So here we have an example problem that says, this tissue is from the lining of the stomach. What type of tissue is it and what makes it unique? And so really we need to fill in these blanks that you can see down below. Now, when I take a look at this micrograph of the tissue, which again is showing the lining of the stomach, the first thing that stands out to me is actually all of this open space that you can see highlighted here in this region. And so identifying the open space is going to be really helpful to identify the polarity of the tissue.
And so notice that we have immediately adjacent to the open space, a sheet of tightly packed cells that are forming a boundary immediately adjacent to the open space. And so this layer here is actually going to be the epithelial tissue layer, and notice it's forming a curved boundary here. And what you'll notice is that the tissue that is underneath is changing its arrangement totally, so it's likely to be connective tissue, the underlying connective tissue. And that means that the basement membrane is going to be separating the two. And, again, the basement membrane is really difficult to see under the light microscope without the proper staining.
So you won't be able to see it very clearly, but we know that it's going to be present separating the epithelial tissue from the underlying connective tissue. And so over here on this side, we can see something similar. Again, the connective tissue is here and you can see the epithelial tissue again is curved. And again, the basement membrane is going to be separating the epithelial from connective tissues. And so now that we've identified those features, it's going to be really helpful to solving this problem.
And what you'll notice is that in the epithelial tissue layer here, the nuclei of the epithelial tissue appear to be all aligned in a single row here. Again, the tissue is curved, but these nuclei are all in a single row, and that implies that this is going to be a single layer of cells. And so because it's a single layer of cells, we know that this is going to be simple epithelial tissue. And what you'll also notice is that the shape of these cells is pretty long and narrow. They're much taller than they are wide.
And so because that's the case, we know that the shape is going to be columnar. And so in terms of the type of tissue, we can identify this as simple columnar epithelial tissue. And so you might recall from our previous lesson videos that simple columnar epithelial tissue actually lines the digestive system from the stomach all the way through the anus. And so here we're showing the lining of the stomach. So, of course, it's going to be simple columnar epithelial tissue.
And so we can actually add the word epithelial here to remind us that this is epithelial tissue. Now, what's unique about the tissue in the stomach here is that it's actually not going to have goblet cells. So, there are no goblet cells in the stomach. And so recall that these goblet cells are going to be unicellular glands that actually secrete a product that ends up forming mucus. But again, those goblet cells are not going to be present in the stomach, and they're more so going to be present in other areas of the digestive tract.
And also, they're present in the pseudostratified columnar epithelia that lines the upper respiratory tract. And so this here concludes our example problem and we'll be able to get some practice moving forward. So I'll see you all in our next video.