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BIOL 2301 Human Anatomy & Physiology I - BIOL2301_lecture07_0912
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00:01 All right, good morning, You guys excited. No,
00:10 no, no. All right. a reminder. We have a test
00:14 on Thursday if you haven't written it or if you've forgotten, we have
00:18 extra credit that opens up tomorrow evening before the exam. 6 p.m. closes
00:22 9 a.m. Ok? Um That link be in the modules at the very
00:28 of the thing. So you'll see credit. All right. So notice
00:31 is a pre exam, extra There are no extensions of this.
00:34 you forget about it, you miss on the extra credit. Um
00:40 you know, make a note of yourself, give yourself an alarm,
00:42 something to remind you. Um They're . It takes like three minutes and
00:47 points to your exam. Uh What doing today is we're gonna be talking
00:51 tissues and I still think the volume funny. I'm funny about that.
00:56 right. Uh We're talking about tissues . So we're, we're slowly moving
01:00 that hierarchy so we can take the and start doing some actual anatomy because
01:04 why you guys came and took the , right? Yeah. And you're
01:08 , where's this stupid anatomy? I want to take biology. Well,
01:12 what? You're going into a field requires you to know some biology.
01:15 right. So, what we're doing is we're going to be looking specifically
01:19 epithelium and we're going to be looking connective tissue and then we're going to
01:22 , oh, yeah. And by way, there's muscles in their nerves
01:24 neurons and stuff like that. But going to kind of more or less
01:27 that, that those two tissues because the rest of the class deals with
01:32 tissues in the context of where they . So our starting point today is
01:37 be an epithelium. And so you see here, we've, we've been
01:41 of talking a little bit about some the characteristics of epithelium as we've been
01:45 along. And epithelium is simply those that serve as a covering or are
01:52 for creating glands. All right. that's what, of course,
01:59 All right. So what we have are, are a tissue that kind
02:03 has two roles here. So when talk about covering, what are we
02:07 about, we're talking about things that on the surface or on the inside
02:10 hollow hollow structures. And their job to serve as a boundary between those
02:15 environments. So they are either a or they may play a role in
02:20 what passes through that tissue to get the other side, glandular tissues.
02:25 the other hand, these are going be the things that make up your
02:27 of your body, right. And seems pretty obvious. And so their
02:31 is to produce materials so that they be secreted into the hollow organs or
02:37 out on the surface of the body different various reasons. Right? And
02:42 we go through the integument, we'll at glands more specifically, but we're
02:45 to see the general structure and how things work now because epithelium is this
02:52 or basically clumps up to create these , they're gonna have these unique um
02:57 uh interactions. And so all those of junctions we talked about are there
03:03 in epithelium so that you can create of material. We've already talked about
03:08 Indian burn and how horrible and nasty siblings were or how they deserved
03:14 right? If you're the older they deserve the torture that you gave
03:19 . Yeah. But if they're they're just cruel and mean.
03:25 And we know the skin doesn't come off because of these kind of specialized
03:29 . There are sheets upon sheets upon that barrier. All right. So
03:35 don't need to go back and memorize the stuff because you've already learned it
03:39 theory important in making these types of or so, with regard to
03:46 this picture, what you're looking at is a cut through the skin,
03:50 ? So through the pega and we see that there's a couple of layers
03:53 , there's a hypodermis, there's a and the epidermis and where we're spending
03:57 time when we're talking about epithelium is down here in the dermis, which
04:01 mostly connective tissue, not down here the hypodermis, which is mostly connective
04:06 , but up here in the right? The epidermis is epithelial.
04:11 right. And so if you look the little cartoon, the cartoon does
04:14 pretty good job of, of showing of the characteristics without you realizing
04:19 So for example, epithelium does not blood vessels in it. It is
04:25 and you can look at the picture here. Do you see blood
04:27 the little red and the blue up ? No, it's all pink,
04:31 ? And so the way that epithelial gets its nutrients because all cells need
04:37 is that blood will deliver those materials close to the epithelium. And then
04:42 materials will, will diffuse from the vessels out into the surrounding connective tissue
04:48 through the connective tissue diffuse upward into epithelium. All right. So we're
04:56 what we need to survive from the environment but not directly from blood
05:03 uh uh vascular or penetrating through that . The second thing that you'll see
05:12 that there are nerves and so we see up here, there's an example
05:15 showing you here is a neuron traveling through and it penetrates up into that
05:21 . And so it is providing the tissues with uh receptors and stuff so
05:27 you can detect what's going on around . So even though you have this
05:32 barrier, it's not by itself, are other types of cell types that
05:36 be found in them, but you find blood vessels, the other
05:40 And you know this because you've probably your knee or, or gotten a
05:43 or something is that epithelium is It's highly regenerative. And we talked
05:49 little bit about this. We you know, when it comes to
05:52 uh epithelium, when you separate them , they are no longer touching each
05:58 , the cells in the epithelium are longer to touching each other. And
06:01 when they are no longer touching like , what they do is that serves
06:06 a signal to tell them to start . And so that's why they start
06:11 and then they come in and they up that space and then they start
06:14 each other again. And so that that contact is the signal to
06:17 stop dividing. So this is what called contact dependent signaling. All
06:23 And so they will, for when you get a cut will fill
06:27 the, the space as long as is nothing preventing them from growing.
06:32 once they touch each other, they each other to stop growing. All
06:35 . So they're regenerative contact, All right. Now, other tissues
06:41 like that. All right. So example, neurons you can uh fix
06:46 neuron under certain circum circumstances. But you destroy a neuron, the likelihood
06:52 that it's gone forever. All So it just shows different cell types
06:57 different things. This is one that's regenerative. We talked a little bit
07:01 polarity and some of you asked the because when you think about polarity,
07:05 think about positive and negative charges, ? But polarity just means you have
07:09 parts, right? So think of , are you polar? Are your
07:14 the same as your head? Now a polar being. Now if you
07:19 left to right, you are a image. But if you take a
07:22 and divide and half, you're not mirror image. So that's where that
07:25 comes from. And so polarity refers the differences that you see on either
07:32 of that epithelia. All right. so part of that is a function
07:37 the presence of those tight junctions we about. But what we see is
07:41 when we look at epithelium, we a side that is connected to
07:45 we have a side that is open the external environment or open to some
07:49 of environment like if this were the of a vessel of a hollow
07:53 And so because of that, that that those two sides are going to
07:57 doing different things. So on the side, which is the side facing
08:03 away from the, you know, external environment or into the lumen of
08:06 hollow organ, you might be either materials or you might be absorbing materials
08:11 there. So you're going to have have the right proteins and stuff on
08:14 side to allow that to happen. on the other side, you're connected
08:19 the basal lateral side. So basal be the bottom lateral would be the
08:24 . You're trying to create those connections that that you can create those
08:28 And so you're going to need the of proteins that create T or that
08:31 desmosome. You're going to need to proteins that grab on and hold onto
08:36 connective tissue, for example, through hemi. And so you may be
08:42 material as well in a specific direction from the apical side down through the
08:48 lateral side and then you might have . So we're going to see here
08:53 the slide here, there might be vili, there might be CIA and
08:58 these allow you to function or have functions on either side of the
09:04 What else do I have up Oh Yeah, basil lateral. So
09:07 talked about this extracellular matrix. All . And so on the basal
09:13 right, right here that, that pink, all right refers to the
09:19 of the basement membrane, the interaction the connective tissue and the epithelium where
09:27 epithelium is putting its proteins. So you're talking about the epithelial proteins,
09:32 refer to that as the basal So these are glyco proteins and other
09:37 molecules hook on with molecules that are in the connective tissue. All
09:42 And so it just makes up half what is called the basement membrane.
09:45 basal lamina, the reticular lamina would the other half of the basement
09:52 And that would be the proteins, glyco proteins and other interacting proteins that
09:56 find on the connective tissue side. collectively, they're basically thinking two parts
10:01 of molecular velcro, right? You play with Velcro, right? You
10:05 the the squishy part, then you the the itchy part, right?
10:09 you put those two things together and velcro hold holds itself pretty well.
10:14 that's the same thing you can just in terms of the basal lamina belongs
10:17 the basement. That could be the part. And then the hooky part
10:21 in the connective tissue or vice whichever way and those two things together
10:25 basement membrane. So underlying connective tissue sorry, underlying epithelium is typically connective
10:37 . This is where I asked the . You don't have to answer
10:39 Anyone here like to hunt, Anyone ever. And if you don't
10:43 to hunt anyone here ever had to the skin off a chicken, like
10:46 you're making like a meal and you're , I've got it. I bought
10:49 chicken with the skin. I don't to take it off. And there's
10:51 , that layer, you pull off the skin that would be epithelium.
10:54 then you have the, the stringy that you have to rip away,
10:57 connective tissue. And so it just you, um where those two things
11:02 in close opposition towards one another. , one of the things when we
11:12 about diffusion is we said, the larger the surface area, the
11:16 things diffuse. All right. But problem is is that you're a finite
11:21 , finite creature and you have finite inside you, right? And so
11:27 large space in your finite space is pretty difficult to do, right?
11:32 how do we, how do we that? So you can think of
11:34 table, this table would be like a side of a cell. All
11:38 . So it, it's finite because next to it would be another
11:41 But if I want to increase my area, there's only one thing that
11:44 can do and that is to go and then come down and go up
11:48 come down as many times as I in that same space and in doing
11:52 I can increase my surface area. right, if I drew this
11:57 just so that you could visualize Here is a right people in the
12:01 can't see that because it's a crappy . Let's see if I can make
12:05 basketball team. I can't. there, that's what I get applause
12:15 stupid, stupid human tricks. All . So, here's your cell,
12:20 ? That's, that's, you can cell by cell by cell. Like
12:23 , but if I want to increase surface area instead of having a flat
12:28 like that, what I would do each cell is, it goes up
12:34 I can increase the surface of each like that. And so at the
12:40 time, what I've done is I changed the size of the cell have
12:45 . But what I've done is I've this massive surface area. So
12:49 it can now have materials move very quickly into the cell. I
12:54 a larger volume or a larger ability absorb materials. This is what the
12:59 of micro villa are. All And that's what that picture is,
13:02 you're looking at. It's showing you , hey, do you see
13:05 So they are like little tiny that's actually going to be micro
13:09 And what it does is it increases surface area so that I can absorb
13:12 material. So you'll find microbial all epithelium, your digestive system and once
13:19 get in the small intestine, so digestive tract is probably, I think
13:24 around 30 ft in total from mouth anus. Your small intestine is probably
13:30 ft of that. All right. if you can take into account all
13:35 bumps and all the micro villa and the other stuff, your effective length
13:39 your digestive tract is about 10,000 So think how big you'd have to
13:46 to be, have a, a surface 10,000 ft long? All
13:51 That's what we're describing here is that , it creates effective surface area.
13:58 saw the furring of the brow up in the front row. Think about
14:01 lungs. How big are your lungs that? Like that big. But
14:04 there are a bunch of bubbles with area, the surface area inside your
14:07 is about the size of a tennis or a basketball court. So that's
14:12 much air you can move across that kind of cool physics and action.
14:19 . All right. So here we cilia SIA kind of look like micro
14:24 except it's a relative size. So at that picture up there at the
14:27 that micrograph. All right. So an electron micrograph. And you can
14:30 all the silly look like big giants jammed together and they kind of look
14:33 that. But these little tiny dots you're seeing all down here, these
14:37 extensions that's micro vill relative to So silly are long relative to micro
14:44 , right? And what the purpose cilia are, is to move material
14:49 the cell. So you have for example, in your airways,
14:53 ? You've ever had mucus in your ? And you're like, oh,
14:56 . Right. What you're doing is , these, these silly are sitting
15:00 going, I'm pushing the dirt in , that's in the mucus in the
15:03 that's captured in the mucus, up up and up and then it gets
15:05 here and that's when you're right, just moving that stuff constantly away from
15:09 lungs. Right. That's what Syl now. Silly. Aren't only
15:14 on, found in epithelium. I , I have it great out
15:18 Um Oh, actually, I don't have a grade out here. We'll
15:21 about that one in a second. , like bacteria have sylla and that's
15:24 they move around your body. They there and kind of use them as
15:27 ores to move themselves around. But cells don't have that. We
15:31 we don't move cells around with The only thing that is a cell
15:36 moves in the body is the spermatozoa it has a flagellum which is closely
15:41 to Ayia, but it's not And this is the only example.
15:46 right. So Celia are on cells are, are embedded, right?
15:50 epithelium and they're there to move things the surface of the cell. Just
15:55 of like go this way, All right. Now, there is
15:59 type of cell that has a it's called a kinocilium. They're kind
16:03 related to sylla. Um We're gonna about them when we talk about how
16:06 ears work and how balance and equilibrium . Um And they play a role
16:11 that, but they're not the same of, of sylla that we're describing
16:16 , but we use the same All right. That's why I grade
16:19 out just so that you understand that word might be used differently, someplace
16:24 . So cilia moved materials across the . And this, I show you
16:28 not to memorize the stuff I remember biology. Way back in the day
16:32 made you memorize the nine plus two because I guess it was interesting at
16:36 time. But you can see it microtubules on the inside that arrangement plus
16:41 presence of motor proteins allowed the CIA move and the and the flagellum to
16:46 in specific ways. I do think is kind of important though that they
16:50 differently. So that's why we have different types. So this kind of
16:54 like a like a uh a So like think about the,
16:58 the uh it's one of those days blades on the motor on a
17:06 That's the word I'm looking for, ? And how it just spins in
17:10 circle like on a fan. That's of what flagella doing. So that
17:13 as a propeller, right? That's word propeller, it propels. All
17:18 . So, so it moves like . So it's propeller like motion.
17:22 the cilia, they're more like uh you would row a boat, how
17:26 like, I know it's stiff where kind of bring the ore out and
17:29 push it in and you push yourself that's kind of how you row.
17:33 can see how they kind of do kind of movement. So if you've
17:36 in a swimming pool sitting on your and you have that beer floating on
17:40 chest, you do this. That's . No, no, that's how
17:45 do this, right? So that be a cilium. So it's different
17:50 of movement. So this would propel whereas this kind of pushes a perpendicular
17:56 the angle. All right. So , what are we dealing with
18:05 All right, lots and lots of . The most obvious one, if
18:08 on the surface, it's, and creates sheets, it's protective. All
18:12 . So that should be like right front. OK? Whenever I see
18:16 , it is protective. Even if is a very, very thin
18:19 it's protecting one side versus the other . The second thing though is because
18:25 typically find these on surfaces of What we're doing is we're deciding what
18:29 between those two sides. So these epithelium is typically selectively permeable to determine
18:36 can pass through. So for if I take water and pour it
18:40 your body. Does your body absorb water? The answer should be.
18:44 , it does not. But if take something that's fat related, like
18:48 and put it on your body, it get, get absorbed?
18:51 it does. Right. So it through, so there's a selective permeability
18:57 uh epithelium in general. All Second thing, it serves as a
19:04 mechanism, right? So it secretes . And so when we're talking about
19:08 things, what we're trying to do we're trying to move things into the
19:11 to organ, or we're trying to things onto the surface of the
19:15 Again, an easy one to think is sweat. Now, typically,
19:19 we think of sweat, it's water other stuff and we're going to talk
19:22 it again when we get to the . But the other stuff could be
19:25 like waste material. Ok. So moving things out onto the surface.
19:31 not just there to cool us it's to move things away from the
19:36 . In terms of the digestive we got materials that we want to
19:39 down into little tiny particles. So will secrete materials into the digestive tract
19:45 to break things down. So the that are responsible for that is an
19:51 in terms of sensory reception. typically, when we talk about sensory
19:56 , we're really talking about the neurons are located with located within, but
20:01 often you will see epithelial tissues associated these neurons and are responsible or can
20:08 to help those neurons do their So you will see them playing a
20:13 in detecting what's going on around whether it be changes in temperature or
20:19 it be a sense of touch. so they will play a role in
20:23 . But for the most part that's , but epithelium can have that responsibility
20:28 well. And again, I'm showing picture right here. So you can
20:33 apiol versus basal. You can see here, I'm attached with hess.
20:38 see, I'm attached with desmosome up . This is where the materials are
20:42 back and forth, absorption and which has to do with the selective
20:49 . Now, all epithelium has All right. Just like you have
20:54 name that's different than your sibling that you unique from your sibling. You
21:02 not clones of each other. You different. Even identical twins are not
21:06 . So my kids go to high , um, at Dawson, some
21:11 you guys might know it. Some you don't, some of you hate
21:14 . Some of you love whatever. right. Right. Now, on
21:16 football team, there are a pair twins. It's very confusing. Their
21:20 named them Bryson and Bryce. fortunately they don't play on the same
21:26 of the ball. There are ones the offense, one's on the
21:29 So it makes easy sense. But is confusing sometimes when you're listening to
21:34 last round, you know, it's , was that Bryson? Was that
21:37 ? I don't know. Yeah. right. But still, it's different
21:40 that the parents can tell the right? So when we name
21:45 what we're saying is that there is difference between this and something else.
21:50 , one of the important things is you look at the name, ask
21:52 question, why does it have this ? What are the characteristics that make
21:57 different than all the other stuff? right. That's one of the ways
22:01 make this much, much easier for . All right. So with regard
22:06 epithelium, all epithelium has two names it. All right, the first
22:12 always refers to the number of layers that epithelium. So when you
22:17 there's two different ones, you can simple or you can be stratified if
22:21 simple, that just means that there's layer that makes life really easy,
22:24 ? Oh It's simple. OK. looking it should have one layer or
22:28 I see one layer that is a epithelium, if it has more than
22:33 . So two or more we refer it as being stratified, all
22:38 and stratified in multiple layers, So all you got to do is
22:41 a question, is there more than ? If there's more than one,
22:43 a stratified epithelium. All right. so we're going to be kind of
22:47 at these. Now, typically, we're talking about single layers, that
22:52 there's not a lot of cells that to pass through. So if there's
22:54 a lot of cells to pass I'm playing a major role, probably
22:58 absorption and or filtration, absorption is the body, filtration is out of
23:03 body. All right, if I more than one, that means I'm
23:07 cells on top of cells. So actually creating barrier. So typically,
23:12 either have, we'll talk in terms protection or in terms of a barrier
23:16 ensure that materials have a more difficult moving between the two sides. All
23:23 . Now, the second name or last name refers to the shape.
23:27 again, these are just cartoons trying demonstrate this, right? And so
23:31 are three common shapes that we refer when we're talking about a Patel.
23:36 first is called squamous. Squamous is . Squamous actually means scale like.
23:42 so when you see hear that you see, OK, my cell
23:45 be flat. Now, what I like to point out here that flat
23:50 there is a basal side that is than the two lateral sides. So
23:55 really very uh you can see where connection is or you can see where
23:59 basement membrane is relative to the So you should be able to go
24:04 , this is the side that's connected connective tissue this side over here is
24:08 . So this is basal side. , that's flat. That's scream.
24:12 right. Cuboidal. Well, it's a cube right now. Is it
24:18 ? Do you have to get out little ruler and measure it all?
24:20 , it's just sides and the bottoms the tops look roughly the same.
24:24 right. So that would be And finally, is columnar. Columnar
24:29 a very, very thin or or basement side, but a really long
24:35 side. So they are like So again, it's a very descriptive
24:38 , columnar. The thing is is sometimes when you're looking at these things
24:43 a microscope in a actual tissue it's not real obvious that this is
24:49 or anything. And so one of things you can do is when you're
24:52 is you'll see that the nuclei of cell actually mimics quite closely what the
24:57 of the cell is supposed to So if you have a cuboidal
25:03 then the nucleus is going to be perfectly round. Whereas if you have
25:06 columnar, it's going to be more and elongate. And if you have
25:09 squamous one, then it's kind of flat nucleus. All right. So
25:16 are other ways to kind of look these tissues other than just,
25:20 what does it shape? You need know where the basement membrane is where
25:23 apical side is, which is usually particularly hard to discover and then
25:28 based on that, which direction am I going? What does my nucleus
25:32 like? And if you can identify three things, you can probably
25:35 pick out pretty easily or pretty what the different types of tissues are
25:39 you're looking at now with regard to simple epithelium. All right, we
25:47 that these are primarily playing a role permeability, but there are different
25:51 right? In other words, we we play a role in either absorbing
25:54 filtering stuff, but we're gonna be all three of those different types.
25:58 there's three types of simple one that squamous, one of that is cuboidal
26:03 one that is columnar and they're in locations because of the type of job
26:08 they do. What makes it even confusing and not so confusing for
26:13 but just for the purposes of understanding you'll hear terms like endothelium or
26:19 which are types of epithelial tissues. often. They might be simple,
26:25 not be, but really what they are just special names for epithelium where
26:31 found. So for example, endothelium a simple squamous epithelium that is found
26:38 the inside of your blood vessels. right. And again, its nomenclature
26:43 from a developmental biology where they're this is where it comes from
26:48 and oh, it's on the And so this is a uh in
26:52 it's, it's an epithelium. So of being on the surface, it's
26:55 the inside. So we're gonna call endothelium. So it's just a nomenclature
26:59 they, that we, we created we kind of stuck with mesothelium.
27:03 the other hand, again, deals the developmental or origin comes from.
27:08 it's the stuff that is responsible for serious membranes that uh cover the inside
27:13 your, of your organs or really outside of the organs covering the
27:17 So it's very thin, again, uh produces that fluid. So you
27:22 the friction between organs as they but they just have a special
27:26 All right. Now in saying all on the test, we are gonna
27:33 to do a little bit of histology not a lot of histology.
27:38 This is not a histology class. do I expect expert histological examination of
27:44 ? No, thank goodness. All . But you should be able based
27:49 these names to identify something. you know, I'm going to give
27:52 really simple examples and if you understand definition, you should be able to
27:55 what we're looking at. All So we're gonna take a look at
27:59 couple of examples. We're gonna see cartoon and we're gonna look at the
28:02 pictures on the planet that this textbook . OK. So my pictures are
28:07 on the test than what you see . All right, I'm gonna point
28:11 why these are crappy pictures to you it's fun to complain about stuff.
28:15 right. First off, we have squama, simple, remember what we
28:19 , simple, single layer, single . But you can see here we
28:22 longer than we are tall. In cartoon you can see here is the
28:26 membrane up there. That's the apical because that would be the alumin of
28:30 it is that we're looking at. you can identify those two locations.
28:34 is the a side? Where is basal side? Ok. Now that
28:36 know that let me find the cell there and which direction is the cell
28:42 ? All right, in this picture here. What we're looking at is
28:44 LVO I of the lungs. And you look at that picture, can
28:49 tell anything from that picture? it's pretty crappy, isn't it?
28:53 they did was they took the weakest they could find and went as far
28:57 from the, of the tissue as possibly could right now without even knowing
29:02 that is. You'd be like. have no idea if we're even looking
29:04 cells. All right, you can even see the nuclei in here.
29:08 if you look carefully, right? ignoring where the corners are where it's
29:13 pretty broad and big, what you're at here. And what I would
29:17 on the exam is, I'd say is the area you're supposed to be
29:19 at, I mean, I literally picture is like graze out everything else
29:23 for the part that you're supposed to looking at. And it says,
29:26 , here, here is the cell you see those little dark, dark
29:31 spots, those are the nuclei of cell that we're looking at.
29:36 Right. And if you look at nuclei, I know, I see
29:38 , I squinting. I'm like, don't know if you look at the
29:41 , you'd see that they're flat, see that the cells are flat and
29:45 and you'd be like, I can't which side is a cool, but
29:47 can see on either side it's kind open space. So that would be
29:52 . All right. It's a terrible . Trust me. Any picture I
29:56 you will be infinite. It'll be to like this. OK? Because
30:02 have the internet at my disposal and don't have to pay fees for pictures
30:06 they, they probably paid like a for this because it's so crappy simple
30:11 and then you're assaulted with this horrible . All right. Now again,
30:16 this obvious, right? I the do these cells look as wide
30:20 they are tall? All right. that's easy, right? Cuboidal.
30:24 can find the base membrane, you find it or the the connective
30:27 there's the basal side. This would the apical side and then they give
30:30 this. Can you find the apical in those in that. So you
30:34 understand, we got, we're looking hundreds of thousands of cells here or
30:38 1000 cells. Can you find a which if you had to pick,
30:41 is a, in that picture, pink or the white or the
30:49 I'll give you a hint whenever you're at a microscope and you're seeing
30:53 you're seeing nothing blocking the light flowing . OK. So where it's
30:58 that would be where there is So you're looking at a side.
31:04 what this is showing you, this uh these are glands in the kidneys
31:09 there's a slice through the kidneys. what you're looking at is you're looking
31:12 tubes like this. All right. , that's, and, but
31:16 there's lots of tubes. So you see a tube there, you can
31:18 a tube there. You can see long tube, there's a tube,
31:21 a tube everywhere, a tube All right. But without me having
31:25 point it out to, you'd be there going, I don't know what
31:27 hell is going on again. What they do in this picture? Oh
31:30 gonna do a two X image. we're just gonna go all the way
31:33 here. And so you can kind , this is like being in a
31:36 trying to identify street names, It's so far away. What we
31:42 do is we would focus in on that right there. And so the
31:46 would be very, very big. what you can see is if you
31:50 , the pink represents the stain of cells. All right, the dark
31:56 represents the stain of the nucleus. right. And you can't see that
32:01 again, the pictures are so So what you do is you're looking
32:04 and you go, OK. Where the nucleus? What does the nucleus
32:06 like? Oh, there's pink stuff , there's white stuff there.
32:09 The white stuff is April. The stuff is either the cell or the
32:13 tissue below the cell. So that you direction. OK? And then
32:18 look at the rough shape. if you have things in a circle
32:21 again, I'm gonna try to do , right? If you have things
32:26 a circle and here's the lumen, your cells gonna be perfect squares?
32:35 uh But you'll see a big old like that that says, hey,
32:40 a cuboidal cell because it's kind of a cube. All right. And
32:44 more like what you're gonna see on test. All right. Again,
32:50 histology class. The third one, is the worst picture of them
32:58 Again, you can see over here the cartoon. Can you see that
33:03 columnar? The base part is pretty , right? You have even long
33:09 then if you look at the it's an oval shaped nucleus,
33:12 And you can see the apical basement side. Now, here,
33:16 is obviously a isn't it up But this to you is probably not
33:21 obvious that this is all connective these little dots represent nuclei. So
33:27 , that's like a pixel. It's . It's you want it to be
33:32 that the cell is obvious. And , I'm going to show you cells
33:34 are obvious, but can you see we're doing here is that we're looking
33:37 the crips in the digestive tract. so what it is is this is
33:41 surface going up and down and up there's one that goes down, but
33:46 slice is weird so that you're seeing bottom half of the crypt, but
33:50 the top half, but it goes and then up and down, up
33:53 down and so on and so And so you can see that they're
33:55 all flat in this direction. What is is that you're turning in this
34:00 . So your cell which is columnar this when it goes into the crypt
34:04 now going in this direction. So have to know relatively speaking, where
34:10 the basement membrane? Where is the side? OK. What shape is
34:16 cell? Oh Well, if this the basement membrane, it's only the
34:20 but the cell goes this way, must be columnar. OK?
34:24 there's nothing over here. That's does that kind of make sense you're
34:31 , I'm the Lord. Trust the pictures I give you are
34:34 much better. And if you get , just go on Google, do
34:39 quick search for, you know, columnar, do a quick search and
34:43 look at a couple of pictures. ? You'll, you'll see very
34:47 Yeah. No, no, no, no, that's to kind
34:52 give you a sense of what's going . So again, where do
34:54 we here? Like you know the here, remember we, what do
34:58 say? It's simple plays a role absorption. It plays a role in
35:03 . It doesn't really play a role protection where we're seeing these tissues though
35:07 in those places where we see secretion we see absorption. So like the
35:13 , the lungs, all right, see them in the digestive tract.
35:16 are places where things are going back forth and when we go to those
35:20 and we start going, hey, this, you're gonna go,
35:22 I remember all that stuff. So this one, I presume I
35:30 the button and I know it's on slide. Yes. OK. This
35:34 is a simple columnar epithelium. But at the name, what is the
35:39 ? Pseudo stratified? What does pseudo fake stratified multiple layers? So it's
35:46 fake layered Elum. You will not to identify this one on the
35:52 You need to know the definition, you do not need to know the
35:54 . OK. The reason you don't to know the picture, it takes
35:57 little bit of time and effort to how to distinguisher stratified from other stratified
36:05 . So, rather than torturing you making you all mad at me,
36:09 don't have to look at this All right. But I want to
36:12 it to you so that you could so you can see here if you
36:15 at all the cells, all of cells that you're looking at it or
36:17 this one that sits way up high actually attached to the basement membrane.
36:22 gives its appearance of having multiple but it's not. All right.
36:29 so like this right here, you're at it going well, that looks
36:32 a whole bunch of cells. Look the nuclear up here, there's nuclei
36:34 there. Yes. But if you to tease those out, you'd see
36:37 each of those cells are attached to basement membrane. Crazy stuff. All
36:43 . So they're located in uh some secretary areas, they secrete materials
36:48 move things along. All right. understand the definition. That's more important
36:54 for that. But let me just you this is the place where I'm
36:57 . If you learn the definition, should be able to take that definition
37:02 translate it into the picture. that's all I'm saying, right?
37:07 we get to stratified, remember what said is that we're going to have
37:11 layers of cells. And this is perfect example of a stratified epithelium.
37:16 they're going to do is you're going start down here at the basement
37:18 This is what we refer to the side. And this is where you're
37:22 to have cells that are going to rapidly dividing and creating more cells.
37:26 as they divide and stuff, what do is those cells that are being
37:31 are being pushed upward and away from basal side towards the apical side.
37:36 right. And as they move, features may change and so they no
37:42 look like the cell that was found the basement side or the basal
37:47 All right. Now, these typically a major role in protection.
37:52 if I have lots of cells, gonna take a lot to penetrate through
37:55 . So that's why these are there's for these protective uh reasons,
38:01 one we focus on and the one we need to know the most is
38:04 stratified squamous. All right. the way that we name stratified epithelium
38:11 we look at the apical surface and ask the question, what is the
38:16 of the cell on the apical We do not care about what's going
38:20 down here. We only care about last layer. So if the last
38:26 is flat squamous, right, if last layer or if that top April
38:31 is square, it's cuboidal. And it's that last apical surface is long
38:39 , that's columnar, even if the below it is cuboidal, it's still
38:42 columnar epithelium. All right. So is an example of the stratified
38:48 You will, again, this is you need to be able to identify
38:51 the test. All right. here's the good news. You don't
38:56 to be able to identify this one that one. All right, this
38:59 the only stratified, you will need be able to identify it. So
39:03 , all you got to do is yourself the question. Are there multiple
39:05 of cells here? And if they , you're pretty good that it's the
39:09 that you're looking for. So that's the easy check the box question.
39:13 I want you to look at this right here. You can see down
39:17 there is the basal side right up . That's the apical surface,
39:23 You can see down here, there's tissue. This is actually your
39:26 This is the epidermis, a slice the epidermis. And you can see
39:30 here if you look carefully in this a better picture, you'd see that
39:32 little circles are more or less So we have kind of a cuboidal
39:37 down there. But remember, we care about that shape and over time
39:41 shape changes and becomes flatter and flatter flatter until you're up here at the
39:44 and that is where you're going to the squamous and why it gets its
39:48 stratified squamous, multiple, multiple layers cells, right, top layer,
39:56 surface squamous. Now, with regard this, we have different types of
40:01 squamous. All right. So you'll the term carats or non carats,
40:08 is that it's enriched and reinforced with protein that makes up desmosome. It's
40:14 , it's tough. Look at your . Are your nails tough.
40:19 that's Carotin. Is your hair hard bend and stuff. I mean,
40:23 , it could be soft and silky I mean, it's, there's a
40:26 to it, isn't there? That's . All right. Look at your
40:30 . Take your finger and run it your skin. Do you bleed?
40:36 , you create maybe a line of cells coming off, but it's tough
40:42 it's carted in there. All Take that same thing. Please don't
40:47 this and put it in your mouth do the same thing on the inside
40:49 your mouth. What's gonna happen? gonna cut yourself, aren't you?
40:54 not carrot. All right. So your mucous membrane, the oral
40:59 um the inside of your nasal your vagina, your urethra a little
41:04 inside the anus. This is non stratified, swam still tough and
41:10 right? But not as tough and as out here on the surface,
41:18 in those cavities, but not as as out here on the surface.
41:28 . The other ones we just mentioned they do exist, we have,
41:31 example, stratified cuboidal. This is rare. It's basically just two
41:35 So it's like this, you can here, there's the uh there's the
41:40 out over here. That would be basal side. You can see there's
41:44 good example. Here's one, there's one on top of it, you
41:47 at those nucleus. So you see much better this picture is. See
41:50 cells are kind of clear, you see where the nucleus is. That's
41:54 type of picture that's better. The thing that sucks about this, you
41:57 use one dye. So you can't one thing from the next. All
42:00 , but those big circles, those nuclei round round nucleus, that's gonna
42:06 cuboidal, stratified columnar, very, limited. You're gonna see it primarily
42:10 the male urethra in a very specific is basically at the bottom. You
42:15 a cuboidal cell and on top of have a columnar cell. Again,
42:19 is it called stratified Klein? A is columnar in nature? I hate
42:30 one. I think it's a cool , but it's not one that's easy
42:34 identify. It's found only in one in the body. It's transitional epithelium
42:38 found uh uh as the epithelium of bladder. All right, your bladder
42:45 and contracts just like a balloon. , more like a water balloon,
42:50 it expands and contracts. All And the reason it can expand and
42:53 is one, it folds on But the other thing that it does
42:57 that cells, it's the cells themselves shape. All right. They're kind
43:01 cuboidal in nature like this everywhere. as the bladder fills up, what
43:06 , it causes the bladder to stretch those cells themselves stretch out as well
43:11 they become kind of like a squamous . So they change their shape based
43:18 how much fluid is actually in the . All right. Other characteristics,
43:24 may be binucleate. Um So there go. Uh you also find them
43:31 the and other structures as well. you can imagine there's a structure that
43:35 the tissue to stretch pretty well, try to identify it. If you
43:39 a picture like that, it would almost impossible to identify it. So
43:44 don't have to identify the picture on test. You just need to know
43:46 definition. Where is it found? is the one where you need to
43:49 where it's found. It's simple uh uh urethra places that are going
43:58 be stretching in response to pressures. right. So those are the
44:05 Is that particularly hard? Good. why like I, I saw three
44:09 just do this. Mm Not Ok. Great. Excellent. I
44:13 want you to feel like this is . You, you, if you
44:15 memorize people's names and a couple of about them. You are in good
44:20 . It's the same principle if you me and can't remember your own children's
44:24 . You're a little bit more And I, I'm not kidding.
44:27 , I have to go through every to get to the right one.
44:33 that is not a function that I more kids. It's just like all
44:37 glands. So here what we're glands are typically one or more cells
44:42 we have to make that definition because going to see there is a cell
44:45 acts by itself as a gland. I think it's the next slide,
44:49 ? So it's one or more Their job is to produce something and
44:54 secrete that something. All right. the production is a product and then
44:59 secretion is to move it out. these are two examples of different types
45:04 glands. Now, the endocrine what we're going to do is we're
45:08 to create that product and we're going secrete it into the bloodstream and then
45:11 travels through the bloodstream and goes through body. So end dope is kind
45:14 indicating to you that it stays within body itself, right? It goes
45:18 the bloodstream and is traveled as a molecule to initiate some sort of action
45:24 distance away. We're ignoring those All right, because typically endocrine is
45:30 dealing with, with uh the nervous and uh uh regulations. All
45:36 it's not necessarily gonna be glandular in from epithelium. It comes usually from
45:41 neuroepithelium. So it's a neural tissue behaves and acts like an epithelium.
45:47 we're more interested in is what you here in the exocrine gland. You
45:50 see here we have a series of or producing a product, they push
45:53 product outside of the cells and then stuff moves up through a duct and
45:57 secreted out onto the surface, whether surface is in a hollow organ like
46:01 lumen or if it's on the surface the skin. So this is producing
46:05 product that is secreted outward and away the body. All right. So
46:11 is really what we're talking about when talking about epithelium here. All
46:15 what we're gonna do is when we at these, we're gonna look at
46:17 and see how they're classified based on structure. And we're gonna look and
46:21 how they're classified based upon what they . So there's two different ways to
46:25 them. Now, before we go start looking at those two things,
46:32 just going to, you know, of distinguish between what is multi cellar
46:36 unicellular. All right. So there unicellular glands and this is the example
46:41 one, this is the goblet All right. And here we have
46:44 epithelium, right? What type of is this? It's columnar. Is
46:51 simple or stratified simple, right? . So you can see here is
46:55 base membrane. This down here is to represent a muscle or something.
46:58 this would be like in your mouth really in your throat. And you
47:02 see up here on the surface of columnar cells, you can see all
47:05 the artist was really good and even you there mucus see the sign line
47:10 mucus up there. Where did that come from? It came from the
47:14 cells. Goblet cells are single cells within the epithelium itself. Their job
47:20 to produce mucin, which are the that make up mucus. Mucus is
47:26 plus these proteins and that's what coats structures. All right. Now,
47:32 the example, right? So they're their product, they're using exocytosis.
47:36 these are are vess that are coming to the surface and then they release
47:39 materials and those materials are then moved the CIA found on the surface of
47:46 columnar cells. All right. So is an example of unicellular goblet cells
47:51 unicellular. All right. The multi . On the other hand, is
47:55 little bit more complex. And so example, this could be a salivary
47:59 or it could be your pancreas. right. And what we have here
48:03 you can see that there is a of structure that goes with that.
48:06 organized, it's not just one cell have. If you go down to
48:10 very end down these little tiny red . Those are where the actual cells
48:15 located that are producing the material. we have a group of cells that
48:18 glandular in nature that are producing some of product that gets secreted. And
48:22 the other cells that are part of larger gland are what are called duct
48:27 , not quack quack, but like the tape. All right, it's
48:34 these ducts that the materials that are are collected and then ultimately secreted outward
48:40 into whatever structure or onto the surface whatever structure that you're looking at.
48:45 , sweat glands are like this. pancreas is like this, the
48:49 well, not the gallbladder. Um liver is like this. The salivary
48:54 are like this. All of these , are structured in the same
48:58 So the cells that produce the they are forming a structure called ascena
49:05 ana ana would be plural. And , so the cells themselves are referred
49:09 as Acier cells just collectively, it's generic term that says this is a
49:14 that produces the stuff. All the duct cells are found in the
49:19 and that's just there to primarily serve a passageway between the ascena and the
49:26 the structure that you're secreting into or . Now, interestingly, duct cells
49:31 do produce materials as well, but don't, uh we're not going to
49:34 in on that for right now. right. So, structurally, this
49:40 kind of like a bunch of You do grapes, right? I
49:44 , you have a little tiny globe then you have a stem and then
49:48 stems are connected to other stems and on. So you can clip off
49:52 the main stem and now you get little personal bunch, right? That's
49:56 you're kind of seeing here is that your little bunch, right? So
50:01 series of cena and its ducks which converging on another uh larger duck.
50:06 its own, there's its own, its own. Each of these are
50:09 are called lobules and lobules form larger called lobes. And so a gland
50:15 this lobular structure associated with it. basically, it's divided and subdivided into
50:21 smaller areas. Where do they Well, they come from the epithelium
50:28 during development. So when you hear word imagination that's taking surface and going
50:34 into the connective tissue and imagination would going upward, right? Forming outward
50:42 so, right. So this is they arise. OK. I just
50:49 asked which one of you of you are freaks. How many of you
50:51 watch those shows? Like pimple All right. See, I just
50:55 know who the freaks are. I, I Yeah. Uh So
51:01 got Pimple Popper and I remember very on before Pimple Pop Popper became an
51:04 show. It is an actual show could go on youtube and there were
51:08 , like, watch us pop. it. And it would be like
51:11 minutes of this goo coming out Yeah, it was horrible. But
51:14 get it. I under, I there's a satisfaction to it. I
51:19 it's gross. But, all All right. Now, the reason
51:23 mentioned that is because the reason that can see have shows like this is
51:27 these glands can have really, really structures. It's not just the pancreas
51:31 complex. You know, you have uh like gala glands and stuff that
51:37 be pretty complex or, or sweat . And so what we have here
51:41 we have a classification based on The problem with this picture is
51:45 the artist was not great in what were trying to do. So what
51:48 want you to do is I want to focus in on the two colors
51:51 best you can. All right. you can see we have a dark
51:54 and we have a lavender. Just, just making sure because all
51:59 guys are looking up there going, purple and purple. All right.
52:03 the light purple versus the dark All right. So what we're gonna
52:07 is we're asking questions about the duct we're asking questions about the Asus.
52:12 right. So the duct, the thing we have to ask is,
52:14 the duct split or does the Uh is it by itself? In
52:20 words, are there branches or are not if there are branches? And
52:24 trying to see here a good branch . Again, the artist did a
52:27 job because what they should be doing more like this and less like
52:31 If you see branches in the duct you should see clearly distinguished, then
52:37 thing is considered to be a compound . All right. So a better
52:43 again, if I can draw this if you have a duck that's like
52:52 there, that would be compound, ? But if the duct is just
52:57 that, that's simple. All then what we do is we ask
53:03 question about what is the shape of anu, right? Is it a
53:08 ? So you can see over there the left that would be a
53:11 And if you look over here on right, is it more round?
53:15 it's round, it's referred to as Avio, if it's a tube,
53:18 just call it tubular, right? for example, here's my straight
53:23 If I get down to the Asus it's like that, that would be
53:26 tubular duct, right? So this be an example of a tubular
53:32 If it's round, that would be . All right. And if you
53:37 looking at the whole gland and you'd , oh, I've got some that
53:40 tubular in shape, some that are alveolar in shape. Then I refer
53:44 it as being tubuloalveolar. All So I can have a simple tubular
53:50 . I can have a simple alveolar , right? Or I can have
53:56 compound duct which is tubular or it be alveolar or it could be compound
54:01 alveolar. All right. I could a simple like that. Do you
54:07 how I still have a single But I have two alveola. So
54:11 still a simple duct. Does that sense? OK. The picture doesn't
54:18 a good job of, of explaining . So what you have to do
54:20 you have to look at the Sorry, I know. All right
54:23 , I'm, I'm there now. very proud. I'm just gonna leave
54:31 up there for the next class. right. So what we're doing is
54:36 we name things here, we have consider both things to the, the
54:40 as well as the. All what else we got? Uh This
54:46 the fun part method of secretion. right. So you can see
54:49 we have three different types of We're gonna go from left to
54:52 All right. When you think of is sweat water or is it thick
54:56 , and gooey like ketchup watery? . So when a gland releases its
55:04 via vesicles, so basically, there's with stuff in them and those vesicles
55:08 to the surface and open up and that material is secreted. We refer
55:12 this as a Merin secret CRE So it's mostly water with stuff in
55:19 . Well, I just died. me a sec. I'm pretty sure
55:22 have batteries called the emergency battery All right. There we go.
55:50 right. So if we're, if producing materials that is packaged into a
55:57 not altered and released, that's The next one is Arin. Apocrine
56:02 a little bit weird. See what have is we create vesicles, but
56:06 of just having the vesicle join up the surface and opening up and releasing
56:08 material, the vesicle is pinched off surrounding plasma membrane. So it's basically
56:16 inside another vesicle. Almost. You're a portion of the cell with
56:22 This is apocrine. All right. is what milk is. All right
56:28 . I mean, you could, you look at milk as it's being
56:31 like in a cow before it gets down, you pull out the cream
56:34 all this stuff and, and homogenize . Homogene doesn't look like this.
56:40 if you've ever looked at mother's you can see how it kind of
56:43 out and there's kind of a, , a difference to it. And
56:46 of it is, is because you that fatty portion. It's because of
56:50 pinch portion of the cell that comes . The third type you're more familiar
56:56 . So the first type merocrine, last type holocrine, you're most familiar
57:00 apocrine is the one that's a little harder to kind of wrap your mind
57:03 . Right. So, with regard holocrine, think about zits whiteheads.
57:08 right. So white heads form or blackheads form because the cells that make
57:15 the sebaceous or the sebaceous secretions, sebum on the surface of your
57:20 basically, what the cells do is produce this material and they keep producing
57:24 until the cell becomes so big that cell pops it ruptures. And so
57:28 material inside that cell is now pushed the duct and then that duct is
57:33 upward and outward and coats the surface your skin. But during puberty,
57:37 have so many of these cells producing much of it that the cells get
57:41 up. Plus you're gross and dirty your teens and so the oils on
57:47 skin start getting oxidized and they clog pores. So those black heads and
57:54 heads are the materials of a ruptured that have been blocked and prevented from
58:01 to the surface and then the bacteria after them and, and that's why
58:05 get the white head. All So that oil, that stuff that
58:09 , you know, when you're dealing black heads are, what is
58:12 Is it B A the, the that you put on your nose and
58:15 peel it off. OK. It's a long time. We didn't have
58:19 like that. We just suffered you know, puberty and woes
58:23 right? But like when you pull that strip and you're looking at all
58:26 little, little single things sticking you guys know what I'm talking
58:31 See you guys want to pretend you know, some of you are
58:33 , I don't want to talk about . So it is, you're talking
58:36 the body here. We get to about all sorts of gross stuff.
58:38 those little tiny things, those are leftover remnants of cells that have ruptured
58:44 that's the material that they were producing coat your skin and protect you from
58:50 and viruses and all sorts of That's what the oil on your skin
58:53 supposed to do. It's, it's antiviral. All right. So this
59:00 time holocrine, the cell ruptures and material and the cell is replaced because
59:06 an epithelial cell. So you're just making new cells that constantly rupture and
59:12 the onto the surface of the OK. Do those three types make
59:19 ? So, watery, like middle apocrine is like the milk that's
59:24 in mammals. All right. That would be like the oil on
59:28 skin. Yeah. Mhm Yeah. it's literally like say you've made all
59:37 vesicles from off the surface. ma is ripping off the top of
59:40 surface. The cell itself doesn't What you're doing is you're just taking
59:44 of the cell off the surface. the cell still sits there. It
59:47 produces it, uh, it regenerates or, you know, repairs
59:53 but it's kind of a halfway between other. The two. All
60:00 So those are the different types of . How are you doing on
60:08 I can go pretty slow sometimes. , so I've got like 30 minutes
60:11 20 minutes to get through connective tissue everything that we have here is is
60:15 be on the exam. All I know. It's like what?
60:19 , I know and see, I excited about stuff and I start going
60:21 these tracks. All right. So tissues, all right. Most abundant
60:26 in the body. Lots of different that you can kind of see over
60:30 again, what is the function? should tell you, it holds things
60:33 , but it's not just to bind support. It also plays a role
60:37 protection. Insulation plays a role in and transportation as we walk through
60:42 you'll go. Oh yeah, that sense. All right. Right.
60:44 , transportation probably doesn't make sense. you'll see. All right. So
60:48 all connective tissues have what is called ground substance. All right. This
60:52 the non living material that's found within uh connective tissue itself. So,
60:57 this picture up here, all this that looks empty right here. It's
61:02 , it's actually water plus other That substance. All right. So
61:07 has uh like proteins. You can the protein fibers here and if you
61:12 kind of go down deep, this what you would see, right?
61:15 would see that there are little itsy proteins filling up the space. So
61:20 types of proteins might be proteoglycan. tells you part protein, part sugar
61:25 on them are other molecules called It's a glyco I can, it's
61:31 , just fancy. I'm just trying impress you with big words. All
61:35 . But the idea here is these things that attract water and hold water
61:38 the area and then you might have adhesion molecules that bind everything up.
61:43 right. Now, this environment, ground substance can be viscous in
61:51 That's what blood is. It's it can be semi solid in nature
61:55 would be like cartilage. You think about this being able to
61:59 you can squeeze cartilage, you like your ear, you can squeeze
62:03 or it can be very solid like , you know. So ground substance
62:10 be vary depending upon what type of tissue you're looking at. But it's
62:13 material in which you find the secretions the cells that make up the
62:20 Every connective tissue has specific types of . All right. So the primary
62:25 that's found in them has a specific . So depending on what you're looking
62:28 . So if you're liking connective you're proper, you're going to see
62:33 . What do you think fibroblasts Based on the first part of the
62:36 fibro, it makes fibers. All right, I'm gonna point something
62:40 here. You see blast and you sight blast is typically the term we
62:45 when we're talking about a cell that's of in its immature state. All
62:48 . In other words, it's out rapidly dividing and, and trying to
62:52 mature the site when you're at the of the word typically means the mature
62:56 of the. So you have a , a fibroblast will mature and become
63:00 fibro site. All right. fibroblasts are going to be found in
63:05 tissue. Proper chondroblast and chondrocytes are in cartilage. So the prefix chond
63:10 usually referring to cartilage and then osteoblasts osteocyte refer to bone. All
63:17 That's where you find them. They're uh bone. But despite this,
63:23 always gonna find other cells as So you might find adipocyte, adipocyte
63:28 fat cells. All right. Um you have the number of cells,
63:32 you're looking at all the cells in most of the cells or the majority
63:34 the cells are adipocyte, then you in fat tissue itself, you're in
63:39 tissue. All right. So that's one place where you can kind of
63:42 things around mazal cells. These are stem cells to all connective tissues.
63:47 when you hear the word Mezin or , they're the stem cells give rise
63:52 these types of cells up here. then lastly, we have immunocyte.
63:56 are immune cells. They can either resident, meaning they stay there and
64:00 live there and they're watching for pathogens what they can do is as part
64:04 the immune response or um immune They're wandering around and they move from
64:09 to tissue to tissue, just kind like cops driving around the street,
64:14 sure everything is safe and sound, ? So they're surveilling, but you'll
64:20 see these cells. The other thing interesting about connective tissue is that the
64:24 themselves are not really in direct contact each other. So I had a
64:28 we saw the cells close together. here now the cells are just kind
64:32 separated. So this is kind of good picture to kind of demonstrate that
64:36 you can see the cells they are and there they may be touching each
64:39 . But for the most part, not all right. And while we're
64:43 at this picture is we want to at the different fibers. And so
64:46 are three basic fibers that you see all connective tissues. The first is
64:50 , very, very long, very . Let me see here.
64:52 collagen. And this is the pink . Um this makes up about 25%
64:57 your body's proteins. So it's a , very abundant protein, they're
65:02 right? So, right, now faces and your bodies don't have all
65:05 strange like wiggly things. But as age, the collagen relaxes and then
65:10 become more jiggly see, that's what does is it causes the collagen to
65:17 up. Don't get caught up in though. All right. Anyway,
65:22 reticular fibers, typically you find reticular that baseline of, of organs.
65:28 , if you were like to strip organ of all its cells and
65:30 you'd see this, this network of . This is usually reticular fibers,
65:35 uh branches, they're interwoven. So particular fibers here are being shown as
65:39 brown stuff. And then lastly are Alaskan fibers like springs, they're very
65:45 . So you've probably done this with ear where you can pull your ear
65:48 like this and it didn't stick like because it has elastic fibers. So
65:52 does it do? Pops right back ? All right. So very
65:56 very recoil. So you'll find all within uh connective tissue in varying
66:02 And so they may the the the may impact what type of connective tissue
66:06 actually looking at. There are different of connective tissues. And so the
66:13 again should be pretty descriptive. We what is called connective tissue proper.
66:19 right, when you hear connective tissue , what does that suggest to you
66:24 it wears a top hat and walks ? Yeah. No, it just
66:28 this is when we think of connective . This is connective tissue,
66:32 This is like this is the example what connective tissue is. And there's
66:36 groups that are classified as connective tissue or two subclasses, what we call
66:42 and what we call dense. So , what do those two terms mean
66:47 is loose? You, you don't cells to be close together and then
66:52 expect things to be close together, ? And not necessarily gonna be
66:56 it could be fibers. So here the three loops. The one we
67:00 at already is called AO. You see the ground substance fills things
67:04 I mean, there is stuff that's there but it looks like all the
67:07 is kind of far apart. This be Ariola, this is the most
67:10 type. All right. So the are sparse, they're regularly spaced,
67:14 few cells. All right. And they are gonna support structures, adipose
67:21 , all the cells are really close , aren't they? So why are
67:24 called loose? Because we're idiots. we look at the microscopes, we
67:28 describe things. And so when you fat tissue and put it underneath the
67:31 , after you fixed it, all all the chemical stuff so that it
67:34 on the microscope, you removed all fat and all you're left with are
67:37 plasma membrane. And so it looks a bunch of empty space. All
67:41 , but it's not. So it's weird one. And then down
67:46 this is a reticular. Why do think we call that reticular? What
67:50 you think? Which fiber do you dominates in it? Reticular? All
67:55 . But it's just like what we here, cells are sparse and the
67:59 fiber is not collagen. In this , the dominant fiber is gonna be
68:04 fibers. All right. But this is what makes up the
68:07 the background of most of the All right, we're gonna dense.
68:14 right. Does that look dense to ? Does everything look jammed in there
68:18 does everything look jammed in there? about here? Does everything look jammed
68:22 here? Yeah. Right there. , not necessarily. That would be
68:25 aluminum a vessel, right? this, that's epithelium and then uh
68:29 muscle and then over here that everything kind of jammed up in there.
68:34 this is why it's called D A . OK. So there's less ground
68:39 , there's more fibers than the fibers compressed up close together. Now,
68:43 do we have? We have regular versus irregular. What do these
68:47 look like? Are they look like all going in the same direction?
68:51 . So they have a regular pattern them. Do the fibers look like
68:54 all going in the same direction No, that's why it's irregular.
68:57 that's, that's where the nomenclature comes . All right. And then down
69:01 it's elastic why do you think we it elastic dominant fiber is elastic
69:07 All right. Elastin. All So you know, it's not particularly
69:13 in terms of how we do The next type is the supporting connective
69:19 . The first class of supporting connective is cartilage. All right, cartilage
69:24 a semi solid extracellular matrix. So can see here that these are the
69:29 and they're kind of close together. you can see the cells are trapped
69:33 that that network, right? That is the network or the extra cellar
69:38 that they created and they're stuck in down here. You can see we
69:42 fibers everywhere. And if you look , you can see that there are
69:45 stuck in it. Here's another cartilage here. You can see the
69:48 but you see the fibers are clearly , right? Tissue doesn't have blood
69:53 , it's avascular. All right. we were looking back here and we
69:56 see blood traveling through here and there everywhere. All right. Um
70:02 very strong, very resilient doesn't break bone, it bends and then it
70:08 of goes back into its original shape the most part. All right.
70:11 always. Uh but if you have fiber or sorry, more elastic cartilage
70:16 it, uh or elastin fibers, would be more bendy. So the
70:20 here, Hein Hyen is the type cartilage that you're going to find that's
70:23 with bones and it kind of allows greater degrees of freedom and movement flexibility
70:29 the ends of the bones. Elastic is like what you see in your
70:33 and your ears. Again, it for flexibility because of the presence of
70:37 elastin fibrocartilage basically absorbs energy and can . So you find these between your
70:45 and so the pressures that are downward are going to be dispersed. So
70:49 not carrying the entire weight of your in one direction. It actually disperses
70:53 forces. Two weird ones, the , connective tissues, blood and
71:03 they're actually the same fluid. All , it's just where you find
71:08 So blood has within it, these elements, what we would call blood
71:12 . They're not actually all cells. , there's characteristics that make them not
71:17 . But the thing that's weird about tissue, whereas the other ones are
71:21 their matrix fluid, connective tissues don't , make their matrix. They're dependent
71:27 other systems that are responsible for But we put them as connective tissue
71:32 they arise from the same tissues, as the other ones we've already looked
71:37 . So the relationship is there, just that they behave differently. So
71:42 we talk about, you know, tissue plays a role in transport.
71:46 is the type of transport we're talking . All right. So these lymph
71:52 the, the fluid that is making the matrix here. The difference is
71:57 don't have the same cells. And you're doing is it's a way to
72:01 . So when fluid is delivering it escapes from the blood vessels and
72:05 all of it comes back. So way that you get this escape blood
72:09 the escape fluid to come back into is through the lymphatics. So it's
72:14 the same material with some modifications to . I think the last one here
72:20 bone. So the bone is this is a supporting connective tissue.
72:25 osseous tissue is the other term. is a living tissue. If someone
72:30 you in the, in the does it hurt? Yeah. If
72:34 break your bone bone will you you will. Yeah, I
72:39 please don't break your bone that My son was in school one
72:44 get the phone call. Your son in gym, broke his arm.
72:47 like, oh great. He broke bones. The both the owner and
72:51 radius in his forearm. It was a you when I went to go
72:54 him up. Yeah. You guys go to medicine. Get ready for
72:58 fun stuff. All right. it's nasty. All right. But
73:05 , so you can see here, little black dots represent the little
73:08 not the big ones represent where the living cells are. You have a
73:12 just like heaven cartilage that are being by these cells. The difference is
73:15 you put calcium crystals on this So it hardens it up. And
73:19 you have a very, very stiff and because of the patterning that it
73:23 , it creates a very, very , very stiff structure. Now,
73:27 going to go into a lot more than what you see here. But
73:30 want to point out that it is living tissue. You have cells that
73:33 responsible for making the matrix and you cells osteocyte that are responsible for maintaining
73:39 matrix. All right, you have vessels and you have nerves inside that
73:45 , keeping it those cells that are for making and building the tissue and
73:51 it, keeping them alive. Is a fun little fact, you are
73:56 your bone tissue, your whole You know, I think every uh
74:03 months, that's how active these cells . Now, you're not actually rebuilding
74:07 entire skeleton, but in terms of activity, that's the equivalence. We
74:17 six minutes and this stuff is easy stuff here at the very end,
74:23 is the extent of what we're going know about muscles. There are three
74:26 highly vascularized, responsible for movement, can be contractions causing locomotion or
74:32 causing the movement of fluid in your or materials in your body. Cardiac
74:36 is for the heart, smooth muscle for the viscera and moves material primarily
74:41 that. So there are three types we get to the muscle we go
74:44 how it all works. So that's tissues we've covered. So far we've
74:50 the epithelium, we've covered connective we covered muscle. Last one here
74:54 the nervous tissue. We have neurons we have glial cells. All
74:58 neurons. These are interesting, they responsible for producing signals to control parts
75:04 your body. The glial cells are for supporting the neurons. Easy way
75:08 think about this is that neurons are the quarterback, the quarterback can't do
75:12 without the rest of the team. right. Do you wanna watch the
75:17 last night? Yeah, that quarterbacks a lot of help all night
75:23 So that's what they are. The cells when it comes to repairing
75:33 tissues do repair themselves. Some are , some are not when we're talking
75:37 regenerative tissues. What we're doing is the damaged tissue with the same type
75:42 tissue. All right, when we're about damage to a tissue and it's
75:49 by something other than a tissue, , usually connective tissue, what we're
75:53 about here is fibrosis. And so this example, this, this uh
75:57 actually this is a prosthetic, you , in other words, not a
76:01 person from a movie, but you see that scarring as a result of
76:05 epithelium growing properly over the surface, the connective tissue being arranged differently.
76:13 , fibrosis occurred underneath and on the . That's where we saw regeneration All
76:19 . So that's kind of the Now, different tissues will do different
76:23 . So, for example, nervous doesn't regenerate almost at all. So
76:28 that would be fibrosis. Whereas epithelial are very regenerative, they basically cover
76:33 replace themselves very, very quickly, , very easily. So depending on
76:37 type of injury you might have, get either one or you'll get both
76:43 , you know, some sort of there in. So, like I
76:46 , if you cut yourself, like like skin your knee, you'll be
76:49 . But if you like get a gash so that you get some sort
76:52 fun scar like that one. When fell off a cliff, you see
76:55 bad boy. Yeah. Yeah. planted right off a cliff, 20
77:00 , broke my wrist, put a old hole in my leg, put
77:02 leg, put a big old hole my chin, right? You get
77:05 beautiful little scar, right? And I got a cool story to
77:10 All right, the process here is basic, right? You're gonna get
77:14 inflammatory response that brings in uh cells break down the things that shouldn't be
77:19 . That's the first step. What does also, it traps the
77:24 but it also forces direction. In words, flow is in that direction
77:29 of away from that direction. So , it isolates the area for
77:33 The second thing is we're going to and protect the purpose of a clot
77:36 your body is creating a band So nothing else gets in there.
77:40 so that it holds um and uh a barrier so that nothing moves in
77:45 out of that area. And then gonna happen is is that we're gonna
77:50 in blood vessels that are going to nutrients and materials into that area so
77:54 it can repair itself. It's also gonna bring in nerve so that it's
77:57 tender. So you stay away from and stop touching. All right.
78:01 here, what we're doing is we're down the, the matrix of the
78:05 that's broken, destroyed or whatnot. then what we're going to bring in
78:09 cells that are then going to regenerate are going to produce those fibers like
78:14 blasts come and create that new network fibers in order to uh rebuild and
78:21 eventually the clot breaks down and gets . And so what you're left with
78:25 that new structure? It's pretty the longer or the bigger the
78:30 the slower it's gonna take. The couple of slides here are just definition
78:35 . I want you to know them you will get a question to ask
78:38 . One of these words, what atos apoptosis with me? Apoptosis?
78:43 not apoptosis. Say again. A you're supposed to sound like you're
78:48 It's aosis. All right. Aosis is cell suicide. Basically, when
78:54 start misbehaving, they have a natural inside them that is preprogrammed to tell
79:00 go away. You are damaging the go and die. All right,
79:06 referred to as cell suicide. So example, cancer is when say the
79:13 of apoptosis doesn't work appropriately. So cells which are supposed to die are
79:17 there doing all sorts of horrible Apoptosis is how we regulate that
79:23 we've talked about this before. This self eating. This is removing organelles
79:27 the cell that aren't working appropriately. it allows the cells to function
79:33 The last three atrophy when you sit the all day long and don't
79:37 you don't use your muscles, you're gonna waste your time or energy producing
79:41 uh trying to maintain muscle strength. what are we gonna do? We're
79:45 atrophy but when you go and work , your muscles are going to go
79:49 . That's hypertrophy. All right. you multiply uh cells at an increased
79:55 , hyperplasia, puberty is characterized by and hyperplasia. It is not a
80:02 , but cancers are also hyperplastic. . So, depending upon the
80:08 if you're multiplying cells too quickly, just basically hyperplasia. But if it's
80:14 , that's bad. But oftentimes it's and good. Those are all the
80:19 you need to know. So, everything up to this little second right
80:23 was on the test. That's, is college. Don't be surprised.
80:28 right. So no problems. No . Huh? You get one more
80:34 . Oh, is there one more ? Oh, good Lord. I
80:38 think I asked a question about stem . I really don't. Honestly,
80:41 there's a question on stem cells just the, I noticed that like the
80:50 five have a grade on that is . No, no. So the
80:59 is, is what I do is the day that you guys are taking
81:02 exam, they should be able to me the day you're taking the
81:04 I go and import any grades that missed. I, you know,
81:07 hit a sync button. Hopefully everything sync up and if they don't have
81:10 physically import all the grades, which sucks, but I can do
81:15 Yeah, you're welcome. Yeah. on over here, come on over
81:19 guys. So I signed up for
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