VIdeo lecture covering the simple squamous epithelia for an A&PI Lab.
Welcome I'm Anna Gilletly
And a continuation of unit one, we're gonna be talking and looking at the different types of simple epithelium
All right as I mentioned in the previous
video lecture
You have two squamous epithelium
And it's going to be flat and thin if it's one layer
Then we call it simple squamous epithelium
And remember it's always important to put the full names simple squamous epithelium. So single row of cells
because so so when you're looking at
Structure of the cells the tissue this is really important because it tells you what the function of that tissue is
so anytime you have a cell type that is really thin and one row it means it's really
easy for things to rapidly move
Across them. All, right
So simple squamous is really functionally important for places where you want to do diffusion, okay
This area will also secrete some serous fluid and where you can find it
locations the alveoli of the lungs glom your ally of the
kidneys
endothelium, so this is the
epithelium that lines the inside of arteries and
The serosa which is where you get the serous fluid. Okay, so this is
Important. All right
You need to remember eyes the function right there
so for every type of epithelium
what I want you to be able to do is ID it I
want you to tell me its
function and even if you can't remember it for one specific thing if you can look at the shape of it you can get a
pretty good guess as to what the function is and then a location in the body, so I'm usually not asking for like
Absolutely, correct identification of an organ yet. That's more anp2
What I want is can you give me an example of where you would find it in the body?
Okay, so we are going to look at the structure of the epithelium
So I am now gonna be over here now notice here. I have a free edge
Because I have a free edge. I know I have epithelium now. I'm gonna look at the tissue shape
so there's my cell I can see that my cell is so thin that all I'm really noticing is
The the nucleus, I mean that's how thin it is, okay
So each one of those is outlining the cell so it's one row so then I know it's simple
alright and
Because it's so flat that I can't see anything, but the nucleus I know it's squamous
okay now because I know
That epithelium is always next to connective tissue
I know that I have some type of connective tissue proper right there and we'll look at that later
Okay now coming over here to this one. Okay, same thing you can see the cell
Alright, you can see the squamous shape is one row, so it's simple squamous
This is my free edge, which is apical
This is my basal layer, which is attached to CT
Okay, let's go on to the next slide
All right, so the big picture right here
All right. This is what you're usually going to see when we're looking at connected to ship property
You're gonna be seeing kind of a side view
Okay. So right here we are looking at a gloomy Rallis in the kidney and what I have are these really?
Thin cells right here. So again, I've got a free edge
All right. Here's my CTP on the basal edge. All right, it's thin
flat
one row
So therefore it is simple
squamous
Okay now over here this is a superior inferior view so top-down
okay, and what you can see is what the actual shape is so you can see it's kind of like this hexagonal funky shape and
Then right there is my nucleus now. This is actually from a cheek swab
So technically this is stratified squamous, but because of the way it's smeared on this slide, you can see the individual cells
We are almost never going to look at that
in fact, we're never going to look at that except for on that type of a slide so
This is what you really need to know is you need to be able to recognize
This then stuff over here. All right next slide
Right, here's another view of simple squamous epithelium. So this is the lumen of a tube
So the lumen is just the cavity that fluids are gonna flow through
All right, so that's right there and that's where your free edge is going to be. So right here
I can see I've got cells now right there. Then the nucleus has been cut out
So right there
Basically right there
Here, so, I've got a free edge. I've got connective tissue proper on this side. It's one row
flat
So it's simple
Squamous, okay next slide
All right. Now we're gonna move on to this simple cuboidal, okay
So again single layer of cells and they're going to be squared to roundish
Typically, they're pretty pretty they might be kind of like this, but they're they're mostly square or cube shape
Okay
Now whenever you've got something with a lot of room in it, that means it's got room for the organelles
That make stuff
All right, simple squamous it can do diffusion of fluids so like for serous fluid, but it's not got the room to
make a lot of proteins or lipids or
Hormones or any of that stuff? It's too flat
There's no room for the organelles much less making something else
But with the cuboidal cell or a column inner cell I can have a big fat nucleus
I can have lots of mitochondria. I can have lots of endoplasmic
reticulum and Golgi apparatus
So those are the things that are making stuff. So what this does is it makes stuff and it secretes it. All right
So like mucus, all right, it can absorb stuff
Alter it and then rese we secrete it. All right
Then if I attack some cilia on it
All right, it can move stuff across its surface now
It's only gonna do movement if cilia is present. So where do you find it lining tubes and ducts?
Okay, common in liver, thyroid etc. Okay, so this
You need to know
Function okay absorption and secretion are the primary functions? Okay. Give me
locations of where you would find in the body
Okay. Now let's look at the structure of the cell. So I've got a free edge and I have connective tissue proper right there
I have one row of cube shaped cells so it is simple cuboidal
Okay next slide
All right, here's an example of a slide we would see in the lab so I have a follicle I have
Some kind of hormone that's inside this follicle. Alright, so this is a free edge
Okay over here is my connective tissue proper and I can see I have a single row of
Cube shaped cells. So I have a simple cuboidal epithelium now I want to contrast this with
This slide up here, okay when you are looking at tissue slide
It's almost never will you have only one type of tissue present? So here I can see I have
Right there
Simple squamous, okay, but then
Right next to it. I have a tube
Where I've got simple
Cuboidal, okay, and then here I have connective tissue proper
Here I have another type of epithelium that's actually in the form of little arterioles and we'll talk about that name to do
Or not get arterial… Sorry capillaries
Okay, we'll look at that later, okay
So right there a simple cuboidal
On this slide, I've already got one two three four types of tissue present and that's normal and you want to start looking for
Those things you want to be looking for changes in color
consistency, content, size of cells
cell …cells …shape of cells all of those types of things …next slide
All right, so now we're looking at a kidney tubules, alright so again I have my free edge here
I have my connective tissue on the base basal layer
Here is a simple cuboidal. So one row of cube shaped cells. So this is
simple cuboidal epithelium
Next slide. Oh wait, and then you can see nicely right here. I have simple squamous right there. Here's some really good ones right here
Simple squamous epithelium there so that is simple
Squamous so again, I'm seeing both types of tissue on this slide and that is normal
Alright simple columnar
Epithelium. Alright, so what you are dealing with is a single row of
Columnar or rectangular shaped shaped cells the nucleus tends to be oval and it tends to float
Towards the basement membrane, but it doesn't have to all right now here right there. I am seeing micro villi
Sometimes you will see cilia… cilia and microvilli are not the same thing
Make sure you know the difference between the two of them, okay?
Function alright, they have lots of room
all right, they're big cells big nucleus lots of
organelles like mitochondria endoplasmic reticulum ribosomes Golgi Abril Jia Parata
They can make stuff. So they're really good at secreting mucus or hormones
So they make it they secrete it. So what is their function absorption and secretion if
Cilia is present
They will move stuff along their surface. Like they will move mucus along the surface or an egg along a fallopian tube. Okay?
Locations. So here's some examples of where you would find it
Okay
Right over here. I've listed the GI tract tends to not be ciliated
So parts of the GI tract have microvilli other parts do not okay
Cilia is really common in the respiratory tracts and the genital urinary tracts. Alright?
Next slide. Oh
Actually, let's really quickly mention this right here is a goblet cell
So goblet cells tend to be kind of like this shape
All right, there are modified epithelial cells so you can see its nucleus right here and what this is is it's filled with something
That's being made and secreted. In this case. It's probably mucus. And then that's gonna spill out onto the surface right here
And over here on the left
You can see the same thing
And then there's the the nucleus this is often found in simple columnar
Epithelium not always but often you can also find it in pcc ii or pseudostratified
Okay next slide
Alright so now we are looking at another example
Of simple columnar. I have my free edge. I
have my
Connective tissue proper
Alright, I can see I have one row of cells
Alright, so they are simple
They're columnar in shape. And I don't know. Can you see these there's like these little fuzzy things that are sticking up to the top
Technically this is also
Ciliated so this would be ciliated simple columnar epithelium. The cilia wasn't present
It would just be simple columnar epithelium next slide
All right, so let's now look at our pseudo stratified
Epithelium, I've got two abbreviations that are commonly used because it's really long to write pseudostratified
Okay, so PCE
pseudostratified
Columnar epithelium now PCC E is pseudostratified
Ciliated
Columnar
Epithelium, alright and it's hard to read but you get the idea so pseudostratified
ciliated columnar
Epithelium, whereas this is pseudostratified
ciliated
Columnar epithelium now both of the pictures here are showing you the ciliated version
Alright, so what I have is a basement membrane down here. Okay. I have my free edge here
And in this case, I've got lots of cilia
Okay, now it is hard to tell but technically every single one of these cells
is
Touching the basement membrane. So this is
one row
of cells
Okay, I can also see the occasional goblet cells squashed in here
These are also all attached to the basement membrane
Alright, when I am looking at this what I notice, is that my nuclei
Don't form neat rows. So when I'm dealing with a
stratified columnar epithelium what I see are
neat rows of
Nuclei, okay, and you can see here. They are all over the place. They are not in neat rows at all. Okay, awesome
Columnar stratified columnar
By the time you put in the two rows of cells
It's really tall whereas pseudostratified is a fairly thin layer because technically it's only one layer of cells
so these are thinner tissues than a
stratified columnar
Okay
a function
Absorption and secretion if cilia is present, then it can move stuff
Where are you gonna find it respiratory track parts of the male urethra?
Some other areas. Alright, let's look at the next slide
Alright so here is an example of PCC so pseudostratified
Ciliated columnar
Epithelium
Okay. I have a free edge. Alright, I have my
Basement membrane with connective tissue proper. I
Have and it's hard to see it's a little not the best slide in the world
And there's a goblet cell right there. There's another one
Okay
So there columnar and… she liks… actually let's find some that are a little easier to see …this is not the best slide
All right, so let's actually focus on the nucleus, so there's a nucleus there's nucleus
There's one there's one so you can see they're kind of gobbled up or kind of mushed up
Okay, but this is still a really thin tissue and it's still columnar in shape
And of course you can see the cilia, okay?
Alright, so that was the last of the slides
For the simple epitheliums in the next video lecture. We're going to look at the stratified epithelium

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