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00:01 All right. Um So just a . We have an exam on

00:06 So you don't show up here, show up at casa at the time

00:10 you're supposed to take your exam. that's that's pretty straightforward. Um What

00:15 gonna do today is we are going look at tissue and remember everything on

00:21 exam. It's up through today's So we're doing whatever we talked about

00:24 is gonna be on the exam. of sucks thursday tests, Tuesday

00:28 but sometimes you'll get the thursday test then the Tuesday lecture. So,

00:32 see. But what we're doing is gonna do the last little bit of

00:38 the baseline or the background information, anatomy and physiology alright. To really

00:44 into anatomy. Alright. So, talked about biomolecules. Biomolecules used to

00:49 cells. We talked about structures of cells and all the little pieces

00:52 And then now we're gonna be all right, what is the

00:56 What are the different types of What are they made up of?

00:59 right. And then once we do , we're now able to dive in

01:02 start looking at other things. And starting point is going to be this

01:06 here. It's the epithelium and there's tissues, there's epithelium, connective

01:10 muscle and nerves. And the thing we're really gonna focus today on uh

01:15 epithelium in the connective tissue and then just kind of say, oh

01:18 and then there's nervous tissue and there's and we talk about them with their

01:23 lectures. Okay. That's gonna be little bit later down the line.

01:28 But what we're doing is we start epithelium. Now, epithelium has two

01:32 to functions in the body. It a covering connect or tissue or it

01:37 a glandular tissue. In other it plays a role in secretion.

01:41 , typically the way that they're arranged , usually they're usually sheets of

01:47 All right. And so you can of see All right, that makes

01:50 . If they cover things, I'd them to be large sheets that kind

01:53 cover over things. The glandular Well, they're not quite Sheedy.

01:58 are some sheets to it, but they have some kind of unique features

02:02 it. Um They have these specialized . Um What I say down here

02:08 they have tight junctions as hemi Desmond . Desmond's those are characteristics. But

02:12 you'll see adherence and often you'll see junctions as well. But what holds

02:17 sheets together are these types of connections really binds cells together. Those tight

02:24 ? Desmond zones and Desmond zones. recall what's the difference between him and

02:29 Amanda Desmond Zone. Do you guys Desmond own self to sell yourself to

02:35 , sell to sell good and what's sell to connective tissue. Right.

02:41 , what we're saying here is got that is holding the cells together to

02:45 those sheets and there's something that's holding sheets onto connective tissue. All

02:51 So, when you think glandular Alright, So, covering that's real

02:55 . Think of skin and the things cover the cavities of the bodies.

02:58 , as we go and look at organs, think, oh, the

03:02 that makes up the lining of this organ is going to be epithelium.

03:08 . And then glandular tissues, these going to be the ones that make

03:10 glands of your body. Sorry, got it. There we go.

03:16 , now, I'm gonna throw pictures here that are related but are not

03:20 the things. So, like what looking at is a picture of the

03:23 or really the integer moment. So, this is actually something we're

03:27 learn about when we come back. it's a good example of showing you

03:32 versus connective tissue. All right. so, up here, the epidermis

03:40 . Down here, the dermis is connective. Okay. And there's some

03:45 tissues in there as well. But wanted to be clear here, so

03:48 you can see because epithelium has a characteristic. It's a vascular a vascular

03:54 you see a at the beginning word without or lacking. So, a

03:58 would be without vasculature without blood Right now, the truth is there's

04:04 a cell in your body. A cell in your body. That is

04:07 than 10 microns away from a blood which kind of tells you you've got

04:10 lot of blood vessels, right? means everything. Think about how easy

04:16 is to cut yourself and get blood out of your body. So,

04:19 because blood vessels are everywhere. But you're dealing with epithelium, epithelium lacks

04:27 blood vessels, That means the nutrients the blood have to traverse from cell

04:32 cell or between the cells to get where they're going. All right.

04:37 , they have no blood supply. they're innovated. Innovative means they are

04:42 that are associated with them. so they have nerve fibers.

04:46 the example here, you can see little cartoon is up here. If

04:49 is all epithelium, you can see is a nerve fiber that is breaking

04:53 and is there in the near surface the skin within this epithelium. The

04:58 fiber, is it epithelium? it is nervous tissue. All

05:03 So, you can see here just in our examples, we start

05:06 in a little tiny. Oh but there's a little more tissue

05:09 There's a little bit of that. epithelium are those cells that are found

05:13 that integrity in that, in the , sorry, in the epidermis up

05:18 . But there's other stuff. And can see here is a gland and

05:21 gonna be epithelium as well. All . Now one of the unique characteristics

05:27 epithelium is that it's highly regenerative. , most tissues have some sort of

05:33 capacity. Even nervous tissue has regenerative in a very limited way. All

05:40 . But this stuff epithelium is incredibly . And we talked about this

05:45 When you cut yourself you get you of get a split in the

05:49 right? And then you get a and we're gonna talk about this at

05:53 end of class. But then the grows over and covers where the cut

05:59 place. Alright. And there's a . So it has this incredible ability

06:04 do that. Most tissues don't have same degree of regenerative ability that epithelium

06:10 and part of that has to do . That contact responsiveness. We discussed

06:15 where the cells are taught when they to each other when they're when they're

06:19 to each other, they don't They stop. I don't know why

06:24 echoing like that. Um They stopped when they're in touch when they're touching

06:30 other. But when they don't touch other, that's a signal to say

06:33 growing. So that's where you get regenerative capacity. Epithelium has polarity to

06:41 polarity meaning it has two different And we talked about this again when

06:44 talk about tight junctions. Alright. what we have is we have a

06:48 side. The typical side is the side. When we're talking about

06:53 So if you're thinking of like for your skin, this would be the

06:57 side. The basil or lateral sides be the part that you can't

07:01 It's the part that's connected to the tissue. It's right when you're talking

07:06 your digestive system, the part that up the tube. The inside that

07:10 be the typical side. The part connected to the connective tissue. On

07:14 outside. That would be the lateral side. All right. And

07:19 when you hear lateral, just think . Alright. And so typically what

07:23 see when we're talking about a pickle and we're talking about basil side.

07:26 talking about different types of activities, things that are occurring. The A

07:31 side typically has micro villi and that's these little bumps are supposed to

07:36 We'll see a better picture in just moment. Alright. You'll see some

07:39 will have cilia. Alright. And have unique purposes. The basil side

07:46 the other hand, basically its job to connect with and hold on to

07:51 underlying layers. And so what you'll is that it plays a role in

07:55 these proteins that are part of the that sit there and hold onto proteins

08:01 are found in the underlying tissue we this the basil lamb inna. It's

08:06 series of glycoprotein glycoprotein are proteins with sugars. And what they do is

08:13 serve kind of as a molecular um , let's see if I scoot this

08:21 . That helps a little bit molecular to hold on to the proteins that

08:25 been secreted by the connective tissue. this is why the the epithelial and

08:31 tissue adhere to each other so So this basil lamin a serves as

08:37 of a structure we call the basement . The other half of the structure

08:43 going to be called the reticulated And the particular lamine is secreted by

08:48 tissue. So the two things the basil lamin and the particular lamin

08:52 connect to one another. Now, you're looking at this world going,

08:55 don't know how I'm gonna remember that , basil is secreted from the basil

08:59 . The reticulated lamb mina is part the reticulated structure of the connective

09:04 Which is gonna be one of the we're gonna learn about when we talk

09:06 the connective tissue. Alright, that's what the basement membrane is.

09:12 right now, the primary protein that's in particular laminates collagen. So,

09:18 one way to kind of remember All right. So, underlying all

09:25 is this connective tissue and connective tissue very unique. It has all these

09:29 features which we'll get to in just bit now. This picture up here

09:35 you microbial life. All right epithelium for the most part plays a

09:41 in absorption and secretion. It plays , many different roles. But whenever

09:45 have micro villi, what you're doing you're trying to increase surface area.

09:50 you have a cell has a limited of space. Right? Think of

09:54 as a as an you know, a cell. You know, just

09:57 a box around me. My surface be about this big. This is

10:00 much space I'm allowed. Right? I'm jammed up to another cell.

10:05 so I don't have a lot of area. But if I want to

10:08 my rate of absorption on my rate secretion, I wanna increase my surface

10:12 . I don't have a lot of to move in this direction. So

10:17 do I do as I grow upward then increase my surface area by creating

10:22 micro villi. Right? So it of looks like this weird hair

10:27 But look if I have to travel distance let's say that's a cell.

10:30 we know the whole thing is look much surface area I now have by

10:34 up and down like this. I magnified my surface area when you go

10:40 A. And P. Two. you talk about the digestive system,

10:43 talk about the length of the small . It's about 33 ft long.

10:48 right. That sounds like a pretty in terms of length. But because

10:52 the modifications of the surface of these . In other words there's these unique

10:59 to to increase surface area. The length of the surface area of the

11:06 intestine is a little under a All right. Think how big you'd

11:11 to be in order to have a long intestine. And because of

11:18 you don't have to do that. right. So microbial life. Their

11:24 typically on absorptive cells. Their job to increase surface area. Now,

11:29 kind of jumping kind of back into some unique features of you know,

11:33 mean I'm looking at things on cells this is unique to these epithelial

11:40 Here's a silly up here. I flag ela because sometimes people confuse these

11:45 things together is only found on one in the human body and that is

11:50 spermatozoa. Alright. But structurally they're very similar functionally. They're very,

11:56 different. So cilia are typically associated cells that play a role in secretive

12:03 alright. You know, musicians as proteins that make up mucus. So

12:07 familiar with mucus because right, little proteins that are sticky that are able

12:13 grab on this stuff. And what do is it moves this material along

12:18 the things that stick to it along surface of cells. So this is

12:22 example. You can see down here's a bunch of micro ville.

12:25 and here's the silly, you can of see size wise how very different

12:29 are. So silly are actually fairly , relatively speaking to the micro

12:34 All right now, structurally, what we're dealing with. We're dealing

12:39 cilia or flag ela is that they internally filled with these micro tubules.

12:44 have this unique array and this unique there And why I pointed out is

12:48 it's these organizations that are associated with things that allow them to move.

12:54 these motor proteins move back and forth it causes the cilia to move back

12:59 forth, or the flag ella to back and forth. And the type

13:02 movement that they make is unique to type of cell that you're looking

13:05 So for example, when you're looking a cilia, cilia is more like

13:10 rowboat, right? It kind of this type of movement. Now,

13:14 if you're waving back and forth like , that's very stiff. So think

13:17 it more like a whip, It kind of moves forward like this

13:21 back and moves forward like this. . This is usually where I ask

13:25 here ever rowed crew and I just a whole bunch of words. They

13:30 don't make a lot of sense to . You've seen those guys in the

13:32 , really, really long boats and these guys are going with the with

13:36 rose and going in the front. little tiny guy going stroke stroke stroke

13:40 . That's crew. All right. they have different sized boats and stuff

13:43 that. The way they move their is similar to how the sillier

13:51 Now, if the cell weren't it would cause the cell to move

13:55 . Used cilia, for example to around. But our cells are

13:59 And so they're not moving the they're moving the stuff around the cell

14:04 that mucus sits down in your esophagus have cilia, so it basically pushes

14:09 mucus up and then you're you make noise and you swallow it and it

14:13 down a different pipe, kind of flag L. A. On the

14:18 hand again has nothing to do with epithelium. Just show you the

14:22 it moves its tail the same But the way that the motor proteins

14:28 is it creates more of a snake movement. I'm going to try to

14:31 this with you know, it's kind like this and it kind of creates

14:35 rotary movement that propels the self Now bacteria also have yellow and they

14:41 in a straight line and so you think about this. What am I

14:44 ? I'm moving things perpendicular to the of the silliest. So if the

14:49 are doing that whip like thing, moves material along the horizontal plane.

14:54 if I had a flagellum, what would do is move fluid in the

14:59 direction as that propeller, basically parallel it. All right, so along

15:05 same axis. So different structures for types of movement, epithelial cells have

15:10 , they do not have leg Alright, so I was kind of

15:13 jump backwards to move forwards. so far we're with me 99 plus

15:21 is just kind of a standard you should probably just kind of tattoo

15:24 your body. You know, there's things in biology, you just kind

15:27 like, okay, I'm gonna tattoo guys aren't into tattoos anymore.

15:32 There was a generation I'd say. right, because I had people in

15:36 and have like caffeine, this it's on my body. I'm

15:39 It's like, dude, you that's it's an organic symbol. Who

15:43 ? Organic chemistry, like you'll ever that again? Mhm. Right now

15:49 are things you tattooed on your Nine plus two people. What's that

15:54 ? Oh, well, let me you the story about silly and

15:57 Six. Starting to sound cool All right. Yeah, Okay,

16:04 let's get into functionality. Epithelium Basic functions. These are the four

16:09 functions where you'll find where epithelial It's doing one of these four

16:13 Alright, Protection, that's the easy , you can think of the

16:16 Right? Oh, that's kind of . Yeah, it's serving as a

16:19 between the external environment and my internal . All right, it's selectively

16:27 Alright. And what that means is where it's found it's deciding what materials

16:32 pass through that substance. So for , your skin is selectively permeable,

16:39 ? It's still a barrier but it's barrier to very specific things. If

16:42 put water on my skin, it's to sit there forever. But if

16:45 put fats on my skin. Think , it gets absorbed through those

16:51 All right. If you've seen some the medicines they now have are those

16:55 patches, right? A dermal patch because it allows the materials that you

17:01 in there are lipid soluble and they able to penetrate through the skin.

17:06 . So there's a selective permeability. plays a role in secretion and what

17:10 means. It's secreted some sort of and we'll talk about what a secretion

17:14 in just a minute, which is . It's different than an excretion.

17:18 . Excretion is what your body is rid of. So, you can

17:21 of defecation, urination, even breathing as excretion. Right? So secretion

17:27 putting some things you're making something and it onto the surface of the body

17:33 alright. Or even into the And the other thing is it

17:38 And this is in conjunction with the and plays a role in sensory

17:42 Alright. And so think about the on on your on your skin,

17:47 ? If someone comes along and barely your skin, your hair is you

17:51 feel it right? Those hairs are of serving as receptors to stimulate nerve

17:56 are associated with those hairs. when we talk about sensory reception,

18:01 what we're talking about, they're not the job of the nerve, but

18:04 there to communicate with the nerve. . One thing we're trying to do

18:14 anatomy is we're trying to learn the . Alright. And so again the

18:20 is there to help us communicate, more clearly and apparently not like what

18:24 doing so cold in here. My is right. It's to communicate clearly

18:30 we're looking at. All right. so when anonymous name things, they're

18:36 them for something that is apparent to that should hopefully be apparent to

18:40 And so with that the thallium, we have is we have two names

18:44 every type of epithelium we have. , so just like you have a

18:48 and last name and please don't come and I've got six names. You

18:51 ? And I know different cultures will hyphen nations and stuff. Now.

18:54 just going to make it simple. name. Last name. All

18:57 And so that's kind of what we . We have a first name and

19:00 name. The first name is always always based on the number of cells

19:04 the good news. There's only two that we use. We have simple

19:07 we have stratified. Simple says we one layer of cells. That's pretty

19:12 . Right? And so when you at a tissue and you see a

19:15 layer of epithelial cells you can say . This is a simple epithelium.

19:21 . The stratified basically says Alright, simple is one then stratified is anything

19:27 than that. So two or more stratified and that just means multiple

19:32 Alright. Now, typically simple epithelium going to be found where we're gonna

19:36 doing either absorption or filtration, Is things coming into the body filtration

19:41 things going out Well, I should in the tissue or out of the

19:45 . Alright, stratified is going to found where protection is needed. In

19:49 words, multiple layers creates a larger . Larger barrier protects the things underlying

19:53 . All right. So, when are naming, while we're going to

19:58 stratified, we're going to now have deal with that last name. Second

20:02 . That second name is based on the most atypical layer is.

20:06 it's not based on this one. based on the one that's on the

20:11 . The one that you can Okay. And so that takes us

20:15 that second name. Alright. The name describes the cell. Alright,

20:22 , looking at the cartoon here, can see three basic shapes which are

20:25 three names. We use a squamous squamous means scale, like So these

20:31 cells that are flat. All And so you can kind of see

20:36 it kind of looks like a flat . How do we know It's flat

20:39 it's not elongate. You need to and see where do I see the

20:44 membrane. So you always need to understanding what you're looking at in terms

20:49 relationship to other cells. Alright. that's quite cute boy. It'll generally

20:55 box like. Alright. So they're like a square. And then the

20:59 are are longer than they are So they kind of look like if

21:03 have the base memory and they look they're tall. So it's kind of

21:06 easy nomenclature. The thing is that world doesn't look like the cartoons

21:11 All right. And so there's some where you can look at something and

21:14 have no idea what I'm looking The good news. This is not

21:16 histology class, right? The bad is you do need to be able

21:20 identify some tissues on the exam. good news is I'm not gonna make

21:25 hard. I'm gonna make it easy see if you internalize nomenclature with what

21:31 look like. Alright, we're gonna at a couple of pictures here in

21:33 a second. All right, one of the things you can do

21:37 you can look at the cell itself say, okay, can I figure

21:40 what this is? But sometimes it's of hard. So if it's

21:43 you can also look at the The nucleus typically takes on the shape

21:47 the cell. So a squamous cell have a nucleus. That's kind of

21:51 . A cute boy. It'll we'll have a nucleus that's more or

21:55 around. And Columbia Marcel will usually an elongated nucleus that goes along the

21:59 of cell uh in uh you in a vertical direction. Alright,

22:06 it's using these two names together will rise to the different types of

22:11 is that you need to know? there's some other specialized ones that are

22:14 there. All right. So, regard to the simple epithelium is

22:19 Simple means single layer. They're involved absorption and filtration. So they have

22:25 a role in dealing with permeability There are three types of interest.

22:30 is our last name. So we simple squamous, simple cube oil,

22:34 Coloman are So there you go There are three different types of epithelium

22:40 on those two names right now, now and then you'll come across something

22:45 is an epithelium that has a weird . Alright, So, for

22:49 you'll see in the feeling you'll hear the film and the vasculature. That

22:53 the type of epithelium that makes up insides of all the blood vessels.

23:00 right. Why? Well, it's uh it's origin is where it comes

23:06 . And so someone name. well, this isn't a thallium.

23:09 rather than following the temple, the number collection that we already have.

23:13 screwed it up and made you learn extra thing over the course of your

23:17 . Right? So, when you in the feeling just think epithelium of

23:20 vessels. Okay, Another one you not see very often, maybe in

23:24 textbook. You'll see it. Maybe you get to that really, really

23:28 crusty old man that's a little bit than me. Okay, I'm going

23:33 . Please just nod your heads. course you're going right. I'm talking

23:38 the really, really old ones. hear them use the word mesothelioma.

23:42 is found in serious membranes. when you're looking at a serious

23:46 Okay, that's still an epithelium. it has a special name. Sometimes

23:50 see it. And that's just that . Right? So, let's take

23:54 look at these simple epithelium. All . Sometimes the pictures suck in textbooks

24:02 because it costs money to buy pictures I make tests. I don't have

24:07 buy pictures. I just pull things the internet. Okay, so,

24:12 , on a test things should be identifiable if you understand the nomenclature.

24:19 . And so, what we're looking is we're looking at some pictures here

24:21 the cartoon. This is an actual . Cartoon, actual tissue.

24:26 so, this first one is a squamous. Alright, now, if

24:30 look at the actual tissue here, can't really see basement membrane. And

24:33 reason you can't see the basement membrane because this tissue is lung tissue.

24:39 , lung tissue are basically a bunch hollow balls so that you can move

24:43 and specifically oxygen into the bloodstream and carbon dioxide out of the bloodstream into

24:50 tissue. So that can or into that that hollow ball. So it

24:53 be expelled. So, the basement is very, very difficult to see

24:58 this. All right. But if look at these cells, do they

25:01 like they're tall or do they look they're flat and scaly? They look

25:06 and scaly. Alright, so, is an example of a simple

25:12 All right. Now, if this a better picture, I think there's

25:16 a like if they could pick a picture, I think it would just

25:19 like someone with a camera taking a of a lung. This is like

25:23 lowest level. They should have actually in there really close so that you

25:27 see it. So, see these pinker spots right there. Like there

25:32 there and there those are capillaries. where the gas blood exchanges taking

25:38 Right? So, really these cells between those cavities. Like right

25:45 You can see here area. There's big area, but right there.

25:49 where the capillaries are. So, where your air is exchanging with the

25:55 . Okay, that makes sense. kind of like, I don't

25:57 I can't see it. And that's . All right. You don't have

26:01 see it today. Right? Q . It'll sell. So, you

26:06 see here flat scale like these are and scale like And again, what

26:09 I say? I'm gonna make it for you? You should be able

26:12 see a basement membrane in the on test. You should be able to

26:15 the orientation of the cell. here is simple cube oil, nice

26:23 in our little cartoon over here, like what am I looking at?

26:27 , again, they picked the worst they possibly took. They should have

26:31 it so that you can see look the nuclear of these cells. They

26:34 of look around the dark purple is nucleus by the way? All

26:39 So that means the thing that's the has kind of that little box shape

26:45 on the test, you should be to see quite clearly what type of

26:50 you're looking at. All right. not going to give you some far

26:53 view. This is like trying to at mountains from 50 miles away and

26:57 to define what they are. Terrible . Okay, but you can kind

27:01 see square, like with around a again, this is even further

27:10 This is the mountain you're looking at 100 miles away. But if you

27:14 at these cells. So, the thing to do is I'm trying to

27:17 an area that's really easy to focus . Let's just focus on here.

27:20 can see right down here, this where the basement membrane is. You

27:23 see basement membrane basement membrane, And then you can see the dark

27:29 represent nuclei And then this thing going and down. That's the cell.

27:34 looks like this. Alright, so nuclei are not round again with this

27:40 picture. It's hard to see for picture. You'd actually be able to

27:44 the cell, right? And what have is these long cells that are

27:50 at their base over here. So makes them elongate. That means they

27:55 they're Colombian are and then the nuclei elongated as well and there near that

28:02 membrane. So, those three you be able to identify on an

28:08 Not these pictures. I'm not going use these pictures. Why they're so

28:13 . Alright. We don't give sucky . We get pictures that you can

28:17 . All right. I'm going to you a picture of one that will

28:21 be on the exam. Alright. need to know it's a definition but

28:24 not going to have to identify Okay, pseudo stratified. What does

28:30 mean false? So, this is is called the false stratified epithelium.

28:38 , so this is a simple calumnies . Alright, but we don't call

28:43 simple kilometer because that's confusing when you the other one. All right.

28:47 is it called pseudo? Well, you look at it, it looks

28:50 there's actually multiple layers. You can down here. It looks like there's

28:53 whole bunch of nuclear up there looks there's a whole bunch of nuclear.

28:56 must mean these cells are stacked on other and the answer is no.

29:00 that's not the case. What's happening is you have a whole bunch of

29:03 that are all attached to a single the basement member. And they just

29:07 different heights. The nuclei are located different areas. Is basically shoving and

29:11 things together. So they have this look like they are stratified layer.

29:17 it's not going to be on the to be identified is because it takes

29:20 little unidentified histological e pseudo stratified epithelium this is not a histology class.

29:29 , So pseudo stratified is a type simple epithelium, right? But it

29:36 the appearance of a stratified epithelium. right, So that gets us to

29:47 stratified. All right. Again, has multiple layers of cells. Two

29:52 more. You can see here you count them all the way up down

29:56 the basement membrane. This is where have the regenerative cells. So they're

30:01 ones that are multiplying and dividing. when they multiply and divide, they

30:05 upwards towards the typical surface. And they move towards the typical surface they

30:11 their shape. Which is why we this type of epithelium based on that

30:17 pickle surface. Alright. Now, speaking, when you have stratified epithelium

30:22 can think of multiple cells equals better . So these are cells that play

30:27 role in protection. Alright. Or that play a role in protection.

30:35 sorry. So down here. This where division is taking place up

30:39 This is where they kind of create unique shape. So our first one

30:44 gonna be the stratified squamous. So we're gonna have the same kind

30:48 names, right? We're just changing stratified from simple meaning we have multiple

30:53 . This is the most common This is the easy one.

30:56 This is what you need to know the exam. Alright. So stratified

31:00 to easily identify. You're not looking here, you're looking at this and

31:04 wow this whole stuff up here looks really scale like. Huh? There's

31:09 of layers that must be stratified Okay that's where the name comes

31:15 Now this you're not gonna have to . You don't need to identify a

31:20 versus non christianized but you need to what they are. Keratin is a

31:25 protein. Alright, it makes up determine intermediate filaments. Alright, carton

31:31 found in some tough tissues. For your fingernails are your fingernails tough.

31:38 . What about your hair? Is hair tougher than your skin?

31:43 Alright. Those are keratin fibers. types of keratin. So your nails

31:47 tougher than your skin or in your ? And your hair is tougher than

31:50 outer skin out here. Right? three of those contain different keratin and

31:57 pretty tough. Now think about the of your mouth, your inside of

32:01 mouth as tough as the outside skin here. No that's squishy. It

32:06 the keratin. Alright. So we chretien ized. Alright fraternized means a

32:14 tissue, right? What we're looking that has keratin in them. So

32:18 nails, your skin and your All our christianized stratified squamous. We'll

32:25 to that when we talk about the , but like when you transition and

32:29 into your mouth and on the inside your cheek, you no longer have

32:32 keratin. And so it's non carotene . So it's a little still protective

32:40 not quite so as protective as the . Alright. If you bite your

32:44 over here, you're not going to it. But when you bite the

32:46 of your mouth, which we've all right? It sucks or you end

32:50 with a big old chunky meat of , right? Because it's not as

32:54 as the outside. It lacks those fibers. All right. Yeah.

33:04 Or is it for all? We're see. So, so this right

33:09 is the most common type. So question was, is this the property

33:12 all stratified? And really this is focus here, what we're going to

33:17 is that the other stratified tissues are rare and very hard to find.

33:23 , they exist. And we're gonna them out. But when you think

33:26 , this is the primary one. . It's pretty easy to identify because

33:35 and flat lots and lots of All right. Notice I have one

33:44 for the other two. Alright. stratified cube oil is pretty rare.

33:50 , we're typically going to be found glandular tissues. Again, here's that

33:54 square cell. Look at that. polar bear square sell this right here

33:58 an example of one of these Now, you can notice the cartoon

34:02 always a lot easier to see what looking at. Whereas when you're looking

34:05 a live tissue, it's a little harder. But look at those

34:08 you can see here, here's one . Here's to layer. That would

34:11 the the optical layer because this is inside. And you can look at

34:16 cells. What do those cells They have Nice round nuclei. So

34:19 would be a stratified, cute boy . All right. So, typically

34:24 tissue, there's also stratified columnar but extremely where you can find it in

34:30 male urethra and some very specific locations the urethra as well as some glandular

34:36 . Alright. Throughout both males and . All right. So in the

34:40 that if this will ever come up again, you're not going to see

34:44 kilometer on the exam. I didn't you an example of it, but

34:47 know what to look for. What would you expect in the a

34:49 layer? Elongate, elongate elongate Columbia . Right? So that's what you

34:56 instead of this little Tony boxy It would be this longer thing relative

35:00 the underlying cell. All right. for the really weird one.

35:05 This is not one you're going to to identify on the exam, but

35:09 do need another definition. Alright. transitional epithelium. Alright. And understanding

35:16 you don't have to identify, it gonna be quite clear when you look

35:19 this. Alright, so here you see the picture looks like billowy

35:23 Alright, now, transitional epithelium is find in the urinary system.

35:28 And specifically you can think about the . It's not the only place that's

35:31 , but the bladder is the easiest . Alright. Think about the bladder

35:35 empty. Alright. The bladder being is like a deflated balloon, y'all

35:40 me on that. Can you visualize ? Now? Think about drinking two

35:43 of water right, a couple of later, what's your bladder like?

35:48 like an inflated balloon. An inflated balloon. Except it's not water.

35:54 ? And so the cells that allow bladder to expand and contract, you

35:59 , the sides the tissue itself, know, it's kind of folded over

36:03 . Kind of like pleats on the and sorry, that's probably not gonna

36:06 all all of you. But you can imagine kind of like a

36:09 , It kind of shrinks down, when it stretches the tissue itself stretches

36:14 it allows it to expand and the it's able to expand is because those

36:19 actually change shape, which means what can go from kind of a cube

36:25 shape to a squamous shape depending upon degree of stretch being applied on the

36:30 of these cells. This is why don't have to identify it under a

36:35 for this class because I could show a picture and you'd be like,

36:39 yeah, that's a stratified squamous Sorry, that's transitional. Oh,

36:42 a stratified, cute boy. That's . It depends on what state you're

36:48 at the tissue in. You know state the tissues in in order to

36:51 able to identify it. Right? , that's why we don't have to

36:54 . It changes shape based on the of distortion. Alright. Hence the

37:02 transitional. Mhm. The glands are a different type of epithelium.

37:10 job is to make and then secrete export would be another word to use

37:15 particular product. All right. it's being very vague there because we

37:19 different types of secretions. Alright, , a product is simply what's being

37:23 by the cell. All right. , typically a secretion is an acquis

37:29 , meaning it's water plus stuff. right. And so typically it's going

37:33 be protein, but depending on where are, it might be lipids,

37:36 might be steroids. Alright, the sweat produced in the axillary region

37:41 more stuff than the sweat that's produced the surface of the skin.

37:45 Different glands producing different types of sweat execution gland is secreted out onto the

37:53 of a structure. All right. , that could be like the sweat

37:58 on your skin. Alright. There'sa water plus stuff onto the surface of

38:02 skin. Hence execrable. An endocrine will secrete into the blood stream.

38:10 typically lack ducks. Whereas the execution usually have ducks. Ducks are not

38:15 , quack ducks are the things that tubes that connect the glandular structures to

38:20 surface. Alright, so, an gland has no ducks. It produces

38:25 products that gets secreted out into the and then they traveled around the body

38:29 does its thing. So, it's screaming. Alright, so, that

38:35 be outside. This would be All right now, these are going

38:39 be classified based on their structures. are not epithelial cell derivatives. There's

38:48 glands are typically neural derivatives. And we talk about specific glands will point

38:54 owns that are which. Alright, , this is one way that we

39:01 look at in terms of structure. right. They're either uni cellular or

39:08 . Some of this stuff is pretty . If a genius celery it means

39:10 many cells. What if it's multicellular more than one. Yeah, it's

39:15 pretty straightforward. All right. This is in the execution.

39:20 we're not talking about endocrine any All right, But you'll hear endocrine

39:24 . So, just understand there's two types of glands in the body with

39:28 to where they secrete. So uni are going to be scattered within epithelial

39:33 . Alright, there's usually one So this is it right here.

39:37 what they do is they secrete by ketosis under the surface and then it's

39:42 kind of out there on the So, this is an example of

39:45 . You can see here we're within whole bunch of Colombian ourselves. You

39:48 see the micro villi, this uni cells called a goblet cell because of

39:51 shape. And what it does is secretes a whole bunch of mucus and

39:55 you can see right there there's the . And what does the cilia

39:59 Pushes the mucus along the surface so picks up all the dust and all

40:02 horrible things that you suck in your your respiratory system. Multicellular are a

40:11 bit more complex obviously. Alright, , what you have, you're usually

40:17 have some sort of duct work. right now this right here is an

40:21 of an extra cream. I mean this would be like a salivary

40:26 This is how your pancreas is structured example, and you can see here

40:30 a series of ducts that kind of like branches and then at the end

40:36 each of these branches you have these bunches of little tiny round structures.

40:41 little round structures are called Messina and the escena that are responsible for producing

40:47 product that you're secretive. All so this is what it would look

40:50 . So, you can see here's duck. Here's a little tiny round

40:53 looks like a whole bunch of And you can imagine these cells are

40:56 stuff goes down the ducks, You all this stuff through the ducts and

40:59 your product is being secreted. All . So think about your saliva,

41:04 ? Your saliva is basically water plus created in producing a structure like this

41:09 it gets accumulated. That's why you're you're producing so much saliva all the

41:14 . Actually, you're constantly producing, about two liters of saliva per day

41:17 think is what you're producing. All right. Um let's see what

41:24 I want to say. Oh So these are typically divided by lobes

41:27 you kind of see here, they're to show you the lobes where you

41:31 kind of see these divisions. And that kind of makes it so

41:36 there's specific regions that are kind of that are producing things. So typically

41:42 we do is we're going to either these things based on their anatomical shape

41:49 we might name these type of millions studies by their motive secretion. And

41:53 this would be an atomic classification right . All right. And again,

41:57 are something you're going to have to able to identify. And again,

42:00 this will be clear on the It's not gonna be. Here's a

42:04 thought. Hopefully you can understand what artist did. Alright, so the

42:11 not quack quack the tubes, the portion. They're either going to be

42:15 or they're going to be compound. , so a simple duct,

42:21 Is basically a single long un So here you can see simple

42:25 You can be simple. There's simple there. See how the duck doesn't

42:29 . The dark purple in these pictures the Messina. The light purple represent

42:34 ductwork down here. You can see . So here the artist did a

42:40 job. But what they're supposed to showing you is the branching. So

42:43 can see this is probably the best where you can see straight into the

42:47 . Branch. Branch here. It be going branch branch so on and

42:51 forth. So, there's like this branching that's taking place. This would

42:57 a compound duct. All right. artist in this picture. Did a

43:04 job. All right. So simple compound. All right. And then

43:09 Messina is going to be named either onions. Gonna be named in one

43:13 two ways by its shape by It can be tubular. Right?

43:18 when it's tubular, it's going to like the same width as the

43:22 So, you can see here very short duct. This long tubular hasina's

43:27 here is a simple duck. And look at the the casino. They're

43:32 like the tube right there elongate when rounded. We refer to them as

43:38 viola. Alright. So they're kind more like a shaped like a

43:43 All right. And that's what we're at there. That's Al viola.

43:46 then some of them some glands will a mix of both types. So

43:51 here, you can see there's a type right over there. That's the

43:54 Viola types. So it's tubular al , meaning it has both. All

43:59 . So when you look at a sometimes you'll hear, oh this is

44:02 tubular tubular valvular compound gland. So just telling you, oh, the

44:08 branch out and it's structurally it has tube shapes and it has these round

44:16 . All right. So while it really complex, all the person who's

44:20 is doing is describing the shape. it. The easier way to classify

44:29 things. And what we typically do is ask how does it secrete its

44:36 ? It has one of three different of secretion. We're just gonna walk

44:40 this one over here on the left the american style. All right

44:44 what you're doing is you're producing a you're putting an investigation and then that

44:47 moves upwards and merges with the plasma and releases that material out onto the

44:53 . Alright, So it's water plus . And all you're doing is you're

44:57 opening up and whatever's in the vestibule to the surface. Alright. So

45:01 it's secretion by exocet Asus. All . And that's what you're seeing

45:06 typically, these would be your lack glands and your salivary glands. What's

45:09 lack of your glands? Tears. . I think it's pretty watery.

45:14 tears watery. Yeah. Okay. about celebrating glenn? Is that pretty

45:20 ? Yes. Okay. So, will be 22 examples. All

45:25 Some of your sweat glands, ones the surface of the skin. Very

45:29 . These are included as american type . A pack Quran glands are a

45:35 bit different. All right. And gonna see they get really different here

45:39 just seconds apart. Quran. you create those vesicles and those vesicles

45:44 to the surface, but they don't up to the surface instead, they

45:47 pinched off. So, now, you have is you basically have a

45:51 membrane structure. Right. So you the plasma membrane that got pinched off

45:56 the vesicles decided all right. this would be a perfect example of

46:01 african. Grand is a mammary So, the milk that's being produced

46:06 pretty pretty familiar with milk. I mean, does the body

46:11 You whole milk. I'm using cows example. I'm not talking human

46:15 You're probably not real familiar with human . Okay. But cow milk,

46:21 milk, rat milk. Human It's all basically the same thing.

46:24 a whole bunch of fat plus stuff it. Right. And what you're

46:28 is you're literally taking bubbles of Right. That's plasma membrane and surrounding

46:33 around proteins and that stuff is being . Okay, so you're pitching off

46:40 of the cell as you go 3rd type. Really weird. This

46:46 the holocaust. Alright, now you're with harlequin glance because you've all gone

46:50 puberty and you woke up that I remember that morning you woke up

46:53 there was that big holes in the of your forehead, that big old

46:56 head that looked like mount Vesuvius, to erupt you frown and you could

47:00 see it quiver, you know what talking? Right? That big old

47:06 head is a is a result of type of secretion holocron. So here

47:13 glands are and sebaceous glands are the , what they do is they produce

47:19 product but they don't secrete, it gets stored up inside the cell and

47:24 the cell gets completely full it begins expand and then it basically pops it

47:31 itself and all that material gets Alright, so this is primarily oils

47:36 stuff like that. Now, when think about is it basically what you

47:39 is you have a structure that has whole bunch of these cells at the

47:42 of it and when you have a of dirt that oil can't get to

47:46 surface. So it gets compacted in and then bacteria coming along. Oh

47:50 dinner and that's when you get that ugly white head. So the whitehead

47:54 is not this but it's the stuff makes your skin shiny and it's what

47:59 your hair greasy when you don't wash . Alright. And the materials that

48:04 security here are antibacterial and antiviral and sorts of fun cool things. And

48:09 wash it off at least once a . Kind of cool or bad.

48:12 don't know whatever you want. You nicer but you make yourself susceptible to

48:17 sorts of horrible things. But you kill the horrible things that you

48:21 All right. So can you identify three different types of secretion? Well

48:27 this very second. Right? But crane watery released by the sell through

48:33 psychosis. Cochran pinching off parts of cell. American cell explodes and has

48:39 be regenerated. New new cell takes place. Okay, that's the easy

48:46 . All right, so that's epithelial . Let's run through the connective

48:52 How are we doing on time Of course because I took my sweet

48:55 walking through all that stuff. All , speed it up a little bit

49:00 . I'll start talking like an Alright. Where I can do that

49:05 the way. Well not like an . Exactly. But I get talky

49:09 fast. Alright, so the connective that are the most abundant tissues in

49:14 body. They're all over the They have different types of compositions.

49:18 have different variety of sales depending upon type of organs you're looking at.

49:22 right. There primary functions across all tissues will fall in one of these

49:27 . Or maybe share some of these . They play their own protection and

49:32 . This is both a physical protection well as an immunological protection. They

49:37 a role in supporting structures. binding things together. Hence the name

49:43 . Right. They may play a in storage. Think fat. They

49:47 a role in moving things around the . Transportation. Think blood. All

49:52 . So, we have some unique of things that are a tissue.

49:57 do some really unique things. the reason all the connective tissues are

50:02 tissues because they all have the same . Alright. They originated from the

50:07 sort of embryonic tissue. And then became all these unique things.

50:12 all connective tissues produce something called ground . All right. Now, if

50:19 looking at this picture up here and trying Well, where's the ground

50:21 It's all the stuff that's not Alright, so, see all this

50:26 . It's not really space. But can't draw it. So, microscopic

50:30 other structures. It is a non material. The cells themselves, with

50:35 exception of blood produce their ground Alright, blood does not produce his

50:42 ground substance. Alright. And so we say is that the environment in

50:48 the cells are found in this We have different cells. You can

50:52 we have different types of cells The ground substance and the protein fibers

50:56 the cells themselves also produce make up matrix in which that sell or that

51:03 tissue exists. Alright, so this what is referred to as the

51:08 Is. The extra cellular matrix is term that you'll hear over and over

51:11 . This extra cellular matrix. Maybe . Alright, So, it could

51:15 watery. That's blood, but blood not produce its own matrix. It's

51:20 the weird exception. But it can viscous in nature. It can be

51:23 solid in nature. Think of cartilage it can be solid in nature like

51:30 . All right now, what is the ground substance? Proteome blackens.

51:34 to be confused with glycoprotein. Same rodeo proteins like cans, sugars.

51:44 , protein sugars are not sugar right? It's like carbohydrates versus

51:50 You eat carbohydrates, you do not higher hydrocarbons. That would be

51:56 You know, hydrocarbon is right? right. So, this down here

52:03 an example of what this ground of . So here you can see there

52:08 fibers. You can see this structure here. That would be the proteome

52:12 can. It's attached to it are whole bunch of little tiny proteins called

52:16 Minogue, like cans. So you can see sugar amino acids

52:21 you know? So, it's basically you have is an environment that has

52:24 whole bunch of sugars. A whole of sugars like to attract a whole

52:26 of water and that's what gives the substance that watery appearance. It basically

52:32 water in play. And so that's connective tissues are kind of squishy with

52:37 exception of bone, which is pretty . All right. And there's some

52:42 adhesion proteins that are associated in here basically buying these things and hold it

52:46 together. Alright, So by nature looks like it's an empty space but

52:52 a whole bunch of stuff in there you can't see. All right now

52:59 connective tissue has its own unique resident . Alright, so they have their

53:05 specific kind of cell. So depending which type of cell you're looking

53:09 So we have we're gonna we have tissue proper cartilage and bone. The

53:13 of primary cell that's going to be in connective tissue proper is the fiber

53:17 . And the fiber site where I blast and sight. Those are just

53:21 about the same cell at different stages development. A fiber blast is an

53:26 , sell it basically secretes matrix and it stops secreting matrix it matures and

53:32 a site of fiber site. Does make sense? So you start off

53:36 a fiber blast then you become a site. Alright if you're in the

53:41 , you're a condo blast. You matrix then you become mature, you

53:45 a condo site, you're no longer matrix. Alright. And then if

53:49 bone the bone sell the thing that's the matrix is called osteoblasts. And

53:56 once it matures and the matrix stops stop screaming matrix, you become an

54:01 site. Alright. So the three cells. So when you see

54:06 fibroblasts or osteoblasts or their site versions should automatically tell you what type of

54:11 you're in in terms of the big . But then there's other types of

54:17 . All right. So for you have a tapas. It's a

54:19 . Sites are fat cells. They appear in small clusters in any of

54:23 tissues. Well, really primarily in tissue proper. But if you get

54:27 whole bunch of fat cells that make that tissue, you're no longer called

54:31 tissue proper. Well you are a of connective tissue proper. But you

54:35 are an adipose tissue which is a of connective tissue. Right? So

54:40 the dominant cell becomes at a post out of post issue mesenchymal cells.

54:46 are the stem cells of connective So you'll find them all over the

54:50 . Alright, primarily early on in . There are fewer and fewer and

54:53 between. But when you're looking at of the connective tissue properties. You'll

54:56 . Mesenchymal cells there and then you immunity sites, immune insights is a

55:00 word for saying immune cells. And are different types of immune cells.

55:05 can actually reside within the tissue That means they're surveilling the area and

55:11 . It's like putting a police department the neighborhood and that's where they the

55:16 hang out and stay. Or you the migrating ones, the nonresident communist

55:23 . And these are more like patrol . They just kind of go through

55:26 neighborhood checking is everything. Okay? , cool. I'm gonna head over

55:29 the next neighborhood and see what's going . So the resident or wanders.

55:33 if they become stimulated, what they're do is we're gonna alert the immune

55:36 to then deal with whatever the problem that they were activated for now,

55:44 other thing about this is that where looked at the potential. I mean

55:46 saw the cells in direct contact connective . The cells are not in direct

55:51 with each other. In fact, usually fairly well separated because of the

55:55 that's around them. So I just of amplified this picture just to kind

56:03 give you that kind of that All right now, this is a

56:07 tissue proper. So boning and and um cartilage look rather different than

56:14 But you can kind of see here a whole bunch of fibers in

56:17 Right? And so the fibers that focusing on our college in particular and

56:21 fibers. Alright. So collagen fibers the things that kind of hold everything

56:27 . All right. They're typically on . They're fairly strong. Their resistance

56:30 stretching. Um they make up about of your body's proteins. Collagen is

56:36 . Alright then we have a particular . These are the ones that have

56:39 glycoprotein. And they're the ones that of create this network surrounding, creating

56:45 that ground substance. All right. tough and flexible, but they're not

56:49 big. So they're they're much much . And very often when you're talking

56:54 certain organs like the spleen and the and stuff there, the structure on

57:00 these organs are built. So in words, once you if you could

57:03 take the organ and dip it in solution that caused all the cells to

57:06 up, you'd end up with like network of particular fibers. That would

57:10 the connective tissue. All right. then you have elastic fibers.

57:16 that's like the brown ones here. basically these are really stretchy. Their

57:20 even tells you the kind of You're familiar with the elastic fibers.

57:23 mean, you can do this with ear, right? And it kind

57:26 bounces right back. Does it doesn't stay down. You can do this

57:29 day long. It's a lot of , right? If you are

57:33 like Samantha from Bewitched, you can your nose because there's elastic fibers and

57:39 that. All right. So, allow uh you know, connective tissues

57:44 bend out of place and bounce right in. But what I want to

57:48 you with this picture, if you see look we have cells. We've

57:51 different types of cells. Mesenchymal cells are the pink ones here. The

57:55 ones are the purple ones here. are fibroblasts, the yellow ones over

58:00 . They represent your added besides. here there's a big giant macrophage representing

58:04 immune inside. And so you can you can see the cells really aren't

58:08 each other, are they? They're kind of everywhere. And that most

58:12 the space if you're able to cram the solids together, you'd end up

58:16 a whole bunch of empty space which at ground substance which is really just

58:20 glucose amino black hands holding things So connective tissue proper. We're gonna

58:31 with the big class. The most class one. When you think of

58:35 tissue is probably what you think of as loose connective tissue. Why do

58:39 think they call it loose connective Look at the pictures and tell me

58:46 why is it loose? Yeah. , cells aren't tightly packed. Well

58:53 adipose tissue is tightly packed but under microscope, what would happen is you

58:57 adipose tissue? You put it on slide, you dehydrate it. In

59:01 words you take out all the water then it looks like you have a

59:03 bunch of space. Which is why falls into the category of loose.

59:07 . But otherwise it's loose. I look there's lots of space in

59:11 Alright. Lots of space. And you counted the the adipose cells,

59:17 of space. So hence the Alright, I'm gonna jump over a

59:20 and then we'll come back. These called dense connective tissues. Why are

59:25 dense connective tissue jam close together. you see how silly it is?

59:33 that there's not a lot of deep in terms when you look at the

59:38 , it's not like, what profound did they name this dense connective?

59:43 all the cells are clos luce close together. All right. So

59:50 loose connective tissue. Few cells. fibers are all over the place.

59:55 fibers are irregularly arranged. Kind of holding things together. Lots and lots

60:00 ground substance and they surround support and uh tissues and organs and tissues.

60:08 . Right? There are three This is the areola. All right

60:13 a post which we've talked about, is the fat. And in particular

60:17 are the things that make up the on which organs are built.

60:23 so this is the one we think when we think connective tissue, we

60:26 about this. It's on which things built, right? Like when you

60:29 of the epithelium. It's on top aerial or connective tissue right out of

60:34 . Pat in particular. This is of connective tissues on which the organs

60:40 built. That's your loose connective dense connective tissues. again, you

60:48 see the cells are very, very together. Um There's lots and lots

60:53 fibers that are densely packed in I should have pointed out the cells

60:57 close together. It's the fibers that close together. Look at the

61:01 You can see their nuclear. They're and far between their cell. There's

61:04 there's a cell. This is a bit harder to see. You can

61:09 this right here is the epithelium this here. That's the connective tissue.

61:16 , So actually, I'm sorry. muscle. That's connective tissue right

61:22 All right. So, what are dealing with here? All right.

61:25 a lot of ground stuff. Since has been kind of pushed out of

61:27 way we have dense regular. We dense, irregular. Then we have

61:31 elastic tissue. All right. You see why is this called regular?

61:36 all the fibers move in the same . Regular. Because the fibers don't

61:41 in the same direction. They're kind pointing in different directions. So,

61:45 create this irregular pattern. All In these cases, the dominant part

61:52 the collagen fibers down here. When dealing with elastic tissue. The elastic

61:57 is there to stretch and bring that back into its original shape. The

62:03 that they're showing you here happens to of an artery near the heart.

62:07 , when the blood pressure, the creates pressure to dry the blood

62:11 The blood pressure causes the blood vessels expand and then as the blood

62:15 it returns back to its original Alright, so that would be with

62:19 elastin fibers. But the elastin fibers all moving in the same direction around

62:23 blood vessel, so they stretch like rubber band in unison. Okay,

62:32 jumping away from the connective tissue proper here to cartilage. All right here

62:37 have a matrix that is semi That's what all this dark purple stuff

62:42 . All right. You can see here um It's these you can see

62:46 fibers that are really, really tight and then down here in the fiber

62:49 , you can see these larger fibers in the same direction. But you

62:54 kind of see here is a little cells harder to see the cells in

62:57 one, but the cells are pretty because this is a much better

63:00 Alright, so the cell type that's here is the Kandra site and the

63:04 blast. The condor blast. Makes matrix. Once the matrix is

63:08 it makes it all directions. And Congress sites have pushed far enough apart

63:12 they can't create any more matrix, differentiate become Kander sites and their job

63:16 to maintain the matrix. Alright, the countryside is a mature form.

63:21 blast is the immature form. There no blood vessels within cartilage fluid and

63:28 materials can move through the matrix just because it's not dense. It just

63:32 like it's dense. Alright? It's solid. If you grab cartilage,

63:37 can squeeze it. You guys have eaten chicken. You pulled out that

63:40 old ligament. You know, it's that, right? You can squeeze

63:45 and water comes out in this case usually fat, but you know,

63:49 done that. Yeah, you can and that's that's basically water because there

63:54 space in there. It's just hard see in these pictures. All

63:58 They're very flexible and they're more flexible bone but they are also strong.

64:03 right. You're all familiar with your , right? So up here,

64:07 a bone. But as I move , that's cartilage, it's bendy.

64:14 different types of cartilage will go into in more detail when we get to

64:19 bone structures, but we have highland . When you think of cartilage.

64:23 is typically what you think of. can see right there. There's that

64:26 . We also have elastic cartilage already you in your ear. That's gonna

64:30 elastic cartilage allows your ear to bend flip flops and stuff like that.

64:35 then we have fiber cartilage. This more of a fibers are going in

64:39 same direction. That's very, very . You find it between the vertebrae

64:43 it's basically the bones sit on top this cartilage and it absorbs the compression

64:48 you walk and move around. jumping the other direction, we go

64:55 to the connective tissue proper. Here's I separated from the other ones so

64:59 you can clearly see how different it . This is a fluid connective

65:04 Lymph also falls in this category. and lymph. It's really plasma.

65:08 for the same thing, the difference plasma and lymph is its location and

65:12 cells that are found in it. has four plasma has red blood cells

65:16 white blood cells. Lymph has no . All right. But it's the

65:20 fluid. All right. So, has what are called form elements.

65:25 don't really call themselves. And there's there's a lot of reasons why I'm

65:29 going to get into it. these are your red blood cells,

65:31 white blood cells known as lymphocytes and sites as well as the platelets which

65:35 parts of cells which these little tiny dots in this picture, you see

65:40 tiny purple dots. Those are the , their parts themselves. Alright.

65:45 ground substance that makes up the blood is called plasma. That plasma when

65:50 goes into the lymphatic system is now renamed lymph. All right. So

65:56 it arises from the blood. Doesn't have cells. It lacks

66:00 It's basically a collection depot to move that shouldn't be in your body back

66:06 the bloodstream. Um So that it be taken care of by the immune

66:11 . That's it in a nutshell. , back to the supporting connective

66:18 Alright, this is a connective tissue . It is bone. Bone is

66:23 living tissue. It is not dead . It's not just some structure that's

66:28 and happens to be in your Alright. It's made up of the

66:31 type of matrix that made up But then you add in some other

66:36 called calcium salt that gives it. rigidity. Alright, so all these

66:42 tiny black circles, not the big ones with the little tiny things.

66:46 are the cells in the bone So they start off as osteoblasts.

66:52 build their matrix and then when they build it any further, they mature

66:56 become osteo sites and they sit in matrix making sure the matrix is sustained

67:02 maintained. All right, So, bone itself. So, these structures

67:09 here, that's where we're gonna find their blood vessels and nerves. Have

67:12 ever been kicked in the shin? it hurt? It hurts because you

67:16 nerves to feel the damage. so, it tells you there's nerves

67:20 , there's blood vessels. You have have blood vessels because you want to

67:23 those cells alive. And so the from the blood, get to those

67:27 through these little tiny passageways, which learn about all later. Mhm.

67:35 tissue. This is one slide. . There are three types of muscle

67:40 . All right now. These are . I'll cells. They have unique

67:44 . They produce different types of movements skeletal muscles. Really about locomotion,

67:49 muscles, about pumping or creating a like action of the heart so that

67:54 can propel blood. And then you have smooth muscles, smooth muscles found

67:58 the digestive system, in the vascular . Anyplace where you have materials that

68:03 to be moved through the body. what they do is they help propel

68:06 move and mix that material um as being propelled through the body. So

68:11 . Don't just think of local It's different types of movement.

68:15 The reason that they're able to do is because they have these unique side

68:18 skeletal elements. So when we talked acting, action plays a role in

68:23 and it's how it interacts with other of skeletal elements to create a contraction

68:28 those cells. So, the three are skeletal muscle that's locomotion. Cardiac

68:33 , that's found only in the heart then smooth muscle. These are found

68:36 your round um organs or the tube . Alright. Anything that's a tube

68:43 smooth muscle in it. Also your allowing you to focus. Alright,

68:48 away your site, far side. smooth muscle. Actually, I take

68:53 back the amount of light into your . I need to be paying attention

68:57 what I'm saying. All right, tissue. There's only two types

69:04 Two types of cells. This is major component of the nervous system.

69:07 have neurons, neurons are like the . Their specialized nerve cells. Their

69:11 is to process information. So they information they process and they send

69:17 Their support cells are called glial Glial literally means glue. So when

69:22 first we're digging into the brain and to figure out how it works.

69:25 recognize, oh these cells are here hold everything together. So they call

69:29 glial cells. There's a whole bunch different types of glial cells. They

69:32 not play a role in nerve Their job is to make sure that

69:36 do their job. Is there a ? No, it isn't. It's

69:41 a nervous neural in origin. So tissues are mesenchymal or from the Mezzanine

69:47 . That's why they kind of stepped . That's why we look at blood

69:51 go why? Why is blood connective doesn't hold anything together. It's because

69:56 its origin. So very often these are named for their origins. That's

70:01 good question. It behaves like a tissue, but it's not How we

70:07 . We got 10 minutes. I I'm going to actually finish. All

70:12 . So, those are the different of tissues. You need to

70:15 You need to be able to identify four of them on the exam,

70:19 identify for remember what for which are three symbols And stratified squamous. That's

70:29 all you got to be able to . It Kind of makes it

70:33 All right. So, what I do is I want to talk about

70:37 repair and I'm gonna use the last of slides or vocabulary. So,

70:40 this won't take very very long. I mentioned, all the all the

70:49 in your body with very few exceptions capable of repair. All right.

70:54 other words, regenerating themselves. There some exceptions to that rural or some

70:59 extreme exceptions. And so, what can do is when we say when

71:03 looking at a tissue, how does go about repairing itself? Alright,

71:07 , it depends on what's there. off, we have method of

71:11 Regeneration simply is taking the destroyed Getting rid of it and replacing with

71:16 exact same type of tissue. All . This is going to restore organ

71:22 . The other type is fibrosis. hear what you do is you take

71:26 tissue that was damaged to remove it replace it with fibers, fibers,

71:30 primarily connective tissue, collagen and And so this is going to give

71:35 a scar tissue. Alright? You structural restoration. See, we closed

71:40 everything. But you do not get same function. All right. I

71:46 this lecture Once a student came up me when I was a kid.

71:49 hit me in the head with a . I was like what he's like

71:54 , I got hit in the What happened in my head? I

71:58 well what happened was primarily fibrosis and nerve fibers worked around where the damage

72:04 , right? So where you had that couldn't replace themselves, you basically

72:08 the cells. And then the fibrous comes in and creates a mesh work

72:12 a network to kind of fill the . And that's why you have like

72:16 his case why he had that fibrous in his brain. But for

72:21 the more familiar one is like what see in the picture up here where

72:24 see a scar, right? If cut myself and it's a small

72:27 it repairs itself and I can't Right? So what I did is

72:31 basically it was a superficial cut. I had superficial regeneration that took

72:37 right? But if I get a cut and again this is an actress

72:41 makeup. So you know um if a deep cut there's gonna be repair

72:47 both fibrous and then it's gonna be by a layer of regenerating cells which

72:52 be the epithelium in this particular Right. Alright. So depending on

72:57 you are, what type of tissue and the severity is what you're going

73:00 be using. So regeneration was on , right to create the surface and

73:08 the fibrous tissue underneath is basically I'm to hold these things together. So

73:11 connective tissue didn't regenerate it reorganized with fibers um Using fibrosis. Now how

73:19 all works. This is going to using damaged skin. So, we're

73:22 with two different types of tissues Alright, So we have four basic

73:28 that you're going to see when you're with wound healing first. It's gonna

73:31 an inflammatory response. What's happening is you damage that means something has penetrated

73:36 probably harm cells and probably allowed foreign to come in. So, that's

73:41 to attract the attention of the immune . And they're going to come to

73:46 location. They're gonna start dealing with damaged tissue and any sort of pathogen

73:50 may have penetrated. All right. there was a cut blood vessel,

73:54 is going to move into the wound well. All right. And so

73:57 trying to show up here. I know where the blood vessel is,

73:59 you can see, okay, blood moved to this area, filled up

74:02 spot and then there are proteins within blood naturally there that are gonna cause

74:08 blood that has flowed in the wound seal the area off and saying nothing

74:13 is allowed in here. So, have fluids moving in. That's gonna

74:18 the inflammation. That's gonna bring with . The immune insights and then the

74:21 is going to seal off at the to prevent things from coming in.

74:25 , that's what a scab does. basically creates a seal from where the

74:29 to the external environment. That would the second step is the formation of

74:33 clot. All right. So, that sealing it off. All

74:37 Now, the immune sites begin Any sort of thing that's broken damaged

74:41 it shouldn't be There starts getting destroyed the immune of sites. Right.

74:45 their job. So, a little on, a couple of minutes,

74:53 days later, you're gonna get signals are going to cause the blood vessels

74:57 start growing and penetrating into that This is called um angiogenesis. All

75:05 now, the reason you're doing this like making roads into the area so

75:09 you can deliver the materials you need . Alright, so, you're going

75:14 regrow those blood vessels, moving the vessels in fibroblasts are gonna migrate into

75:21 area and then they're gonna start laying fibers. Now. Again, they're

75:28 to match structure, but if there's lot of damage, there's not a

75:30 of structure to match too. they're gonna be laying down fibers in

75:34 way they can. There are still be immuno sites, primarily macrophages.

75:40 come in and start removing any of damaged tissue along the way.

75:45 while we initially brought in immuno these are sitting around going OK,

75:49 let's help the process along by removing by the fourth stage. This is

75:56 the epithelial cells. So, notice we have. We have epithelial cells

75:59 and epithelial cells there in between There is space, it's just

76:03 they're not talking to each other so going to cause the epithelial cells to

76:07 back together. So there's that regeneration taking place and what it's doing is

76:13 place it's repairing the outer layers where epithelium is underlying it, where this

76:20 tissue is. In this case, that fibrous growth. Alright, so

76:24 there's a lot of damage you're gonna up with very little scar tissue.

76:27 not gonna really appear that much, ? But if there's big damage where

76:31 have lots of separation, that granule that's taking place isn't going to match

76:36 surrounding connective tissue. And then the which is just growing over it is

76:40 growing over the new shape that happens be there. Now the people in

76:44 front row can look and see I've got this big beauty, see

76:47 beautiful scar right down there. I talked about this. I did

76:50 20 ft face plant off a It was beautiful it's like a swan

76:55 . Not on purpose. Alright. one jumps off a cliff on purpose

76:59 you're in Mexico and there's water underneath right? I was climbing a mountain

77:03 I know you want the story We're in Utah. I was hiking

77:08 we're in this canyon and the trail and was just scrub this stuff was

77:12 us and it wasn't fun, I hey I'm a billy goat, I

77:15 to climb things. I will climb hill over here, this cliff face

77:18 I will try to see where the is. It was stupid. So

77:22 climb up there and look, there's there like I got to come down

77:25 so I'm coming down and the first I did um is I'm coming down

77:32 all fours like this backwards, which okay and I'm trying to get down

77:37 a ledge, it's about this far from the bottom of my foot.

77:40 only sits at about this far and 20 ft below me. So it's

77:43 a big deal, but I started and when you slip, what do

77:46 do? You panic? Right, the first thing I did is I

77:50 slipping. Instead of just going like , I would have slid down and

77:53 just fine. I was like, no ! And I grabbed the first

77:55 that was near me which was a . The first thing they tell you

77:59 do when you're climbing is don't grab green because you grab something green,

78:03 gonna come out And that's what it . It came out and my life

78:06 a cartoon. Mhm. Right, holding this plant. I remember to

78:11 day is mormon tea and holding this and I'm looking at it going,

78:15 plant is in my hand And then slowed down those six inches, hit

78:20 little ledge propelled me forward and free . I became a tom petty

78:26 And then I landed on my my face apparently. And I put

78:32 big old giant hole in my which I'd be happy to show

78:35 But it's right there and it's hard pull up your pants. All

78:38 But that's an example of that Now, I know you guys are

78:41 to get out of here. It's . I got three slides here.

78:43 just had to the term that you to know and there's just three

78:47 Trust me, it just takes more a minute. I'm sorry. Apoptosis

78:52 it with me. Apoptosis Apoptosis. . I had a professor. If

78:57 said it wrong, he got If you gave a talk, he

79:00 stand up in the middle of the and saying that is not how you

79:03 that word. Don't be such an . You do not want a professor

79:06 you're trying to get your graduate calling you an idiot in front of

79:08 the other professors. So it's It's not apoptosis, you will

79:14 It's not apoptosis Apoptosis. Apoptosis is . Cell death basically. Cell suicide

79:21 , not supposed to be there. comes along and says, hey,

79:24 not supposed to be here, you die in a fire sale says yes

79:27 . And it goes dies in a . All right. When you were

79:31 , you had webs between your just like a frog. You do

79:36 have that now. The reason you not have that now, Apoptosis.

79:41 right. There's a whole cascade that donated tautology, tautology is self

79:47 self eating. Right? And so is a way to take things that

79:51 broken damage in the cell and destroy in a in a programmed way so

79:58 materials don't go floating off and cause to the cell. Alright,

80:02 this is a different type of of of dealing with damage within the

80:06 This is primarily how you deal with or needed cells. Cancer cells,

80:10 example. Alright. Three other Three terms here, atrophy. When

80:15 sit on the sofa and do nothing watch youtube, you don't ever move

80:19 muscles. Atrophy. Alright. what you're doing is a decrease in

80:24 of an organ or tissue from lack normal stimulation muscles. An easy one

80:28 think of If you get a cast I had when I took that cast

80:32 on this arm, I had this skinny scrawny thing because I didn't use

80:36 muscle on this side. I was , Popeye, because I did everything

80:39 this hand. All right. Atrophy is when you see an increase in

80:44 size of an organ or tissue from stimulation. So, when you work

80:48 the muscle tissue is going through All right. Usually when you hear

80:54 word hypertrophy, you think you hear in a negative connotation. So like

80:59 are undergoing hyperplasia as well as Things are growing getting bigger. All

81:06 . So hyperplasia. Just localized acceleration growth during puberty. Your cells were

81:12 plastic. Alright. They were multiplying dividing. So when the cells get

81:18 , that's hype that's hypertrophy. When dividing quickly. That's hyperplasia. But

81:24 when you hear both, those terms used in a negative way as opposed

81:28 their strict definition. Okay, lastly is the last slide has to do

81:33 stem cells. All right. Because gonna be dealing with tissues and how

81:37 grow and stuff. Stem cells are that give rise to all the other

81:41 in the body. They have unlimited my atomic ability. And typically what

81:45 doing is they are differentiating or creating differentiated descendant. Alright. And so

81:51 can happen. One of two ways cell divides. Right? So this

81:55 asymmetric. One cell remains as a cell. The other one is the

81:59 that differentiate and continues to migrate away change or differentiate into the future

82:07 Alright. So that way you can and repurpose or keep a pool of

82:12 to allow this to happen to to . We'll see this in skin.

82:18 example, the cells that the basement doing this type of generation one stays

82:23 kind of a stem cell. The commits and move forward. The other

82:27 is the symmetrical basically stem cell divides you get to uncommitted. One will

82:33 back to the stem, the other differentiates and becomes committed. So this

82:37 just a way to ensure that you a continuous pool of cells that continue

82:43 divide over and over and over Mhm. Test on thursday. Don't

82:51 here, I won't be here. be a very cold and silent

82:56 Okay. Have a great day and luck on the

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