In this example, it says that the slide below shows the wall of the small intestine, and here is this image where it's a section of the small intestine that we're looking at through a microscope. Alright. So what it wants us to do here is first, it says to draw a box around 1 villus. So do you remember what a villus is, and where do you find it on this image? Well, remember a villus, those are those like finger-like projections that kind of reach out into the lumen, from the mucosa of the small intestine. And as I look at this image, well, here's a villus. Here's a villus. Here's another villus. Right? Each one of those things sticking up, those would be villi or one villus. So I'm just going to pick one of them, and I'll put a box around. How about this one? Alright. So there's 1 villus. That thing sort of sticking up to increase the surface area.

B says draw at least three arrows pointing to where you would expect to find microvilli. Alright. Where do you expect to find microvilli in this image? Remember, microvilli, well, those are even smaller than the villi. Those are the projections of the cell membrane of those cells lining the edge of the villi. So as we look here, we have these columnar cells all the way around the edge of all of these villi, and it's on the edge of those cells that you'd expect to find microvilli. So I'm just going to draw the arrows just anywhere to right on the edge. It says three of them right on the edge of these villi. That's where I'd expect to find microvilli.

Next, we want to draw a star, where you expect to find a lacteal. Alright. First, you've got to remember what a lacteal is, and where do you expect to find one. Remember a lacteal, that's a vessel of the lymph system, and in each one of these villi, there's going to be at least one lacteal running up the middle to absorb fats. So in anyone of these, I can put a star, right sort of in the middle of one of these villi because in each one of these, there's going to be one or maybe two lacteals just sort of running up the middle like that. Alright. My star is a little hard to see. Let me draw it in a little better. Gotta make a good star, you know. Alright. A little bit better there.

Okay. Next, we have a draw a triangle where you expect to find capillaries. Well, where would you expect to find the capillaries? Same thing. Those capillaries, you would find in those villi. So just anywhere here, I'll put a triangle, but those capillary beds are running up through the middle of those villi so that they can absorb those nutrients. You'd find it in every one of those villi. Alright.

Now one thing that we haven't identified in this image that we did talk about is those intestinal crypts, and you can see them here. You see these down here. These are intestinal crypts. Now, the intestinal crypts do connect to the surface, but when you take a cross-section, sometimes it doesn't all line up correctly. Now you can sort of see it here. This is sort of one of those intestinal crypts sort of going down there, but what you're seeing here, these sort of circles, those are the intestinal crypts. You're just not seeing it perfectly lined up, so you can see the whole thing leading up to the surface of the small intestine. With that, practice problems after this. Check them out.