| 00:03 | All right, good morning. Can you hear me in the |
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| 00:06 | All right. Yes. No, kind of sort of you guys stare |
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| 00:11 | me like I'm a dead fish in back. Can you hear me? |
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| 00:16 | . So today before we begin, a reminder, we have a test |
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| 00:20 | Thursday. If you show up in classroom, you will be sad and |
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| 00:22 | , because you'll be the only person and there's nothing more depressing and sad |
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| 00:26 | showing up into an empty classroom. . So make sure you've signed up |
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| 00:31 | your test. Uh You're gonna go the building that they tell you. |
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| 00:34 | don't know which one is it? ? Ok. So it's gonna be |
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| 00:38 | if you don't know where that Wander around campus for a little while |
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| 00:40 | Thursday because you don't want to show late because they won't let you |
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| 00:44 | All right. And there are no for, oops, I forgot. |
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| 00:47 | , I got, got to campus boo hoo, hoo. Yeah, |
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| 00:50 | adults now be responsible. Second thing that today's lecture is on the |
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| 00:55 | So be sure to include it in studying. All right. So we're |
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| 00:59 | all the way through. So what we're gonna do is we're gonna |
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| 01:01 | about a little bit of anatomy a bit. Not a lot. All |
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| 01:05 | , we're gonna, we've been talking far about uh working our way up |
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| 01:09 | the hierarchy of organization in the Today is tissues. And so that's |
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| 01:14 | we're gonna go. We're gonna be at the four basic tissues of the |
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| 01:17 | . Do you remember the four basic are? Yeah. Epithelium, |
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| 01:21 | What else? Nervous and muscle and . All right. So that |
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| 01:27 | that is today's story and we're gonna kind of run through this stuff so |
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| 01:31 | you can kind of see there are be images, some histological images. |
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| 01:36 | will need to know good news on exam. I'm not gonna be tricky |
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| 01:39 | this. I'm probably gonna show you picture that looks very much like the |
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| 01:42 | you see up here. All And I'm gonna point out which ones |
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| 01:44 | need to know there's like only three them because I'm not gonna sit there |
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| 01:48 | just start throwing histology at you because , this is not a histology class |
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| 01:51 | two histology is a real pain in butt. All right. It takes |
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| 01:55 | to get good at it. And we're only gonna do a couple of |
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| 02:00 | just to make our lives simple so we have some definitions in our |
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| 02:03 | And so today, what we're gonna , we're gonna start with Epitel and |
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| 02:05 | gonna move to connective tissue. And we're gonna briefly mention uh muscle and |
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| 02:09 | tissue since uh basically half of the is about muscle and nervous tissue. |
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| 02:14 | , uh we're just kind of ignoring for the most part today. |
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| 02:18 | what we're looking at here is kind the beginning of epithelium. All |
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| 02:22 | what is epithelium? It's simply a of cells. Typically, the sheet |
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| 02:26 | cells is gonna cover the body And so the one thing you need |
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| 02:29 | remember, your body is that you a donut, you are not a |
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| 02:33 | structure that has stuff on the You are a donut, you have |
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| 02:37 | hole through you. And so the includes what you see on the |
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| 02:41 | but also the portion that makes up donut. All right. So it |
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| 02:47 | the surfaces of the body. All . And if you think about when |
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| 02:51 | talk about those cavities, those cavities are gonna be covered in epithelium. |
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| 02:56 | right. So there's two basic types epithelium. We have what is called |
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| 02:59 | epithelium. This is what we think when we think about epithelium. It's |
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| 03:02 | that covers the bodies uh in in the cavities. But the other |
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| 03:06 | is glandular epithelium. These are the of your body and we're gonna see |
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| 03:11 | some wild differences today between the types glands. All right, we have |
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| 03:17 | and we have multicellular glands and there's types along the way now, |
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| 03:21 | because we're creating sheets, these sheets to be held together. And so |
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| 03:24 | you're gonna find are these specialized So all this stuff that you've been |
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| 03:29 | about where you're going, why are keep doing this and why aren't we |
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| 03:32 | this? Um Why aren't we talking anatomy? It's because we're leading up |
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| 03:37 | it. So the specialized connections are things you've already learned about like the |
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| 03:41 | Desma Zoos and the desmosome and tight where we gave examples of your skin |
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| 03:46 | held together when your big or your sibling gave you Indian burns or if |
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| 03:51 | were the torturer when you gave those siblings, the Indian burns. All |
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| 03:57 | . So Piel is characterized by these uh connections. There we go. |
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| 04:04 | right. First off, epithelial tissue a vascular, all right, but |
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| 04:10 | is innervated. All right. What that mean? A vascular when you |
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| 04:13 | an a at the beginning of the usually means not. So it doesn't |
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| 04:16 | blood vessels, all right, but does have nerves traveling through it. |
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| 04:22 | other words, there are special neural that allow for you to sense the |
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| 04:27 | the surrounding environment, whether it be or externally. Now, in terms |
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| 04:32 | no blood. Well, how do cells stay alive? Well, generally |
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| 04:37 | , there is not a cell in body that is more than 10 microns |
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| 04:40 | from a blood vessel. All But with the case of epithelium, |
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| 04:45 | you're gonna have is you're gonna have vessels that are nearby, they release |
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| 04:48 | materials out into the surrounding tissues. a connective tissue and that stuff works |
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| 04:54 | way between the cells to get to that epithelium is actually located. |
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| 04:59 | you know, this because you've skinned your knee before and it didn't |
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| 05:04 | right? Or you've cut yourself and didn't bleed. That means you didn't |
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| 05:08 | far enough down to get to where blood vessels actually are. You only |
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| 05:13 | through a couple layers of the But when you got down further. |
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| 05:17 | this picture, what you're looking at is an example of your skin. |
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| 05:20 | here you can see this portion right . That's epithelium, the pink stuff |
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| 05:25 | then the stuff underneath that, that's tissue. And so that's where the |
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| 05:29 | vessels are all located. Look, get really, really close, even |
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| 05:32 | this is a cartoon, this is that closeness. So the living cells |
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| 05:37 | here in the epithelium are receiving their from the surrounding or the nearby connective |
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| 05:44 | , the blood vessels that are located . And you can see here |
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| 05:47 | I have a uh a neuron penetrating into the epithelium. So that's demonstrating |
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| 05:53 | innervation. All right. One of other neat uh uh characteristics of epithelium |
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| 05:58 | that it's regenerative if you've ever cut . You probably notice that you bled |
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| 06:04 | then you got a scab and then the scab, something magical happened and |
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| 06:07 | couple of days later your scab disappeared you had new skin again. All |
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| 06:12 | . That's regenerative. Meaning your skin replaces itself and is not just the |
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| 06:17 | , but that's the easiest one to think of. So epithelium is |
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| 06:20 | to replace lost or damaged cells. , what's really interesting about this type |
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| 06:25 | regeneration is if things are allowed to and divide on their own, they |
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| 06:30 | continue to do so on infinitum until have big, horrible ugly tumorish looking |
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| 06:35 | on your body. But do you that when you cut yourself? |
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| 06:38 | So what's interesting about epithelial tissue is is what is called contact inhibited. |
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| 06:43 | when the cells are touching each they send signals to one another saying |
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| 06:48 | divide. But when you break that , then the cells go. Oh |
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| 06:52 | , I'm not touching another cell like . So I'm gonna grow until I |
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| 06:56 | touch a cell like me. And that's the contact inhibition. It's when |
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| 07:01 | touching, don't grow when I'm not , grow contact inhibition. All |
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| 07:07 | tumors do not have that sort of inhibitor in place. Now, in |
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| 07:14 | picture here, what we're looking at a generic epithelium and what you can |
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| 07:19 | in this epithelium. If you look this little picture, you can see |
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| 07:21 | here on the top and you can at the bottom and you can see |
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| 07:24 | they are very different looking in the , right? You see that, |
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| 07:29 | , top looks like it's a wave looks like it's flat. All |
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| 07:32 | So whenever there's differences between two we call that polarity and epithelium demonstrates |
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| 07:39 | sort of polarity because they have different to their body or to their, |
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| 07:44 | their surfaces. All right, we this previously, we said look on |
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| 07:49 | side that faces outwards towards whatever the environment is, whether it's the inside |
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| 07:56 | a tube. So this would be external environment, your digestive tract is |
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| 08:00 | or whether it's on the surface of skin. This is typically the side |
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| 08:03 | we're gonna secrete or absorb materials. so what we're gonna see is we're |
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| 08:09 | see on that surface, which is the apical side, a unique environment |
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| 08:14 | allows it to do one of those things. And then on the opposite |
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| 08:19 | , that would be the basal And then we typically count the sides |
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| 08:23 | the cell as part of that basal . It's lateral, but we collectively |
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| 08:28 | to it as basal lateral. So what we have here, basal |
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| 08:31 | lateral surface. So basal lateral is be the side that's connected to |
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| 08:36 | And so there you're gonna see different and molecules that allow it to hold |
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| 08:40 | to the thing that's connected to all . So in the case of the |
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| 08:45 | side, what we'd have is we'd proteins like the parts that make up |
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| 08:49 | hemidesmosome that are penetrating down into the tissue that hold it in place. |
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| 08:54 | the lateral side, you might be desmosome or tight junctions or adherence junctions |
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| 08:59 | are holding it to the uh That's right next to it. So |
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| 09:03 | we have two different functions, apical , absorption secretion, basal lateral |
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| 09:08 | primarily for a holding in place. so the characteristics of what proteins and |
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| 09:14 | molecules are gonna be found on those are gonna be unique to those two |
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| 09:18 | . All right. Now, on basal side, we refer to that |
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| 09:24 | that's coming out, that's being put by that cell as the basal |
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| 09:30 | All right. And that means the tissue is gonna be producing another half |
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| 09:35 | well. It's basically a series of that basically serves as molecular velcro. |
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| 09:39 | then the connective tissue has its half molecular velcro and together those two things |
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| 09:44 | up just like velcro does. And what holds everything in place and collectively |
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| 09:49 | uh basal lamina and the I'm blanking the other name right now, it's |
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| 09:54 | uh reticular lamina. There we I knew I'd find it eventually. |
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| 09:57 | the reticular lamin together are referred to the basement membrane. All right. |
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| 10:02 | you probably heard basement membrane before and you haven't, that's OK. This |
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| 10:06 | why we have the class, So the basement membrane are the proteins |
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| 10:12 | those two tissues that are holding everything place in apposition towards one another. |
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| 10:17 | right. So this how we hold cells in place on the basal |
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| 10:22 | So the connective tissue is typically what see right next to epithelium. Not |
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| 10:26 | , but usually. All right. so that's what it said. We're |
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| 10:30 | proteins upward. That would be the lamina and collectively ba uh uh basement |
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| 10:35 | is formed by the reticular lamina and basal lamina coming coming together. So |
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| 10:41 | wanna flip for a moment and go to the apical side. All right |
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| 10:45 | kind of what we're doing. We're back a lecture just to kind of |
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| 10:48 | at some other features of cells. these are very specific to epithelial |
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| 10:53 | So one thing that epithelial cells may , not all of them do but |
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| 10:58 | have. And that's why you see this little picture, the little bumps |
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| 11:02 | something called micro VLI. Now, VLI means little fingers and what a |
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| 11:08 | villa is is simply saying, I have a very limited amount of |
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| 11:13 | , but I wanna have a larger area than I'm allowed to actually |
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| 11:18 | All right, see, see I stuff and I secrete stuff. And |
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| 11:22 | the more surface area I have the my ability to do those things. |
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| 11:26 | because I'm stuck next to other cells I'm limited to how much space I |
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| 11:30 | have. The only way I can more surface area is if I go |
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| 11:34 | and down. Like so, and why we create these little tiny |
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| 11:38 | And this is what it actually looks . So you can imagine for a |
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| 11:41 | , just think of a surface of cell being as wide as his |
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| 11:44 | In order for me to make more area, I'd have to go upwards |
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| 11:48 | then come back down and upwards and back down multiple times. And that |
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| 11:52 | my surface area up uh multifold when get to the digestive system. One |
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| 11:58 | the things we're gonna talk about or Doctor Ogletree or Doctor Gill will talk |
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| 12:03 | is they'll talk about the, the the small intestine and the micro vla |
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| 12:09 | with the small intestine. Your whole intestine is by length, probably about |
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| 12:13 | ft long, right? Which is impressive in and of itself that you |
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| 12:17 | something that long in your body. because of the, the way that |
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| 12:21 | structure of the cells are and the or the the folds of the uh |
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| 12:26 | intestine, you have an effective meaning it's like having uh a small |
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| 12:32 | that's roughly a mile long because of those little tiny bumps, which is |
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| 12:37 | impressive if you think. But think big you'd have to be to have |
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| 12:40 | mile long, smooth intestine it would pretty big. All right. So |
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| 12:46 | of the micro vili to increase surface , it's only found on the apical |
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| 12:52 | . And typically we're going to see on cells that are playing a role |
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| 12:56 | absorption, absorbing materials. And that be an example, would be the |
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| 12:59 | tract is gonna, I'm gonna absorb . Something that looks like a |
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| 13:05 | but it's actually a little bit All right, kind of sticks up |
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| 13:09 | called cilia. All right. So this little micrograph, you can see |
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| 13:13 | things right here sticking up are the , the micro villa, see these |
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| 13:18 | tiny things down there. That's the villa. So you can kind of |
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| 13:21 | a sense of proportion. All So cilia are typically associated with cells |
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| 13:28 | are gonna secrete mucin. Now, is mucin mucin is simply the protein |
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| 13:33 | you find in mucus. All Think of the nasty mucousy thing that |
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| 13:37 | can possibly think of. That's about water. And then the rest of |
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| 13:41 | is proteins about 1% which is mucin . And there are about 20 different |
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| 13:46 | proteins and that's about all you need know about them. All right. |
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| 13:49 | , what the cilia do is they there and move, they sit there |
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| 13:54 | go like this, go away, away, go away. And so |
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| 13:56 | you're producing the mucus, the cilia pushing the mucin and the mucus along |
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| 14:03 | surface of the cells. So it propulsive in nature. Now, in |
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| 14:09 | micro organisms like bacteria that have typically Celia is used to propel the |
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| 14:15 | around. But because your cells are , what they're doing is they're not |
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| 14:18 | the cell, they're propelling the materials the surface of the cell. The |
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| 14:23 | type of propulsive extension from a cell the body is called the flagellum. |
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| 14:32 | right. So flagellum and CIA are are bacteria, SIA are found on |
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| 14:36 | surface of cells that are uh uh materials. Flagella is only found on |
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| 14:41 | cell in the body. It is epithelium, it's called a germ |
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| 14:44 | This is sperm. And so I'm showing you the difference here between a |
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| 14:48 | which is much, much longer and cilia, which is a bunch of |
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| 14:51 | put together. All right, that's only thing you'll need to know |
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| 14:55 | All right. So there's a lot information on the slide. I don't |
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| 14:58 | I've ever asked a question about But what I want to show you |
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| 15:01 | that silly and flagella are related to another. They structurally internally. What |
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| 15:06 | have are a bunch of microtubules and bunch of kinesin that help the silly |
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| 15:10 | the flagella uh move and how they is kind of the important part |
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| 15:15 | So flagella serve like a propeller. it uh it pushes a cell forward |
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| 15:20 | so silly. On the other is like a row uh or an |
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| 15:24 | where you sit there rowing a it would push sideways like, |
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| 15:28 | so you can see how the multicellular took it to be able to push |
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| 15:33 | along the surface. Having flagella would useless because it would just mix the |
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| 15:39 | in a circle. All right. , cilia are found on secreting |
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| 15:45 | Micro vli found on absorptive cells. now that's gonna lead us into. |
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| 15:50 | what does epithelia do? What do cells do? All right. |
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| 15:55 | we have uh they're either covering in or they're gonna be glandular in |
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| 16:00 | So typically what we do is we , hey, um epithelium have a |
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| 16:04 | of roles. They play a role protection and they're actually really good protecting |
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| 16:08 | . Have you ever scraped the surface your skin? Like, so take |
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| 16:11 | long fingernail, scratch along the surface does your skin start bleeding? |
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| 16:17 | because the cells are really strong. right, they are protective in |
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| 16:21 | They keep the outside, outside and keep the inside inside. So that's |
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| 16:26 | one, they are selectively permeable. , I'm gonna ask this of the |
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| 16:31 | lesson of the guys because I know guys probably don't do it. But |
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| 16:34 | , how often do you put lotion your skin frequently? Yeah. |
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| 16:39 | And why does it just sit there the surface of your skin? |
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| 16:42 | it gets absorbed in and the reason gets absorbed in is because it is |
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| 16:48 | permeable. It is what decides that into the body and what comes out |
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| 16:53 | the body on the surfaces. All . So again, I'm pointing at |
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| 16:56 | skin as an easy example, the , but this is true throughout your |
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| 17:00 | body. Uh Just the opposite of . If you go into a bathtub |
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| 17:05 | if you go swimming, does your swell up like a balloon because of |
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| 17:08 | the water that had been absorbed in ? No, it doesn't, |
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| 17:11 | Because it's a barrier to water. right, lotion is primarily fat. |
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| 17:16 | you can kind of start saying, a second here, I'm starting to |
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| 17:18 | something fats get absorbed pretty easily through because it's made up of fat on |
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| 17:23 | surface, right? But water, a barrier to that. All |
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| 17:28 | So we have something that is selectively and also uh we'll often see Epitel |
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| 17:35 | playing a role in secretion. And here what we're doing is we're secreting |
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| 17:39 | one of two directions. And you got to think in terms of |
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| 17:42 | am a donut. All right, are what you eat. Maybe you |
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| 17:46 | eat donuts. I eat donuts. that's an easy example for me. |
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| 17:49 | I secrete things on the surface of skin. All right. What's something |
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| 17:52 | I secrete on the surface of my ? Sweat? Well, I see |
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| 17:56 | going for an easy answer here. , sweat. Yeah. So sweat |
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| 17:59 | water plus stuff. All right, not even gonna describe the stuff. |
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| 18:03 | did you know that some of the are things that are really, really |
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| 18:06 | to you? For example, we some enzymes, RN A and DNA |
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| 18:10 | , for example. So one of things we do is we defend against |
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| 18:15 | invasion by actually having enzymes that will down RN A and DNA. This |
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| 18:19 | one of the defenses against viruses. skin, we have all sorts of |
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| 18:24 | things on our body. You, wanna find out, go find |
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| 18:27 | go go to a lab, get agar plate, just take a Q |
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| 18:31 | , wipe your skin and uh run across that agar plate. Let it |
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| 18:35 | for a while and watch how many nasty things grow on it. All |
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| 18:39 | . But that doesn't happen to us though we have all sorts of gross |
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| 18:44 | . And the reason is, is part of what we, what we |
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| 18:47 | as a measure of protection is secrete on the surface of their skin that |
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| 18:52 | against pathogens. But there are other we secrete, right? So when |
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| 18:57 | eat my cheeseburger, right, it into my digestive system. And so |
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| 19:01 | secrete all sorts of enzymes to break that cheeseburger, to break down the |
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| 19:07 | of the cheeseburger, the proteins of cheeseburger, the carbohydrates of the |
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| 19:10 | All the yummy goodness is broken down the enzymes that my epithelial cells of |
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| 19:15 | digestive tracts secrete outward. Does that sense? Yeah. All right. |
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| 19:21 | we have a role in secretion. are just two examples. We can |
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| 19:24 | about the, the mucin that are our body cavities or the mucus |
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| 19:29 | that our bodies produce. We can talk about lungs just to make our |
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| 19:32 | happy. All right. So we have to talk about all the gross |
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| 19:35 | . All right. But that's the we protect against the dust in our |
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| 19:38 | , creating water and other materials. , the last thing that epithelial cells |
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| 19:45 | , and it's really more of the of the neurons that are found |
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| 19:49 | But there are often times you'll see epithelial cells that work with the neurons |
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| 19:54 | play an important role in determining what's on in that environment. All |
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| 20:00 | So there is oftentimes some sort of reception that's taking place. All |
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| 20:07 | But typically that's done in conjunction with it's done by solely the neurons that |
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| 20:13 | not epithelial in nature. Ok. , the way that we name epithelial |
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| 20:21 | has a pattern, this is kind like chemistry. If you learn |
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| 20:24 | everything is named a specific way. a nomenclature and epithelial cells have a |
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| 20:30 | that goes with it. It has first name and it has a last |
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| 20:33 | which makes it easier for easy for . All right, because it's not |
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| 20:37 | be this real complicated thing like three 4-0 methyl yada, yada yada, |
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| 20:46 | ? The two names, the first um has to do with the number |
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| 20:50 | cell layers. So it has two . You're either gonna be simple or |
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| 20:56 | gonna be stratified. Simple means I a single layer of cells. So |
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| 21:02 | a g simple, simple, All right. If I have more |
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| 21:06 | one, so two or more, called stratified. That makes it pretty |
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| 21:10 | , right? So all I gotta first off is when I look at |
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| 21:13 | epithelium and I'm told it's epithelium. first question I need to ask is |
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| 21:17 | many layers do I see? Do see one layer or do I see |
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| 21:21 | than one layer? That's pretty All right. So single layers are |
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| 21:27 | where you're gonna have absorption or That means there's not a lot to |
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| 21:30 | through it. So that one little cells makes it really, really easy |
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| 21:34 | materials to travel one way or the . So that absorption, the opposite |
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| 21:37 | absorption is filtration. All right, . On the other hand, is |
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| 21:42 | found where I need protection, the layers I have the greater that uh |
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| 21:48 | does at protecting. All right. , what we'll see is the nomenclature |
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| 21:55 | the stratified cells is not based on outer layer, but it's gonna be |
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| 22:00 | on that basal layer. All So that's where we're gonna be focusing |
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| 22:04 | we look at the second name. right. So the second name comes |
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| 22:09 | shape. Now, the picture that looking at here, these cartoons are |
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| 22:14 | because they have an artist who can a perfect picture in the real |
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| 22:19 | Is it incredibly obvious all the What you're looking at? No, |
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| 22:24 | course, not. All right. what we can do is we can |
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| 22:27 | these very basic shapes to help us the second uh name. All |
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| 22:32 | So all epithelia, like we I have two names. Second name |
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| 22:35 | gonna describe the shape of the The first is a flat shape. |
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| 22:39 | call that squamous. Squamous means scale . And so you can imagine if |
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| 22:44 | have ac cell that's flat where the side is longer than the uh the |
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| 22:51 | , you know, the the uh that would be squamous. All |
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| 22:55 | then we have something called cuboidal. roughly cuboid in shape or cubed |
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| 23:03 | All right. So the sides and length are roughly equal. Is it |
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| 23:06 | be equal? No. And are gonna get a ruler out and try |
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| 23:09 | measure these things? No. All . But you can look at it |
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| 23:11 | say, hm, yeah, that more like a square than anything |
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| 23:14 | All right. So that would be example of cuboidal. The last is |
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| 23:19 | and here the basal side is but the vertical length is long, |
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| 23:24 | ? So it's like a column and where that comes from. All |
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| 23:27 | So it's a tall column like So you can take one of those |
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| 23:32 | names, simple or stratified. And you add the second name, it's |
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| 23:36 | cuboidal or columnar. And that's basically we use this nomenclature. It's very |
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| 23:42 | . Now, when you're looking at of these and this is your small |
|
| 23:47 | lesson of the day when you look a cell and you're sitting there |
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| 23:50 | I have no idea what I'm looking . I can't tell if this, |
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| 23:53 | the shape of this thing is because life is never like the perfect |
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| 23:57 | Let me look at the nucleus because nucleus basically conforms to the shape of |
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| 24:02 | cell. So if I have a cell, my nucleus is gonna be |
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| 24:07 | and flat. If I have a cuboidal, I'm gonna have roughly a |
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| 24:12 | nucleus. And if I have a , I'm gonna see the nucleus kind |
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| 24:16 | ovoid but elongate in the vertical plane that you can kind of tell. |
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| 24:22 | if you're ever like, I'm not sure, just kind of look for |
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| 24:25 | nucleus as well. Those two things of go hand in hand. So |
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| 24:30 | epithelium, we are going to learn three simple epithelium. We're gonna learn |
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| 24:35 | of the stratified epithelium for identification. a total of five different tissues that |
|
| 24:43 | have to know. Yes, ma'am . Mhm Sorry. I'm trying to |
|
| 24:49 | backwards this one. But th th one, yeah, she asked what |
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| 24:58 | pseudostratified we'll see in just a All right. I, because I |
|
| 25:02 | want to focus on that one yet that's, it's kind of like this |
|
| 25:07 | too, but is transitional. We'll there. All right. It's gonna |
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| 25:12 | these first five. All right. it's good eye. All right. |
|
| 25:17 | first off, we're gonna look at epithelium. We're gonna learn it. |
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| 25:20 | is primarily as we said, concerned absorption filtration. It also plays a |
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| 25:23 | in secretion, right? It's it's not so uh large in its |
|
| 25:29 | of protection. All right. So have simple squamous, simple cuboidal, |
|
| 25:33 | columnar, pretty simple nomenclature, Just by looking at the name, |
|
| 25:37 | can say, 01 layer shaped like . All right. Now, that's |
|
| 25:43 | simple part of, of the There's always gonna be things that screw |
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| 25:49 | up. All right. So an of a simple epithelium that doesn't follow |
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| 25:53 | nomenclature is something called endothelium. Thank very much scientists who named this. |
|
| 25:58 | right. Now, you're gonna hear word. I'm not gonna put it |
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| 26:01 | the test and say, what is ? I'm not gonna do that because |
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| 26:05 | an important today. All right, is the simple epithelium of the cardiovascular |
|
| 26:11 | . That's all it means it's part part of the cardiovascular system. So |
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| 26:15 | you look at blood vessels, you'll endothelium over and over and over and |
|
| 26:20 | again. All right, that's just language that we use there. Another |
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| 26:25 | is mesothelium. And so when we about the serous membranes of the body |
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| 26:30 | , so the stuff that surrounds the and the lungs, you remember when |
|
| 26:33 | talking about the, the pleura, are serous membranes. And so they |
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| 26:38 | collectively referred to as the mesothelium. from where they originate from the |
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| 26:44 | which is a developmental thing and that's it got its name from. |
|
| 26:47 | I'm not gonna ask you what is ? Can you identify mesothelium? That's |
|
| 26:51 | the goal. I just want you know just I'm teaching you a couple |
|
| 26:54 | words, doesn't mean that that's the of the vocabulary. There's a lot |
|
| 26:58 | other stuff out there. So don't be surprised when something new pops |
|
| 27:02 | So ready for some pictures. All . Not scary. Simple epithelium, |
|
| 27:09 | ? We said we have simple So here we have an elongate |
|
| 27:13 | right? You can see the nucleus gonna be flatter. This would be |
|
| 27:17 | example of that. Now, I'm tell you right up front. The |
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| 27:21 | that you see here are the worst that this book company could purchase. |
|
| 27:27 | went. How do we spend as money as possible to get pictures that |
|
| 27:32 | one can interpret or understand? All , on the test, I'm not |
|
| 27:36 | by funds, right? I can on the internet and find anything I |
|
| 27:40 | . I'm not, I don't even to give credit for it because it's |
|
| 27:42 | test, right? So my pictures gonna be a lot better than what |
|
| 27:45 | see here. But I'm just trying show you can you see, see |
|
| 27:48 | cells being flat in this picture, ? No, you cannot. |
|
| 27:52 | All right. So if you look , you can see right there the |
|
| 27:56 | purple. Do you see the dark ? You see surrounding it, the |
|
| 28:00 | purple. Do you see that the is next to another cell which is |
|
| 28:04 | to another cell, which is next another cell like that? There's |
|
| 28:07 | they're not stacked on each other. right. So typically when you see |
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| 28:11 | Squamous, they are connected in this , there's nothing on the top or |
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| 28:15 | the bottom. If it was this , it would be, that would |
|
| 28:20 | stratified, columnar. But you'd expect see lots of them next to each |
|
| 28:24 | . They're not gonna be stacked that . They're stacked this way. This |
|
| 28:27 | the alveoli of your lungs. All . Now, I promise you 100% |
|
| 28:36 | the question that I throw. If get this question and you see this |
|
| 28:39 | , you're not gonna see that right? The simple Squamous will be |
|
| 28:44 | . I don't want to sit here say, let me see how I |
|
| 28:46 | trick you. I want it to obvious. So it will look more |
|
| 28:50 | this where it's really obvious to As long as you understand your |
|
| 28:55 | that's the key thing. All Now, this one's a little bit |
|
| 29:00 | . But again, they was we're gonna take a picture and we're |
|
| 29:03 | make it so far away that you see what's going on. All |
|
| 29:06 | the, the images I use, right up close. So it's, |
|
| 29:10 | , it's this obvious with simple you have the cuboid like cells, |
|
| 29:15 | have more or less round nuclei. if you look carefully at these |
|
| 29:19 | you can see how there's just tons tons of them, they're connected to |
|
| 29:22 | other, but there's only one Can you find the basal layer in |
|
| 29:26 | things? Can you find? let's make it easier. Can you |
|
| 29:29 | an apical layer? What's apical mean the surface? So in this, |
|
| 29:34 | you find a surface? What do think? Remember? Think about a |
|
| 29:40 | is the inside of the tube? nod your head, everyone nod your |
|
| 29:44 | said yes. Right. Apical. here's a tube, there's a |
|
| 29:49 | This is a tube that's a They're all tubes. And so if |
|
| 29:53 | find the tube, do you see cells stacked on each other or |
|
| 29:59 | No? OK. So we automatically by looking at this, oh, |
|
| 30:04 | not still stacked on each other, next to each other. So it |
|
| 30:07 | to be simple. All right, see the look on your face. |
|
| 30:09 | I'm gonna come over here and I'm point with my finger instead of |
|
| 30:12 | All right. So if this is tube right then right there, there's |
|
| 30:17 | cell, is there a cell sitting it? No, I mean, |
|
| 30:21 | can pick any one of these No, there's no cells underneath |
|
| 30:24 | OK. Now again, remember this a terrible magnification. You can look |
|
| 30:29 | something that's more like this. All . In fact, I already know |
|
| 30:33 | the picture is. So it's, not this, but it looks a |
|
| 30:37 | like one of these close up. . Just saying. All right. |
|
| 30:42 | anyway, so if there's my there's my cell. So I'm only |
|
| 30:45 | thick. So it has to be . And then I start looking at |
|
| 30:48 | nuclei because I can't really see the of the cell. And what does |
|
| 30:51 | nuclei look like? Kind of Don't they? So they're not |
|
| 30:56 | they're kind of squat. So that be cuboidal. Does that make |
|
| 31:02 | OK. So those two you will to be able to identify not this |
|
| 31:08 | but something that looks more akin to . The picture you're gonna see is |
|
| 31:12 | be a lot closer like the it'll and I'll highlight and say, what |
|
| 31:16 | this area, you know, ready the third one? All right. |
|
| 31:20 | that's simple, squamous, simple Then the next one must be simple |
|
| 31:26 | . Again, worst picture they could picked ever. But can you find |
|
| 31:30 | apical side? Where's the apical up ? See that? Do you see |
|
| 31:38 | it goes up and down and down then back and then like this, |
|
| 31:41 | apical, what you're looking at here the glands of the digestive system. |
|
| 31:45 | right. And what you can see if I know this is the apical |
|
| 31:49 | , then I need to look here the cells that are near the apical |
|
| 31:53 | . All right. And what you see is as it goes down and |
|
| 31:56 | back up, I've got these really long cells. Do you see |
|
| 32:00 | long cell? They're all jammed up to each other, right? And |
|
| 32:03 | you look at the nuclei, what the nuclei look like? Are they |
|
| 32:06 | or are they this direction? And , I know this is a terrible |
|
| 32:11 | . I know it'd be, imagine that 20 times magnified. Would you |
|
| 32:16 | able to tell her? Then if looked like this, would you be |
|
| 32:20 | to tell? Yeah, that's, the idea. OK. Now, |
|
| 32:25 | though you're playing on pathology, that's you have to memorize and learn and |
|
| 32:30 | a horrible nightmare. So anyway, simple columnar. All right, |
|
| 32:37 | you'd probably see the image that's like like in that area. And it's |
|
| 32:41 | necessarily gonna be in this orientation, might be on its side, it |
|
| 32:45 | be upside down, find the apical , find the basal side and from |
|
| 32:50 | , make a decision. That's the thing to answer your question. All |
|
| 32:59 | . Now, this is a little better picture. This is a better |
|
| 33:02 | still not great. But what we're at in this picture is pseudo |
|
| 33:07 | Now, what does pseudo mean false stratification? Do you think I'm gonna |
|
| 33:14 | to make you identify something that's called stratification? No, that's would be |
|
| 33:18 | unfair, right? It takes effort a lot of time to learn how |
|
| 33:23 | identify that. So it says false . So this is a type of |
|
| 33:29 | epithelium. All right. The problem simple or pseudo stratified is that your |
|
| 33:35 | will get I'm coming over here instead it, it looks like there's multiple |
|
| 33:39 | . You see you've got a cell , cell or nucleus, there, |
|
| 33:41 | , there, nucleus, there you on the way up, it looks |
|
| 33:43 | there's lots of layers but they're they're actually cells of varying heights jammed |
|
| 33:50 | next to each other. All So here, what I want you |
|
| 33:54 | know is the definition a pseudostratified is simple co or simple columnar epithelium that |
|
| 34:02 | like a stratified epithelium. All That's what I want you to |
|
| 34:07 | I'm not gonna throw this picture up you because that would be mean, |
|
| 34:12 | . So you will not get a of pseudo stratified. All right. |
|
| 34:18 | some of the cells in this will reach the apical surface but all the |
|
| 34:23 | are attached to the basement membrane. they weren't at attached, then it |
|
| 34:26 | become stratified. All right. So types of simple epithelium that you need |
|
| 34:37 | know, be able to identify stratified . All right, multiple cell |
|
| 34:45 | So you can see here in the , multiple cell layers typically down |
|
| 34:49 | we have a bunch of living And as they progress towards the apical |
|
| 34:54 | , those cells will begin dying off they get further and further away from |
|
| 34:59 | nutrient source. Also, along the , they're gonna change their shape. |
|
| 35:05 | the way that we typically uh name is gonna be based on what we |
|
| 35:09 | down here at the basal side. right. Now, again, their |
|
| 35:14 | stratified epithelium of which there are many are going to be primarily playing a |
|
| 35:19 | in protection. So we need to simple stratified ST or sorry, simple |
|
| 35:25 | , simple cuboidal, simple columnar. is number four that you should be |
|
| 35:29 | to identify and then this is going be the list, right? So |
|
| 35:33 | got one of four. All So here is stra stratified, uh |
|
| 35:40 | ep I said uh you're naming it the basal side, I apologize. |
|
| 35:43 | , you're always naming it on the side. So my mistake. So |
|
| 35:47 | out what I said earlier. It's on the apical side on which I'm |
|
| 35:50 | things. All right. So here can see down at the basement, |
|
| 35:55 | gonna have uh some sort of But as I move up, I |
|
| 35:59 | my shape. And so that's what gonna identify. This is your |
|
| 36:01 | this is what your skin would look . So down here you can see |
|
| 36:05 | the living cells and as you move , they start changing their shape. |
|
| 36:08 | up here they're more flattened and elongate they were when they started off. |
|
| 36:13 | that's where it got its name from . With regard to stratified uh |
|
| 36:19 | There are two basic types. All . And this is how you can |
|
| 36:23 | the difference. You can take your and run it across your skin. |
|
| 36:25 | can see that's kind of tough. . Right. It's pretty good. |
|
| 36:28 | if you take that same finger, not suggesting you do this right |
|
| 36:31 | but on your own, take that finger, move it to the inside |
|
| 36:34 | your cheek and then go on the of your mouth. Does it feel |
|
| 36:38 | same? No, it's a lot . If you run your finger across |
|
| 36:42 | inside, you feel the cells actually off, don't you? Right? |
|
| 36:47 | could do that. You can pull off if you, we've all bit |
|
| 36:51 | inside of our mouths. Right? a lot of fun. Bite the |
|
| 36:54 | of your mouth, you're bleeding, bite someone's cheek, it takes a |
|
| 36:56 | of effort to make it bleed. bite people's cheeks. I don't think |
|
| 37:00 | need to say that, but just . All right. All right. |
|
| 37:04 | stuff on the outside has these intermediate called keratin. All right. If |
|
| 37:10 | watched enough commercials or if you've shopped enough lotions you've seen about the beta |
|
| 37:14 | and blah, blah, blah, , blah. And how they, |
|
| 37:17 | they make it stronger and stuff like . All right, Keratin is on |
|
| 37:20 | outside. That's what makes your skin and strong. Your nails have keratin |
|
| 37:24 | them. Your hair has keratin in . All right. The inside of |
|
| 37:28 | mouth is again, it's a stratified epithelium, but it lacks the |
|
| 37:33 | So these are gonna be found in openings of, of the um of |
|
| 37:39 | body primarily in these uh mucus um cavities. So we're talking urethra, |
|
| 37:47 | anus vagina mouth, nose. All have the uh the nonin squamous or |
|
| 37:57 | squamous epithelium. All right. having said that those are the four |
|
| 38:02 | you'll have to be able to identify you can, it's pretty obvious. |
|
| 38:05 | this look different than the other three we looked at? Yeah. |
|
| 38:09 | So you should be able to identify pretty easily. Yeah. Right. |
|
| 38:15 | what? Yeah. So with with the simple, the question |
|
| 38:17 | so am I looking at the apical to name it? All right, |
|
| 38:21 | answer is yes. But with your , how many layers do you have |
|
| 38:24 | ? So it doesn't matter what it because it's always just the outer |
|
| 38:29 | right? That's the idea when, you have one, there's, it's |
|
| 38:32 | outer cell. OK. So there , and you do not need to |
|
| 38:38 | able to visualize this one. All . So you can know if I'm |
|
| 38:41 | at a cuboidal cell on the it's not gonna be this. All |
|
| 38:44 | . But they do have stratified we have stratified columnar. All |
|
| 38:49 | So this, for example, you see here, there would be the |
|
| 38:53 | surface, right? Because that's the of the tube. And you can |
|
| 38:57 | I've got 123 cells, 12 12 cells all along the way. |
|
| 39:02 | I have a stratified and in this case, what I'm gonna do is |
|
| 39:06 | gonna look at the outer portion and see the, the nuclei, what |
|
| 39:09 | the nuclei look like for the most they've kind of roundish or they kind |
|
| 39:16 | elongate? Are they, they're kind round. All right. Again, |
|
| 39:20 | not gonna be perfect there, there's perfect. You're making a judgment |
|
| 39:23 | All right. So I'm not gonna you to identify these, but you |
|
| 39:26 | see these are for the most part cuboidal. All right. So they're |
|
| 39:30 | be found in some very specific Typically, two layers of cuboidal cells |
|
| 39:35 | located in glandular tissue. All So when in your glands is where |
|
| 39:40 | gonna probably see these, then we things like stratified columnar, they're very |
|
| 39:45 | where they're found, uh the male for one and there's glandular ducts um |
|
| 39:50 | also have these as well. And , what you'll probably see in these |
|
| 39:54 | , again, not having to identify , but it'd probably be a cuboidal |
|
| 39:57 | at the bottom. And then a cell on the upper layers is typically |
|
| 40:02 | they do that. And then there's really weird one. All right. |
|
| 40:06 | so we have to introduce it because exists and you need to know where |
|
| 40:10 | is and what it does. But not gonna have to identify because you |
|
| 40:13 | to be really skilled at being able identify transitional epitel. All right, |
|
| 40:18 | you hear the word transitional, what it sound like to you? It |
|
| 40:22 | , right. So great. Thank very much. I got something I |
|
| 40:25 | , I gotta identify that changes That's not very helpful. Is it |
|
| 40:31 | piel is found uh in the uh system? It's makes up the wall |
|
| 40:36 | the bladder, it makes up the of the urethra coming out and part |
|
| 40:41 | the ureters as you're going into the . All right. So typically, |
|
| 40:45 | you'll see here is you'll see um cuboidal or Kalmar cell down low. |
|
| 40:50 | as you get up to the then they start getting these really weird |
|
| 40:53 | . And the purpose is as you imagine, what do I do with |
|
| 40:55 | bladders? I fill it up with right. So that bladder needs to |
|
| 40:59 | able to stretch and when it it changes the shape of those apical |
|
| 41:03 | . The ones that are finding are , that are lining the inside of |
|
| 41:07 | bladder. So when you have a bladder, these apical cells look like |
|
| 41:12 | cells and when you have an empty , they look like they're cuboidal or |
|
| 41:16 | . So, good luck. All . So that's why we don't have |
|
| 41:20 | identify them. All right. No. In fact, that's that |
|
| 41:27 | is what's really kind of unique about is only found in this one |
|
| 41:30 | So part of the reason why you have it in the stomach is that |
|
| 41:34 | need to have an epithelium that plays major role in just simply absorption. |
|
| 41:38 | the strategy of the digestive system is just gonna keep these simple layers of |
|
| 41:43 | . But what I'm gonna do is going to change the folding of the |
|
| 41:48 | tract. So I can increase my area. So it's a different strategy |
|
| 41:52 | increases increasing surface area, but good . All right. So, transitional |
|
| 41:58 | changes shape. All right, primarily uh found in the urinary tract, |
|
| 42:03 | bladder. So, those are the types of covering epithelium. Are there |
|
| 42:08 | other questions about them? Any fears the exam? Yes, ma'am. |
|
| 42:15 | huh. We'll get to that on very second to last slide. |
|
| 42:23 | I may not answer that specifically but that thought because I want to talk |
|
| 42:27 | the scarring and uh, repair of and then you can say, |
|
| 42:31 | what about this? And if it answer the question, then hopefully. |
|
| 42:34 | right. That's a good one All right. Questions about the |
|
| 42:41 | No. All right. So, we're gonna do now is, |
|
| 42:44 | let's deal with the glands. All . So when you hear gland, |
|
| 42:47 | is one or more cells. So can already see here, I've got |
|
| 42:51 | type and another type. All And their job is to make and |
|
| 42:54 | secrete some sort of substance. And what we use is export is |
|
| 42:59 | So when I secrete it's different than , excreting is getting rid of |
|
| 43:02 | secreting is putting something. All And then the product that I'm producing |
|
| 43:07 | just referred to as a secretion. it's gonna contain multiple materials that are |
|
| 43:12 | . All right. So typically what is, it's water plus stuff. |
|
| 43:15 | typically we say it's water containing some of protein, but you'll also see |
|
| 43:20 | some of your secretions will have lipids them and o other materials like |
|
| 43:24 | which the type of lipid. All . So two basic types, we |
|
| 43:28 | the exec gland and the endocrine So typically, when you think of |
|
| 43:31 | gland, you probably think of an gland. All right. So what |
|
| 43:35 | doing is you're excreting to the surface outward. All right. And |
|
| 43:40 | gotta think I am a donut. when I'm secreting materials into my digestive |
|
| 43:44 | , I'm secreting them outside my All right. That's not inside your |
|
| 43:49 | because it's exposed to the external If I'm secreting into my lungs, |
|
| 43:54 | is to the outside of my But if I'm secreting into my |
|
| 43:58 | that's secreting into my body, that be an endocrine gland. All |
|
| 44:03 | So that's kind of the, the thing there. All right. So |
|
| 44:07 | the products are going on on the or into the body cavities. They're |
|
| 44:09 | be classified. We're gonna see here on their structure. The endocrine glands |
|
| 44:14 | the other hand, are typically producing , they're ductless. They have blood |
|
| 44:18 | that are intimately associated with them. so when they secrete their materials, |
|
| 44:22 | material goes straight into the bloodstream and it travels around the body. |
|
| 44:27 | the endocrine glands are mostly not endocrine not. Um epithelial in nature. |
|
| 44:33 | right. They're usually coming from another tissue source. Typically it's gonna be |
|
| 44:38 | , not always. So, so cell uh glands can be both unicellular |
|
| 44:45 | multicellular. So, unicellular is just cell. The example is the goblet |
|
| 44:49 | . You can see why it's called goblet cell. It looks like a |
|
| 44:52 | . It's a goblet filled of Yeah. Yeah. Uh So here |
|
| 44:57 | can see we have a uh uh epithelium. You can see here are |
|
| 45:02 | columnar cells sitting in between. You see the micro vli and then here's |
|
| 45:06 | goblet cells just jammed in between So they're uh intimately associated. All |
|
| 45:13 | , what they do is they release materials by exocytosis and you can see |
|
| 45:16 | am I doing? This would be uh your trachea. So I'm just |
|
| 45:20 | mucus to catch all the dust and things that I'm breathing in and |
|
| 45:25 | The other type is multicellular. This typically what we think about when we |
|
| 45:29 | about a gland. Um So you see here is a very complex |
|
| 45:33 | There's a duct work that's associated with . At the end of each |
|
| 45:37 | you have these little tiny structures called . Uh The ascena are are uh |
|
| 45:43 | the structures where the cells are producing materials that are gonna be secreted. |
|
| 45:50 | uh here is an example of an see Aina plural. There's the duct |
|
| 45:55 | I knew it was gonna die. came prepared. I'm almost like a |
|
| 46:08 | scout. There we go. All . So you can see here, |
|
| 46:12 | my duct work. So these cells are the things that are producing the |
|
| 46:16 | that are being secreted, they travel through the ducts, all that material |
|
| 46:19 | being collected and uh exiting via that into or onto the surface of the |
|
| 46:25 | or the surface of the body. right. So the ducts are |
|
| 46:30 | the, the athena themselves are gonna grouped into structures called lobes. So |
|
| 46:35 | can see here is a lobe or whole thing, they're calling a |
|
| 46:37 | But basically, it's just a bunch athena. Think about it like |
|
| 46:40 | think about a bunch of grapes. you think about a bunch of |
|
| 46:43 | So if you cut off a branch those grapes, the ones that you |
|
| 46:46 | on, right? That would be a lobe. And so you can |
|
| 46:49 | imagine groups of athena and their ducts form lobes and what's separating them from |
|
| 46:54 | other lobes are, is connective All right. And then they're usually |
|
| 46:58 | in connective tissue as well. All . This is where I ask a |
|
| 47:01 | . How many of you guys gone youtube and watch those zip popping |
|
| 47:05 | Yeah. Yeah, I know everyone's , I don't wanna admit it. |
|
| 47:08 | yeah, the really nasty ones where like £7 of ooze. Yeah, |
|
| 47:12 | just, yeah, I don't There's, there's a type of person |
|
| 47:18 | watch one. I'm like, I do this. Yeah. So, |
|
| 47:22 | one of the things why I mentioned is because I want you to think |
|
| 47:25 | the structure in which that material is coming out of. That's the, |
|
| 47:30 | , the shape of the structure is we're interested in here. The reason |
|
| 47:36 | those zip popping videos and they're not just zits, there's something pus |
|
| 47:40 | The reason they're so interesting is because that the thing that it's in is |
|
| 47:45 | that looks like this. And these simple versions. And again, these |
|
| 47:49 | that you're looking at are very, poorly drawn. All right, I |
|
| 47:53 | happen to grab this particular one. when we look at a gland, |
|
| 47:57 | gonna classify it based on the structure its ducts and the structure of its |
|
| 48:02 | . All right. So the duck be simple or compound. All |
|
| 48:06 | Now, I'm gonna point out Do you see here is the |
|
| 48:10 | It, it's just straight, it's it's not uh uh have any |
|
| 48:15 | of branching whatsoever, right? Even there might be branching in the |
|
| 48:19 | that's not the duct that's being All right, when you have branches |
|
| 48:25 | your duct. So the better picture be like this that's branching, |
|
| 48:31 | So you can see here in the the light is it lavender? Help |
|
| 48:35 | ladies because guys are gonna look at just purple. Ok. Yeah. |
|
| 48:40 | blind. You told me. So the light color versus that |
|
| 48:47 | that's where you see the branches. . Now, if you have to |
|
| 48:52 | in the test, do you think gonna give you a crappy picture? |
|
| 48:55 | , I don't like crappy pictures on because then you all come complaining for |
|
| 48:59 | points and that's more work for So I look for easy things. |
|
| 49:02 | right. So depending on whether the is branched or not branched and it |
|
| 49:08 | be color coded so that you can light versus dark. Ok. Um |
|
| 49:13 | should be able to say, this is simple or this is |
|
| 49:17 | All right, simple, no branches compound. Then we look at |
|
| 49:23 | athena. If the athena have roughly same shape as the duct, then |
|
| 49:27 | we do is refer to that athena being tubular. All right, if |
|
| 49:31 | more shaped like a grape, you , round it, then we refer |
|
| 49:35 | it as being alveolar. And then the gland itself has different types of |
|
| 49:40 | , some that are shaped like the , some that are shaped that are |
|
| 49:44 | , then what we refer to it is tubular have alveolar. All |
|
| 49:49 | So tubular alveolar or combination of the . All right. So this is |
|
| 49:55 | example of that compound tubular alveolar. up here, we don't have a |
|
| 49:59 | alveolar as an example. All So glands have unique shapes and we |
|
| 50:06 | look at a gland and we can it when we come jumping into the |
|
| 50:11 | right after the test, we're gonna jiving in and looking at all the |
|
| 50:14 | types of glands and what they And there are three types of |
|
| 50:19 | All right. This is a little more complex but not so horrible. |
|
| 50:24 | we're gonna just kind of work through and see if you can connect |
|
| 50:27 | We have Merrin Merin glands produce secretary inside the secretary vesicles we have water |
|
| 50:35 | stuff and then those vesicles move to surface and they open up and they |
|
| 50:39 | the materials on the surface of the , plus the stuff. All |
|
| 50:42 | So, salivary glands, lacrimal That's your tears. Very watery. |
|
| 50:48 | have stuff in them. All Pretty easy. All right. So |
|
| 50:52 | the easy one. All right. we move on to a apocrine |
|
| 50:57 | All right. Now, apocrine is little bit weirder because what we're gonna |
|
| 51:00 | , we're still gonna make vesicles, instead of the vesicle coming to the |
|
| 51:04 | and opening up, what we're gonna is we're gonna pinch off a portion |
|
| 51:08 | the cell with that vesicle in So, basically, what we're doing |
|
| 51:12 | we're creating a structure within a structure goes off and travels. All |
|
| 51:17 | And so this is what milk is of. So, when you think |
|
| 51:20 | cream, right? That fatty part milk, that's what that is. |
|
| 51:25 | fat bubbles inside of another fat in essence. All right. So |
|
| 51:31 | portion of the cell is being pinched , the cell state remains behind and |
|
| 51:36 | pinches off portions of cell. So that would be apocrine. The |
|
| 51:43 | type is weird. It's the holo gland, the holo gland is what |
|
| 51:49 | gonna find in the surface of your on your face. So, think |
|
| 51:54 | zits. All right. Think about clogged pores. What are they getting |
|
| 51:59 | with? There's dirt coming from this , but there's oil coming from that |
|
| 52:04 | . Right. And so these are oil glands on the surface of your |
|
| 52:07 | . And also, uh in uh know, for your hair. And |
|
| 52:12 | you're doing here is that the cell producing this material, but it's not |
|
| 52:18 | it. Instead, it's building up building up. And finally, what |
|
| 52:20 | up happening is the cell ruptures and releases the material that it's uh that |
|
| 52:25 | produced and that stuff just kind of that space and then if you're producing |
|
| 52:30 | lot of it, it just kind keeps moving upward and onward. All |
|
| 52:33 | . But when we have, I don't know, mid puberty and |
|
| 52:37 | have just tons of hormones telling every in your body secrete everything all at |
|
| 52:42 | . Then what happens is, is you're just oozing out oil in this |
|
| 52:45 | and you're also haven't learned how to yourself yet. I mean, I |
|
| 52:50 | 13 year olds that still refuse to until you scream at them. All |
|
| 52:54 | . But what ends up happening is the dirt fills those pores on one |
|
| 52:58 | and so they get clogged up and why, where does it come |
|
| 53:01 | It's a function of holo glands producing oil that are there to protect |
|
| 53:06 | Right. But on the other side the dirt that's clogging the pore. |
|
| 53:11 | holo, the cell dies and ruptures releases the product and apocrine, the |
|
| 53:20 | remains alive but it's pinching portions And then when you're talking Merrin, |
|
| 53:24 | cell is there and it's just releasing through the process of secretion, which |
|
| 53:28 | what we normally think about that make . All three of those. All |
|
| 53:34 | . So you can think about when hot and sweaty. That would be |
|
| 53:41 | , right? When you're in puberty have oil and grease on your |
|
| 53:45 | that is holo quin OK. And this is what uh breasts produced during |
|
| 53:57 | . All right. Questions about shapes of glands, types of |
|
| 54:03 | simple or si single cell versus multicellular with us. Ready to sprint through |
|
| 54:11 | one. Connective tissues. All So we've done epithelium. We're moving |
|
| 54:20 | tissue number two. Remember we said and four are gonna be like one |
|
| 54:23 | and we're done with them. All , the difficult thing about connective tissue |
|
| 54:27 | they look very different from one The origin of connective tissues are from |
|
| 54:34 | uh developmentally are from the mesoderm All right. And I know when |
|
| 54:39 | sitting there, I haven't learned any about that's OK. They're just saying |
|
| 54:43 | have the same origins, all But in the process of differentiation, |
|
| 54:48 | go in all these different directions. so the different types of connective tissues |
|
| 54:52 | very, very different from one All right. So different types of |
|
| 54:58 | , different types of quantities depending upon organ you're looking at but they're all |
|
| 55:02 | the place. All right, in of functionality, protection and insulation, |
|
| 55:06 | is both physical protection, as well immunological protection. They'll play a role |
|
| 55:11 | that they play an important role in things together. So you can think |
|
| 55:16 | it as a glue to hold your together. Hence the name connective |
|
| 55:20 | they play a role in storage, of materials and nutrients and they play |
|
| 55:25 | role in transporting materials around the which is really weird given that it |
|
| 55:30 | also something that holds everything together. right. So generally speaking, and |
|
| 55:36 | is a picture of a specific but we're using it as a general |
|
| 55:41 | . So there is a nonliving material called ground substance in connective tissue. |
|
| 55:48 | right. Now, in this we're gonna just point out a couple |
|
| 55:51 | things. Can you see the cells the cells? All right, not |
|
| 55:56 | substance. Can you see the the little fibers there, the big |
|
| 56:01 | fibers there, there's a larger purple there. Do you see those? |
|
| 56:06 | . So far I've named cells and named fibers. If you look between |
|
| 56:12 | this stuff there, that's the ground . All right. So it's the |
|
| 56:19 | that you can't see in the Ground substance is water plus tiny proteins |
|
| 56:27 | other solutes that are floating around. right, they are the materials that |
|
| 56:33 | up the uh the matrix in All right. So it's the environment |
|
| 56:39 | all the cells and all the proteins . So if you were to take |
|
| 56:42 | microscope and go down to the molecular , it's not even a micro electron |
|
| 56:46 | . This is what you'd see. you can see the big pur pink |
|
| 56:49 | there. That's the collagen. And if you look here, you can |
|
| 56:54 | hiding within all that stuff are these tiny proteins. All right, the |
|
| 56:58 | of these proteins, they all sorts things. But typically what we do |
|
| 57:01 | we call them Proteoglycan prote protein. sugars. So that's their proteins and |
|
| 57:07 | is what they're made up of. the gags is glyco amino glycans, |
|
| 57:11 | is sugar, amino sugars. Don't about them. I'm not gonna ask |
|
| 57:15 | what they are. All right. it's little tiny things that attract water |
|
| 57:19 | hold water in place. And so is why connective tissue is kind of |
|
| 57:25 | is because the matrix in which all materials are gonna be found is primarily |
|
| 57:30 | that's being held in place. All . Yes. Substance, water plus |
|
| 57:41 | . Notice how I always say plus because it's not just water. All |
|
| 57:44 | . And it's being held in place there's proteins and other materials that attract |
|
| 57:48 | hold that water into place. All . So let's have a little |
|
| 57:53 | Here. Is your ear stiff. you do this to here? Did |
|
| 57:58 | play with their ears? Yeah. you do that? All right. |
|
| 58:02 | you squeeze your ears? It's Right? Because there's a lot of |
|
| 58:07 | tissue in your ear. You can that with your nose too, but |
|
| 58:10 | higher you go up then you can feeling the bone, which is also |
|
| 58:12 | tissue. But it's a different type connective tissue. We'll get to that |
|
| 58:14 | just a moment. It's just a water comp uh stuff. So the |
|
| 58:18 | substance is simply the nonliving material that's by these cells. All right. |
|
| 58:23 | it's water plus stuff. Now, terms of the cells. So |
|
| 58:27 | we're just, we're using this as example. You see the different types |
|
| 58:30 | cells. There's 1234 types of cells we're seeing in this picture. All |
|
| 58:36 | . Again, not to identify They're just there. So every connective |
|
| 58:40 | houses its own special kind of All right. So those cells are |
|
| 58:47 | named for the tissue that they're found vice versa. So you'll see fibrocyte |
|
| 58:51 | fibroblasts in fibrous tissues. All So this would be connective tissue |
|
| 58:57 | right? In cartilage, you're gonna cartilage cells which are called chondrocytes and |
|
| 59:03 | . And then in the bone, gonna see osteocytes and osteoblasts. So |
|
| 59:07 | you, when you look at that suffix, that site versus |
|
| 59:11 | it tells you something about the cell are always cells that are immature. |
|
| 59:16 | right, sites are always cells that mature. So their roles are |
|
| 59:21 | So an osteoblast is doing something, it changes and becomes an osteocyte. |
|
| 59:26 | chondroblast is doing something and then it and becomes a chondrocyte so on and |
|
| 59:31 | forth. But those are specific cell that are found in their specific types |
|
| 59:36 | connective tissue. But then we also other types of cells that you may |
|
| 59:41 | . They're not always in this in the tissue that you're looking |
|
| 59:44 | but they typically can be seen in types of tissue. For example, |
|
| 59:49 | are typically found in adipose tissue. a fancy word for saying fat. |
|
| 59:54 | right. But adipocyte are also found other types of connective tissue, like |
|
| 60:00 | connective tissue. So they can be . And that's what you see in |
|
| 60:03 | picture. There are some adipocyte in little picture. All right. Other |
|
| 60:10 | of mesenchymal cells are mesenchymal cells. right. Mesenchymal cells are the stem |
|
| 60:15 | for all the different types of connective cells. So you might find |
|
| 60:19 | So I think in this case, this or this one's showing you the |
|
| 60:23 | cell. All right. Again, doesn't matter. All right. And |
|
| 60:27 | you might see immunocyte. So we about there being immunology involved in |
|
| 60:32 | And so typically, what you'll have you'll have cells that are kind of |
|
| 60:35 | around going. Is there anything going wrong in this tissue? Is there's |
|
| 60:38 | that's not supposed to be here? right, that would be an immunological |
|
| 60:42 | hunting for, um, foreign All right. So these are wandering |
|
| 60:47 | . So, typically it might be , um, um, it's gonna |
|
| 60:53 | a, uh, macrophage or it be a neutrophil. That kind of |
|
| 60:56 | that. In some cases, some tissues have resident, uh, immunological |
|
| 61:02 | that just hang out there and say a potential for something bad being |
|
| 61:05 | And so I'm gonna hang out So there's different cells, but it's |
|
| 61:09 | primary cell that kind of matters. right. The other thing is that |
|
| 61:12 | cells themselves are not necessarily in direct with each other. If you see |
|
| 61:16 | , these cells are kind of all the place. All right. So |
|
| 61:20 | not always gonna be touching one but they're all in association with one |
|
| 61:25 | because of the surrounding materials. So , here's that bigger picture. So |
|
| 61:31 | can see it right? And you see all the different cell types, |
|
| 61:35 | can see the ground substance in And then here's all the fibers, |
|
| 61:38 | red things here are blood vessels. you can ignore those. All |
|
| 61:43 | But here there are different fibers and fibers are being produced by those cells |
|
| 61:48 | make up the the connective tissue. made by fibroblast made by the chondrocytes |
|
| 61:54 | the chondroblast made by the um So there's different types. We have |
|
| 62:00 | fibers. All right. This is of the fibers or one of the |
|
| 62:04 | that is most abundant in the All right. And so here your |
|
| 62:08 | is gonna be the big pink So you can just see it's kind |
|
| 62:11 | running things. Its job is to stretching, uh stretching, flexible. |
|
| 62:16 | right. So this is why you grab your ear and pull it like |
|
| 62:19 | or your skin because of the collagen it has that flexibility to it. |
|
| 62:24 | you have that aunt who grabs you the face and does this stuff? |
|
| 62:28 | reason your face can be so malleable because of the collagen. All |
|
| 62:33 | ladies, I know you're gonna worry this later in life. So I'm |
|
| 62:35 | gonna, you know, put that already but that, that little thing |
|
| 62:39 | here, you know, in the that's coming. Why, why do |
|
| 62:43 | have that? Is it because you're ? No, it's because collagen and |
|
| 62:48 | just starts sagging. That's why our our faces right now, you're young |
|
| 62:51 | youthful and all pretty and, and and stuff and then you get my |
|
| 62:54 | and you get all the waddles. right. Collagen weakens over time. |
|
| 63:01 | fibers. Reticular fibers are a type fiber that typically organs are built |
|
| 63:06 | All right. So if you were to strip away the cells and all |
|
| 63:10 | have left are the fibers, you see a lot of reticular fibers uh |
|
| 63:14 | are there, they're very tough, they're also very flexible and that's what's |
|
| 63:19 | shown here, I think in the purple. Yeah. No, those |
|
| 63:22 | the last, and these are the fibers down there again. The cartoon |
|
| 63:25 | matter so much. The last one the Elastin fibers. Elastin is just |
|
| 63:29 | very stretchy. They're kind of like . That's why I was saying, |
|
| 63:32 | with your ear. You know, you fall asleep on your ear, |
|
| 63:34 | wake up, your ear is just pop back in place. That's the |
|
| 63:37 | of Elastin, right? They're elastic nature. All right. So with |
|
| 63:43 | in mind, these are some generic , all uh connective tissues, let's |
|
| 63:47 | run through them really quickly. All . So the first group, the |
|
| 63:50 | family of connective tissues are the ones we typically think of when we think |
|
| 63:53 | connective tissue. So we gave it name connective tissue proper. Ok. |
|
| 64:00 | mean it's special. It's just, the one we think about. So |
|
| 64:05 | first one here is areola. All . That's what we were kind of |
|
| 64:08 | at. Um, it's, these the things that have very few cells |
|
| 64:13 | . Um, the fibers themselves are all over the place. Again, |
|
| 64:17 | are cartoons, they have lots and of ground stuff substance. If you |
|
| 64:20 | to, you could squeeze them and get lots of water out of |
|
| 64:23 | Um uh in terms of uh the functionality, it basically they support |
|
| 64:31 | All right. So number one, areolar connective tissue. That's kind of |
|
| 64:34 | generic connective tissue that we think When we think about connective tissue, |
|
| 64:38 | tissue falls into this category. Um , the reason for that is because |
|
| 64:43 | you looked underneath the microscope, uh didn't see all the fat inside the |
|
| 64:47 | . So it looked like it was empty space. So they're like, |
|
| 64:49 | look, it's like it's like the . But you can see here an |
|
| 64:53 | connective tissue or the cells they're jammed together. All right. And then |
|
| 64:58 | is the reticular. And so this the one that you find as a |
|
| 65:02 | or the baseline of many organs. like your spleen and stuff. If |
|
| 65:06 | were to strip all the way the , you'd see um the reticular um |
|
| 65:12 | network or framework on which that organ built. So these collectively are called |
|
| 65:17 | connective tissues and the family of connective proper. So, why loose? |
|
| 65:23 | it's very, very empty because of the ground substance, very empty. |
|
| 65:29 | of ground substance. It looks Sorry. So if I have a |
|
| 65:34 | connective tissue, what do you think next one must be dense? It |
|
| 65:37 | to be dense. And if you at these, you'll see why they're |
|
| 65:40 | . Does this look dense? Do see a lot of ground ground substance |
|
| 65:43 | there? No, it looks like bunch of stuff. Do you see |
|
| 65:46 | lot of ground substance in here, see a little bit but no. |
|
| 65:50 | I see any ground substance in Not so much. All right, |
|
| 65:54 | is really kind of the stuff I'm at in there. Not so |
|
| 65:57 | All right. Now, here, we're seeing pre predominantly the thing that |
|
| 66:00 | out is the fibers. All Now, if you look carefully, |
|
| 66:04 | is the easiest one to see. you see the little purple dots? |
|
| 66:07 | purple dots are the cells. All . Are the cells touching each |
|
| 66:13 | No, all the pink stuff in picture. Those are fibers. All |
|
| 66:18 | . So that's the dense connective All right. With regard to the |
|
| 66:22 | connective tissue you can see here we regular dense. So the fibers are |
|
| 66:26 | moving in the same direction in a fashion. So it looks like somebody |
|
| 66:30 | making something nice and neat. All . So it's a very, very |
|
| 66:35 | um organized connective tissue. Here's the compare regular to irregular. Does this |
|
| 66:44 | irregular? Relatively speaking, do the go in the same direction? |
|
| 66:48 | they're going all over the place. why they're regular. All right. |
|
| 66:52 | dense fibers are in the same the irregular in all over the place |
|
| 66:58 | , in multiple directions. And the one, the elastic tissue is named |
|
| 67:02 | because the fibers are dense and close . But you're using elastic fibers instead |
|
| 67:07 | collagen fibers. All right. So , these are all connective tissue |
|
| 67:13 | loose versus dense, so dense, dense, irregular elastic fibers. So |
|
| 67:19 | again, the question on example, be which connective tissue contains elastin and |
|
| 67:27 | a connective tissue properly. That's the I'm gonna ask those type of questions |
|
| 67:31 | straightforward. Next group is the supporting tissues. So family number one, |
|
| 67:39 | tissue, proper, family number supporting connective tissues. All right, |
|
| 67:43 | have cartilage, they have three different of cartilage. All right, the |
|
| 67:48 | here we have cells that are producing matrix. You can't really see the |
|
| 67:53 | so clearly. But what you have a a uh material that has fibers |
|
| 67:58 | it. The cells are producing and pushing the, the the themselves away |
|
| 68:02 | each other. So the cells get in their own matrix. They live |
|
| 68:07 | that matrix. They're very much alive the surrounding environment is the fibers and |
|
| 68:11 | ground substance, but the fibers are together, but they're not organized like |
|
| 68:16 | you see previously, the tissue itself a vascular. So being there are |
|
| 68:22 | blood vessels. So the nutrients and come by. There are nearby |
|
| 68:26 | the materials get released and they travel the ground substance and they keep the |
|
| 68:30 | alive. If you're producing matrix, a chondroblast. If you're living in |
|
| 68:34 | matrix supporting the matrix, you're a . Those are the distinctions there. |
|
| 68:39 | , cartilage is strong. All but it's not bone strong. You're |
|
| 68:47 | learn when you have Children that they're resilient. All right, you can |
|
| 68:52 | a child bounce down a stair and get up and they'll look at you |
|
| 69:00 | they'll see your expression on your face that's how they'll respond based on your |
|
| 69:04 | . So if you're a mom and , they're gonna go like, and |
|
| 69:10 | start crying if they look over at and you give them that look, |
|
| 69:16 | like, and they'll just go on merry way. All right example I |
|
| 69:21 | is my son and III I can the example of that because literally there |
|
| 69:25 | a two year old girl at my house once and she went down 13 |
|
| 69:29 | of stairs or 13 steps and she up and her father was sitting there |
|
| 69:32 | he says, who's tough as nails ? All right then and she got |
|
| 69:39 | and went, my son fell out a tree. You know, he |
|
| 69:44 | in and he landed like though and came in and he says my wrist |
|
| 69:49 | . My wife is a physical Mind you right? We both looked |
|
| 69:52 | him and said, all right, take a look at it and it's |
|
| 69:54 | , all right, it looks like OK. Go on out and |
|
| 69:57 | OK. No problems. A week on my wrist still hurts. |
|
| 70:02 | maybe we should go get that checked . Had a compression fracture. But |
|
| 70:08 | could he fall out of a tree not break his arm because he's made |
|
| 70:11 | cartilage. All right, the younger are, the more cartilage you |
|
| 70:14 | the older you get, the more you become because your cartilage gets replaced |
|
| 70:17 | bone. All right. So types cartilage, we have, we have |
|
| 70:22 | cartilage. This is the type of we think about when we think of |
|
| 70:24 | . So like in your nose and your ribs, that's that cartilage, |
|
| 70:28 | have elastic cartilage that's gonna be found here, like on the edge of |
|
| 70:32 | nose. Not up here. I just said that was highland, |
|
| 70:35 | , that was my mistake, but your ribs. All right. Um |
|
| 70:38 | then we have the elastic cartilage that's be your ears, it gonna be |
|
| 70:41 | tip of your nose, um very squishy and um and mobile. |
|
| 70:46 | the last type of cartilage fiber cartilage cartilage is um uh much more dense |
|
| 70:51 | terms of the fibers and the fibers more organized, but they play a |
|
| 70:55 | important role in compression. And so gonna find them between the vertebrae. |
|
| 70:59 | they're, they bear the weight of uh body. Next group is a |
|
| 71:05 | connective tissue. This is your blood your lymph. It is weird. |
|
| 71:09 | right. Now, the reason it's this is because it uh from where |
|
| 71:12 | derives, right? It's from the . That's why it's a connective |
|
| 71:15 | Uh blood and lymph are basically the thing. It's just where they're |
|
| 71:20 | uh blood contains blood cells. Blood do not produce the fluid of |
|
| 71:26 | but they do not produce the They just happen to be in |
|
| 71:29 | All right. So it's the one where the matrix is not made by |
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| 71:33 | connective tissue cell. Now, when fluid escapes into the surrounding tissue gets |
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| 71:41 | up by the lymphatic system. That which was plasma is now lymph. |
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| 71:46 | so it's technically the same thing. just missing the blood cells. All |
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| 71:52 | . But it is a type of tissue is derived from the mezzanine. |
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| 71:59 | , we have uh bone, this also supporting connective tissue. You might |
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| 72:03 | the word osseous tissue. Uh We're talk, we have a whole lecture |
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| 72:07 | bone itself, but in essence, it is, it's cartilage that has |
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| 72:11 | up um these uh salts. Um so these calcium salts make the bone |
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| 72:17 | , much more uh rigid, much . It uh resists all sorts of |
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| 72:22 | and torques and torsion. Um but is not a dead tissue. All |
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| 72:28 | . And very often we think of as oh it's dead. No. |
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| 72:31 | you see the little tiny dots not the big dots, the, |
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| 72:34 | the kind of the flat ones. are the areas in the bone matrix |
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| 72:39 | those osteoblasts got trapped and they converted osteocytes and those cells are very much |
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| 72:46 | and they're very much keeping that matrix . And being able to resist the |
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| 72:53 | that and stresses we put on So it is a very much, |
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| 72:57 | is a living tissue. The other is bone is vascularized and it is |
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| 73:02 | . Uh You can't see the, big circle here is where you're gonna |
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| 73:06 | structures. And again, we'll talk in more detail where you have blood |
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| 73:09 | and nerves traveling up and down through structures that are going up and down |
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| 73:13 | the bone. All right. And what's providing the nutrients to those |
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| 73:19 | All right. So it's a supporting tissue similar to cartilage, but |
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| 73:23 | much tougher different cell types are responsible creating it. All right, we're |
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| 73:33 | down to like seven minutes before the class comes roaring in here. So |
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| 73:37 | gotta just run through these um just briefly, muscle tissue. There are |
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| 73:42 | basic types, highly vascularized. Their is movement, whether it be locomotion |
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| 73:47 | whether it be movement of materials in body. All right, we're gonna |
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| 73:51 | about them in more details, but essence, they are capable of contracting |
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| 73:56 | those contractions create the movement. And reason they are able to do these |
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| 74:00 | is because they have unique side of elements within them. All right, |
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| 74:05 | what we're saying, with regard to plays a role in movement. |
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| 74:11 | we've got a couple more. So know you guys are anxious to get |
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| 74:13 | here. I got that too. gotta answer her question right. |
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| 74:17 | nervous tissue, nervous tissue again. it's the main component of uh uh |
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| 74:23 | the nervous system. Two major cell , we have neurons. These are |
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| 74:27 | uh the cells that play a role sending signals around the body. We're |
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| 74:31 | spend a lot of time talking about . But in order for them to |
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| 74:35 | , they have to have a support . These are called the glial |
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| 74:39 | So glial cells are like they are , but they are like the connective |
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| 74:44 | of the nervous system. All they're more complex than that. But |
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| 74:48 | an easy way to think about Neurons can't do their job unless they |
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| 74:52 | glial cells there to support them. right, glial cells do not play |
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| 74:56 | role in direct transmission of signals. right. So this last little bit |
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| 75:04 | deals with tissue repair and hopefully to your question. All right now, |
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| 75:09 | are capable of repairing themselves. Not tissues are very good at it. |
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| 75:13 | some are really good, some are , really bad. So generally we |
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| 75:17 | two different types of repairing. We regeneration and we have fibrosis regeneration is |
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| 75:22 | you're taking that destroyed tissue and you're it with the same tissue type. |
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| 75:27 | if I take a cut and it go too deep and those cells regrow |
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| 75:31 | replace it, that's regeneration. But I cut myself and I create damage |
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| 75:37 | further, then what's gonna happen is not necessarily gonna replace those tissues with |
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| 75:43 | same tissue. The best example I come up with is a student of |
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| 75:48 | a couple of years back and gave lecture. He said, hey, |
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| 75:50 | Wayne, I've got this question. I was a kid, I got |
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| 75:54 | in the head with a pickaxe, ? It went down into my |
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| 75:57 | right? And they took it out what happened? It was like, |
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| 76:02 | , let me tell you what The neurons are really bad at regenerating |
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| 76:05 | . They just die off. But you'd have this big giant gap sitting |
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| 76:08 | your brain. So what does your do? Well, the glial cells |
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| 76:13 | and divide and fill up that space create kind of a scar tissue and |
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| 76:18 | the neurons have to work around the tissue right now. Was he |
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| 76:22 | No, but you know, sometimes walked in a circle. I'm just |
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| 76:25 | him just trying to keep you guys , right? No. So that's |
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| 76:31 | example of fibrosis where different tissues are along and filling out that space. |
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| 76:37 | typically what they're doing is they're putting in place to fill that out. |
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| 76:40 | this would be fibrosis. Now, is an actress with makeup. She |
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| 76:45 | in a car accident. This is , you know, makeup and you |
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| 76:49 | see here the example regeneration would be happens to your skin. But when |
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| 76:53 | go down deep and you're now penetrating the connective tissue, you're not gonna |
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| 76:57 | able to replace it exactly the way was. This is why you get |
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| 77:00 | weird scar. Right. And then , the skin can grow over the |
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| 77:04 | because it's not open to the but you have a different structure on |
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| 77:08 | that skin is now overlaid. Mhm . That's exactly where I was gonna |
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| 77:26 | . So, so the question is or not question. But the |
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| 77:29 | because it's, it's a correct statement like, hey, so what's really |
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| 77:32 | on here? Well, when you rebuilding something like let's say you knock |
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| 77:37 | a building, you're gonna put up framework on which you're gonna build all |
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| 77:40 | materials, right? So that's what's is these fiber blasts are coming in |
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| 77:45 | they're producing a framework on which the stuff is gonna be built and that's |
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| 77:49 | you see down here, right? here I've done the damage, I |
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| 77:53 | it with a blood clot. I cells that penetrate and move into this |
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| 77:57 | based on some signaling they come So the green cells are the |
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| 78:01 | those fibroblasts are now laying down the and then on those fibers, that's |
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| 78:08 | we're restructuring that tissue. All right , depending on where the damage took |
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| 78:13 | and what type of damage it you're gonna have different types of |
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| 78:17 | right? So you have a deep , it's not gonna look the same |
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| 78:21 | when you started. Right. But you have a shallow wound or |
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| 78:24 | a soft wound and it's on the this, it's, you can repair |
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| 78:27 | skin. I mean, I don't if you guys can see. Can |
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| 78:29 | guys see the scar on my chin ? I don't know. It's |
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| 78:32 | can you see? Yeah. So when I fell off of, |
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| 78:35 | off a cliff, 20 ft face . It was beautiful. I flew |
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| 78:39 | like a microsecond. It was And then I hit the ground |
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| 78:43 | That part sucked. The flying part cool. Well, sort of, |
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| 78:46 | think I might have screamed. I know. All right. But that |
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| 78:49 | be the example, right? So scar is a result of because it |
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| 78:54 | itself open. You could see my . All right. So there's four |
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| 78:59 | steps here. The steps are Basically, you get an inflammatory |
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| 79:02 | immunocyte. Come in. Let's kill anything that found its way in. |
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| 79:06 | start tearing up the broken stuff. what we're gonna do is we're gonna |
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| 79:11 | the clot and that's basically your body's aid to make that area special and |
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| 79:16 | , right? So we can do work. And then the third step |
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| 79:19 | go oh OK. We're gonna bring vessels in and then we're gonna bring |
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| 79:22 | those cells that are gonna produce the , this is granulation. And then |
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| 79:27 | I produce those fibers then the cells are on the surface are gonna slowly |
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| 79:32 | away that blo the blood clot, blood clot starts going away and the |
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| 79:36 | of cells start growing towards one All right, those are the four |
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| 79:42 | . And if anything gets disrupted along way, it's gonna change how that |
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| 79:46 | regenerates. So the stuff underneath this be fibrosis. This up here would |
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| 79:52 | regeneration. Ok. And different tissues , we're looking at the epithelium and |
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| 79:58 | tissue. That's that model. But tissues use different aspects of both those |
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| 80:05 | . Now, just before you I'm not gonna go through the |
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| 80:09 | You can read them uh just as as I can, I can do |
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| 80:12 | . You need to know what apoptosis need to know what autophagy is. |
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| 80:15 | need to know a fevers with hypertrophy hyperplasia. You're gonna get one of |
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| 80:19 | questions on the exams. Just know to define them. All right. |
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| 80:24 | Thursday do not show up here. a great day. If you need |
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| 80:27 | come see me, I'll be in |
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