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BIOL 3324 Human Physiology - BIOL3324_lecture09_0921
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00:02 How are y'all doing today? I it like a good uh, all
00:13 . Apparently we're not binary. We're kind of me today. We're going
00:18 cover a lot of ground. Problem a lot of this stuff. I
00:22 go off on wild tangents. So wants to be my designated get back
00:27 track? You will. All when I start going off, just
00:36 , just, just do that. not gonna be offended. I just
00:38 you do tell me. All So I want you to imagine for
00:42 moment that being the good student that are, that you have decided to
00:47 late at night over at the right? You start studying around six
00:52 at night, like a good student you stay there till it closes,
00:55 is what time? So we don't anyone who stays till it closes.
01:03 , around 2 a.m. All right. being the, uh the not the
01:08 student that, that most people but you're a late student. You
01:11 arrived on campus and you parked way in BFE. You know what BFE
01:16 ? It's a bad word, It's, you are so far away
01:21 campus that you have to march a long way to get there. All
01:26 . So here it is at 2 at night, you're marching into your
01:29 across campus and you're going through the lot. Now, it used to
01:33 over here on the north side of that the parking lots were covered in
01:37 . And so when you walked across parking lot, you'd hear the
01:40 crunch, crunch of the shells so . Are you with me in my
01:43 story? Great. So here you , you're walking across campus 2 a.m.
01:48 marketing across the parking lot and you feel your crunch, crunch,
01:51 And you hear behind you crunch, , crunch. Ok? You say
01:59 see yourself? Hm. There's a behind me. Do you turn around
02:02 look at it? No, because how all the horror movies end
02:07 So you know, better than to around and look and see what's marching
02:12 you. So what do you Crunch, crunch, crunch,
02:15 crunch. And then behind you, hear the crunch, crunch,
02:18 crunch, crunch. It gets faster you. So what happens to your
02:21 rate? It increases? What happens your respiratory rate? What happens to
02:25 blood pressure increases? Right? And now painting every scenario on the that
02:32 can possibly think of is going on your head. You're wondering all
02:37 when this maniac catches up with what do I do? But of
02:42 , you know, you're not allowed turn around because like every other horror
02:45 , if you turn around that ax is gonna get you. So
02:49 crunch, crunch, crunch, crunch, crunch, crunch. And
02:51 you hear behind you, the crunch, crunch, crunch. It's
02:53 closer and closer and all of a the hand touches your shoulder and you
03:01 really have two options here. Scream elf on the ground, wet
03:06 Poop yourself. Hope the predator gets and runs away. Number two,
03:12 can you do? I'm gonna fight thing. Right? And so what
03:19 here? That's the fight or flight ? This is a sympathetic response.
03:23 all the things you are getting ready the emergency and you are preparing for
03:28 exercise or the excitation that you're gonna to be dealing with. Now,
03:33 course, what happens is, is that hand touches your shoulder and you
03:36 around and your fists are ready to . It's the person you've been studying
03:40 all night, right? And they to let you know that you left
03:45 phone and they want to make sure you got it before you left.
03:49 right. Now, your heart's beating 220 beats a minute, right?
03:55 breathing at roughly 4000 breasts per Your veins are popping and your arteries
04:03 popping from the blood pressure. You're profusely. Your eyes have dilated.
04:08 these things that your body wants to in? And is this a state
04:11 your body wants to be in? right? You want to bring it
04:15 back down. And so what we're here is what the parasympathetic is responsible
04:21 , is to maintain regular home or housekeeping activity. In other words,
04:28 you're trying to do is you're trying reverse everything back to normal.
04:32 we could do a sympathetic system and having a para sympathetic can be just
04:37 . Right? I mean, if were on the highway going 60 75
04:41 an hour, let's say, driving to Galveston and there was no traffic
04:45 you needed to stop. Could you without a break? You're saying,
04:52 , you say yes. What about rest of y'all? What do you
04:54 ? Could you stop? You say , I didn't say stop right
04:59 I just said stop. Right? you stop and say if you took
05:04 foot off the gas, would you slow down and come to a
05:08 Yeah. Would you waste a lot energy doing that as far as the
05:12 is concerned? Yeah. Waiting for uh for the resistance of the road
05:17 slow you down and come to a would allow that car to expend too
05:21 energy. So, having a reciprocal like a brake to challenge what the
05:29 pedal is doing becomes beneficial. It you to return to normalcy or to
05:34 state that you want to return to , very quickly. And so when
05:37 look at the A N SI A and we look at sympathetic versus
05:41 you need to treat one as a pedal and one as a break.
05:44 problem is, is when we do we typically think oh, sympathetic is
05:47 gas pedal, parasympathetic is a break that's not actually true. See if
05:50 sitting on the sofa watching TV and popcorn down your gullet, which system
05:55 really, really active, the it's a gas pedal and it's basically
06:01 the activity of the sympathetic. So are times when the parasympathetic is the
06:06 pedal and the sympathetic is the break as when you normally think of sympathetic
06:12 being a gas pedal and para symp as the break. So we have
06:16 what we call a dual reciprocal system , right? You can treat both
06:22 at any given time as being in , right? And one will happen
06:27 dominate over the other depending upon the . I mean, I don't know
06:31 really goes on in a horror but I mean, you're going sympathetic
06:34 to parasympathetics, you know, you're kind of going back and forth,
06:38 know, but in a normal everyday type of situation while you're sitting there
06:43 food, you'd be parasympathetic dominant if phone rang and you jumped up and
06:48 to go get it. You'd be with, say sympathetic, especially if
06:50 was somebody that you wanted to talk . All right. So when you
06:56 about these things, think sympathetic is . That's a fight or flight,
07:01 , think rest and digest. we've been talking about these systems and
07:06 differences for the most part. And I'm going to do is I'm going
07:10 try to set up a way to and contrast these two systems. All
07:14 , the good news is that they are easy to compare and contrast.
07:18 The first thing I want to talk is about neurotransmitters. All right.
07:21 there are two neurotransmitters that are associated the autonomic nervous system, Aceta Cole
07:26 Orrin. Uh This is just a question to help me gauge how I
07:30 explain it. How many of you up watched Sesame Street or saw Sesame
07:34 . Now, did you turn it after Elmo was on? And then
07:37 watched the whole thing? So, you familiar with the one of these
07:41 is not like the others? One these things is, it's a whole
07:52 . My entire childhood has been formed song I remember Oscar Mayer Weiner songs
07:58 commercials. All right. Oh, wish I was an Oscar Mayer
08:02 you know, I mean, maybe that one, but I mean,
08:07 Street was all about songs. one of these things is not like
08:12 others. One of these things is of the same. They're trying to
08:17 you how to identify something different in group of things. So one is
08:23 the same when you're dealing with neurotransmitters receptors of the autonomic nervous system.
08:29 Sesame Street, it is easier to one thing being different than memorizing four
08:35 and trying to figure out which one different. So all we gotta do
08:37 let's identify the one that's not the . All right. So we have
08:42 Colne. When you hear those we also have a term that we
08:47 to reference the type of fiber that releasing that particular neurotransmitter. So for
08:52 , a colergic neur or sorry colonic is going to be releasing acetycholine,
09:00 something that is auric is going to releasing something that is either epinephrine or
09:05 epinephrine. And really it's going to no ephrine. All right. So
09:08 you hear that it's like, which one is colergic? Which one
09:11 adrenergic? That should be your frame reference? Oh, it's asking which
09:13 is it releasing? All right. with regard to what I'm releasing
09:17 Aceto colon abbreviated ACH up there, gonna see everything that is sympathetic.
09:22 in our little little chart down you can see it's four little
09:25 You have pre gang fiber, post fiber, looking in the sympathetic
09:29 looking in the parasympathetic, you get , that's pretty straightforward. So,
09:34 that is uh preganglionic that is going be a sea of cooling. So
09:39 can put an a or an ach whatever you want there. All
09:42 when I am parasympathetic and I'm a ganglion cell, I'm releasing Aceta coin
09:48 well. All right. So the thing that's not like the other here
09:53 the sympathetic post gang ionic fiber that no ephrine. How do I remember
09:57 ? All right, we've already talked where the name comes from.
10:00 Norine has another name. It is and its cousin nor adrenaline,
10:09 Adrenergic when I am running a if I am scared, what is
10:14 through my body? Adrenaline? That's you already know. So it's very
10:20 to think about when I am talking the second neuron in the sympathetic
10:24 It is releasing that adrenaline really? not adrenaline, it's nor adrenaline or
10:30 Epinephrine. So that's the one you . If you remember that one,
10:34 already know the other three. OK. So now there is a
10:44 bit of uh uh well, you it here on the line, it
10:50 almost all sympathetic. So there are exceptions to the rule. But if
10:54 remember the rule that I just gave , you're gonna be good to
10:57 All right. So you have a ganglionic fiber, it is terminating on
11:01 post ganglionic fiber. So it is information from that pre gang ionic
11:06 That means it has receptors for whatever neurotransmitter is, the post gang fiber
11:11 sending its information down to whatever the cell is. That means the target
11:15 has receptors for whatever that signal happens be. All right. Now,
11:20 when it comes to the type of , here we have colergic receptors and
11:25 receptors that already makes sense. All , with regard to the colonic,
11:28 are two types. We have the receptor. We have a muscarinic
11:33 They are named for what binds All right. Now, you've probably
11:37 taught that when you're a scientist, have a scientific method and you go
11:40 the laboratory, you come up with idea and you start doing experiments and
11:43 still have some sort of plan along way. That is 100% a
11:50 What's truthful is like you have an of something you want to do and
11:53 start randomly doing stuff and if something , then you kind of go backwards
11:58 say, OK, let me test this actually happens. And so how
12:01 got their name was they were hm, we got these receptors.
12:04 wonder what binds to them. What we have on the shelf? And
12:08 started pouring, pouring liquids on these types of receptors to see what would
12:12 bind them. And as you can , a nicotinic receptor binds to
12:18 great what is nicotine? Anyone know in cigarettes in tobacco? So it's
12:24 by, it's produced by the tobacco . It is a chemical that is
12:29 poison that the tobacco plant produces so the tobacco worms don't eat the
12:35 It just happens to bind these It makes us feel really, really
12:40 for those of us who use tobacco have used tobacco. You kind of
12:43 you get that buzz going on and you get an addiction, your body
12:48 it. All right. What about other one? This weird one?
12:52 . What are the muscarinic receptor? ? Well, again, we're just
12:56 off the shelf. Let's just start chemicals and we poured this chemical on
12:59 shelf. It was Musca, what musk come from? It comes from
13:03 stools. It is the poison that produce. So you can look at
13:10 . One of two ways we have that these, these mushrooms have or
13:15 , for a chemical that these mushrooms . But really the better way to
13:17 about it is oh, mushrooms don't being eaten by humans. So they
13:20 producing a chemical that happens to kill people that eat it. And so
13:24 , the ones that survive are the that aren't getting eaten and keep producing
13:28 chemical. But anyway, we have Musca receptors or muscarinic receptors, but
13:35 , they are both aceto cole It just happens that the shape of
13:40 the shape of nicotine binds to that thing and can activate these receptors.
13:46 right. So those are two and the other ones are the adrenergic
13:51 Adrenergic receptors are ones that are gonna able to be bound by none or
13:56 . There's a bunch of different You see them up here, there's
13:58 major classes and then there's a bunch sub classes. So there's the alpha
14:02 , alpha, two, beta, beta, two beta threes. Um
14:06 , I think we have one person on pharmacy here, right? But
14:09 of you have at least paid attention commercials at least once in your life
14:12 planning on a career in health Have you ever heard of beta
14:15 What do you think they're blocking beta ? There you go. And those
14:20 primarily play a role in regulating blood . All right. So it kind
14:25 makes sense. Oh, you mean dealing with the autonomic nervous system
14:29 Yes. OK. So where do find these? So you can see
14:32 again, we got our little chart four post versus target. So we're
14:35 shifting down to the receiving side, ? So the post is receiving from
14:40 pre. So all pres are going be getting what type of neurotransmitter,
14:46 all receiving Aceto colon. So they're to have a colonic receptor. So
14:50 type of colonic receptors we have? , nicotinic ones are found on both
14:54 sympathetic and parasympathetic postganglionic. So, you want to put a big in
15:00 post under both sympathetic and parasympathetic, in good shape. Where do we
15:04 the muscarinic? Well, it's gonna on the one that receives Aceto Cole
15:11 of the last two. So who's Aceta Cole? Is it on the
15:16 cell that's downstream of the parasympathetic or the target cell of the sympathetic?
15:22 parasympathetic, right? What are you from the sympathetic side? Remember,
15:28 scared. So I am producing no right? So what we have here
15:34 the target parasympathetic downstream, you're gonna a Musca receptor and then over in
15:40 target, over by sympathetic, you're going to put adrenergic. All
15:45 it's an adrenergic receptor. And we're not going to care about alphas
15:49 betas right now. Um the reason is that it's, it's there's not
15:54 a little nuance here, there's a going on. Uh the alpha and
15:57 receptors. These are um predominantly So the idea is that there's these
16:05 depending upon where they're located, they different responsibilities. We're going to
16:09 for example, that the presence of stimulation will cause vasoconstriction in the,
16:17 the blood vessels traveling to and from . But when you arrive in the
16:21 , you get vasodilation. So sympathetic speeds up the movement of blood,
16:27 then also opens up the blood vessels the blood is being delivered. So
16:30 you can have a greater delivery of if that makes sense. So,
16:35 different effects that um none can have a blood vessel depending upon where it
16:42 dependent upon the type of receptor, receptor that's present. Right.
16:48 receptor type matters, but we're not to do the details right now.
16:53 right. I have up there, two is the inhibitory one. The
16:58 of them are excitatory. Um But , when, when we get to
17:01 cardiovascular system, we'll look at it more detail. All right. So
17:07 you were paying attention on Tuesday, saw each of these halves. Do
17:11 remember seeing this thing? And it like a scary picture. Not a
17:15 picture. All right. I'm just point out in the center we have
17:20 our tissues and we're just saying here the sympathetic, here is parasympathetic.
17:26 look and see how they're different. of the things that we said was
17:29 is that it has the para um vertebral ganglia that cause forms that sympathetic
17:36 . And then we have a series prevertebral ganglia that are specially named and
17:41 in special locations. All right. we're not diving into the anatomy of
17:47 all. It's just understanding that those exist. All right. Now,
17:51 that in mind, one of the that we can ask is all
17:54 in each case, both for the and the parasympathetic. We have a
17:58 in a post ganglionic cell. That there must be ganglia over in the
18:02 as well. And there are, can see them, they're just trying
18:05 point them out. But generally what we want to say is the
18:10 of those ganglia are gonna be All right. So here we have
18:16 that are close to the vertebrae. right. So if they're close to
18:21 vertebrae, that means the preganglionic cell be pretty short. So,
18:27 So I leave the, the spinal and I just travel short distance and
18:31 I'm gonna terminate on my post gang cell, right? So it's a
18:34 one, right? And then what's to end up happening is I'm going
18:38 end up with a very long fiber ends up going to whatever the organ
18:42 for the parasympathetic. It's the I have these very long fibers that
18:46 preganglionic and then there's gonna be a on or near the organ of
18:53 So these, these cartoons are trying say, look, they're very close
18:57 the thing that I'm actually innovating or you don't see anything here, that
19:02 it's actually on or in the organ interest. All right. So the
19:09 of the ganglia are opposites of each and they're dependent upon the length of
19:14 fibers. I have a slide about length here. We're going to get
19:18 that in a second. All Well, where are the cell bodies
19:21 the pre ganglia? All right. , they're located, we talked about
19:25 the thumb thoracic and the lumbar region the sympathetic. So, basically your
19:31 . Well, what about the We said it was located in the
19:35 and in the region. So, your head and your butt. So
19:40 have really opposite direct or really opposite for the parasympathetic and the sympathetic.
19:47 feel like I have skipped something All right. Well, what about
19:52 ? All right. We're gonna start sympathetic. Let's go back to the
19:57 lot when the parking lot situation was on. And you heard that crunching
20:03 on was the response local. In words, did the sympathetic just
20:08 Ok. Uh Heart, I think need to be beating faster. Um
20:13 , yeah, lungs. We want to beat faster as well or was
20:16 just like we're gonna send a general everywhere all over the place? What
20:23 you think? It's more of a message? Right? There's a reason
20:27 this. Ok. It's not Not only because we're sending the signals
20:33 this particular location, but it's reinforced the adrenal gland. All right.
20:38 adrenal module is a modified sympathetic And what it does is when it
20:43 stimulated, when the sympathetic response comes , it releases epinephrine, no ephrine
20:48 into the bloodstream and now you don't a neurotransmitter. Now you have a
20:53 that's literally traveling over your entire And what it's doing is it's saying
20:57 you have the right receptor, then going to respond. All right.
21:03 other words, if you have an receptor, you are going to
21:06 So think about all the things that when you run or when you get
21:09 or when you are in an emergency , your heart is beating faster.
21:14 I mentioned your blood pressure goes your respiratory rate goes up, your
21:19 dilate. Why would my eyes All right. Well, interestingly,
21:25 of the things that it does is allows more light into your eyes.
21:28 you have a clear understanding of the around you. Not so much that
21:31 blinds you, but the idea is where is the danger? And how
21:36 I escape? Right. I I need to sweat. Yeah,
21:43 do. You need to cool yourself because your system is going crazy at
21:47 moment right now. When we talk parasympathetic, we don't see that type
21:53 response. Oh, and the other I'd add here and it's probably on
21:56 next slide is the reason we get mass activation is because there is a
22:01 distribution of fibers. So one preganglionic might terminate on to 20 or more
22:09 fibers with the sympathetic and the para . It's quite the opposite. We
22:14 have one pre gangling fiber going to or two or three and they're very
22:20 . The responses are local responses. don't have an endocrine response like you
22:25 in the sympathetic and it's there to balance out. So when the sympathetic
22:29 this direction, parasympathetic is like, well, this is out of
22:32 So we need to bring it back , into balance. So you don't
22:37 the widespread response for it. It's hit each one as it goes
22:43 Yeah, this is the the thing was describing here, you can see
22:49 long pre gangling on it, post gangling on it, short,
22:52 gangly on it for sympathetic, long gangling on it. Noticed what does
22:56 pre gang leon have that post gangling it doesn't have for both myelin.
23:01 right. So the initial signal is , the rest of it's a little
23:04 slow. All right. And this why I say the number of preganglionic
23:10 . All right, I throw this chart up here just to get if
23:12 want to fill it out, you . So in a very general
23:16 we have a lot of opposites going here. Now, there are some
23:21 where we don't have opposites. So example, in blood vessels, there
23:25 no pre or there is no parasympathetic , it's all sympathetic. So if
23:31 want to vasodilate or vasoconstrict, it on the degree of sympathetic activity,
23:37 . So you can say, I'm always sending a signal, but
23:40 I speed it up, I'm going get vasal constriction. But if I
23:44 down the action potentials then I So there's a tonic response. All
23:50 . But that's the exception to the everywhere else. It's like,
23:54 I'm pressing on my gas, I'm on my brake. What do I
23:57 ? Now? What do I need do if I see a red
23:59 What do I do? I break I see a yellow light? What
24:03 I do? Yeah, see this . We speed up. Ok,
24:10 . Now, with regard to the of the autonomic nervous system, hypothalamus
24:13 king. That is where the master is, but those signals are going
24:19 be relayed through the brain stem. the brain stem is involved and it
24:23 its way down through the spinal So when you're looking at these different
24:26 or you see these nuclei, you'll them localized in the brain stem.
24:30 ultimately, the hypothalamus is determining the . Now, the Poth Theus doesn't
24:37 alone, right? So again, you're watching a scary movie, you
24:42 kind of suspend your disbelief for a while and realize that Jason or Jigsaw
24:46 whoever the scary person is of of the month. You know
24:49 what? Oh my goodness, it's . And so you allow the,
24:52 thrill of the fear, you to kind of control you, but
24:58 also know, well, it's not . So you can also go
25:00 ok. It's like how many of guys like haunted houses? Anyone likes
25:04 go to the haunted houses? You know, haunted houses. Why
25:07 you go? Because you want that of like, but you know that
25:11 person that's, you know, coming you with a knife isn't real and
25:15 gonna be stuck behind whatever that barrier . Although I don't know if you
25:18 saw that story about someone thought it a fake knife there. They thought
25:22 had a fake knife and actually stabbed . It was terrible. It was
25:26 a 12 inch buck knife too and had to stop the show.
25:30 it was just awful. It was two or three years ago and it
25:32 here in Houston. It was someplace . But it was like,
25:35 it was, it was like they went into the belly and it was
25:37 like they didn't realize it. And were like, you know, it
25:42 like someone put it wrong. They didn't know the prop was a real
25:47 , which is a shame. I to be that customer. Yeah.
25:52 right. But anyway, so the is is that you can, your
25:56 can give you a sense of real judgment as to how to respond.
26:01 used to throw a picture up here somebody like in, you know,
26:05 boot camp and he had the drill yelling at a person's face and that
26:08 was just sitting there like blank face stuff. And why, why could
26:12 do this is because they understand that drill sergeant isn't allowed to touch
26:16 But it's still kind of scary, you can kind of sit there and
26:19 knowing that you're not really in Whereas the rest of us, if
26:24 came and yelled in our face, probably be quivering and wondering how do
26:27 get out of this situation? So for the autonomic nervous system,
26:32 you OK? Does it make Gas and gas and break sympathetic first
26:41 , fight or flight? Ok. also know your charts. Just remember
26:45 versus post. Where are the What does a what does colergic
26:53 How bad was that? 26 She never said shut up. All
26:59 . OK. I'm all right. doing good. We got a lot
27:02 cover here. All right. So we want to do is for the
27:05 couple of lectures, what we're gonna covering is we're looking at the
27:09 So the information coming in. So already kind of described, we said
27:13 central nervous system, it processes a peripheral nervous system, it sends
27:18 in, pulls information out. So we want to do is we want
27:20 look at what kind of information comes . And so that's kind of what
27:24 crux of the next couple of lectures And so first off what we're really
27:28 with here is a processing of So the receptor is the thing that's
27:32 for or receiving a stimulus. And what is a stimulus is basically some
27:37 of sensory input? Right? It's internal or external. So like if
27:41 looking at this room right now, see the bright light that is a
27:45 of stimuli, it's, you it's light energy that we're detecting,
27:49 ? But in our bodies, we have receptors for say chemicals, like
27:53 simply just say salt. And so bodies are measuring osmolarity and trying to
27:58 how much salt is in our how much water is in our body
28:02 we have enough? So this is type of thing we're talking about is
28:06 are detecting some modality and then they're to be sending that information up to
28:12 CNS. So the CNS can determine to do with that information. Your
28:17 to understand a stimulus is called a . So that's your conscious awareness of
28:23 stimuli. So if we looked at room again, we'd say,
28:26 this room is bright, right? know that's relative. If we turn
28:31 all the lights, the room would dark, right? Again,
28:37 Because we perceive we understand so that is going to our conscious awareness,
28:43 means that it's going to the cortex we're processing that so that we are
28:48 aware of that information, not all are we consciously aware of, who
28:54 tell me right now what your internal is? That's the number. But
28:59 mean, are, are you Are you dehydrated? I mean,
29:04 can become aware of the consequences of ? For example, if you are
29:09 , that is an example of being and your body letting you know you
29:13 to put water in me, But you couldn't tell me at any
29:16 moment what your osmolarity is. So is no conscious awareness of all stimuli
29:22 there's all sorts of stimuli, there's all sorts of different types of,
29:28 things out there that our body can't or even understand. And I used
29:33 just throw this philosophical question is is the world that we know,
29:37 it reality? You know, and you know, you can argue and
29:41 OK, this is stupid. But a from a biological standpoint, the
29:45 is no, I mean, let just ask this question. Anyone
29:49 are anyone here in this room able detect radio waves? No, but
29:55 exist, don't they? Right? can create machines that can actually capture
30:00 and produce sound for us, Or even TV. Waves, which
30:04 again a type of radio wave or , let's make it, let's put
30:08 the realm of real reality. I , how about um ultraviolet light infrared
30:15 there in the spectrum right next to wavelength, but I can't detect
30:21 But bees can and with regard to , I can't detect infrared but uh
30:28 vipers can they have organs that do , right. So receptor has a
30:36 or modality of being able to recognize things that um that are going on
30:43 the world around us. Right? there is things beyond our conscious awareness
30:51 is kind of interesting but also kind spooky. Maybe, I don't
30:57 The idea here is if we don't it, does it exist? And
31:01 think the answer is clearly it does . Not, not all things.
31:06 mean, I'm still wondering about this alien thing that we keep talking
31:11 So what are receptors? What are doing? Well, what they're doing
31:15 they're transducers. And what that means that they take an energy form and
31:19 convert it into the language of the system. And the language of the
31:24 system is graded potentials and ultimately action , right? And so it's the
31:29 of those action potentials. It's just what a computer does a computer takes
31:33 and converts it into some sort of , either it's a bit code or
31:38 might be even more complex language so the computer can understand it. So
31:42 fact that Siri can understand what you're or Alexa can understand what you're saying
31:46 because it takes those sound waves and it into the language of Alexa or
31:51 and then Siri then processes that and comes up with an answer and then
31:55 that answer back into something that we . So the potential that we're talking
32:02 here, the change is from whatever modality is to that receptor potential,
32:07 a greater potential that ultimately can become action potential. So the purpose of
32:12 receptor that is to first establish and a resting membrane potential. So every
32:17 that has receptors has some sort of point and then what you're going to
32:22 is you're going to be able to that resting membrane potential into some sort
32:27 activity. All right. So you some sort of gated channel that allows
32:32 to detect this whatever that thing So there's a whole bunch of different
32:35 of receptors and this is not a list by any means. All
32:39 So, but it's, it's one covers most of the stuff that you'll
32:42 , right. We have chemo they have specific channels that are responsive
32:47 specific chemicals, mechanical receptors. When manipulate cells and twist and turn
32:53 you're going to manipulate the channels that in the plasma membrane. And so
32:57 is what you're detecting is the maneuvering the manipulation of the channel thermo
33:03 they change shape in response to changes temperature photoreceptors. Well, they're detecting
33:10 wavelengths of, of, of I I have visible wavelengths, but it's
33:15 things on the radio spectrum, So the idea is is when you
33:22 your radio spectrum is basically this wide of, of waves, right,
33:27 include the visible wavelength, but it x-rays and radio waves and all sorts
33:31 fun stuff. So we're able to a narrow band in that broader uh
33:38 of energy Osma receptors. Again, concentrations of solute no c acceptor,
33:45 is the fun one, these are receptors. We'll talk about those a
33:48 bit, they detect damage to So they kind of fall into different
33:54 in terms of the modalities, they some of the sensations you have are
34:02 the result of a single receptor. the example I use here and I'm
34:05 there are others. But this is one that I've stored in my memory
34:09 is wetness, right? When something on you that feels wet, it's
34:13 that you have a wetness receptor. have touch receptors, a pressure receptor
34:18 a thermal receptor. And it's a of all these three signals that tell
34:22 body, oh you have water on skin or whatever, that's what wetness
34:28 . So, sensations are not just from a receptor. It's a combination
34:32 information that's coming in. This is I'm going to get at. So
34:37 is where it gets dangerous for me we're going to talk about two different
34:40 of receptors today, these are both receptors. And we're going to talk
34:45 two of the special senses. We're to talk about gustation and we're going
34:49 talk about olfaction and then hopefully we'll on to the sense of touch and
34:53 no section as well. But the here is I like food a lot
35:03 course. So the answer to that yes. Any time you stimulate a
35:17 , you're, you're basically producing some of greater potential. The truth is
35:21 that a greater potentials remember have different . So sometimes if it might be
35:26 the magnitude is so great that it results immediately in an action potential.
35:31 it's again, it's a nuanced I mean, depending on which system
35:35 looking in. All right. So and olfaction are both systems that use
35:44 . All right. Do you guys eat lunch today? No.
35:50 I'm so sorry because today I'm gonna about food and in order to talk
35:56 food in this sense of taste, need to have something big. So
36:01 want you to think about a big cheeseburger. If you're a vegetarian,
36:06 it into a tofu burger, I care. All right, just make
36:11 big and make it yummy. What all the different parts of a
36:16 We have, we have a So we have carbon there,
36:19 We have some meat. So we protein in there. If it's good
36:23 , it will have some fats as . Right. And if it came
36:26 a cow or a plant, it DNA and RN A in there as
36:29 . Ok. Burger is not enough me though. I don't know about
36:34 . I always have to have a with my burger. What do I
36:36 to have on the side of my ? I don't know which restaurant you
36:42 to, but no, I need . Now. Some of you want
36:48 sweet potato fries? That's fine. want my good old fashioned russets.
36:52 . I want them nice and big lots of them and you know,
36:57 a glutton so I like to have and probably chili on top of mine
37:02 far, so good. But that's not enough. I need a big
37:05 milkshake too. I'm gonna go for chocolate. All right. Does that
37:11 good? 44 ounces? Why Ok. At my age?
37:19 but at your age. Yes. . Now, what I bring all
37:24 stuff up for is I'm actually probably off the rails here, but we're
37:27 to come back to this meal when talk about digestion because it covers all
37:31 different parts of a meal. But I want to bring up here is
37:34 you can see there are a lot different types of molecules in the food
37:36 we need to know whether or not food that we're putting in our body
37:40 us the materials we need in order survive. That's really what taste is
37:44 about. Ok. So the sense taste is to determine whether or not
37:48 food you have has all the right that your body is seeking.
37:52 we know how to circumvent that. is why Cheetos and Doritos taste
37:56 right? We can put other chemicals there that make our brain think that
37:59 is going on. But that's kind how our body works. And then
38:02 it's missing the chemical, it says hungry again. So then you go
38:05 to the bag of Cheetos or Doritos you keep eating the same thing over
38:08 over again. All right. So purpose of our gustatory system is to
38:14 the contents of the food and the that we're eating. You'll also note
38:18 when you eat that, your sense smell, olfaction plays a major role
38:23 you actually appreciating the meal. Have noticed that when you're sick, food
38:28 taste good with you all topped Nothing tastes good because you can't smell
38:33 . It's just the stupid taste buds it's not all the olfactory stuff that's
38:37 your nose. All right. So do we have as far as the
38:43 system is concerned, your homework apart from whatever it is that you
38:47 to do that I make you do night, right. Reading whatever I
38:51 you to go look in the mirror I want you to take a look
38:53 your tongue, go and look at tongue closely or if you have a
38:56 friend who will let you do that you can stand their breath. That
39:00 also. All right. But I you to look closely at their
39:03 You'll notice that there's a whole bunch bumps on your tongue. All
39:06 These are called the pail. All . And there's different types of pali
39:10 we're not going to go through them . But there are two major types
39:14 you're probably concerned with. The papilla are rough that we have no
39:18 And then if you notice there'll be tiny bumps. Does this one show
39:21 there together? It's a terrible But they're like, oh,
39:24 there's little tiny bumps and these little bumps are the types of Popil called
39:30 pali. Fungiform fungi sounds like which is referring to mushrooms. They
39:37 like a little tiny button mushrooms on tongue and you'll notice that they're scattered
39:40 over. There's about 300 of them your tongue and they're obvious once you
39:44 them, you're like, oh, kind of like freckles. They're
39:47 right? Every now and then you have noticed that you'll get one that
39:50 of stands up and it's the one you can flick with your teeth and
39:52 hurts. It's like, oh, . Yeah. Yeah. You've done
39:56 . Ok. That's fungi. Form you can see in a little cartoon
39:59 , there's others, there's, there's group of them that kind of sit
40:02 here on the side. They're called foliate. Um, they're not particularly
40:06 in adults. They're more active in . That's why kids put everything in
40:09 mouth to kind of taste their to kind of learn about it.
40:12 then we have this really weird group them that are called the circum
40:15 You won't see them unless you can like cut the frum of the tongue
40:19 then like pull your friend's tongue you know, because it sits like
40:22 about here, it divides the front thirds of the tongue from the back
40:26 of the tongue. Notice those right? But they form this large
40:31 and there were these really, really structures and they kind of serve as
40:36 that barrier. So like when you that really nasty flavor in the back
40:39 your throat and you're like, it's that you're, you're stuck with because
40:43 the like the last thing that tastes . But generally speaking, these structures
40:49 where you're going to find the taste . And this, this picture is
40:51 to show you where the taste buds roughly located for these different types of
40:56 . And remember there's another type that's on your tongue. And what they
40:59 is they basically serve the scrape and on the food So, like,
41:03 about an ice cream cone when you an ice cream cone, ice cream
41:07 off the cone because you have a tongue. All right, they don't
41:11 taste buds. So almost 80% 90% the pail are these rough fingerlike
41:18 Yeah. They have really, really ones and they use that to lick
41:21 and water. No, that's just , it's there because, and look
41:27 dogs, dogs have the same type tongue. So do cows. They
41:30 rough tongues. The reason is they these long papilla so that when they
41:33 , they're not, they don't like do, we create a vacuum to
41:37 food in and water in. They to go right. And they use
41:42 . So just like us when we an ice cream cream, that's why
41:44 think about licking an ice cream cone the ice cream, if it was
41:47 smooth tongue, it would just be ice cream all over the surface of
41:52 . But the, the scoop I to think of the word. All
41:56 . Now, notice the shape. is what a tastebuds looks like.
41:59 right. What does it look like you? It looks like an
42:02 You see, uh notice this because will come up again. Here.
42:06 can see that there's a small opening a pour. And from that
42:11 you have a little tiny cylia sticking from the surface of each of those
42:14 and each of these represent the different of taste or taste receptor cells.
42:19 right. And there are four different and we'll get to those. So
42:21 are also referred to as gustatory All right. So the statutory cells
42:26 grouped in a taste bud. They exposed to the external environment by their
42:31 surface with these little tiny SIA. the silly is just basically taken that
42:35 surface. So yet you have a surface area. Here's another terrible cartoon
42:40 you roughly that same sort of thing to demonstrate the four different types of
42:45 . Now what we have here, is a specialized neuroepithelium, meaning it
42:50 epithelial in nature, but it is from the neural tissue. These cells
42:55 be damaged and they can be replaced they can be replaced roughly every 10
42:59 . You ever had a Starbucks coffee you forgot that you were drinking Starbucks
43:02 at 180 degrees, right? You your tongue and what happens? You
43:09 taste anything for about a week. tastes like pennies and then all of
43:14 sudden it's like, oh things taste again. It's because those cells that
43:18 damaged were replaced. And then what can see here, there's a varying
43:23 of cells in there and they have , what see, what am I
43:26 ? Oh yeah. Uh this would the dendritic side. So this is
43:30 the receptors are primarily located out here to feel the stuff or trying to
43:35 uh input from the saliva containing all little molecules that you've eaten. All
43:41 . So the four different types, have type one, type 23 and
43:44 , the four are the least They give rise to the other
43:48 So this the stem cell, all , the type ones respond to sodium
43:56 . So basically when sodium um is the, uh we'll get to that
44:00 just a second, I'll just show these, the type two, these
44:04 the weird ones. They all have protein couple receptors, they cover the
44:08 , they detect sweet, they detect , they detect bitter. All
44:13 And then lastly, the type they detect sour. Now when I
44:17 in your seats, which was like when the dinosaurs were on the
44:22 when the Egyptians were still building, the pyramids, there were only four
44:26 tastes sweet and sour, right? then we had bitter and then we
44:35 what would be the other one? blanking right now. Salty. That
44:41 . All right. Those were the flavors. We now have five in
44:47 couple of years. We'll probably have , and I'm not making that
44:53 I'll show you here in just a . Am I going? All
44:56 Does this taste? Ok. All . I'll pick it up.
45:00 Salty. All right. Detect the of sodium through sodium channels.
45:06 here you go, these are the , the enac receptors. I'm just
45:09 to show you what is salty just case you don't know. All
45:13 sour what we have here is we something that recognizes free protons and what
45:20 doing is it's blocking a channel, potassium channel. So the cells are
45:25 becoming hyper polarized. And so when proton comes along, it causes the
45:31 to close and so the cell begins depolarize. All right, don't worry
45:37 the actual receptor name here. All . Think of things that are
45:42 What are things that are sour Something sour that you eat sour patch
45:46 , everyone does that or the atomic because that's what students eat. No
45:50 eats lemons or limes. No one pickles. Uh, but it's the
45:56 chemical, what chemicals are used in patch kids used in uh atomic warheads
46:03 in pickles, acetic acid or right? So, acetic acid.
46:10 right. Here's the easy one. you're talking about lemons lines,
46:14 what is the thing that makes it ? Citric acid, notice protons.
46:21 you just got to remember if it dissociate a proton. It's gonna be
46:25 proton is now capable of giving you sour flavor. All right. So
46:31 what that, that's what we're looking here. Those are the type
46:33 So the ones and the three is straightforward. The type two is,
46:36 is where it gets all crazy. right. So sweet. What we're
46:41 is we're detecting a shape of The type of receptor here is a
46:44 protein coupled receptor. It's called the shaper, uh or it's called a
46:47 trapper uh G protein coupled receptor because looks like a Venus fly trap under
46:52 uh not under the microscope but uh ball and stick model, right?
46:58 , what we're doing is we're detecting that looks like glucose. So can
47:02 picture what glucose looks in your You've all done bio two or bio
47:07 and bio two. Some of you done biochemistry. Can you picture the
47:12 molecule? OK. So there are molecules that look like glucose. There
47:19 well, yeah, I mean, got the other sugars, the other
47:22 sugars look like them. They're not they're not exactly like glucose but
47:26 they're kind of like it. So is kind of sweet. All
47:32 Have you guys ever had? I don't know a sugar substitute as
47:38 . Yeah. No, sucrose, ? Which is now linked to mutations
47:42 the DNA. It's like gray. you. Not doing the yellow packets
47:47 . All right. But let's do team real quick. What does Asper
47:49 anyone know? Say again, it an artificial sweetener. But do you
47:55 what its chemical chemical composition is? a dipeptide. It's two amino
48:02 Asper or it's a it's not it's aspartic acid and I never can
48:06 what the second one is. You look it up real quick.
48:09 you see, and if you look it, you'll see that there is
48:11 ring on there that looks like That's why Asper is, or Asper
48:15 sweet. It's because it looks like and all the other ones clos is
48:20 sugarless and just add an X or hydroxyl group on it. Can't digest
48:24 , but it sure does taste All right. Umami. This did
48:29 exist when I, I mean it but we didn't, we didn't name
48:33 . When I first started teaching this , I pronounced this word. Anyone
48:36 speak Japanese. No. So when I said it the first time
48:42 called it Y mami, I'll say again. I called it your mommy
48:53 . Now, you'll never forget All right. It's umami. All
48:56 . And it means savory. So have things that are savory if you
49:01 like me, find your other savory . All right. Again, it
49:05 for a G protein coupled receptor. then we have this class of
49:10 The bitters here, we have a of different receptors. They're all still
49:13 type two cells, they still use protein coupled receptors. But bitter is
49:19 , very interesting. It's very unique I'm just gonna point out so we
49:23 , you know, a whole bunch different types of receptors that take different
49:26 of bitters. So I try to out a couple of things that are
49:29 that humans like to eat. what's this? Where does it come
49:34 ? Cocoa? Ok. What are ? Ok. It's a member of
49:39 Nebraska family. Anyone here like, mean, really like Brussels sprouts?
49:44 can always find one or two. . Brussels sprouts actually taste better now
49:48 they've been able to cross breed them create an actual flavorful one. But
49:52 the longest time, it basically tasted dirt. And then we dave down
49:56 . What are this? What's this ? You said that like a
50:01 That's that you're, you're, you're messing with me now. Is it
50:05 ? I could not, I don't . I've never seen something like
50:08 What could possibly have a large foamy ? All right. So we got
50:15 when we're talking about beer with Where does that bitter flavor come
50:20 Do anyone know? No, that's good guess though. Well, let's
50:27 with the IP. What makes an a bitter? We don't know.
50:34 right. Now it's your lesson to . Beer. Beer is made from
50:39 things, water malt, which is some sort of grain that has
50:46 um, processed by a microorganism. microorganism we use is yeast and then
50:52 serve as a preservative, we throw another chemical or not a chemical,
50:58 item which is hops and it's to different degree of hops give rise to
51:02 degrees of bitterness. Anyone know what is based on what you see up
51:08 ? What would be a common Where does cocoa come from?
51:13 I heard a plant comes from the , treat the bean of the cocoa
51:19 . All right. And then Brussels are a form of mustard,
51:26 That's the brassica family. So, you don't brassica, that's broccoli,
51:30 . Brussels sprouts. You're saying, it up. It's much more fun
51:34 way. Yeah, I'm, I'm setting you up. Thank you for
51:38 me up though. All right. anyway, so hops is a
51:42 It's a flower from a, a . And so each of these things
51:46 mech mechanisms just like the nicotine and . They produce chemicals that tell other
51:53 not to eat it yet. We it tasty and yummy. If you
51:58 cocoa to a dog, what They die. Oh, don't give
52:03 to a dog then. All So, ska, what's it
52:07 You don't eat me. Yes, like it. But you give it
52:13 AAA certain other animals like moths and , they die. Mustard is
52:20 It's a poison for many other And then hops is, again,
52:24 just a chemical that's in that flower says don't eat meat. It serves
52:28 a preservative. The reason IP A are highly hopped is because you're taking
52:32 that you're making in England, putting on a boat in it and you're
52:35 it around the coast of Africa over India and it showed up and it
52:39 going to spoil you hopped it. . Just trying to show you here
52:47 we've only recently discovered the receptors. right. So this shows you when
52:52 of these receptors were most recently discovered , we've known salty since the dawn
52:58 time, but the receptor was only 14 years ago. Yeah, I
53:04 other taste receptors. Are we limited these five? Obviously? Not?
53:09 right. Um If you've ever enjoyed soda and you're like, man,
53:14 like soda. I like the way feels. That's actually there's uh receptors
53:18 your mouth that actually detect the presence carbon dioxide. And that's usually done
53:22 microorganism is a byproduct of their metabolism carbon dioxide. So spoiled foods are
53:27 be fizzy. And if you're putting in your mouth and it feels tingling
53:32 your mouth, it's probably gone bad as a general rule. But for
53:36 reason, we like sodas, Car receptors. So that might be
53:42 taste in the future, considered You guys like eating cheese.
53:47 cheese, good fats, good. body actually prefers fats for fuel,
53:52 ? We have fatty receptors. They exist. All right. And they're
53:57 on type one cells. So a of years these will be in the
54:02 . So there's just an example, , last thing, uh for this
54:06 , since I'm supposed to speed up , um, you're gonna hear or
54:11 , I've actually gone to conferences where have argued with me about this.
54:15 the there is what is called the Bud map. And so you'll see
54:18 like what you see down below what already Xed out and he says,
54:22 , you get a sense of salty , a sense of bitter here,
54:25 sense of sweet here and so and forth. And this is all based
54:29 a misinterpretation of the original paper where identified the location of the taste
54:33 So if you look at this notice where the locations are, look
54:36 the top, you see it like the uh uh the superior or the
54:41 the anterior surface of the tongue, ? You can see over here
54:45 over on the sides and then you see way back in the back.
54:49 if you go back and look at taste bud map that I showed you
54:51 , the the presence of fungi forms presence of the foliate and the presence
54:55 the circum vals, right? So where the taste buds are located.
54:59 notice that in the bottom one, they did was when this guy discovered
55:04 these things were located, they misinterpreted said, oh, we have different
55:08 buds located in different locations rather oh, they're all located equally in
55:13 different areas. All the same taste are located in the or the same
55:17 taste receptor cells are located in taste . The upper map is more accurate
55:23 you can test this yourself if you to see, go get something that
55:26 a lot of dimension to it. sour salty, all that and roll
55:30 around your mouth and see if it flavors. It doesn't, it's the
55:34 flavor no matter where you roll it ? Action, I'm going as fast
55:42 I can. I promise this is sense of smell. Again.
55:46 we're detecting airborne chemicals. When we're food in our mouth, we're detecting
55:51 in solute or in solution. The being the solution, it allows us
55:56 sample our environment for things like think of barbecue in the springtime or
56:01 the fall. It doesn't matter of anywhere. It's just good identifying other
56:07 . Have you noticed that the people you are close to actually have a
56:10 smell and you can identify it. might be a false smell like they
56:14 a perfume or a clone on or have a specific soap that they
56:18 But that's one way that you can somebody ladies. Your sense of smell
56:23 a million times proven, a million greater than men. You will be
56:28 to recognize the smell of your Children they're newborns and for about four or
56:34 months, maybe six months after you can kind of get used to
56:38 and then they start stinking when they teenagers. I'm not exaggerating about
56:43 You can, moms can detect if is their baby or not. So
56:48 can use it as a way to each other and then danger. Like
56:51 many of you guys have pulled that out? You know, the one
56:53 you found in the back of the ? And you're like, all
57:03 now, if it's danger or ok. Now, in saying all
57:07 , we have a very powerful olfactory , but clearly, we do not
57:12 the most powerful. I mean, already know about dogs. Other animals
57:16 a much more uh sensitive or developed system than we do. We have
57:23 4 to 6000 different types of receptors are located in our olfactory epithelium.
57:28 right. So we can detect about to 6000 different chemicals or near 4
57:34 6000 different chemicals to understand where we . This is a cross section through
57:40 nasal cavity. You can see there's na where we're looking is right up
57:44 at the very, very tip That is where the Olfactory Epithelium is
57:48 . Think about when you smell something , you're walking along campus, you
57:52 that barbecue and what do you You pull in and up and what
57:56 doing is when you normally breathe your stays rather low in the nasal
58:01 it just kind of goes right around . But when you breathe in,
58:04 pushing it upward and along the outside of the nasal cavity, you have
58:08 are called the turbinates. All What are called the nasal concha?
58:13 right. So these are bone structures what it does is that when the
58:16 rolls over or goes over them, way that they're shaped, it causes
58:19 air to move in a t a fashion. So you get more air
58:26 instead of just a linear flow. so that exposes more particles that happen
58:32 be in the air to that olfactory . In that epithelium, we have
58:36 types of cells of interest, olfactory cells. These are the neural cells
58:40 are responsible for detecting odors near them the support cells. They produce
58:46 right? They are the ones that provide nutrients and materials for the olfactory
58:51 cells. And then they have cells we refer to as basal cells use
58:54 neural stem cells. They can be and become either a supporting cell or
59:00 olfactory receptor cell depending upon need and regenerate these and replace them roughly every
59:05 months. So again, here's another of a neuron that actually is capable
59:09 replacing itself. There are also factory that produce mucus, but they're not
59:13 shown in either of these pictures. is a cartoon where you kind of
59:18 a better view of this. You see here's sport cell here, you
59:22 see the olfactory receptor cell, there's , the the basal cell or stem
59:28 . And you can kind of see you look at that olfactory receptor
59:31 It also has a shape that looks of like an onion. It's just
59:33 different type of onion, a green , right? So I always just
59:38 of associate my chemical receptors look like . All right. Now, what's
59:43 about this? This is a type bipolar cell. There's two bipolar cells
59:46 stand out in the body. This one of them in the eye.
59:49 have the other one in the It's called the bipolar cell. It's
59:52 pretty easy to recognize what it And you can see we have receiving
59:58 , this would be the dendritic side then here's the cell body and up
60:01 axon it goes on the receiving on that dendrite, you'll see extensions
60:07 it's basically an extension of the So it kind of looks like the
60:10 of that green onion, right? it's here where you're gonna find the
60:15 for this particular cell. And each receptor cell only has one type
60:22 of these types of receptors. So there are 4000 different receptors that you
60:26 have, that one cell only has of them and they have thousands upon
60:31 of these cells. So you might many cells with the same receptor.
60:34 that allows you to kind of spread wealth a little bit. All
60:39 Now, this one cell can only it has this one receptor can only
60:45 one type of chemical. And then it's stimulated, that fiber will become
60:51 , send the signal up its And you can see here a series
60:55 axons are going to come and join and this is what forms the olfactory
60:59 . So this is cranial nerve number . Now notice I set a plural
61:04 when you see pictures of this, is kind of what it looks like
61:08 can see and everyone kind of points this and says, oh look,
61:10 the olfactory bulb. That's Randal Number one, it is not the
61:14 nerves are the brushes on the Do you see the toothbrush there?
61:19 the bristles of the toothbrush are the nerves. That's your cranial nerve
61:24 plural olfactory nerve number one. So receptor responds to a discrete molecule.
61:31 are thousands of these receptor cells and cells, there can be more than
61:36 cell that detects the same receptor but 11 cell can only detect one type
61:42 of chemical I said detect receptors but think you got it. So what's
61:48 odor? What are the things that detecting first off? I want you
61:52 look at this upper picture. What you see what do you notice about
61:54 picture? Who's doing the stiffing Why they smell better? All
62:06 They don't have a better odor, I'd agree that they do that
62:10 But here they have a better sense smell. Ok. This is actually
62:15 they detect whether or not deodorants This is a professional sniffer. I
62:19 know how much they make, but probably make more than me because that's
62:23 . And who wants to do So second picture from the, one
62:31 the best shows that was ever produced least the first nine seasons after
62:34 it turned into garbage. But what have here is we have mo looking
62:37 a picture of a, that a drew of him and you can see
62:40 it's a very classic picture of showing who stinks. What do stinky people
62:46 ? They have molecules of stink moving from them. So when you talk
62:50 an odor, an odor must be , volatile, doesn't mean it
62:55 Volatile means it becomes um uh it's molecule that becomes um able to move
63:03 um aerosol, right? It's able move in the environment. So if
63:08 took a drop, for example, perfume and put it on here,
63:12 would actually evaporate and start moving away then eventually you guys would smell as
63:18 diffuses throughout the room. All But for example, you can't smell
63:23 desk itself because the desk doesn't right. So, characteristics of an
63:31 , it must be volatile, the that make up a smell. There's
63:36 more, there's not one, there's ones. These are called odorant.
63:40 , odorant are volatile odorant are going be water soluble. And the reason
63:43 need to be water soluble is they to make it their way through the
63:46 mucus is water plus a bunch of called mucin. And so if you
63:50 work your way through that, that , you can find that receptor and
63:55 to it. Now, we've already about deep breathing, the odorant themselves
64:01 going to diffuse through the mucus. if you breathe that in and bring
64:04 up, that odorant is gonna get there and it's going to get in
64:07 mucus and it's gonna to work its through it. What's interesting is there
64:11 proteins found in that mucus that are of binding odorant and actually chaperoning those
64:17 odorant to the right receptors, which kind of really cool if you think
64:21 it and there's actually a massive organization this whole system that we're just
64:27 Now, this is what the transduction looks like. And when you look
64:32 that, you should immediately see. , that's recognizable. I see exactly
64:36 you're talking about. All right, got our receptor, we got a
64:39 protein and we have some sort of that's producing cyclic K MP that cyclic
64:45 P is second messenger. It's binding a channel that allows ions to pass
64:49 , it causes the cell to So all I need is the right
64:52 to cause the cell to polarize that to polarize, send the signal right
64:55 up and into the olfactory bulb. it's a signaling cascade that you've already
65:01 about. And as I said, are 4 to 5000 different receptors.
65:06 you just learned 4 to 5000 different of G protein coupled receptors. The
65:13 when you get up to the olfactory , this is the first place that
65:18 of the sense of smell takes So the olfactory bulb consists of a
65:23 of secondary neurons that are joining up those axons from the olfactory receptor
65:28 And they form these round structures called . All right. And so this
65:34 where the primary neuron, that's the receptor cell is terminating on a secondary
65:39 and they're deciding what sort of information to go on up to the olfactory
65:45 . So, weak signals are not to be distributed forward. Strong signals
65:48 going to be moved forward. There's 2000 different glome lines. So what
65:53 is trying to show you is like is my mitral cell or tough
65:58 Here is the yellow, those are olfactory receptor cells. And so you
66:02 see, I've got different cells joining and moving into a specific glomeruli So
66:08 glomeruli is responsible for a specific smell . If that makes sense for a
66:13 odorant. And so whichever ones are activated, then that signal gets moved
66:19 . And from what it's going to is it's going to move along from
66:21 olfactory bulb along the olfactory track. going to work its way up into
66:26 primary olfactory cortex where your brain is to say, oh, what you
66:29 smelling is blank, right? It's to go to the hypothalamus in the
66:36 , the limbic system. What is limbic system for? He's like
66:42 I gotta go look that up for . So when you smell that burger
66:47 I just brought out, right? the burger shows up and it's sitting
66:50 the table and you take that big , what are you gonna do?
66:54 gonna go hm. Happy. All . It is one of the only
67:02 the sense of smell does not project the thalamus. I don't know why
67:06 just doesn't. So we've already mentioned all factor receptors have um will have
67:16 one type of, of, of that they're able to detect. So
67:19 if you're looking here, we're just a three model system. So we
67:23 recognize uh we're gonna use Sonic Is that ok? So green is
67:28 , red, cherry blue is That, that work. No,
67:33 doesn't. Ok. So you can the red ones. These are all
67:37 ones, if, if I'm drinking or smelling something that's cherry, it's
67:41 drinking, smelling something cherry, then going to activate all the red
67:43 I'm going to activate the glomeruli. is the cherry glomeruli. The signal
67:47 up to the olfactory cortex via those neurons. And then my brain
67:52 hm, you're smelling cherry, If the red ones are all being
67:58 , but some of the green ones , then I'm going, oh,
68:01 gonna get two signals. So it , oh, this must be cherry
68:05 . You see how that kind of ? OK. So it's the mitral
68:10 here in the second or the second neurons in the glomery li that are
68:14 whether or not a signal gets to forward. So if there's a little
68:16 of blue coconut and it's not enough really kind of activate the mitral
68:20 then that signal gets suppressed here. so you're actually doing the preprocessing before
68:26 brain ever gets the opportunity to know all the signals are. Is this
68:34 scary looking chart? It shouldn't Yeah, you got a question.
68:38 ahead. The question is how do mitr cells do what they do?
68:48 the answer is, is uh the here is that yes, there is
68:51 of a threshold. Um It's not an actual potential threshold here. What
68:55 is, it's a degree of So uh we talked a little bit
69:00 lateral inhibition, right. And so idea is that you'll have cells that
69:05 sending signals across glomeruli. And so may actually suppress signals or uh or
69:11 signals. So that's why you kind get that, that more of that
69:14 before it ever goes forward. And this does is it frees up your
69:18 from having to do all the processing your eyes do the same thing.
69:22 We take everything that we look at we break it down into its component
69:27 and then that is preprocessing before it gets to our brain. And then
69:31 it's those component parts are sent, get processed independently and then all that
69:34 is brought back together and, and so that you understand what's going
69:39 So the sense of smell is kind the same way and what this graph
69:43 trying to show you is a little of how this works. So
69:47 we're going to keep it a simple . We have five different types of
69:51 . We're going to say we what is that? Eight,
69:53 seven different odorant over there. And this those balls represent is the degree
69:58 stimulation that each of those receptors, they respond to that particular odorant.
70:05 right. So the big ball, example, we're just going to use
70:09 , this big one right here. almost 100%. So, odorant B
70:14 stimulates activates this to 100% of Whereas odorant B only acts activates this
70:22 let what make up a number 50% ? But it's activating both of them
70:26 the same time, isn't it? , when odorant B is around,
70:30 stimulating red and blue, but not . And so both those signals are
70:35 sent up via to uh you up to the glome where it's processed
70:41 then the brain takes that, that and then it takes that pattern and
70:46 when you smell blank, then this the pattern you see and we said
70:51 an odor is not just one it's many odorant. Think about an
70:55 file. You know, an neile see, you're learning all sorts of
70:59 today. No, I'm I'm I'm . I know, I know I
71:02 it was like 2 10, 28 it's just like uh you are reminding
71:06 it's good. And in a file someone who enjoys wine and what do
71:16 ? Yeah, come up with all different flavors. All right.
71:20 Current hints of chocolate mouse, which a flavor and you don't want that
71:28 ? But the idea here is I'm releasing those odorant. I'm pulling
71:33 up and I'm activating the receptors with different odorant, getting different combinations.
71:39 then the brain is saying what you perceiving is this particular smell. Have
71:45 noticed that fake strawberry smells a lot real strawberry but not quite it's activating
71:52 receptors, right. So that's why get that pattern. All right.
71:57 it's the pattern of the glomeruli and degree of stimulation along all 4000 of
72:04 plus receptors that give you a sense what it is that you're smelling.
72:10 , it's a pretty complicated system. I think kind of straight forward if
72:16 get the gist. All right. to 5 minutes here, we'll see
72:24 we're gonna do. OK. Are questions about gustation or olfaction? Are
72:31 regretting that she didn't eat lunch? had a question? Yeah, go
72:38 . I, so the answer to is we believe there are. So
72:42 have been taste receptor cells located to gut. There are taste receptor cells
72:47 along the esophagus. And so what purpose is is we don't know because
72:52 don't go to the gustatory cortex instead are receptors that recognize these molecules.
72:59 so that means they serve a purpose something and the likelihood is that they're
73:04 to tell you like in the it's to let you know that something
73:07 or dangerous is going down the throat the stomach. It's probably telling you
73:10 presence of peptides or uh specific peptides specific uh molecules in terms of the
73:17 that you're receiving. But I've only one or two papers on this over
73:22 course of me looking at stuff and of the stuff you pull from a
73:26 . But I was like, I wonder and I looked it up
73:28 , yeah, they are. But one has really kind of said this
73:32 why they exist. Kind of Yeah. Uh-huh. Anyone else?
73:39 . All right. Let's deal with question real quick with regard to a
73:45 . We have receptors that can adapt a response and we've already talked a
73:49 bit about adaptation. All right. basically what we do is we can
73:53 at a receptor and say, if going to classify receptor, I want
73:55 know what type of ability does it to adapt. And then we can
73:58 it's either a slow adapting or a receptor or it is a fast adapting
74:02 a phasic receptor. And so the that you can think about this in
74:07 , really simple terms is that a receptor is one that's telling you about
74:12 over time, right? So for , when you're sitting upright and this
74:16 not an example of a receptor, is just an example of how it
74:20 be working, right? Is that you're sitting upright, your body wants
74:24 know that you're in an upright And if you start leaning far forward
74:28 backwards, that you can actually topple , so you need to know the
74:33 of those muscles and the contraction of muscles at all times. So,
74:37 receptor that would be tonic would be that's constantly sending a signal to the
74:42 saying this is what's going on. when changes occur, then you're going
74:46 see changes in that receptor right in and how it's activated. That's what
74:52 thing is trying to show you right? If you look at the
74:56 , you read this in a binary . So here is off up here
74:59 would be on. So it's on off and you can see there's no
75:03 and then all of a sudden there a stimulus for a period of time
75:06 then there's no stimulus again. And it's saying here is a receptor
75:10 So you, it results in a of action potentials that are formed over
75:14 whole time that stimulus took place. when stimulation is taking place, you're
75:19 signals with regard to a phasic, not so much what is going on
75:24 terms of the stimulus, it's the that you're trying to get answered is
75:27 is the stimulation stimulation occurring? So did it start? And when did
75:31 stop? And so these are the that are adapting quickly. So you're
75:35 getting constant signal, you only get signal when there's change that takes
75:39 So again, you look at it , here is stimulus off, then
75:42 on, then time happens and you back to the opposition. And so
75:46 regard to the receptor potentials, you see I get a potential that change
75:50 it on and then I get another . When it's off, I got
75:55 while it's going on. In other , it adapted to that signal and
75:58 , I'm not going to send a . It's not necessary. So here's
76:01 I'm getting all those action potentials is the on and the off position.
76:05 , where would be a good example this? All right, up until
76:09 finish this sentence, you probably didn't the clothes touching your body. Now
76:15 I pointed out to you, you probably feel your clothes, can't
76:17 Right? Notice how unimportant during the it is that you know that the
76:21 are touching your body, right? basically you have receptors that are
76:26 yeah, I've been touched. You your clothes on good on you go
76:29 your day and it doesn't matter until you're walking along in a tree,
76:33 your shirt off and you're like, I don't have my shirt. It's
76:36 to know that I don't have my on. So that would be an
76:38 and off, right? It's a example. But it's one that you
76:42 visualize, I hope maybe, So the idea is is that when
76:48 I need to know the change of , I'm going to have fast acting
76:52 not fast acting, slow adapting these tonic receptors. But when I just
76:57 to know when there's a change that taken place, you know, an
77:01 change. That's when I'm going to the slow adapting. I'm going to
77:07 finish these three slides because they're pretty . I've actually changed the order of
77:12 in here. So I'm going to that out to you. So,
77:14 the skin, the sense of touch going to be dependent upon the presence
77:17 meca receptors. All right. So are primarily located in the dermis.
77:21 are some that will work their way into the epidermis, but that's uh
77:26 and far between. And these types receptors can be either what we refer
77:29 as simple or complex. And when referring to simple and complex, what
77:33 talking about structurally are they simple or ? Simple receptors are basically just free
77:40 endings that just penetrate in through the . Whereas the complex ones have some
77:45 of connective tissue wrapped around the dendritic of that particular receptor. They're what
77:51 refer to as being encapsulated. All . So I just kind of said
77:57 already. So the un encapsulated these are responsible for your general
78:03 So again, I said touch is primary one, but you also have
78:06 thermo receptors, no c acceptor, cano chemo receptors, these simple types
78:11 receptors are going to have basically a nerve ending. So like what you're
78:15 at here where you could see the endings of that neuron, you
78:19 they're there to receive some sort of , they aren't particularly sending very important
78:25 . So they're not particularly uh So there's three types, that's the
78:30 nerve ending. We have the root plexus, whereas our hair, they
78:33 have a hair in here. So you can imagine when you pull on
78:35 hair and you can feel the tugging the hair, it's because at the
78:38 of the hair, you have a that's wrapped around that root. And
78:44 the last one is what is called Merkel disc. The Merkel disc is
78:48 a cell that's associated at the tip the epithelium and you have a neuron
78:51 goes right up to it. So Merkel disc receives the information and then
78:56 the neuron next to it. These the basic ones, this is the
79:01 that I change the order and I the order. And you may want
79:04 just kind of say number one, two, number three, number
79:06 to make it easier for you to it. All right, because when
79:10 start memorizing these things or trying to these things, they get kind of
79:14 . All right, the encapsulated ones the ones that really play a major
79:18 in the sense of touch. These all mechanical receptors, they're all located
79:21 the dermis and they detect different types mena or different type of touch.
79:29 the first one I want to point here is the one that's not like
79:32 others. The closest thing it's it's to is the Mesner core puzzle where
79:37 is found is in the dermis of mucous membrane. So think of mucus
79:42 , right? Where are your mucus , nasal, oral urethral, vaginal
79:48 . All right. Those are those are the basic places. And
79:51 they do is they play a role light pressure, low frequency vibration,
79:56 are rapidly adapting receptors, right. they give you the sense of touch
80:01 those particular areas. Meissner's core puzzles like the krause is, but it's
80:07 found in the mucous membranes. It's everywhere else. These are predominantly located
80:13 the surface. So if this is , this is derm down here.
80:17 , epidermis versus dermis, this is location of the miser's core puzzles right
80:22 near the surface. Again, light , light vibration, rapid adaptation.
80:29 right, they play a role in simple touch. So when I run
80:35 fingers across the surface of something me that that movement is because of the
80:41 core puzzles moving further into the All right, we have these weird
80:47 things that look like Sty's head from guy. All right. Easy to
80:52 that it looks like Sty's head. are Ruffini uh core puzzles. Ruffini
80:57 puzzles. We have connective tissue that's around them in such a way that
81:02 the skin gets manipulated, when you in a little bit deeper you'll detect
81:06 , uh, sense of pressure. the type of vibrations you get here
81:10 the fluttering vibrations, right? the vibrations have to penetrate deeper.
81:15 not going to be light like you up here. All right, these
81:19 slow adapting. They're the ones that out. Again, if you're doing
81:22 of these things is not like the , they're the slow ones. And
81:26 , it's on glabrous and hairy glabrous skin is palms of your
81:30 hairy skin is everywhere else inside of mouth is the mucous membranes. The
81:35 ones are Pacini and here you can there is the, the neuron and
81:41 you get a series of concentric connective wrapped around the surface of these
81:46 All right, what this does is expands the receptive field. So you
81:50 detect a larger or broader range than where the tip is. Again,
81:57 is going to be the deep high frequency vibration. They're the ones
82:01 can travel the furthest and these are to be rapidly adapting. All
82:06 So I reordered them so that you kind of think, oh yeah,
82:10 close to the surface. It's kind in the middle is deep down.
82:14 then you could just think in terms that, how, what type of
82:18 gets down that low. All So we'll stop there. I'm
82:21 I just, it was my It wasn't his. Yeah, you
82:30 have a great day. Good Enjoy the football game. Don't study
82:34
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