's what transaction and that's what these systems do.
28:12 for example, your your brain cannot what light is. I mean I
28:17 conceptually can understand it, but it understand light wavelengths. Right? I
28:23 drill a hole in the back of head, shine a light directly on
28:27 occipital lobe. Right. That's where is is processed and your brain wouldn't
28:33 a clue that it has a lamp shown on it. It would have
28:37 idea because it doesn't understand lightwaves. only understands action potentials. Alright,
28:45 , this is how we get perception by converting one form of energy into
28:49 form. All right. So, see with receptors at first we're gonna
28:54 some sort of resting membrane potential and kind of We've already talked about
28:58 So, every cell you have has specific resting membrane potential. And then
29:01 we're gonna do is we're gonna have channels that can open and close in
29:06 to a specific modality which allows that that receptor cell to then produce a
29:12 potential which ultimately results in an action . That makes sense. So,
29:19 you perceive is a function of this activity right here. So, what
29:24 of receptors do we have? We a lot of them. All
29:27 this is not a complete list. these are the common ones. We
29:30 chemo receptors. So, we're specific specific chemicals McCann receptors? Mechanical
29:36 thermo receptors, heat cold. You know what cold is? It's
29:41 the absence of heat. Have you learned that? Okay, so,
29:47 receptors detect visible wavelengths of light. , these are specific molecules that are
29:55 to the energy in those, in photons. Osmo receptors, we have
30:01 to detect solute concentrations in our And you actually do have a perception
30:06 your osmolarity. It's just different. do you think it is thirst?
30:12 ? When I get too much salute body tells me I'm thirsty, I
30:17 to get water in the body. C receptors is just a fancy word
30:23 pain receptor. No C comes from word noxious. So this is what
30:27 us to determine damage. What is waiting for the adventure? Someone always
30:33 an answer. Is it a That's that's that's what? Okay,
30:43 was looking for? Uh Morning The the one that I always hear
30:48 in classes, it's pain leaving or is just weakness leaving your body.
30:53 , that's one. But really pain a signal to your body is saying
30:56 killing yourself, so stop doing Yeah, I'll tell you how blood
31:04 and you feel like shaky, which be What do you think? She
31:13 know? What do you guys Low blood sugar? What do you
31:15 it's gonna be chemo? Osmo? vote. Who thinks chemo. Who
31:21 Osmond, Who doesn't have the courage vote. It's keep them all
31:27 And and that's a really good question gotta ask. You gotta ask just
31:31 of like what am I trying to and why am I trying to detect
31:34 Now? Osmo receptors are a type chemo receptor but what they're doing is
31:38 looking at salutes in in essence number salutes relative to the amount of
31:42 You also have barrel receptors in your , that's for blood pressure. So
31:49 pain actually you don't actually there so has two aspects. There's a portion
32:01 your brain forgets and there's a portion your brain remembers. I remember asking
32:05 friend of mine before I ever had , a friend of mine had had
32:08 kids and I was gonna ask one you can have your third and she
32:11 as soon as I forget what labor like and sure enough about two years
32:16 they had their third child right? but we do things we don't we
32:21 actually remember what pain feels like. brain doesn't remember pain in and of
32:27 but what it does do it remembers experience that it was unpleasant. So
32:31 example when you hit your finger with hammer I'm just gonna use that
32:34 you're gonna remember. Well maybe next I shouldn't hit my finger with the
32:37 but you're not gonna actually remember what that feeling was. Alright. I
32:43 point out that there are some sensation your body are combinations and so what
32:46 talking about like a wet there. know the perception of wetness. If
32:50 splash you with water you'd be like I am wet and what does that
32:55 ? Well there are no wetness It's a combination of different receptors being
32:59 to give you that perception of that feeling. And this is just an
33:04 of one. I mean there are , many others of which I couldn't
33:07 you off the top of my head now. I know I saw that
33:09 on your head and I don't know , but I saw this one.
33:12 think it was a really good right? So what I want to
33:16 is I'm I'm like I said I'm ahead of what I probably should be
33:21 . I should be teaching you just touch receptors first. But I want
33:24 jump here because it just makes it in terms of the time. So
33:29 we finish where you're like okay we've a couple of things and so what
33:33 station is if you don't know it's sense of taste and I'm just gonna
33:36 you know right now. I go on wild goose chases on these talks
33:39 I love food a lot. See right and what we're doing with gas
33:47 were actually detecting within the food that eating the stuff we're eating. We're
33:51 the chemicals that our body needs in to survive. So we're just basically
33:55 kemo these are chemo receptors looking at chemicals and I remember once I was
34:00 lunch with um the other biology faculty and excuse me, doctor cheek awry
34:06 late she said I'm sorry, I'm late, I was out in front
34:08 the library there was a red tail ripping up a squirrel and it was
34:12 cool and all these people were watching and you know of course all the
34:15 students were like ooh and all the class students were like you know and
34:19 she was just like it was really and I said something so stupid,
34:22 is what I'm telling you this I said I can never understand how
34:27 a hawk or another animal can you know the raw in trails of
34:32 else and she just looked at me the like you've gotta be the dumbest
34:36 I know look and she says it's of the chemo receptors on you know
34:40 their oral cavity because that's telling them know that the nutrients that that animal
34:45 are there and it's like well of duh, but at the moment I
34:49 eating lunch and I couldn't perceive that . So what we're doing is we
34:54 sampling the contents now, have you noticed that when you have a stopped
34:58 nose or you're sick food doesn't taste that great and the reason for that
35:02 because the sense of olfaction couple with station really gives us a sense of
35:09 alright so there is a great deal coupling between these two things. But
35:15 going to focus first on go station we'll go to olfaction. So in
35:19 mouth you have a bunch of of are called papillae. Alright. And
35:24 Papillion, if you take your finger rub it across your tongue, I
35:27 recommend it because you don't know what touched, but you have a whole
35:31 of these bumps on your tongue. about 95-98% of them are the type
35:37 people that don't have taste receptors on . All right? And you can
35:42 look in the mirror, you can your finger on but you can go
35:45 in the mirror, you're gonna see have these little tiny bumps that are
35:48 more like um they're sharp more than else. And then basically what their
35:54 is is to rake food and grass and to hold onto food. So
35:58 if you're thinking about an ice cream , right? The reason the ice
36:01 goes onto your tongue and then stay the cone is because you're basically scraping
36:06 the edges of the cone with your and with these little tiny papillae.
36:10 there are three types of people that have taste buds associated with them and
36:14 what you're seeing here. So one is the fungi form and these are
36:18 be on the on the surface of the anterior third of your tongue.
36:24 the part of the tongue you can is your anterior tongue. And then
36:28 from here on back there's actually tongue keeps going down, that's the posterior
36:31 thirds. So the anterior third is you see. And if you go
36:35 in the mirror you'll actually see these tiny bumps all over your tongue there
36:39 kind of spread everywhere. Alright. those are, the fungi form,
36:43 look like a little tiny button Hence the name fungi form like a
36:48 , right? So little mushrooms. then what you can't see is right
36:53 here there's a dividing line between the and the posterior portion of the
36:57 And like I said, it's it's little bit back here. So let's
36:59 we can decouple your jaw and let fall forward, then we can pull
37:02 tongue out a little bit, then be able to see. And it's
37:05 12 massive bumps. And there they kind of like bullseye. Their their
37:10 in nature and they have a sorry, I just what I
37:15 There we go. And I advanced slide what three times and what they
37:21 is they have they have taste buds with them in that kind of that
37:25 . Those are the circum valley and back here on the edges we have
37:29 things that kind of look like slits gills on the sides of our
37:32 Again, they're really hard to You have to kind of pull on
37:35 tongue. And these are really active in Children, but adults still have
37:39 and they're not so active. But are the foliate, they're like leaf
37:42 is what they kind of look So these three are the areas where
37:45 have your taste buds and the little dots in these pictures rep the taste
37:50 and you can see right here, kind of what it looks like.
37:52 a bunch of cells that are kind encapsulated in this little tiny region.
37:57 has this opening up at the That's a poor so that those cells
38:01 actually come into contact with the saliva the material that does dissolve in the
38:05 . And the surfaces of those cells a little tiny cilia. So you
38:09 their surface area. So you kind see it kind of looks kind of
38:12 an onion, doesn't it? Kind Okay, alright, so these cells
38:18 this taste bud is what are called cells and there are four different
38:23 All right, So again, these are not going to do these things
38:27 . But you can kind of see a silly up here. This is
38:30 entirely accurate in terms of each cell , Or sees only one type.
38:35 but generally speaking, what we say that there are type one, Type
38:39 , Type three. And type four the type four cells are the least
38:42 there the stem cell that gives rise all of them. So these cells
38:46 gonna be replaced on a very regular about every 10 days. These cells
38:50 replaced. Uh you know this because had hot coffee before, right?
38:55 drink hot coffee, you burn your , everything tastes like metal for a
38:58 of days and then after a while like things to return back to normal
39:02 the cells that you just killed have replaced to be able to detect
39:06 All right. So um Type these respect respond to sodium type two
39:15 the interesting ones because there's about 100 types. Some of them detect
39:20 some detect umami, some detect That's where the majority of them come
39:24 are the different bidders. They use protein coupled receptors in terms of their
39:28 . Type three is sour. So you can really kind of see
39:34 we kind of can break these things and what I want to do is
39:37 kind of talk about the different So when I was in your seat
39:39 were only four flavors in the Now there's five. Apparently by the
39:44 you get to my age you'll be or seven and I hope to show
39:47 to you. Yeah, the Well, it's just it's just kind
39:56 labeling them out and so we're just kind of see how they do
39:58 All right. And again, we're keep this simple over here. You
40:02 see some examples of what we're talking over here. And if you want
40:06 see the actual activity, that's what is. But I want to keep
40:09 simple for us to detect salty. we're gonna do is we're gonna stimulate
40:14 type one cells, right? And it does is actually detect the direct
40:19 of sodium in the cells. basically, you have a channel called
40:22 channel, and that channel opens up allows sodium to come through the cell
40:26 polarizes. You're detecting salt. just the presence of sodium is gives
40:32 the sense of salty. That's pretty , sour on the other hand,
40:37 a little bit different. What we're is we're protecting free protons.
40:42 This should make sense to you. you've never understood ph right. If
40:47 never understood ph and I guarantee you people in here that don't understand ph
40:51 that's okay. It took me a time to figure it out. I
40:53 I was in grad school, and finally went, oh, that's what
40:57 mean by that. All right. what an acid is is simply a
41:01 that can disassociate a proton from that in in water. And what a
41:07 is is basically the number of free in that water as a result of
41:11 dissociation. Right. It's that And you've learned that. And it's
41:15 , yeah, I remember that I can calculate it out,
41:18 So what we're doing is we're putting in our mouth, you get that
41:23 for the proton becomes free. And that proton does, it binds this
41:27 , which is a potassium channel. when potassium leaks out of the
41:31 what are we doing to the Not re polar hyper polarizing. So
41:39 I block that channel, so when proton comes along it binds that channel
41:43 it, I'm no longer hyper So the opposite of hyper polarizing is
41:48 polarizing. So the cell basically is from a state where it's hyper polarized
41:53 a state of deep polarization. That's it fires. And you get that
41:56 of sour. Now let's think of that are sour name of food.
42:02 our lemons, limes. So these citrus. What acid do we know
42:09 associated with citric citric acid. See easy this is? All right,
42:15 got up there, a whole bunch jars of pickles and peppers and other
42:20 when I pickle things. What do put them in? Which is what
42:25 of acid? Acetic acid? The of acids, Right? Reason these
42:33 are sour is because of that acetic . Right again, goes through this
42:39 you ever had an atomic warhead sour , kid, that's acetic acid and
42:44 citric acid that they use to make things sour. And then they turn
42:50 at least that's what the commercial tells . I eat them too fast you
42:55 ? Alright so these are the type . Again I don't care about this
43:00 of this receptor has changed so many . It doesn't matter what it is
43:02 understand what I'm doing is I'm blocking potassium channel that's causing hyper polarization.
43:10 . And umami when I first started this class I didn't know how to
43:13 that word. I just called it mommy. Easy way to remember that
43:19 . Right, this is why we to class. So these you get
43:23 stupid associations. It's like oh yeah don't know how to pronounce that
43:26 So sweet. That's an easy Sweet is I am looking for
43:32 Alright. And so anything that looks glucose by shape is gonna be able
43:37 bind to this type of receptor and activates that sweetness receptor. And we
43:42 oh sweet. So aspartame, why do they activate the sweet receptors
43:52 they look like glucose you know aspartame actually it's a dye peptide Spar asp
43:59 acid and I can't remember what the one is but it's those two.
44:04 a dye peptide, here's another little pursuit thing when you feed asper tame
44:09 they perceive umami they don't perceive sweet it's a di peptide. So they
44:17 it's basically meat. Umami is triggered amino acids in particular glutamate. Hmm
44:28 , glutamate and food when I hear two things together, what do I
44:31 of Msg? Monosodium glutamate? When I use Monosodium glutamate? Right,
44:42 you primarily think about it in terms asian dishes and the reason they use
44:45 asian dishes because it's easy to You basically make it from seaweed.
44:49 can act extracted from seaweed. But the purpose of it is not
44:56 um you know, to over salt what it does is sodium as well
45:01 glutamate cause food to have much more to it. It basically creates a
45:07 sensation of of that flavors. So you ever cooked without salt you need
45:11 and like and then you put salt it like that's good. Now what
45:14 doing is you're basically using that and what what Msg does is it has
45:19 glutamate that gives it that umami That that sense of wow savory
45:26 That's what I'm trying to demonstrate here a nice juicy steak. For those
45:29 are vegetarians suck it up. it's it's just the sense of savory
45:37 . Right? So again, you can put your fingers in your
45:42 like you can go yeah, yeah. So when you suck on
45:43 piece of meat and it just makes mouth water and taste good and feel
45:48 and makes it like this is perfect life is great. That's umami.
45:53 right now when I was in school didn't have a mommy. Right?
45:57 didn't exist? Or at least they teach us about it. It was
46:00 by a japanese group, which is you have this name. Right?
46:04 so it's just that savory nous and was a result of activating another type
46:09 g protein coupled receptor. So, can see now what the what the
46:13 has done is they're taking these similar of receptors and they're using it to
46:18 understand the chemicals in our body. want to show you the third
46:21 and we're just gonna go through What is this over here?
46:25 it's definitely better. But what's Chocolate And chocolate is really cocoa or
46:31 would be Right. What's this? right. What's this? Okay,
46:39 for those of you who are have you ever had chocolate or Cacau
46:44 sugar? How does it taste Right. I mean, I remember
46:48 like five years old sneaking into the , seeing that box of baker's
46:51 Like he was like, I've discovered then you take a bite just like
46:55 , nope. Never touching that stuff , brussels sprouts. It even tells
47:02 it's trying to kill you. But it's it's a bitter it's a
47:07 vegetable. It's part of the cruciferous group and then beer has something in
47:13 that gives it its bitterness. What that? Hops What Hops?
47:19 it is. What part of the . What what plant is it?
47:22 anyone know what not a leaf? actually a vine. And so if
47:32 ever see they actually up near college I think there are people who are
47:36 hops and these vines are like 30 40 ft tall and they have little
47:41 flowers on them. And what they is they pluck the flowers and it's
47:44 flower that they're using. That's the and that's what you're using to flavor
47:49 beer. Now why would you do ? Why would you put bitterness in
47:54 beer? And I'll tell you the now see this is the problem.
47:57 get on these stories right For those enjoy beer there's a beer that has
48:04 lot of happiness and a lot of to it. Which beer is that
48:08 . P. A. C. is I. P. A.
48:12 pale ale. Now the story of India pale ale is not that it
48:16 invented in India right? It's that was shipped from England to India to
48:23 soldiers in India. The british If you ship anything from Britain to
48:31 you have to go around the Cape africa with Cape Horn. I can't
48:38 . Um Yeah so you gotta go africa and all the way back up
48:42 coast and over to India that takes little bit of time. Beer doesn't
48:46 a very long shelf life if it's well preserved. So it would
48:50 And so what they found was that is actually a preservative to the
48:56 So they over hop the beer. by the time it gets to India
48:58 not spoiled. And that's where you the India pale ale. It's from
49:03 . All right. So we have cow. What does a cow come
49:08 ? What is it? Cocoa beans got? What is a brussels
49:16 It's a cruciferous vegetable. It's basically modified modification of the mustard plant along
49:22 broccoli, cauliflower, cabbage, I'm probably missing something in there.
49:29 asparagus, not lettuce, mustard Oh yeah. Say it again,
49:36 kohlrabi, They're all the same They've been mutated over time to have
49:42 features and that's what you eat. each one of these plants are trying
49:46 do something. What are they trying do? Kill things that eat
49:50 See, I told you so that is there to say, don't eat
49:56 ? You're going to die. If you give chocolate to a
50:00 what is it gonna do? It's die If you give brussels sprouts to
50:04 , what's gonna happen? Thank you playing a lot. We have what
50:13 have here are series of alkaloids These chemicals are what we're detecting and
50:18 alkaloids are the defense mechanisms of the . Right? So for example,
50:25 is an alkaloid, you know, is what we find in chile's
50:29 So what makes food spicy? You a chili to a bird, bird
50:34 detect it. That's exactly right. it to a mammal, you feel
50:41 , you want to see something go feed a jalapeno in one of
50:44 squirrels out here, they'll take that and they'll eat it from you and
50:48 will not be happy with you for very long time down low.
50:57 so what's interesting and this has been down rabbit trails is that many of
51:01 receptors are actually located along the length the esophagus and there are some of
51:05 receptors actually located in the stomach and parts of the digestive track. So
51:10 know these ideas that oh well we circumvent things by just not doing it
51:14 the mouth is actually you know, about something where you've tasted something so
51:18 that it makes you or smelling something noxious that it's like, you
51:22 because you have receptors in the throat well. So it's basically to protect
51:26 body. Alright anyway, so there's 5100 different types of different types of
51:32 receptors in our bodies because the world full of poisonous plants that want to
51:36 us. And so our bodies are there to say don't eat this detectives
51:41 Lloyd, don't eat this. So have a whole bunch of these,
51:46 that's how we detect different things. , obviously hops doesn't kill us and
51:50 spouts, even though they're trying they don't kill us, cow doesn't
51:55 us. We actually have found ways make bitter pleasant. It's actually something
52:01 our palette that we actually enjoy. if it doesn't kill us we can
52:06 a way to make it pleasurable. , a lot of these kind of
52:12 have different magnets. Yes. So , I honestly I really wouldn't know
52:26 answer to that. I mean I know the answer, I could probably
52:29 , you know, so part of is so for example when we're dealing
52:33 questions like cap season, so we're with a thermal receptor that actually is
52:38 a chemo receptor. And so you like my kids can't eat the level
52:43 spice that I can. I mean think one of my kids, it's
52:47 if it says mild on it, get upset and I'm sitting there scooping
52:51 pepper and eating it off the Right? I mean I I grew
52:56 , you know, eating very, spicy food, you know, and
53:00 haven't found a spice that I don't . So why is it? Well
53:03 just me, you know, enjoying that rush of endorphins as a result
53:09 of putting those spices in my right? But I'm detecting the heat
53:16 I've activated the receptor the receptor is saying heat is occurring ergo danger,
53:21 danger and I'm just ignoring it, ? But I I recognize hot
53:28 it's just like it's just like it doesn't bother me. So that's probably
53:33 neuromodulation um as well as probably pain as well. So it may be
53:40 or in the pathway the feedback When we talk about pain I'll kind
53:44 briefly mention that that could be the of how well it binds to the
53:50 . So their glucose receptors. So there there are what are called texas
53:55 . Alright but they may be they be more glucose specific and so you're
54:00 to bind glucose or galactose or fructose in a particular configuration. I know
54:06 actually has that Penta more type shape it binds with different affinities. And
54:10 when it binds glucose let's say it a really really strong binding but when
54:15 binds galactose it's very very weak And so that might be the sweetness
54:20 right there. Yeah. Mhm. a little bit off topic but this
54:31 not that I'm aware of. I I've heard stuff like that but primarily
54:35 are a result of bacterial activity in gut by all this. Yeah I've
54:47 to restaurants where I said please make cry and and only one restaurant has
54:52 able to do that and we actually the chef asked the chef to come
54:56 and thank him for doing that. let's say I eat a brownie today
55:03 then tomorrow I eat the same brownie the same place and it tastes the
55:07 same but on one day it tastes because my body, it's probably just
55:20 , so you're asking a really difficult which I don't know the answers,
55:26 to answer your question, you've all of the pregnant woman that has a
55:31 for blank, right? Why does woman demand pickles and ice cream?
55:38 because her body knows that pickles have agents that her body needs in order
55:44 do whatever it's supposed to do and ice cream to do. So there
55:48 that sort of aspect that's done at subconscious level, right? I mean
55:55 are groups of people in this I mean I've seen this in it
56:00 like Asia minor someplace might have actually in like the Ukraine or something years
56:05 where it shows people just grabbing handfuls dirt and eating the dirt and was
56:10 , why would they do this? it's because they recognize that they are
56:13 minerals that they need in their So they've been taught that, you
56:17 , if you go there and it's like I just scoop up the dirt
56:20 go and then the body says, , you're good, you're good to
56:23 . So there are things that your knows that you don't know. So
56:27 does the brownie taste better? Probably you're happier alright. Things you do
56:32 need to memorize and I wanted to this because Well I wanna waste your
56:37 . And and I think this is of interesting is that we didn't even
56:41 which receptors did what until about year and I know this is now 2021
56:46 you're all probably younger than 2000 at point, right? I mean maybe
56:52 of you were born 1998, But mean I've been I've been learning about
56:58 stuff even when I was in college we didn't have the actual receptors
57:02 So we've known about the taste and , we just didn't know what did
57:06 . And part of the reason I to show you this is look how
57:08 it was. But also look how we actually know about the world,
57:12 how long it's taken us to figure stuff out. The other thing I
57:17 to point out is that there are things that influence how you perceive
57:22 All right. So we talked about receptors. These this plays a major
57:26 in perception of taste. But I think about other receptors, I mean
57:30 look at food if it looks that is gonna taste unpleasant to you,
57:35 ? Presentation is half the battle. know if you're watching cooking shows you'll
57:39 know that right? But if someone a big old spoonful of gray glop
57:43 you put it on there, you it and you see it and you're
57:46 I'm not touching that right? You to be hungry enough to eat it
57:51 that perception is like this isn't gonna good. So you're all your receptors
57:56 your perception of taste. Last thing point out is remember I said there
58:00 five receptors now and there's probably So if you are like me and
58:05 like cheese, why do you like ? I mean it's you know,
58:10 is it about it and it happens do with fat. You know,
58:14 is basically fat there's protein in but a lot of fat and the truth
58:18 is that humans are designed to eat and fats, sugars are the bonus
58:24 our lives. And it's supposed to seasonal when the fruits come out then
58:27 go and then we eat fruit and the rest of the time we're
58:31 we're primarily carnivores. Alright, we omnivores but primarily fat. There are
58:37 F F. A one receptors which on type one cells that are fatty
58:42 . And so notice how when you things like cheese, how satisfying it
58:46 or if you're like me and you a rib eye which is really,
58:48 fatty, you know, or for wagyu beef just it's like 60% fat
58:57 , you know, it just melts your mouth and the reason that it
59:00 in your mouth is because you have receptors for it, we also have
59:04 dioxide receptors on our tongues. So you like, soda is part of
59:08 reason is you're actually stimulating this type receptor and it's really a way that
59:12 body actually detects whether or not there actually a pathogen inside the food that
59:18 eat. So bacteria produces a byproduct their metabolic activity, Carbon dioxide.
59:24 if you put food in your mouth it has that tingly flavor, that's
59:27 of an indicator of oh maybe there's bacterial um growth in this and that
59:34 causing this up regulation of carbon Maybe I should spit this out.
59:39 was after you. Say again. , So well it's stale because the
59:47 dioxide is left at this point, ? But but it gives that tingle
59:52 that tingle in our mouth is kind exciting if you've ever had pop
59:55 Pop rocks is a better way to this because it's sweet. But you're
60:00 that feeling in your mouth. Have ever had a pop rock? It's
60:04 a candy that has carbon dioxide built it. And it's oh and then
60:11 all sorts of myths that are attached them, like a kid once died
60:14 eating three bags of pop rocks. , it didn't happen. Last thing
60:19 want to point out um you will across people who will teach you this
60:25 you'll read about it and it's And what they'll say is that different
60:29 of your tongue have different receptors. , so that's not true. Alright
60:34 I showed you where the receptors you have the foliate on the
60:37 right? So you can see there be the foliate, you have the
60:40 valley which would be way back there you can't see them. And then
60:43 have just along the surface of your , you have the funds of
60:47 right? And each of those contain four of those different cell types that
60:52 described. And this was actually discovered early on 1901. This guy in
60:57 published this paper, I'm not gonna that handbag probably, he published his
61:01 saying, look I've discovered where the receptors are located, they're all over
61:05 tongue. But the person who translated the German into the English basically said
61:09 are different places on the tongue for receptors. So where he said you
61:14 see here over here on the back here in the back and up
61:16 in the front. Whoever whoever translates said there are different places and you
61:21 this to be untrue, right? you put food in your mouth,
61:24 it change um what it tastes like you roll it around? No it
61:28 the same flavor. It's just that touching different parts of your mouth and
61:33 if anyone ever tells you that, tell them they're full of crap and
61:36 that's not true, this is the accurate thing is these three locations is
61:42 you have the receptors. Yeah. um I guess so because I used
61:54 parents would sit me down and say not leaving until you eat all this
61:57 . No I think the answer is , your body will start saying I
62:01 eat this because it's gonna provide the I mean right I mean you hear
62:08 people eating other people right, donner type thing you know? So how
62:14 you get past that revulsion? Well sense of the preservation of self becomes
62:20 , really important and so when you're you will eat things that you wouldn't
62:25 eat just by virtue of trying to those things in. How am I
62:31 terribly of course. Alright. Alright. Olfaction is a sense of
62:37 chemo receptors. So I want you point out here the two things that
62:40 talking about today so far have been receptors. And so we're looking at
62:44 we're looking at the detection of airborne . What we can do here is
62:48 can sample food, right? We sample each other and or we can
62:54 danger. Right, Have you ever up a container from the fridge?
63:01 of look at, you can kind see the growth in there but you
63:04 maybe maybe it always makes that noise noise. Right? So this is
63:12 we sample our environment. All right , even though we have a pretty
63:16 sense of smell, we do not the best sense of smell. So
63:18 not very sensitive or as developed as organisms, you know, of
63:22 But we are not the we are are many, many other animals that
63:26 that. If you don't understand the of other individuals, I'm not just
63:31 about cologne, you can actually detect smell of family members. Women in
63:36 . I'm just gonna let you know now, your sense of smell is
63:39 million times greater than men. And not an exaggeration. There's actually been
63:45 study where they proved this. I , they got into like men smell
63:50 . I don't remember what the sample was. It was like men got
63:53 a point it's like, okay, can't smell this. And women did
63:56 more delusions, tenfold dilutions all the down. And they can smell that
64:00 . Women can smell their Children and , that is my child. Men
64:05 look at it and go, I know close enough. Yeah. All
64:10 . But this is also true between . It's you know, sense of
64:15 is a way to identify one So, what I wanna do here
64:18 I want to focus on the nasal . So here is the nasal
64:21 This real region right up here at very tippy top is where the olfactory
64:26 is located. So it's really high when you normally breathe, you breathe
64:31 and out. And it stays kind low in the nasal cavity. All
64:35 . But some of that air gets roiled or terminated inside the nasal cavity
64:41 kind of gets wafted up into the . It's because we have these terminates
64:46 part of the nasal con show which don't need to worry about the
64:49 But what that does is spin the and it allows you to get up
64:52 to that nasal or the olfactory And it's here where all these receptors
64:57 located. And if there are chemicals there that are interesting to us then
65:02 do we do when we smell something we think is kind of interesting?
65:05 go and we breathe deep and what does now is it pushes the air
65:10 so that we can expose more of air with those chemicals in it to
65:14 olfactory epithelium so that we can smell better. All right now there are
65:19 cell types up in that area. here is a cross section through that
65:23 tiny area up top we have the receptor cells the cells were interested
65:27 They're the ones that actually have the to detect the different types of chemicals
65:32 have support cells that are sorry that are the little things that look like
65:35 onions. See they have the bulb here little hairs on the bottom.
65:39 right. This is an affront um we have support cells. So the
65:46 cells are the green ones in And what they do is they produce
65:49 and they help provide nutrients and materials keep the other cells happy. And
65:53 not shown in this picture but it be kind of like these little tiny
65:56 cells. I guess they are labeling there those are the stem cells So
65:59 do or are able to replace the two types. So the regeneration of
66:04 types of cells about every two months . So these are not a cell
66:09 are permanently lost. You can actually them over time. And then there
66:14 other glands in here as well that not showing here. Alright. What
66:18 want to do is focus in here you look down So this is a
66:22 bit clear. You can see it does look kind of like a green
66:25 . So you can now see my chemical receptors look like onions, one
66:29 like a big onion one looks like little. Yeah, you should.
66:42 . Yeah. So those should be back now. Here's the question,
66:46 we destroy the cell or did we some aspect of the cell? And
66:50 don't know the answer to that. haven't seen any uh claimant on what
66:54 actually going on? Why that? the smell is lost. It could
66:57 be up in the um the well in the olfactory bulb could be occurring
67:05 the level of secondary neuron. It even be occurring up there at the
67:08 cortex. I don't have the answer that one. All right. So
67:15 thing I want to point out here these old factory hairs. All
67:18 So the olfactory hairs are just extensions the of the cell. And this
67:21 where you're gonna find the olfactory They have each of these individual
67:26 So this cell right here has a specific receptor. That cell has a
67:30 specific receptor. And so each individual has its own receptor. That's that
67:36 That is specific to that cell. doesn't mean you could have two cells
67:40 have the same receptors. That's But you can't have one cell that
67:43 two types of receptors. That makes . All right. And so you
67:48 see that's what I'm gonna do the and then the axon, this is
67:54 bipolar cell. This is the first you'll see the bipolar cell. So
67:57 axon travels up and then they converge they join up with the other axons
68:02 they form what are called the olfactory . So this when you think of
68:05 nerve number one, it's really a bunch of different nerves and the way
68:09 can think about it. If you up here, most people they think
68:13 this green portion right? There is olfactory nerve number one. But it's
68:17 it's actually all the little tiny fibers are red in that picture. So
68:20 like the hairs of a toothbrush. when you look at it you're really
68:24 of looking upwards at it and all all the nerves are actually pointing at
68:27 . And that's why a lot of can't really identify them straight up the
68:31 time. Alright. So each receptor responding to one portion of an odor
68:39 is a combination of multiple chemicals. . And so each of these receptors
68:44 responding to one chemical within that broader we call that chemical and odorant.
68:50 . And so you eat like this detect one odorant that's going to detect
68:54 order that one. And so it's be the combination of all these different
68:57 that make up that whole thing. I love this picture. two
69:02 What do we have up here? not just a funny picture. What
69:07 they doing smelling armpits? This is job. What do you think they're
69:15 deodorant? That's right. And who doing the sniffing? Why they have
69:21 better sense of smell? And look the guys in this picture. What
69:26 the guys, they're all thick, ? I like that, they're all
69:31 . Why? Because they have a sense of sweat. So what we
69:36 here basically a bunch of fat guys and a poor bunch of women who
69:39 a super sense of smell detecting whether not the deodorants work alright and down
69:44 the bottom picture, this is something can mostly relate to. We draw
69:48 of people when you say that your , what do you give them?
69:52 give them stink lines because it shows what the odor is. An odor
69:56 two characteristics to it. Right it's volatile, volatile. Doesn't mean
70:01 it's explosive, It means that it's of vaporization. That means it's able
70:05 escape wherever it's located and then penetrated of the air and travel away.
70:10 second thing that all owners have is they're water soluble because if you go
70:16 , what you'll see here is that have a layer of mucus that protects
70:19 olfactory epithelium in order for one of odorant to get to that receptor,
70:24 has to penetrate through that mucus to receptor. Now, if you don't
70:29 what mucus is, it's basically water proteins. The proteins are called the
70:34 and that's really all it is. so you basically can work your way
70:38 there. And also on top of there's actually other proteins that our chaperone
70:42 that oh I know you, I'm grab you and I'm gonna take you
70:45 I'm gonna put you to the receptor you need to go to but all
70:50 water soluble to break through that mucus they have to be volatile to be
70:54 to get up into your nasal cavity the first place. So what happens
70:58 what I described we deep breathe, bring those molecules up high to where
71:03 olfactory epithelium is the odorant diffuses through mucous. It binds to these proteins
71:09 help carry them as a chaperone to receptor. That receptor cell which has
71:15 receptor then binds to that odorant and now able to de polarize to tell
71:20 that that particular chemical bound to that cell and it uses a simple G
71:26 coupled pathway. Alright, the G here is called G O L F
71:31 . O. Factory. See how you do this? And the reason
71:34 this is the most populous uh type signaling system in the body. These
71:39 proteins is because of the olfactory There are about 4000 to 5000 different
71:46 here of receptors in G proteins. that kind of tilts the scales a
71:52 bit in favor of the G All right. So what happens is
71:56 bind the odorant binds to the G or the receptor which activates G protein
72:00 receptor and then it activates a channel causes cell to polarize and that's all
72:07 is to this that sell to It basically sends a signal up into
72:11 olfactory bulb where that signal is then be processed for the first time.
72:16 what we have here is the olfactory cell is neuron one. So it's
72:20 primary of the first order neuron and it's gonna terminate onto a neuron inside
72:26 olfactory bulb. Now, if you inside the olfactory bulb, you're gonna
72:29 these regions of of structure. They glomeruli. Glomeruli just means ball or
72:35 a realist means ball. And so it is, it's the the receiving
72:40 , the dendrites of the second order and the sending in of the primary
72:46 or the first order neuron. And , if you look at this,
72:49 you're able to take a slice through stay in it, you basically see
72:51 structure as like ball ball ball ball ball ball ball ball there's just 2000
72:56 these things. All right. And what we have here is a mechanism
73:00 organization. Before information even goes And actually, if you mapped out
73:05 olfactory epithelium, you see that there an organization to it as well that
73:10 not just sells willy nilly that the or similar chemicals are are near receptors
73:17 each other. And that there's kind like it's kind of like keys on
73:21 keyboard A to G. It's kind like the same thing. Your nasal
73:25 the olfactory epithelium has one type of all the way back to another type
73:29 chemical across that across that lane or that distance. So what we're gonna
73:36 is we're gonna process here. And we create a strong enough signal that's
73:40 fire the secondary order neuron up to olfactory cortex. All right. So
73:45 we're gonna do from the secondary right? We're going to the primary
73:49 cortex. Go the hypothalamus and This is gonna give us our sense
73:54 personal perception. But uh an emotional to that smell. If you smell
74:01 that you're attracted to, what does make you do smile? You're telling
74:08 no, that that's not what you . Smell someone you're attracted to.
74:11 don't go. You go. All , fine. Think of when you
74:19 smell the food that your grandmother makes , How did that make you feel
74:25 ? Right. So that's kind of this is. It's because that sense
74:29 smell these chemicals are present that reminds of grandma, grandma makes me
74:33 That's all happening at the level of limbic system. Notice these do not
74:39 to the thalamus, this is one those systems that doesn't go to the
74:43 . So, what I want to out is that remember I said that
74:46 can have cells with the same receptors so that's kind of what this is
74:51 you is that we're using three different of receptors in this little system.
74:55 you can see there are multiple cells all detect the same chemical.
75:00 So you can see here the blue , the red chemical in the green
75:03 , we can say it's the sonic , you know like ocean water,
75:08 , lime. Right? So if have enough cherry cherry, it's gonna
75:14 up to a lot of different chair of the my sense of cherry smell
75:19 way way up, Right? Let's only activate one of the blue
75:24 Well, at the level of the Alice, this is where I'm modulating
75:28 . What's a false positive, which the dominant things. So I'm gonna
75:32 my inhibition and facilitation here. So information that's going forward has already been
75:38 processed, that I can perceive Yeah. Question every right?
75:50 it's probably already there is. Now you're doing is you're you're attaching smell
75:55 something new, Right? It's oh, here's a novel smell.
75:59 you will associate it with something you know or you'll take that particular combination
76:04 chemicals and you'll say this now is . Yeah. Yes. So when
76:15 bind the receptor, you want to it up as quickly as possible.
76:19 so what it's saying is that when that odorant binds there are enzymes that
76:23 up that odorant so that that receptor freely available again. So that's what
76:28 means three minutes. How much time I have here? Yeah, I'll
76:33 do this one. All right. what I wanted to show you here
76:37 how complex and how interesting this All right, So, I want
76:41 to represent each of these individual squares the degree of activation. So you
76:46 see right here, this is like activation. That would be like 90%
76:50 , right? This would be a less. Let's make up a
76:54 What do you think? 15% sure not? Okay. So imagine if
76:59 only had five different receptors In your your body because that's easier than
77:05 Right? And let's imagine that we an odor that's made up of.
77:09 is that? seven different utterance odor a for example could bind to four
77:15 the five receptors but it really binds strongly to the red receptor. It
77:21 weakly to the purple receptor, not all to the green. And you
77:23 see varying levels there. And this true for every odorant in that
77:29 And so what you can imagine is I smell something I'm activating each of
77:34 receptors to varying degrees. And the that is produced in the olfactory cortex
77:41 gonna look like this little map right . So the smell of strawberry,
77:45 just making up would look like The smell of artificial strawberry would look
77:50 different because it's very similar to strawberry not quite like strawberry because we all
77:55 fake strawberry doesn't smell like real strawberry it, but it smells a lot
77:59 And so that pattern is there that's be slightly different. And so when
78:03 smell something, I can't remember where was right there. When you smell
78:08 , what you're gonna do is you that same pattern and your brain says
78:12 pattern equals strawberry. Yeah. Uh . Every single one it tastes like
78:31 that place. Right? I would would probably And this is what I
78:37 think of, right? But so that's that's that's exactly right?
78:42 as you smell more and more things as you begin to explore and expand
78:47 olfactory palate, you'll create more and and more patterns. You guys doing
78:53 in a file is I know you want to get out of here in
78:56 file. I don't know if it's particularly Eno is wine. So think
79:05 wine lover, you know, file lover. What do they do?
79:10 got your goblet, you twirl why would I why would I twirl
79:15 so I can get those volatiles up into the air. And then what
79:20 I do is I stick my nose my glass. I take that deep
79:26 . And then what I'm doing now I'm like looking for hints of current
79:32 , some smokiness, a little bit leather. You don't like it?
79:38 , you haven't done it enough. , not necessarily, but what you're
79:43 is you're basically you're trying to find chemical combinations that remind you of other
79:48 that you've already done, yep. right, you guys Tuesday we come
79:54 , we'll go faster.
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