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BIOL 2301 Human Anatomy & Physiology I - BIOL2301_lecture05_0609
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01:28 Or a minute and a half and not a single voice. So now
01:31 turned on, everything is good. at a minute and a half,
01:34 is when all the stuff is going come on. So, um,
01:39 right, today, we're talking about . So we're finally moving away and
01:44 dipping our toes into the anatomy area we're still not doing anatomy. We're
01:49 just kind of building that foundation. that when we come back on
01:53 we can actually talk about an actual and our first system is gonna be
02:00 uh integument. So today, what doing is we're gonna go through specifically
02:05 different types of tissue, how many were there? Four. So our
02:09 tissue is gonna be epithelium. Then gonna spend a lot of time talking
02:12 connective tissue. And then we basically , oh yeah, there's muscles and
02:15 because really a majority of this class gonna be done talking about the nervous
02:21 . And so we kind of leave nervous system with uh the and the
02:27 with the nervous system. And then gonna have like two full lectures on
02:29 muscles. So, you know, , we kind of just ignore them
02:33 . We, we'll point to them say, look, there are muscles
02:35 there's three types and blah, blah. But that's really kind of
02:38 focus today. So we have four things that we're gonna be looking at
02:43 that's more or less our lecture Now in saying that we have these
02:47 different types of tissues, we're gonna of take a deep dive into these
02:52 epithelial tissues and the connective tissues because quite a few different types of connective
02:56 . But our starting point here in tissues, all right, epithelium is
03:01 we refer to them as. And you look at this, what does
03:04 say? Well, epithelium comes in two types, right? Epithelium
03:09 are always going to be sheets of . It might be one layer
03:12 it could be multiple layers thick. their purpose is one of two
03:15 either they're going to be protective and , when they are a protective
03:19 we just refer to it as a epithelium. All right. So these
03:23 be the things that are going to lining the tubes or going to be
03:27 on the surface of the body or surface of an organ. And so
03:30 , their job is to basically to that out that outer coating or that
03:35 coating of that structure. So when think about a blood vessel the inside
03:39 a blood vessel is epithelium and it have some special names and we won't
03:44 to that today. The other type epithelium is the ones that make up
03:48 glands of the body. And we this glandular epithelium, you know,
03:52 that the names tell you what they . So we have ones that cover
03:56 that make up glands. And so is how we're going to kind of
03:59 of divide these two things up. , one of the main characteristics of
04:04 epithelial tissues is that they have these unique specialized contacts. So they're gonna
04:11 what are called sens or what are continuous sheets. All right. And
04:16 what that means is is that they're layers and layers and layers of a
04:20 layer and this these cells are all each other. And so it's like
04:23 like a blanket or a sheet in of a structure and to make that
04:29 , what you're going to have is going to have all those types of
04:31 junctions and gap junctions and desmosome and these other things that we describe so
04:36 you create something that is uniform and together in one in one way.
04:41 so that picture that I showed you we talked about the different types of
04:44 kind of serves as that to look. So here's our sheet,
04:47 can see the multiple cells there. being held by all these unique types
04:50 junctions. Of course, I have push the button. There we
04:58 All right. So this picture right here is not epithelium. This is
05:03 slice through your skin. So we're come back to this picture like the
05:08 time right after the exam. All . But I want to show you
05:11 because it shows you where the first of epithelium is actually located.
05:16 Epithelium is right here. All this stuff. And what is the top
05:23 here? That's brown. It's the layer. This is all epithelium.
05:27 down here that you're looking at is or less connective tissue. All
05:31 So epithelium has one characteristic. It's of interesting, it is avascular avascular
05:36 you ever have a at the beginning it means without. So it's without
05:40 vessels. So these cells up here not have blood vessels penetrating through
05:47 Instead, blood vessels come near to epithelium. You can see right here
05:51 the connective tissue of blood vessels right . Blood vessel right there in the
05:55 cartoon. And what happens is is materials in the blood are going to
06:00 out through the capillaries and kind of through the matrix of the connective tissue
06:05 kind of move through the interstitial fluid the cells that make up the
06:10 So they still receive their nutrients, still produce waste and stuff. But
06:14 of them actually being fed directly, fed from blood vessels that are kind
06:20 a distance away. Now in saying there's no blood, there's no cell
06:25 your body. That's more than a of microns away from a blood
06:28 But you have experiences. Have you scraped your knee or your elbow?
06:33 it hasn't started bleeding yet? And the reason is, is you've
06:36 off several layers of epithelial cells, you haven't actually broken down. So
06:42 gone, you've maybe shed something like , but you haven't actually penetrated down
06:47 where the blood vessels actually are. right. That's just kind of an
06:53 . The second thing that's really kind unique about epithelial cells is that they're
06:57 . Now, most cells in your have a regenerative capacity. All
07:02 there are some cells that have no regenerative capacity and we're not going to
07:08 one which ones do which, but cells themselves are cells that can actually
07:13 themselves very well. All right, hair is epithelial in nature. And
07:20 I shaved your head, how long you'd have stubble pretty quick,
07:27 Yeah. So it's always kind of itself. It's growing if I scrape
07:32 or get a cut, how long that cut seals over itself and then
07:36 have skin back where you have the pretty quick. It's a very,
07:41 fast regenerative tissue. And part of reason that it's so regenerative, it's
07:47 regenerative and it goes through this process regeneration, except when it's in contact
07:52 other epithelial cells. And what we is we call this contact, inhibit
07:56 inhibited, contact responsive. So when cells are all touching each other,
08:01 they are right now in your they're basically telling each other don't
08:04 don't grow, don't grow, But if you somehow break the interaction
08:09 the cells, there's no longer an signal to tell the cells to stop
08:13 . So they begin to grow and till they fill up the gap again
08:17 they're touching each other, which is you can cut yourself, you
08:22 in a minor way, not in hard way, right? And it'll
08:26 up over itself and, and, repair and that you'll get skin right
08:29 again. OK. That's the nature the of, of these cells kind
08:33 cool. Now, this, we've talked about, we talked about it
08:40 polarity, the polarity basically just means the regions are going to be different
08:44 they have different characteristics to demonstrate how a side and the basil lateral side
08:53 . So on the a side, of the differences that you might see
08:56 micro vili or SIA, which we talked about yet. They're coming up
09:00 in just a second. So they're have uh features on their surface to
09:06 them to function and interact with that . All right. And on the
09:11 lateral side, you're gonna have different because what you've done is you're attaching
09:17 to um the underlying connective tissue and is usually overlying connective tissue. So
09:24 you do is you secrete proteins and which are called the basal lamina and
09:28 interact with proteins and other materials that being secreted by the connective tissue called
09:33 reticular lamina. And together those things the basement membrane and that's how they
09:37 of hold each other together. there it is right there based on
09:47 . So, connective tissue underlies. you can see here here is a
09:51 tissue, there's our April cells or AOL, those are our epithelial cells
09:56 the differences here or the changes, the things that we're screening here are
10:01 different than what you're gonna find up . So what's a microvillus via is
10:07 ? Villus is uh singular. you can kind of see in the
10:12 it looks like this little tiny that's what a villus is, hair
10:16 , it basically points upward and what is, it's an extension of the
10:21 cell surface of the plasma membrane. so what they're trying to accomplish here
10:26 they're trying to increase surface area. if you can imagine you have a
10:30 of cells that are next to each like, so their surface area is
10:34 as, as far or as big what's being exposed, right? So
10:39 not a very big area. If want to increase my surface area,
10:42 have to increase the size of my , but I don't have room to
10:45 that. So instead, what I is a cell extends upward like
10:54 And so now I've increased my surface without increasing the size of my
11:00 And so this increases my ability to materials because now I have a
11:04 much larger surface area. And remember we talk about diffusion, diffusion,
11:09 of the things that is advantageous to promoting diffusion of materials is to increase
11:15 area. And that's really what you've . So more materials can get into
11:18 cell now because I have a greater , a greater surface area, great
11:24 a area. That's really what a does or micro villa plural here.
11:35 I still think it's cool. It a magnet in it and I just
11:38 that CIA kind of look like micro , but they're not, they're
11:45 much smaller. So just to put in perspective, see the little tiny
11:49 down here. Those are micro that's a silly guy or lots of
11:56 I should say. All right. , these you'll find primarily in mucin
12:04 cells. Now, what's mucin mucin a protein? It forms that horrible
12:09 stuff that we call mucus. Excuse . Right. So mucin are sticky
12:22 . They're really kind of just a that's kind of found in water and
12:25 job is to grab and hold on stuff. And then the CIA is
12:29 there going, ok. Well, don't want the sticky stuff with all
12:32 bad stuff that you grabbed in I want to get rid of
12:35 And so what the sylla does is there and waves like so, and
12:38 helps to push the mucus with all gross stuff in it away from the
12:44 . So you have a uh in uh a trachea, for example,
12:50 have what is called um the um elevator. That's kind of its
12:56 So all your trachea is lined with cells with the ciya. So every
13:01 you breathe in and out, you , you're picking up dust and
13:03 it gets trapped in the mucus and that elevator is just kind of slowly
13:08 up the mucus with the gross stuff it comes up to here and that's
13:11 you go and you swallow the mucus all growth stuff and goes down to
13:15 belly and your body deals with it you could spit it out if you're
13:19 but you know, whatever um we're see the term CIA used as
13:26 I I grade this out on purpose it's not what Ayia is. But
13:30 we go to the ear and we to um the question of equilibrium and
13:35 question of hearing there are cells that these things called stereo. All
13:42 they're not true cilia, it's a type of structure, but because it
13:46 upward from the cell, they use same term. All right. And
13:49 part of a signaling mechanism that we'll with when we get there. So
13:53 recognize that there are two different The other thing is I mentioned
13:57 flagella and I should point out cilia not just found on mammalian cells.
14:02 is how bacteria move around. They little SIA it looks like little tiny
14:05 . So they kind of sit there move themselves around. But our cells
14:10 move with CIA. Instead we have one cell in our body or at
14:15 in males. Ladies, you'll have on occasion, but you have a
14:19 that has a flagellum singular flagella, , right? So spermatozoa use this
14:25 it's the same type of structure. just behaves differently and its purpose is
14:29 propel the cell flagella in other Like there are bacteria that will have
14:34 flagella and they kind of use them a motor and they kind of put
14:37 around and stuff like that. So still motility. All right. But
14:41 I'm bringing these two things up is not only because they're found in epithelial
14:47 , Ayia found in epithelial cells, their job, their function, as
14:51 said is one of two things, propulsion in the case of flagella,
14:55 it's movement of materials in terms of , so they behave differently in how
15:00 move. So you can kind of here with the flagellum, it kind
15:03 spins like a propeller, that's its motion creates this propulsion. So that's
15:08 it moves. Whereas Ascii uh moves like an ore in water,
15:15 you know, like when you're rowing boat, but if your cell is
15:19 , then what you're doing is you're the things on the surface. So
15:22 kind of what it's doing. It's like that structurally internally. There's those
15:27 filaments, what we call those our side, intermediate fillings, but
15:30 microtubules, they're in that our arrangement I mentioned that nine plus two.
15:35 down the center, there's your two then around the outside, there's nine
15:40 and in between them, if you really, really closely at this
15:43 you'll see that they have these little uh uh dines, these, so
15:48 motor proteins and what they do is sit there and grab on to
15:52 the two sides and they do their wiggle dance. And that's what causes
15:56 to move the way it does, ? So the key thing here is
16:04 , cilia push things, flagella, things. All right. So why
16:14 we care about epithelium? Well, , it has multiple roles we've already
16:19 um that it covers so it plays role in protecting things. And so
16:24 kind of a simple thing. I , um, I'll just do this
16:27 myself. You don't have to do to you. But if you want
16:29 , you can just get your army take your fingernail. If you're a
16:31 , sharp fingernail, you just run across your skin and you can
16:35 Do you cut yourself? No. know, a couple you can see
16:37 scraped, there's a little bit of white stuff. I pulled a little
16:40 of the skin off. Right. notice I didn't, I didn't go
16:44 very, very hard. I this thing protects against all sorts of
16:48 . It's, um, your skin , for example, it's chemically
16:54 It's P H tolerant, it's bio , um, temperature tolerant. Trying
17:01 think of some other things you can a lot of stuff to your,
17:05 your body, you know, and it doesn't really effect.
17:13 epithelium does a really good job of the inside of your body from
17:19 outside of your body. Now, gonna pause here because I want you
17:25 be able to picture something you are you eat? Did you know
17:32 Well, I'm what I eat. a doughnut. Are you a
17:38 Yes, you are a doughnut. don't know if you eat the
17:40 but you are a doughnut, I'm just gonna draw a doughnut so
17:43 you understand what I'm talking about. doughnut remember is circular and it has
17:47 hole through the center So if I like this, it come through like
17:51 . Now you are a doughnut as . Please forgive the drawing. Uh
17:58 I already screwed it up. Can't a neck. Do you have a
18:06 through your body? Yes, you . Where does it start at the
18:12 ? And then it goes through and does all sorts of fun stuff.
18:15 where does it go out? The ? That's all right. See,
18:20 can say these words, this is isn't a gender studies class. This
18:24 anatomy, we can say things to this school, right? So you're
18:30 doughnut as well. So what I to point out here is that the
18:33 canal is exposed to the external just like the whole throat. Doughnut
18:39 all right. So your whole elementary is coated with epithelium. It protects
18:45 inside of your body from the outside . Your lungs are exposed to the
18:52 environment. Your renal system is exposed the uh and the urethra and the
19:00 to the external environment, right? these are openings we can talk about
19:06 the you know, the opening in of the vagina, the nasal
19:10 right? These are things that are to the external environment. So any
19:15 that you are exposed to the external is gonna have an epithelium, you
19:20 , and to serve as a a protective barrier to that environment,
19:25 is selectively permeable. All right we've talked about selective permeability already
19:31 in a kind of a general sense terms of cells. But um,
19:34 I were to take water and put on my skin, would water get
19:39 in my skin like a sponge? look at the swimmer and ask the
19:42 . Does water go into your body a sponge? Not? I don't
19:46 , it actually doesn't at all. only way you're gonna get water in
19:48 body is if you swallow it right , you get that wrinkly thing.
19:52 ? Going on. I mean, don't know about you. When I
19:54 in the water, my fingers wrinkle , my toes, wrinkle up every
19:57 of my body wrinkles up. It's sad, right? It's like walking
20:02 like a human prune, right? , but the idea here that's not
20:07 going in or escaping from your That's just your body trying to deal
20:10 the, with the change in All right. It's very different.
20:16 water, for example, is Water rolls off you. All
20:22 How many of you ever taken like lotion and rubbed it on your skin
20:27 it disappears. Now, you're not rubbing it until it becomes a molecule
20:33 . It's actually getting absorbed because it lipid soluble and your cells on the
20:38 , you know, are basically And so what it's doing is it's
20:41 getting absorbed. So it demonstrates a just like cells do, it decides
20:49 comes in and what goes out and are certain chemicals that your body will
20:53 almost immediately. And then there are things your body will completely ignore because
20:57 epithelium is selectively permeable, right? plays a role in secretion,
21:06 When we say secrete what it's it's putting things onto the surface of
21:10 cells. All right. So here can be onto the surface of the
21:15 . So think about all the oil skin produces or the sweat that your
21:19 produces. This would be an example a secretion. Actually, sweat is
21:22 of an excretion, but just play the game with me for a
21:26 right? So I put it on surface of my body. That would
21:29 an example of secretion. But in digestive system again, we said is
21:35 , right? I can secrete materials will help in the process of
21:40 That would be again, secretion into structures. I can also secrete into
21:47 body. Now, we haven't really about what's in the body, this
21:52 , your meat, right? The that are not exposed to the external
21:56 is internal to the body, That would be the. So it's
21:59 if you take a bite of the , all the doughy goodness that is
22:05 the donut, the hole is not the doughnut is it the hole just
22:09 to pass through the doughnut. So think of all that stuff.
22:13 so we can also secrete into the via the epithelial cells. And last
22:19 we can also detect. And so can see here we got nerve fibers
22:23 can penetrate through. So while the is a vascular, it is not
22:29 um a um wow blanking on the right now. It's uh you're,
22:39 gonna see nerve fibers is the word working. It's a, it's
22:45 So it's not lacking innervation is the I'm looking for. Right now.
22:49 cells of the nerves themselves are but they may be associated with epithelial
22:56 that can serve as receptor cells. so it's the uh the receptor cell
23:02 to that neuron that allows you to recept. All right. And we'll
23:07 about those. When we go into skin, we're going to talk about
23:09 very specific receptors located in the skin play that role of detecting what's going
23:15 in the surrounding environment. You ready your first deep dive into some
23:21 Now, now that we have a understanding of the epithelium. Ok.
23:26 what we're gonna do is we're gonna at how we name epithelium. All
23:33 . All Epithelia have two names, ? They have a first name and
23:37 have a last name. The first is always going to be based on
23:41 number of cells in a number of layers that you see. So you're
23:45 gonna be simple or you're gonna be . That's easy, right?
23:51 I have a single layer of So you can see, I've got
23:53 simple, I've got a simple, got a simple, it's pretty
23:57 Stratified is two or more. So more than two. OK.
24:03 there's two. Uh We're gonna deal this one a little bit later.
24:06 Look, here's more than two. , what we'd say is these are
24:11 epithelia. All right. Now, , when you're dealing with simple
24:15 what you're dealing with is where I to have absorption or filtration. In
24:18 words, I don't want a big . I just need enough of a
24:21 so I can regulate what's going in what's going out. So absorption is
24:25 goes into the body filtration is what out of the body. All
24:31 So that's what we're, we're looking here when we're dealing with stratified,
24:34 is where we actually need protection. right. And so when we look
24:39 this, when we deal with the name, so we said the first
24:42 is the number of layers. The name um when we're dealing with stratified
24:46 gonna be dependent upon the outermost layer we're looking at. OK. So
24:51 would be this layer, it would this layer here. Although this is
24:55 a good example to be using. right. So first names, simple
25:02 stratified. One is for absorption The other for protection. The second
25:09 just describes the shape of the right. I've already told you,
25:13 are simple people. You know, doesn't seem like it always. We
25:17 things for what they do or for they look like. All right,
25:20 have three common shapes. The first is a flat shape. So when
25:26 look in the microscope, what you'd is something that looks like this.
25:30 right, when you look at it's like OK, it's, it's
25:32 . This is what is referred to Squamous. Squamous literally means scale
25:37 So if you were to look at from the top, it would be
25:40 and looking kind of like a But when you're looking through a
25:44 it's gonna look flat like. So second has more of a boxy shape
25:48 it. So it's Cuboidal right It's not like you have to get
25:54 a little ruler and kind of is this the same width as the
25:57 ? Right? It's roughly the All right. So if it's like
26:01 , then it's still Cuboidal. But it's like this, it's not
26:04 right? So Cuboidal is roughly like the last one is columnar,
26:10 is taller than it is wide and really overt in terms of that right
26:18 , cartoons in the classroom are easy identify because they make it as overt
26:24 possible to see what you're looking But when you're looking at a
26:28 the real world rears its ugly head not everything is 100% clear. All
26:34 . But one thing that does stand over and over again is if you
26:37 at the nuclei and compare the nucleus that cell to the shape of the
26:43 , the nucleus roughly matches the shape the cell. So cuboidal cells will
26:50 really round nuclei elongates or um uh cells will have elongated nuclei that match
26:58 shape of the cell as it's going and then squamous will have these kind
27:02 flat elongate, you know, wide as well. So if you're ever
27:09 , kind of figure out, I know that epithelium are connected to
27:13 basement membrane, right? So I got to find where is the top
27:18 where's the bottom? And then I ask, OK, which direction is
27:22 cell going? And then when I at the cell, it's like,
27:25 right, well, is the nucleus what I expect it to do based
27:29 that, that kinda make sense. . So let's deal with these.
27:35 are the basic types. There's simple and there's three types of simple
27:40 Let's learn them. Now, we're to have on the test for
27:47 You will have to identify some real types of tissues right. Now,
27:53 I say that first off, we not a histology class. OK.
27:59 classes is when they're like let me how many different ways I can trick
28:02 . Right. We're learning basics So, on the test, it's
28:06 to be basic, it's gonna be . So if you've learned the
28:11 you should be able to identify right . Right. That's the idea.
28:16 , I'm not gonna throw, you , curveballs at you. I'm not
28:18 throw up a transitional epithelium or sort stratified epithelium, which are really,
28:22 hard, you know, it takes and effort to learn what you're looking
28:26 to understand what they are. So not gonna do stuff like that.
28:29 will just be like it's, here's simple squeamish, here's a simple
28:33 What, what is this? And just tell me what it is based
28:37 the definition that you've learned. you have homework assignments to actually practice
28:41 couple of those as well. All , but we're going to see them
28:44 . All right. So the three of interest, simple squamous, simple
28:49 , simple columnar. So this tells how many, how many cells thick
28:55 then this is simply the shape. right. So remember, I
29:00 love telling you guys this everything you to know in college and in
29:03 you learn in kindergarten, right? learn how to cut and paste,
29:07 ? So you learn how to do with, with your computer,
29:10 And cut and paste all the right? And the other thing you
29:13 to do you have to deal with and colors. I'm driving in the
29:16 . Is that red? Is it ? Is it yellow? What do
29:19 do when I see yellow? I the gas. Right. So here
29:23 like, do I know my All right. Now, as far
29:28 simple epithelium is concerned, these are ones you're gonna have to be able
29:30 identify, but sometimes you'll come along you'll be reading and you'll see a
29:35 like endothelium or mesothelium. These are epithelium. But what we've done here
29:43 because sometimes bio biologists think that they're or they're trying to name something based
29:49 an origin and they start using language doesn't follow the simple thing that we
29:55 learned. So, endothelium is the that lines the hollow organs of the
30:02 system and also the lymphatics. So you're looking in a blood vessel and
30:06 describing the epithelium there, you refer it as endothelium. All right.
30:11 part of it is, it's, , it's origin, it's, it
30:14 from developmentally from a specific group of during development. That's the uh endoderm
30:22 . Mezo means middle. And so is what the Sears membranes are made
30:27 of. All right. Now, still simple. It's just given a
30:32 name. All right, we're not show you pictures of those and
30:35 ask you to name them. That's our goal here. All right.
30:38 trying to point out that sometimes a comes with something complicated, but we're
30:43 focus here. OK. So here examples of simple epithelium. All
30:50 This is simple squamous right here. there's the cartoon we're expecting, you
30:55 , flat cells with these nuclei. , I'll be the first to admit
31:00 are the worst pictures. Um, understand that some publishers do not have
31:04 budgets. And so when they go buy slides or something like that,
31:08 don't know. Well, first off publisher doesn't know what they're doing and
31:12 author doesn't have enough clout to be to say this is a terrible
31:16 This is a terrible picture. All , it's really hard to see the
31:20 here. But what you can see that each of these little things here
31:24 I know this is coming from that right there. Those are all individual
31:29 , each of these things as you're around. This is the alveoli of
31:32 lung, right? So it's basically hollow balloons. And so the alveoli
31:37 your lungs here are basically cells. if you look closely at this and
31:41 from your seat, you're not gonna able to do that. But like
31:43 you were looking in your textbook on laptop or whatever, and you're looking
31:46 that picture you'd see, OK, is an elongated cell. All
31:50 And if I look at the the nucleus does the exact same
31:53 the nucleus is, is usually gonna darker. So like here that dark
31:57 thing, that's the nucleus, the pinker thing around it. That's the
32:02 . OK. Good news. I'm constrained by copyright laws when I'm writing
32:09 . So when I go on the and start looking for really good examples
32:13 things so that I can test What am I gonna find? Am
32:16 gonna find a crappy picture? I'm gonna find a good picture.
32:20 if you know the definition flat elongate cell, uh you know uh
32:25 , you should be able to identify . All right, that's what we're
32:28 for here. Simple cuboidal cube, see how the nuclei in this.
32:37 . Terrible picture. Look at, like it's like trying to identify a
32:40 from a mile away and then all , can't even see the individual
32:45 But if you look at the they're nice and round. And if
32:47 look at the actual structure, it's of like this cube shape to
32:52 So that would be an example of , simple cuboidal. Right?
32:58 the homework assignment has better stuff. test will be easier to see they'll
33:02 at much greater magnification. So you actually see the stuff. This is
33:07 terrible picture. Again, look at far away we are. We are
33:13 I'm down here. All right, we're looking at here is the digestive
33:17 . And what you see here is going up and down are the crips
33:22 are found in the stomach. The that you're looking at are, are
33:26 things that you're seeing right here. can see that, that purple
33:30 that dark thing. That's the what ? And so the cell extends upward
33:35 there. So this whole thing is cell and you can see up there
33:39 would be the cell. Then over , those are cells. So really
33:42 you're looking at, you're looking at wall of the intestine going up and
33:46 like so, all right. So we do again, we ask the
33:52 , where is the basement membrane? , if this up here is the
33:57 and that's loin, then that's the , that's the part of the cell
34:01 then I just go down and that's the basement membrane. Well,
34:05 I know that's basic memory because all stuff in there that looks like little
34:07 raisins. Those are cells in connective . All right. Now again,
34:14 it gonna look like on the It'll be prettier. I promise.
34:17 what I also do on the questions I put a big box around the
34:21 to say which type of cell is ? So that you're not confused,
34:24 not like, is he pointing at cell down here? Is this the
34:26 that I have to note? it's the big one with the box
34:29 it. All right. That's how do that. All right. So
34:34 three you have to know. All , this one, you should know
34:39 definition of, you do not need identify it. All right. And
34:43 reason you don't need to identify it you can look at the name
34:46 what does pseudo mean, fake, , false, stratified epithelium. This
34:53 a simple epithelium. All right. weird thing about this is that every
34:59 that you're looking at. So here the cartoon, even these that are
35:02 up high are actually attached to the membrane, right? It looks like
35:08 stratified epithelium because the nuclei are all the place you can see right
35:12 This is a better picture, Because you can see down here,
35:16 is connective tissue up there right up . That would be the you can
35:20 see the CIA on top. Do see the silly up there? And
35:23 you can see this looks like a bunch of cells stacked on top of
35:26 other, doesn't it? I mean right there is a nucleus that right
35:31 is a nucleus, that's a nucleus didn't look like a whole bunch of
35:33 stacked on top of itself. it's not, it's pseudostratified, it's
35:38 this. And so if you were tease the cells apart, you'd
35:43 oh they're all attached to the Some have really, really thin
35:46 some have fat bottoms and they all up to the surface or almost near
35:50 the surface. It's one layer All right. So it's a
35:56 very different structure. It's found in whole bunch of different areas. But
35:59 understand, stratified is still a it's just arranged weird stratified epithelium.
36:09 far, we're good with the right? Sys are pretty simple.
36:13 are also simple. They're not, not particularly difficult. They play a
36:19 role in protection. We have a of cells down here on the
36:24 they're very much alive, very active , making more cells. And what
36:28 do is as they regenerate, they divide and they push the cells upward
36:33 upward and upward. And as you further and further away, um you're
36:38 further and further away from your fuel . So the cells that are furthest
36:41 really kind of die, then not cells are going to do this.
36:44 you can see now because of that capacity have multiple layers of cells and
36:48 have very different appearances along with along way, right. So this is
36:55 direction they move from the basal direction the apical surface. Now,
37:02 we have three basic types. We stratified, squamous, stratified multiple
37:08 squamous, meaning the flat scale likes now, remember how we name
37:12 we always look at the outermost So if you look at this layer
37:15 here, that is squamous, even here, it's kind of cuboidal,
37:18 we don't care about the shapes down . We care about the top shape
37:22 here. All right. Now, are two different types of stratified
37:26 We have carin and non carin. the characteristic here is that they have
37:30 has carat and one doesn't. All , go like this on the surface
37:34 your skin, you can see my is protected because I have tough carrot
37:40 fibers in my skin that prevent me tearing off all those cells. They're
37:45 very, very tough. If I that same fingernail and run it on
37:48 inside of my mouth, I'm gonna an alley. I'm gonna actually cut
37:52 mouth because the inside of my mouth filled with non carin. This is
37:59 inside of my mouth. Not so . So here, non Crain is
38:04 be found in the internal cavities. actually you'll notice if you go home
38:09 look in the mirror, you can , you can look at your mouth
38:11 your skin around your mouth and go . Yeah, that's kind of
38:13 I go to my lip. My are kind of tough and then I
38:16 of pull my lip open and all a sudden now it's like,
38:19 there's soft squishy tissue there, You're, that's a transition from Crain
38:24 non. All right. So has lot of carrot. Now in looking
38:30 this, you can see here is , if you look real closely down
38:33 that would be connective tissue. So here, those are the layers that
38:38 regenerative and as you move further and and further away, this is your
38:41 . By the way, um the , those become way up there at
38:45 top. Those become squamous in The other two stratified are a little
38:51 more rare. So we just kind lumped them together. And again,
38:55 named based on that outer layer. uh the stratified cuboidal rather rare,
39:02 see them primarily in glandular tissues. basically a cuboidal cell and another cuboidal
39:07 on top of it. And that's this is. All right. Um
39:11 this one, you will need to for the test. I'm not gonna
39:13 you identify these, OK? Because harder to identify and it's hard to
39:18 pictures of them. They're, and few and far between. All
39:22 Then we have the stratified columnar. do you think they look like?
39:27 cuboidal or Cinar cell? And then columnar cell on top only found in
39:32 places, the male urethra, not the female urethra, the male urethra
39:38 glandular ducts. So, again, very common. Here's the weird
39:45 You will not need to identify this the exam. You should know the
39:49 transitional epithelium. It's called transitional because changes its shape depending upon the pressure
39:55 being put upon it. It's found one location in your body, urinary
40:00 , particularly in the bladder. All , your bladder is like a
40:06 not entirely like a balloon, but a lot like a balloon. And
40:08 happens is that it fills up with , it begins to stretch like a
40:13 . And the reason it's able to is because these cells are stretchable.
40:20 you can see right now they look fluffy clouds out on the surface,
40:24 of cuboidal in shape. But as stretches, they're gonna start looking like
40:29 cells. So they basically stretch If you look closely in some of
40:37 , you'll see that some of them two nuclei. They're very, very
40:41 uh type of epithelium. So, epithelium changes shape and found primarily in
40:49 urinary tract, especially in the So far. So good.
41:04 we got the thumbs up. You're to get out of here. You're
41:06 , you just talk faster, So let's deal with glands. All
41:12 . So a gland can be one more cells. So you can have
41:15 gland. That is a single This is true, right? And
41:18 job is to secrete a substance into specific environment, right? So here
41:25 we say secrete the product we're not define. All right, we're going
41:30 see that there are different types of . When we go into the epithelium
41:33 when we go into the integument, talk about the skin, we're gonna
41:36 about the oil that your hair and skin produce. We're gonna talk about
41:40 sermon that your ears produce. When talk about mammary glands, the milk
41:44 you produce, these are all glands produce these types of secretions and they're
41:49 , very different and tap. In , the types of sweat glands you
41:53 , you have two different types of glands, ones that produce watery sweat
41:56 some that produce kind of a, sticky uh proton. So a lot
42:01 protein type of sweat. Those are ones under your pits. Ok.
42:07 , a secretion simply is an aqueous . So it's water plus stuff and
42:12 stuff here happens to be proteins. you may find other things in there
42:16 well. We have two types of . An endocrine gland is a gland
42:24 secretes its material into the bloodstream. right. And we're not gonna talk
42:29 those right now. So these are ones that are producing the hormones they
42:31 have duct work in essence, what doing is their job is to produce
42:36 material to regulate parts of your It still might be epithelial in
42:41 but most of them are not, of them may be neural in nature
42:46 terms of structure. The glands we're about right now are the exocrine
42:52 So indo tells you it's secreting into body, exo screening out to the
42:57 of the body. All right. here you can see what we're going
43:01 have is we're gonna have a we're going to have a structure that
43:04 the material and the duct opens out the surface. And so that's where
43:07 material is going to go. All , we're going to classify these primarily
43:13 on structure, but we'll also classify or have a different type of classification
43:17 can use to talk about um what actually secreting. So here's the structure
43:24 , well, almost structure. So have the unicellular gland. So
43:28 here is an epithelium. You can here, we have columnar cells here
43:32 the surface. There's your CIA and cell right here. This cell right
43:36 is that right there. That's a cell. A goblet cell is a
43:41 cell gland. It produces mucin and its mucus out onto the surface.
43:48 you can see the little line right that's representing the mucus. And so
43:52 is how you coat these epithelial cells mucus because you have individual goblet cells
43:59 around secreting that stuff. That's our example for the unicellular, most of
44:07 glands that we're gonna be looking at you're gonna learn, learn about are
44:11 . All right. So as a , they're fairly complex, they have
44:16 duct work that goes to it. they have unique cells that line that
44:20 and have specific responsibilities within that And then at the base of each
44:26 these ducts, you have this structure an ace. All right. So
44:32 there, you're going to have specific , we refer to them as asar
44:36 . So ana A N R, A inner cells are the things that
44:41 responsible for producing the the secretion for gland. So again, this is
44:47 terrible picture probably the on the I mean, just from this.
44:52 each of these little red dots are to represent the ascena. And then
44:57 can see the little tiny yellow ducks into the bigger ducks which go to
45:00 bigger ducks, which go to the ducks. And you can see there
45:03 our gland and so the ascena are of encased in a structure that's called
45:09 , a lobule and then a group lobules form a lobe. And so
45:14 glands have this lobular structure where it's a a branching system that looks like
45:20 tree with a bunch of leaves It is kind of the way that
45:23 might want to think about it. might be blood vessels to help bring
45:30 to, to help uh aid the of what you're producing. There might
45:34 nerve fibers that will help direct the as well. Now how these are
45:42 if I go back is you're gonna imagination of the epithelium. So if
45:48 were your skin, it's an easy you can imagine during development, this
45:51 flat, then what would happen is that, that um epithelium would
45:56 downward and then it would push inward ultimately form this glandular structure. That
46:01 be an example of the imagination of skin. So, multi cellular,
46:08 little bit complex. Now, we're to classify these either by what they
46:13 or what they look like, but they look like, this is a
46:16 artist's rendition, but I'm gonna try point it out using these up
46:20 So you name the structures based on shape of the duct or the shape
46:25 the Asus or both together. All . So a simple gland looking at
46:30 ducks. All right. So this no duct. This is the actual
46:34 itself, right? This right You can see the duct,
46:40 So the duct is very simple. one little portion here right here.
46:44 a simple duct there right there. a simple duct. When you get
46:48 here, this is where I got because the duck should be this,
46:54 that. It's all the branches. will not see this picture on the
46:59 because it's terrible. All right. what we're trying to get out here
47:03 I'll, I'll draw over here for change. So if the duct doesn't
47:13 , it's simple. So this would the duct. But if the duck
47:22 , that's a compound gland, So you see the difference between those
47:30 things. So here's the duct, just gonna highlight the duct here is
47:35 duct. So if the duck doesn't , it's a simple. All
47:42 if the duct does branch, it's compound gland, get out of the
47:48 . So you can see that. this artist did a terrible job because
47:53 didn't demonstrate the branching very well. was trying to say, look
47:59 but they're not showing the branches. right. The other half of the
48:06 refers to the race over here. I draw, I can be
48:16 All right, if the Asus has same shape as the duck, so
48:20 my duct, I'm gonna draw the or the, the anu over this
48:27 . See it looks like the Does it look like the tube?
48:33 . So it's tubular. OK. my duct. If it looks like
48:44 grape or it's round in nature. right, if the ace is like
48:49 , it's alveola. All right. you can see up here tubular
48:57 it's more rounded, you know, artist. So this would be
49:03 alveola, tubular. Notice all the works are like tubes, alveola,
49:11 all rounded. OK. And then have weird ones. The compound tubular
49:19 , meaning, well, some of are tubular, some of them are
49:24 . So yeah, let's just make both. All right. So we
49:30 look at a gland and ask the , what's its shape? And we
49:36 classify a gland based on its That's the first thing that's what an
49:42 would do. Physiologist. On the hand, would say, um,
49:45 could care less about the shape. just want to know what it's producing
49:49 how it's producing it. So we at a gland and ask the
49:53 Is it merocrine apocrine or holocrine? right. And this refers to the
49:59 that this particular cell or uh cells the ascena are producing. Now,
50:05 of these are going to seem obvious some are gonna be a little bit
50:07 complex or weird. We're going to with the merocrine because it's easy to
50:12 here. What the cell is doing producing material. You can see the
50:15 vesicles, the vesicles go to the , they open up, you release
50:18 material by exocytosis and so you're secreting materials from the cells. All
50:24 this would be an example of a type of gland. So like your
50:29 glands like on the surface of your are these types of things. They
50:33 these glands that kind of go down this. You've seen as like
50:36 actually, they're more coiled and shaped that. But what they do is
50:40 cells secrete this fluid and the fluid up through the duct and gets released
50:44 the surface of your skin. It's watery, very basic, your lacrimal
50:49 . So do that as well. your lacrimal gland? Your tears,
50:56 . Think about your Salisbury glands. you think about a juicy stick.
51:00 you guys hungry yet? Have did you guys eat breakfast there?
51:02 got the food right there. Think about something. Think about
51:06 Think about your favorite thing. I mean, I'm just gonna say
51:09 right now because it just drives everyone when I think about a double meat
51:12 from water burger with all the fixings make your mouth water. Maybe those
51:17 on the side fresh out of out of the fat. Yeah.
51:21 that make your mouth water a little ? Yeah. OK. If it
51:27 close to 11 o'clock, many of would be like just screw you.
51:30 right. That's merocrine, very watery of secretions. All right. Get
51:40 the memory glands, memory glands are type of apocrine gland. This is
51:45 little weirder. OK. So what we're doing is we're producing a
51:50 that has proteins and other things in . So it's a little bit thicker
51:54 so the vesicles contain all that but instead of the vesicle joining to
51:59 membrane and opening up and releasing materials of the environment. What happens
52:03 is the vesical remains inside the uh cytozole and you pinch off the vesical
52:11 some cytozole plus plasma membrane so that end up with this weird type of
52:17 zone. All right. So you here the vesical still there, you've
52:22 off a portion of the cell itself So what you end up with is
52:27 thicker material. And that's kind of milk is. I mean, we
52:32 talk about human milk but you probably haven't experienced human milk. So let's
52:35 kind of move to milk that you're experienced with. I mean, have
52:38 ever had cow's milk or goat's milk rat milk? Ok. No one's
52:44 rat milk, but they're mammals, produce milk. Ok. It's a
52:48 thicker. Right? And if you've milk, that's actually the watery
52:52 there's another portion that you can It's called cream. All right.
52:59 the cream is the thicker stuff of and other proteins. And what you've
53:04 is you've actually separated out those You can sell one for a lot
53:07 than the other. And we drink milk and the cream we buy to
53:11 baked goods and stuff like that or put in our coffee, that cream
53:18 that watery stuff. Is this all . And then we get the
53:23 really weird stuff. You ready for gross? All right. So let's
53:27 about our sebaceous glands. These are oil glands on the surface of our
53:32 . Right now. We're friends. we, have we become friends
53:34 I mean, it's been like four . Are we, are we cool
53:37 each other? Can we talk Ok. We can talk about gross
53:39 , right. Have you ever had whitehead? Is it? Oh,
53:42 . All right, we are All right. Now, we're not
53:45 talk about our popping techniques or anything . All right, that's when you
53:49 to dermatology, you get to talk how to pop a zit. But
53:53 right. What is an actual What is this? All right.
53:56 , it is a gland that has clogged because there's been dirt put into
54:02 duct. And what's happening underneath that the cells that are found in the
54:09 are this type of cell. What do is they produce their materials just
54:14 you do everywhere else, right? create these vesicles, but the vesicles
54:18 up inside the cell and the cell to swell and swell and swell until
54:21 gets full and then the cell dies ruptures and releases all the materials that
54:28 had stored up. And then that just kind of moves up through the
54:32 work and out onto the surface of skin. So think about like you
54:35 washed your hair all day. You , I mean, I know most
54:38 us wash our hair every day. of us do every other day.
54:41 you know how you get that oily or if you, you know you
54:45 that oily skin, that oil is your body protects itself from microorganisms.
54:51 that oil is that sea bump. so that Sebum is this material right
54:56 . So if you get dirt and on the surface of your skin.
55:00 it does is it fills up that and so that oil gets stuck in
55:04 it and then it causes a blockage the bacteria there on, in,
55:08 the dirt go, oh, this awesome. And they start eating everything
55:11 then your body recognizes bacterium and it , oh, this is bad.
55:15 so what I'm gonna do is I'm to fight it and then that's when
55:17 get the zit and that's when you , right? But do you,
55:22 I'm trying to get you to focus on is why is that there?
55:25 because the cells here in the ascena rupturing and releasing their material. That's
55:32 the C B M is. This the holocrine gland. All right.
55:37 watery, kill the cell release don't kill the cell, pinch off
55:44 of the cell. So merocrine ain me make sure I'm pointing out the
55:49 word Ari. And over here Ok. So the type of
55:56 the way that it secretes is what looking at. Wow, a whole
56:02 to talk about Epithelium. Good It goes by faster. Now,
56:09 about this stuff you wanna talk about some more. Yes. Mhm
56:23 So the gland itself is in the , but it's not exposed to the
56:27 surface instead what it's gonna do, gonna release its secretion, whatever the
56:32 it's secreting directly into the bloodstream onto surface of the body someplace. So
56:42 example, your digestive system has exocrine , you're secreting digestive juices into the
56:49 tract. We think as humans that digestive system is inside our bodies,
56:54 is not as on the surface of bodies. We just can't see
56:57 Why, why is it on the of our bodies? Because we're
57:01 right? So we need to remember exposed to the external environment is on
57:06 surface of our body. Anything that's exposed to the external environment is not
57:11 the surface of our body. It's of a weird way to do
57:14 but that's kind of how you do when I, when I talk about
57:19 in A MP two, when I a MP two, that's one of
57:22 very first things I teach you guys we're doughnuts and, and I,
57:26 prove to you why that's on the surface. It's kind of fun.
57:30 I'm not gonna waste your time right . Did I answer the question?
57:35 . Cool. Any other questions wanna ? Connective tissue? Now, connective
57:40 is weird. All right. There's that makes absolute sense and then there's
57:44 in it that's like, huh? we need to understand that uh while
57:47 tissue is everywhere, it's the most , most widely distributed. It has
57:53 very strange parts to it. Like example, I mean, this,
57:58 are things so we have things that gonna call connective tissue proper. We
58:00 things like cartilage and bone and these of makes sense. But then you
58:04 something like blood and it's like How does blood, blood is a
58:08 tissue? Yes, blood is a tissue. The reason all of these
58:12 in the same category is because of origin. All right. So just
58:17 quick, quick, quick, quick exposure to um immunology, you
58:22 start life as a single cell, you begin dividing, dividing,
58:25 you become what is called a trip , uh triple blastic uh gammy or
58:31 . What that means is that the of your body divide into three different
58:35 and then those cells then have specific to where they're gonna go. All
58:40 . So when we say we're triple , that 11 of those three types
58:44 cells, the one that's called the gives rise to this stuff. All
58:51 . I think I'm right. I it's me. So I may have
58:54 screwed that up. And if I , you can come and tell me
58:57 , don't, don't embarrass me in of the class. So you can
59:00 tell me I'm wrong. I I don't have a problem with
59:03 All right. So that's the first you need to understand is that even
59:08 they're weird and different in some it's because of their origins.
59:12 in terms of their function, they play a role in uh protection as
59:15 as insulation. Think about a does a bone protect you.
59:20 you have a helmet, right? bone is protective. So it does
59:24 a role in physical protection but also a role in immunological protection. That
59:28 be the blood, for example, a role in binding things up supporting
59:32 structure. Again, bone cartilage, connective tissue in and of itself,
59:36 connective tissue pro proper holds things together a role in import or it's it's
59:41 important role in storage fat is a of connective tissue. And what do
59:47 store in fat energy? Right? . And then also plays a role
59:53 transportation. What is blood, it materials throughout the body. So it's
59:58 of these weird things that we gave a name because when we first
60:01 it was like, oh look, thing that holds things together. But
60:04 we started exploring where it all comes , then we started realizing all these
60:08 tissues that probably weren't gonna be fell into the same category. So
60:12 a little bit broader. Now, connective tissues have what is called a
60:18 substance. A ground substance simply is nonliving material that's found within the connective
60:26 . It's the stuff that's produced by connective tissue cells themselves. We're going
60:30 use this picture as an example over over again. So it's OK to
60:33 this as I mean kind of as frame of reference even though not all
60:37 tissues look like this. But in picture, what you can see is
60:41 the things that look like stream or everywhere. I think with the exception
60:46 these, yeah, this is a vessel. Those things are blood
60:49 In this little cartoon, all the things except for those two blood vessels
60:55 fibers that are produced by the cells the connective tissue. All right.
61:00 if this whole thing is connective those fibers are being produced by the
61:04 there. And if you look what see is that there's a whole bunch
61:07 cells. We got this type of there, we got this weird cell
61:10 . We got that weird cell. got the yellow cells up all over
61:13 place. So these are cells that up the connective tissue itself. And
61:18 you see in here we have this of lighter space, it's not quite
61:23 . They actually the artist covered uh uh colored it and it's that white
61:29 space that we're actually looking at this little space. This is the ground
61:34 and really what it is, it's plus other things that are found within
61:39 . And this is what it It's primarily proteins. All right.
61:44 these large molecules which are not visible the naked eye. But if you
61:48 in there and stain it with the stuff, you can find it,
61:50 type of proteins are called proteoglycan. right. And this is why I
61:54 them the other day. So this the proteoglycan can. It's here.
61:58 have this long protein and on the , you have these gags which are
62:02 Aino gly cans. Again, you even know that name. I just
62:04 saying it out loud because it sounds I know stuff, right? So
62:09 gags are basically sugars and these sugars are attracted to water. So the
62:18 kind of comes up and so it up this space and gives it
62:23 All right. So the ground substance an empty space. It's this network
62:30 proteins and adhesion molecules and stuff that up with water and hold everything
62:38 And then on top of that, where you're gonna have all the other
62:40 as well. So, um let's of look and see the types of
62:49 that we'd find in these types of . So each connective tissue has its
62:59 primary cell that's located there. There's specific nomenclature to cells in the
63:07 If a word ends with blast, that is is that's an immature
63:13 All right. It's a cell that finished maturing and it's, it's,
63:17 it's gonna do stuff and change its . Once it matures. If a
63:22 has sight at the end of the , then that's the mature form of
63:26 cell. So we have fibroblasts and . That's what we found in connective
63:32 , proper chondroblast and chondrocytes. These cells that are responsible for making
63:38 And then we have osteoblasts and These are the cells that are responsible
63:42 bone. All right. So, will only find fibroblasts in those areas
63:48 are connective tissue proper. You will find these cells, the chondroblast chondrocytes
63:54 cartilage, you'll only find osteoblasts and sites in bones. You will not
63:58 them in all the connective tissues. when you're looking at a specific tissue
64:02 you see one of these things that tell you, oh, this is
64:05 tissue type that makes sense. So I see fibroblasts, I'm in connective
64:11 proper. If I see Condra I'm in cartilage. If I see
64:16 , I'm in bone. All And then depending on which tissues you
64:23 , you might see these things. see things like adipocyte. Now,
64:27 are gonna def definitely be the primary type in adipose tissue. So when
64:32 thinking of fat tissue, oh Yeah. Every cell I look at
64:36 like it's an adipocyte. Yes, would be correct. But you'll see
64:39 connective tissue proper, you might see located there. You'll see zamal
64:50 the zamal cells, these are the cells of connective tissue. So they
64:54 , are formed from the, which why I say mesoderm. All
64:58 And then you might see immune An immunocyte is simply a cell of
65:02 immune system. So there might be , which was the word I kept
65:06 yesterday when we were talking about. , you know, um, you'll
65:09 macrophages. You might see other types immune cells that are either hanging
65:14 In other words, they live Right. Or you might see wanders
65:18 a wander is one that just kind like, it's like a cop on
65:20 beat. It's like the cop that see driving through the neighborhoods,
65:23 Just making sure everything is going Everything's cool. Everything's OK. I'm
65:27 keep moving. All right. So either resident so they live there or
65:33 can be wanders if I go back the picture right there. This is
65:37 macrophage and our little cartoon and oh look, there's even a bigger
65:43 so we can play with this and we have the different types of
65:46 And so you have collagen fibers. is the most abundant protein in the
65:50 . Um very, very strong, flexible and it's resistant to stretching over
65:56 . It begins stretching. This is the older you get, the more
65:59 you get right. You get this of weird stuff because the collagen begins
66:02 relax a little bit. This is Botox fixes. It tightens up the
66:07 . All right, we have reticular . These are the ones that have
66:10 glycoprotein. So I don't know, think it's the purple ones in
66:13 let's see where the fibers nope, reticular fibers are the little brown ones
66:17 here, but they're very tough, flexible. They, these are the
66:21 on which cells kind of like to . So they kind of hang out
66:24 top of them. And so they of create the network on which the
66:27 are going live. And finally, have the elastic fibers, these are
66:30 that branch and stretch. And so is what allows your ear to do
66:33 like this. You ever done that can play with your ear all day
66:38 this, don't try, right? different types of fibers. So we
66:50 three things that we should be aware , right? Connective tissue have a
66:56 filled with ground substance. They have cells that live in them and they
67:00 fibers that they produce. And it's three things that we then look at
67:04 determine what type of connective tissue we we're dealing with. So connective tissue
67:10 has different subtypes. All right. first type of subtype is a loose
67:16 tissue without even reading anything on the . Go back to what you read
67:19 night. What do you think loose tissue looks like loose, right?
67:29 does it mean to be loose that you look at it, you see
67:33 , right? So the first type Ariola. All right. A you
67:39 see here is, is kind of when we think of connective tissue.
67:41 what we kind of think of. right, the fibers themselves, they're
67:45 , very sparse, they're regularly They don't have a lot of cells
67:49 them. There's protein everywhere and you're find this, you know, a
67:53 of ground substance. So there's a of space in there. These support
67:58 structures and your organs. All So when you think of connective
68:02 this is probably what you're thinking of a second type of loose connective tissue
68:09 adipo. Now, does this look to you? No, it looks
68:12 everything is jammed in there. All , let me tell you why they
68:15 it loose. Why they put it the category of loose when you take
68:18 slice of adipose tissue and put it a slide and you dissolve and you
68:22 it through all those xylene washes and those other things in the end,
68:25 you're gonna see is you're gonna see membrane and all the fats have been
68:28 away. So it looks like a of space with a bunch of lines
68:33 it. In other words, all see are these things and where the
68:36 are located. You're no longer seeing big old fat bubble. So it
68:40 like there's nothing there. That's why call it loose. But it's basically
68:45 tissue. It's just a bunch of cells, reticular reticular has more reticular
68:53 than it has collagen fibers, hence name. But does this kind of
68:57 loose to you? Like there's a of stuff, a lot of free
69:00 in there? Yeah. Now we'll you why this makes sense because the
69:04 slide is gonna be if this one's , the next one is gonna be
69:08 connective tissue without me, flip the . What do you suppose? You
69:11 there's gonna be a lot of space the dense ones? No. And
69:15 absolutely right. Dense connective tissue is and there's two different types of
69:21 there's dense, regular and there's irregular. All right. So dense
69:26 , if you look at this, can see all the fibers are running
69:28 the same direction. There's not a of space, there might be a
69:31 bit of space, but there's not lot of space in there. The
69:33 are interspersed between the fibers. So is a really, really organized looking
69:38 , right? So lots and lots protein fibers, very little ground substance
69:44 it's primarily collagen. All right. , this is what like a tendon
69:49 look like. That would be that of connective tissue. So there's
69:54 So it looks normal. And then does this look regular at all?
69:59 look like absolute chaos to you regular . It looks like chaos,
70:06 Well, that's why it's irregular. makes me happy. It's like a
70:12 M R for biologists this total This feels like, like I have
70:18 dent exam or something right now, still space, but you can see
70:22 fibers are going all sorts of different , right? The cells they're in
70:27 , you know, they're few and between as you'd expect, but it's
70:31 kind of going everywhere. So this what forms like the capsules around
70:36 And then here we have elastic. again, elastic is pretty dense.
70:40 picture is not gray, I guess the better view over there,
70:44 But you can see the fibers are , really close. But here the
70:47 fiber is not collagen, it's All right. And so this is
70:55 to be allowing the thing to expand contract because they're stretchy. Lain fibers
71:00 stretchy, so dense, connective tissue straightforward. Then we get to the
71:09 . All right. Here, the matrix is a little bit more
71:13 it's like a dense. But you see fibers. What you do is
71:16 see the ground substance for the most , right? The cells are there
71:22 they're surrounded and embedded by the structure they created. So they're actually secreting
71:28 and that matrix traps the cells in . So it's the blast that's making
71:33 matrix. And then once the cell trapped, it matures and becomes the
71:37 and now it's stuck inside the matrix its job is to maintain the
71:42 So it's a semi solid. You know where your cartilage is, I
71:46 , you have cartilage on your you have cartilage between your vertebra.
71:49 here's the fun one that you want play with. There is cartilage right
71:53 . And if you want to have lot of fun, we have this
71:55 of cartilage right there, like I , in the ear. All
71:59 That would be the elastic cartilage. of the cartilage we're talking about is
72:01 to be this highland cartilage again, , we get all our nutrients.
72:06 these cells are very much living. get all their nutrients from surrounding blood
72:10 , uh not in the matrix itself outside. Very, very strong,
72:15 , very resilient. Um And, flexible I always kind of laugh with
72:21 we have, we have four You're gonna learn this about me.
72:24 say it probably at least three I have four kids, two sets
72:27 twins. It's awesome. Yeah, wakes people up two sets of
72:31 I didn't give birth. That was other part of the equation,
72:39 We let our kids do all sorts crazy stuff. You know, we're
72:41 , we were never helicopter parents, know, we let our kids do
72:45 because that's how you get resilient kids we're not concerned about broken bones and
72:49 because when the kids were young, made primarily of cartilage and cartilage is
72:55 . It bounces a lot. So they fall out of trees, you
72:58 , it's All right. Brush off dirt. Go cry to your
73:05 It really was that bad. I a kid, one of the kids
73:07 fall the tree. My wrist Oh, I'll just shake it
73:12 Two days later, my wrist still . Well, maybe we should go
73:15 that checked out. They did break wrist. It wasn't a big
73:21 It was more of a sprain. , anyway, so three types.
73:25 have the hyaline cartilage, we elastic where you can actually see the last
73:28 of lots of elastin fibers that gives that bounciness. And then the fibrocartilage
73:32 can see here the fibers, the cells are kind of embedded in
73:35 This is more resilient for compression. so that's what actually sits in the
73:40 intervertebral discs. And then we got weird ones. I told you we
73:45 weird connective tissue, blood and All right. So blood and limp
73:50 arising from that meeny that we Um they have formed elements. So
73:55 have a whole bunch of cells that found in them. But these cells
73:59 not make the ground substance in which found. All right. So the
74:04 , the environment of blood does not from the cells that exist within the
74:09 itself, which is one of the things about this connective tissue. All
74:13 , this ground substance is called So when it's in the blood,
74:17 what that liquid is this stuff that's around, that's plasma. But when
74:21 escape from the blood and you go the lymphatic system that so that's what
74:25 see here. You no longer call plasma. You now call it
74:29 All right. And then that lymph then gonna be pumped back into the
74:33 stream. And so it becomes plasma . So the name is dependent upon
74:36 you're located. You don't change the of the, of the matrix.
74:41 blood and lymph are this type of connective tissue. Bone is a connective
74:48 . Yes, ma'am. OK. . Uh Usually I'll, I'll do
74:55 . Yeah, I'll usually see erythro R BC or red blood cell.
74:58 , I'm really big about not typing out because is forever, you
75:04 I type, I still hunt and mind you. That's how old I
75:08 , right? Um But generally it's gonna be like formed elements because
75:13 what will again, we're not gonna this in a MP one but erythrocytes
75:18 really truly uh cells, platelets aren't cells, leucocytes are. So there's
75:24 is why we use the term formed because there's characteristics that make them not
75:30 . But don't like I said, just threw something at you like you're
75:33 , do I need to store No, you don't need to store
75:35 information a day, right? So understand that the cells themselves. So
75:40 cells that you find in blood do form the matrix, they're just found
75:45 . That's the key thing here. right. So bone arises from
75:53 All right. So it has a matrix to that of cartilage. So
75:57 means the cells, the osteoblasts are this thing and they're producing this matrix
76:02 they get trapped in their own And so that's when they differentiate.
76:06 this matrix actually contains within it, calcium salts, it's calcium carbonate and
76:12 what gives it this hardness to And so it's much, much more
76:16 , more resistant to torsion. Torsion the twisting. All right, we're
76:21 talk a lot about bone. All . So, um so what you're
76:25 at in this picture right here, is a slice through the bone.
76:28 so each of the little black dots the space in which those cells are
76:34 . So your bone has living cells it. It's not just some hard
76:40 . Have you ever been kicked in shins? You ever wonder why it
76:42 so much because one, you have and two, you're trying to protect
76:46 bone from breaking and the cells in need to have those types of nerves
76:51 kind of let you know that. , we're still here. So we'll
76:56 this a little bit more detail. any anyway, so it's still a
76:59 tissue um proper because of those um because of the matrix it makes and
77:07 cells that are living in it, it is vascularized, it is innervated
77:13 we'll go in a lot more We have like two lectures on
77:18 All right, we are coming to end. How are we doing on
77:22 ? We are rocking now? ma'am. It's, it's similar.
77:30 , so when you make bone, start off life as basically a cartilage
77:35 and then you use that network, matrix of cartilage and you're again,
77:40 are gonna be different cells, they're be, they're gonna replace. So
77:43 osteoblasts and the osteocyte actually migrate They kick out the Conroys and the
77:49 and then they start using that matrix build the bone in which you now
77:54 your skeleton. So the, the thing here to understand is that it's
78:00 to cartilage. It's, but it's because one, we have the different
78:04 types. But two is because we're build on this matrix and we're gonna
78:09 these salts that make it hard and . So your bone is tougher than
78:14 cartilage. Children can bounce down I've watched it happen. All
78:22 adults cannot bounce down stairs when the gets to the bottom of the
78:26 there's usually something broken. Ok. bone and stuff or right still wear
78:38 helmets. Kids when you're riding on at 1000 MPH on the highway.
78:51 , tissue muscles. All right. are contractile cells in the body,
78:58 job, their role is to produce , whether that movement be locomotion or
79:03 movement of materials through the body. right. So when we think
79:07 you should always think movement highly, vascularized. That means uh whenever you're
79:14 something, when you're sending blood that means you're providing materials for that
79:19 it is in desperate need of So this is something that uses a
79:23 of energy. Right now. We're gonna describe how it all works.
79:27 just saying that there's three different tissues . All right. So these contractions
79:33 they're gonna produce are the result of cytoskeleton elements that are found within
79:39 So, we've talked about those micro , they have special arrangements of micro
79:43 inside them so that they can make cell change shape. And when you
79:47 the shell, the cell change that's what's gonna cause the movement,
79:51 it's going to be this type of or whether it's pushing stuff through your
79:55 . All right, three types, . This is what we'll spend all
80:00 time talking about because it's the one most interesting. Then we'll talk a
80:04 bit about smooth muscle, smooth muscle the type of muscle that lines the
80:08 of the body and moves material through body. So like your blood
80:11 your digestive system, so on and forth. They, they're structurally
80:15 very different. The one that sits the middle is the cardiac muscle,
80:19 muscle looks a lot and behaves a like uh I should say looks like
80:23 behaves a lot like skeletal muscle, structurally is very, very different.
80:27 can kind of see here and looking it that it's different. We will
80:30 about all those differences and similarities when get to the muscle thing. So
80:34 right now, I understand movement, different types. Ok, nervous
80:47 Again, we're gonna have a lot nervous. In fact, just
80:50 you know, the last two weeks of this course is the nervous
80:54 That's, that's how much time we talking about it. So that's why
80:58 said it's better just to kind of you the brief overview here rather than
81:02 actually kind of walking through neurons and cells. But those are the two
81:06 types. So they, these are main parts of the nervous tissue and
81:11 tissue is far more complex than what giving it credit for here. But
81:16 kind of covers everything you need to . All right. So there's two
81:20 cell types, we have neurons and have glial cells, neurons. These
81:25 the cells of transmission and and thinking producing action, right? These are
81:31 control cells of the body. The cells are their support cells. All
81:38 . Glial literally means glue. So , so initially they thought glial cells
81:42 connective tissue of the brain, but didn't come, they come from neural
81:48 . It's not just connective tissue, actually have major, major roles,
81:52 in just support, but also in and protecting. They play uh roles
81:57 immune response. They play uh roles , in uh regeneration. They do
82:02 sorts of really interesting things. But they don't do is the whole thing
82:06 we would look at the nervous system in the first place, which is
82:08 transmit nervous signals. So here this the communication portion. This is the
82:15 portion, but they're still very important though we don't give them that much
82:22 . What we're gonna do is we're start landing the plane here. I
82:24 I have what? Four slides, slides or is it, do I
82:31 a lot more? Five? Oh goodness. Uh I'm tired too.
82:37 right, what I wanna do is wanna talk about regeneration here. Now
82:41 this is a talk about regeneration in , but whenever you start looking in
82:48 a MP textbook and they talk about regeneration, they spend all their effort
82:52 about well, for the most epithelial regeneration. And why is
82:58 Because epithelial cells are the most regenerative of cells. And so that's where
83:03 spend all our time focusing. But cells in the body are regenerative.
83:08 some very few cells that are incapable regeneration. All right. So like
83:14 have a real difficult time regenerating. if you damage a neuron it's basically
83:21 . There are some cases where you repair them, but for the most
83:25 , it doesn't happen. All the basic method of regeneration or what
83:31 is, is when you're taking the that's been destroyed or harmed and you're
83:36 it with the exact same tissue. right. So this is what is
83:40 to restore organ function. And so , I'm going to use epithelium as
83:44 example when I make and cut my , I now have a wound.
83:50 what's gonna happen is that that wound I damage, that tissue is going
83:54 be replaced by the very same tissue was damaged. So I'll get epithelium
83:59 . I'm not gonna grow something else its place. All right, if
84:04 can't be regenerated, instead, what is this process of fibrosis. And
84:10 this is where the underlying or the connective tissue fills in. All
84:15 So in other words, you don't organ function or repair organ function,
84:20 actually have damaged organ function. And you're doing is you're filling up the
84:26 and you're trying to work around that . Now, this is where I
84:29 the part about a friend or not friend, a student that I had
84:33 12 years ago after I gave this regeneration, he came up to me
84:37 , actually. No, he didn't up to me after he said this
84:39 the class. He said, Doctor , when I was a little
84:43 I got hit in the head with ax or it might have been a
84:46 ax. I don't know which. it penetrated his skull and went into
84:50 brain. And he said, what there? I said, well,
84:56 survived is what happened. And he no. So again, you
85:00 nervous tissue has a real difficult part terms of regeneration. And so it
85:06 replace the neurons that you damaged in particular case. And so instead,
85:10 happened was the glial cells which behave connective tissue played the role of fibrosis
85:17 filled up the space where the damage occurred. And then the brain worked
85:23 that damaged area to create the networks stuff so that you can think and
85:28 and do all the things that you . And then he walked in a
85:32 like this for a little while. is that cruel. Yeah, he
85:37 do that. But my point is that the, the idea is
85:42 you know, when you damage a , if it's not repairable, then
85:46 system tries to work around that, ? It tries to work alongside
85:51 But so fibrosis here is replacing the with the fibers resulting in a scar
85:59 . And so with the case of uh kid where he'd gotten hit when
86:02 was much younger, you can imagine scar tissue throughout the brain around which
86:08 nervous tissue works it no longer can that space. Now, if you
86:13 a scar someplace, right? Like one, what's happened there is that
86:20 underlying tissue got damaged and so it replaced through this process of fibrosis and
86:27 now working around that fiber. All , it doesn't correct itself completely.
86:34 right. So you can see this with epithelium, but the underlying tissue
86:39 the muscle and everything else was, so severely damaged that it's not going
86:43 repair perfectly. So this would be you're seeing fibrosis with regeneration occurring on
86:49 . All right. So wind occurs depends on type of tissue damage and
86:54 depends upon the severity of the So for example, if you just
86:58 yourself, you know, shaving that away and you never know. But
87:02 you take a knife and stabby, , you're gonna see damage.
87:07 with scars. No, it's, not that. So. So you
87:13 be careful here. So, so example, if you have a,
87:17 an area of large damage. um I don't know. Can you
87:20 the scar there? Is it, it visible still? It's not.
87:24 I fell off a cliff when I like 18 years old, full face
87:28 . It was beautiful for about 13 . I flew. All right.
87:35 I broke my wrist and I actually a big old gaping hole in my
87:37 . But it basically, I put big old gaping hole on my
87:39 All right. So, what did do? I tore the muscle,
87:42 went all the way down to the . Right. So, the muscle
87:45 torn, the skin was torn, connective tissue was torn, nerves were
87:49 , all sorts of stuff. All . And then what do they
87:52 Anyone who's gotten a big old face like that? What do they
87:55 They take you in? They give a couple of stitches, they give
87:58 a couple of Tylenol and they send on your way, right? They
88:01 just give that. I mean, broke my wrist and all that other
88:03 stuff, right? But what's happened is, you know, your muscles
88:07 are responsible for that are say like have been torn apart. So,
88:12 know, you're gonna try to get to repair, but you're not gonna
88:15 able to repair them perfectly. They're now be there's gonna be dysfunction,
88:20 ? So they don't behave in the way that they normally do. That
88:25 is a representation of how they tried , how their body is trying to
88:29 under those conditions, right? So may feel like if you have a
88:33 , it's like I don't feel the thing when I touch that, you
88:38 , that's kind of numb in that , right? So why?
88:41 because the nerves were damaged and so weren't able to go in place,
88:44 the fibers filled up that space because space needed to be filled up.
88:48 right, that would be an Right now, all sorts of tissues
88:57 go through, repair, bones, themselves. One of my four
89:00 I told you about the kid that on the tree. My other,
89:02 , this was my, one of younger sons, my other younger son
89:06 at school and you know how they, you have terrible,
89:09 uh coaches now they just make you in the gym in circles and stuff
89:13 that. They don't, you don't to play dodgeball in other games of
89:17 , you know, like we did we were kids and so they're running
89:20 the gym and one kid kicked my while they were running around, you
89:25 how you do that? You're ha ha, I'm gonna knock your
89:27 out from underneath you and you fall the ground. It's like, ha
89:29 , you suck and I'm gonna beat up later type thing. No,
89:33 , no, you, you, that's what we did. So he
89:38 , he put his arm down and and broke his arm, ulna and
89:43 . When I went to go pick up, it was a U,
89:46 know, which is horrible, Um Where was I going with
89:50 Oh, right. So you take to the hospital? Like I
89:54 his, his arm was a U both bones in his lower limb were
89:58 and then they reset the bone. , when they go to reset,
90:03 basically drug you. So you don't anything. You're like, you go
90:06 and then they start manipulating and as as they can get five de within
90:10 degrees of repairing in others, getting set back into place, they're good
90:15 go. And if they can't get 5% that's when you go into
90:18 So they set the bone and if look at it, it was like
90:22 , right? So it was, was within five degrees, but that's
90:25 his bone looked like his like you know, so bone regenerates itself
90:34 upon the tensions that are put upon . So once the bones have reformed
90:38 we're gonna walk through this process real , then as you're working and creating
90:43 , the bone remodels itself so that can actually do the same function that
90:48 did previously as best it can. if you didn't reset it, and
90:51 just say if they didn't reset it it was like the U, I'll
90:55 it that way. You like then the bone would eventually work its
90:59 to create the strength that needs to able to function as close to as
91:02 as it did the first time. is why we actually try to reset
91:07 . Yeah, it's just a function the nature of epithelium because uh what
91:14 doing is we're creating AAA protective barrier on us, literally layers and layers
91:21 layers of dead cells. And so regeneration is a function of trying to
91:25 that protective barrier in the first right? So your 1st 20 layers
91:31 cells on the surface of your body absolutely dead and they're squished together like
91:35 . And we'll talk about that on . It's really kind of cool.
91:38 right. So what are the steps ? I'm, I'm, I'm really
91:42 not to make the class go I just, I do tell
91:46 All right. So when it comes regeneration. All right. So that
91:49 using skin as an example here. the first thing you're gonna get is
91:53 inflammatory response. An inflammatory response is there for two fold. It's
91:58 the trap uh pathogens in the area what happens is the blood vessels
92:03 So fluid begins to flow out of blood vessels into the area. And
92:07 what it does, it creates positive into the area. So things can't
92:12 . That's really kind of its And the other thing that you're doing
92:15 you're going to get uh if you like say a cut blood vessel,
92:19 will happen is blood will go into wound like what you're seeing down here
92:23 it will fill up this space. now what you're doing is you're now
92:27 , putting a, a lack of better term, a band aid on
92:31 structure. And so what you're doing you're creating a seal to say nothing
92:35 can come in. Right. That's a scab is, is basically a
92:40 barrier to say nothing else can come and we're going to use this space
92:44 kind of uh correct or fix So that's kind of uh the,
92:49 second thing and then that's gonna hold together. So it doesn't keep tearing
92:54 and tearing apart. Now, if have a wound that's really, really
92:56 , like let's say you, I know, have an eight inch gas
92:59 across your leg. Is this gonna real well? No, but if
93:04 small enough and the pressures are, , are great enough, it will
93:07 do its job, right? Second is to actually form the clot.
93:12 is the result of the blood coming and all the materials that come
93:15 Basically, it, it actually includes flow of materials and basically seals the
93:21 and protects it. So think about you have a wound, right?
93:25 first thing it does, it kind swells up and turns red, doesn't
93:28 ? That is that inflammation, And then the second thing is
93:34 If you actually broke a blood then we're going to cover it up
93:37 a scab. So that would be formation of the clot. The next
93:42 , there's only four steps is angiogenesis granulation, which are fancy, fancy
93:46 , for saying, um what we're do is we're going to create new
93:51 blood vessels that are gonna fill the so that we can deliver the materials
93:55 to do the repair. All So that's what the angiogenesis is.
94:01 we're sending signals to kind of attract the immunocyte, say, destroy things
94:05 shouldn't be there. Bring in the vessels, the blood vessels come
94:09 I'm going to start delivering materials and to rebuild. I'm going to have
94:13 migration of fibroblasts into the area. , the things that you find and
94:19 to tissue proper, they're going to and then they're going to start laying
94:22 new matrix. So this is where get that fibrosis that's taking place.
94:27 so the process of granulation is the of the environment where that damage took
94:35 , right? So it's the laying of the matrix, allowing the tissue
94:38 repair itself. And you can see here, what are we doing?
94:41 slowly breaking down that scab. are you guys like me and you
94:47 at your scabs? Like if you a cut, it's just like,
94:55 you do that or do you leave scabs alone and they slowly disappear over
95:01 . Come on. I thought we friends. I'm a gab picker,
95:05 ? I can't help it. it's fun. It's like this is
95:08 supposed to be on my body. , there. OK. Yeah.
95:13 if you leave a scab alone, will go away on its own because
95:17 actually the materials that make the scab have chemicals in them that are naturally
95:21 to break it down. All And finally, what we're gonna do
95:25 all going along during this process of in the fibroblast and starting to rebuild
95:30 structure, taking away the old damaged . That's when the epithelium,
95:35 we said it's contact, inhibit, . And so because they're no longer
95:40 and as we begin breaking down that , the epithelium grows closer and closer
95:45 closer together until finally, it right. So in terms of the
95:50 , it repairs the epithelium and then the underlying tissue like here in the
95:55 tissue where the granulation is occurring, when you rebuild the matrix by those
96:02 . And now you have fibrocyte and rebuilt everything and everything should return back
96:06 normal. Now, if it's big , is it going to return exactly
96:09 to normal? The answer is no . That's when you're gonna see the
96:15 or the damage because you have the take place, the bigger the,
96:21 , the damage, the slower it's take two more slides. Last two
96:28 or definition slides. All right. these are things I walk out of
96:33 with new words in my brain. right. The first word is a
96:39 that we use to describe what happens cells begin to misbehave and we need
96:44 get rid of them. All we have a process that cells are
96:48 to do. So, if you a cell that's misbehaving, say it's
96:51 in a cancerous way. Tumo Right. It's like, no,
96:55 not supposed to be doing that. it, go away, die.
97:00 so the cell does. And this is called aosis. All right.
97:05 you say it with me, apoptosis, apoptosis? All right.
97:11 am I making you say that? when I was in grad school,
97:15 , everyone who sees this word usually it incorrectly. They say apoptosis.
97:20 looking at me like this is how were taught to fit, right?
97:23 I was in grad school, I , I was at MD Anderson right
97:26 the street over here. And one the guys in our department was one
97:29 the leading experts on apoptosis. And you gave a talk and if you
97:32 apoptosis, he would stop the All right, we're talking in front
97:37 professors and colleagues and visitors or whatever he would berate you for your ignorance
97:43 how to pronounce the word, It's apoptosis. So I'm gonna teach
97:47 the proper way to say it All right. Medicine. They have
97:51 word without that a at the it's ptosis. So it's ptosis.
97:56 I think some people kind of try do it's apoptosis. Yeah.
98:01 So a lysosome is what is using process of Yeah, that's good
98:09 You're starting to think it's like, right. So when things go
98:12 we want to get rid of things are going bad, we don't want
98:15 die because our cells start misbehaving. , I, I love to tell
98:19 a little bit. Your body right probably has a cancer cell floating around
98:23 there. And your body says I want that cancer cell right. Here
98:27 go away. And that cancer cell is misbehaving is like OK, and
98:31 goes through the process of apoptosis, apoptosis, apoptosis. I'm not gonna
98:39 you. I'm just trying to help , right? So this is a
98:42 thing when cancers occur. When you getting tumors, what those tumors are
98:48 is they're circumventing the process of right? That's one explanation. Another
98:58 , as we mentioned is auto, is self eating. So, what
99:01 looking at here is as a cell misbehaving, it may have say an
99:06 or something that's misbehaving something that is behaving in a correct fashion. So
99:11 we want do we want to get of the thing that's not working,
99:14 ? So just think about your If your muffler is not working right
99:17 time, it's gonna cause larger issues the car. So what do we
99:21 ? We go get a new I'm just using Muffler. It's not
99:24 great example. Uh we could do fuel injector. Right. That's probably
99:28 better example. Right. But the is we fix the part that's broken
99:33 that we can keep the cell. don't want to get rid of the
99:36 until we have to get rid of cell. So, auto is how
99:41 deal with those things are that are . The other time we use auto
99:46 that cells remember are in the process producing these biomolecules to do their
99:51 If we have too much of these , then what will happen is let's
99:55 rid of some of them, So it's a way to deal with
99:59 producing too many materials or during periods stress, how to reduce activity and
100:05 consumption. The last three terms, of them should be easy, atrophy
100:13 familiar with, right? If you on the sofa all day long and
100:16 nothing, your muscles don't get If your muscles don't get stressed,
100:20 body is not going to waste the or energy to uh keep those muscles
100:25 . So those muscles go through it's a normal decrease in the size
100:31 an organ as a result of a of stimulation. If you ever had
100:36 wear a cast, you ever ever to wear a cast besides me?
100:39 right, when you, after you the cast off, what happened was
100:42 arm or leg, leg? So you've looked at your leg afterwards,
100:46 like what the hell is happening This leg doesn't look like that leg
100:50 because you're doing all the work with leg and you're protecting the other one
100:54 had atrophy. All right, the of atrophy is hypertrophy. This is
100:59 increase in the size of an organ to overstimulation. So when you go
101:03 work out all the time, what doing to those muscles is called
101:08 It's not a bad thing necessarily, ? So, hypertrophy is when something
101:14 bigger as a result of overstimulation. if you have a normal cell,
101:19 can make the cells bigger, that be hypertrophic very often, you'll see
101:23 next word associated with cancer, but doesn't necessarily have to do with
101:28 And the last one is hyperplasia. is just accelerated rates of growth,
101:34 ? So, tumors are typically recognized being hyper tropic and hyper plastic,
101:40 that's because they're misbehaving themselves. Can have cells that have a localized accelerated
101:45 of growth that is normal. Let's . Um Do you remember sixth
101:52 All of a sudden? You're oh yeah, the dreaded years.
101:55 . Do you remember you went away fifth grade, summer and you came
101:59 in sixth grade and people were like ft taller, you know, for
102:02 guys, remember all the girls that back and they had turned into women
102:06 you were like uh boobs, Hyperplasia? That's why. Ok.
102:15 these are normal things that, that occur. But there are times when
102:20 can be used to describe abnormal everything we've talked about from Monday to
102:28 at this very moment. I don't there's anything. Oh, nope.
102:30 have stem cells. Damn it. , stem cells. All right.
102:37 want to point out just one thing this. So, stem cells are
102:40 those cells that have unlimited mitotic That means they can divide and divide
102:44 divide. We have two different ways they can do this. They can
102:47 asymmetrically or symmetrically. When we say , what happens is is that the
102:52 cell divides and creates two daughter cells one daughter cell is kept behind to
102:57 as the stem cell. And then happens is the other daughter cell differentiates
103:01 then becomes whatever the downward path is asymmetric, the division occurs in such
103:09 way that one cell is going to committed to becoming down this path where
103:14 other one stays behind and serves as stem cell. All right, what
103:19 does is it allows us to ensure we maintain a pool of cells that
103:23 , always always are there for the of regeneration. Easy examples think of
103:28 skin, right? We have that layer that's near that connective tissue.
103:32 always regenerative. It is serving as stem cell layer to give rise to
103:37 other layers that are ultimately moving upward serving as the protective barrier. That
103:42 be an example of of that sort stem cells. So this is kind
103:47 a mechanism of self renewal and Now, am I done? So
103:53 through this slide will be potentially on exam right now in saying that I
103:59 you guys top hat questions, those are to help guide you to try
104:03 understand what it was we're trying to about. I remember at the beginning
104:06 every class, I said this is we're learning today. So you should
104:09 asking yourself, did I learn this at the end of every class?
104:14 . And you know, if you've taken me or if you've heard anything
104:18 me, my tests are hard. shooting for a 65 average, you
104:21 that. So if you get a year earning at, at minimum ac
104:26 what we're shooting for right there. ? Don't panic about numbers. We'll
104:29 about numbers later. Let's find out we're even having an exam because right
104:33 , Casa is just not being helpful all. Um Actually I'm sure they're
104:37 really hard, but they have like people to have to reprogram everything and
104:40 don't know what's going on over But anyway, I will email you
104:44 moment I find out something. All , I'll, I'll post it through
104:48 uh through canvas and it will tell time to sign up. All
104:52 I would recommend signing up and taking exam during this period when we normally
104:56 class that way you're done for the and you can just go get margaritas
104:59 Chewy and enjoy the rest of your or something like that. All
105:04 Any questions about the test? Any about what's coming up for those you
105:09 here late. I'm still trying to out why top hat isn't posting on
105:13 , but your grades are on top . So we'll get it all figured
105:17 . We got plenty of time. . No. Have a great
105:23 You have a question. All Let me turn off the
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