 Hello there, fancy meeting you here in this place, wherever you are watching video lectures about anatomy. So today's topic is connective tissue. And not only are we going to look at the characteristics of connective tissue, and we're going to look at different types of connective tissue in lab, but we're also going to look at membranes, which are compound structures built out of connective tissue and epithelial tissue. We're also going to look at the integumentary system, which is our first body system. And the integumentary system is actually a membrane, which is one of the reasons why we're talking about it today. So let's start out this lecture with a definition of connective tissue. Connective tissue. Are you ready? Connective tissue is cells. Thank goodness. In a matrix of ground substance, yeah, that's a substance, and fibers. That's what I'm talking about. Cells in a matrix of ground substance and fibers. So three primary components in a connective tissue. You've got your cells, you've got your ground substance, and you've got your fibers. If you talk about the ground substance and the fibers together, you call it the matrix. So the cells sit in the matrix, and we'll talk about the structure of the connective tissues in more detail in the next section. But before we go there, let's make a list of some of the characteristics of connective tissue. Guess what they do? They connect. Really? Yeah. They connect or support. Okay, we'll throw a support in there as well. If they connect two different things, is it possible that they line a space? They never, they connect two things. They never line a space unless of course you get stabbed in which case then they will be lining spaces but that wasn't on purpose. Usually connective tissue is highly vascular. Oh my gosh. Compare and contrast epithelial tissue and connective tissue. In a compare and contrast question, you have to say something that's similar and you have to say something that's different. What is something that's different between connective tissue and epithelial tissue? This is a great one. Epithelia, you remember, was not vascular at all. It was avascular. Most connective tissues are highly vascular. There is an exception. Except, as you may know, cartilage. Really? And I expect you to know that. That's fair game on a quiz at this point. Even though we haven't studied cartilage in specific or in particular, that's the word. Cartilage does not have a blood supply and that actually is a structural characteristic of cartilage that affects its function. So keep that in mind. Most of them are highly vascular. No free surfaces. Your cells are far apart. How is this different from epithelial tissues? Remember, our epithelial cells were tightly packed together. Like you had a really nicely organized bunch of cells. In connective tissue, it looks like a mess. If you look in there and you're like, whoa, there's a whole lot of stuff going on in there and I don't even know. It's because the cells are in this matrix and the cells are actually really far apart. Remember when I drew that picture in epithelial tissue, we were doing basement membranes and I was showing you how the basement membrane connects to the connective tissue. Underneath it and that connective tissue just looks super messy with blood running through it because it's vascular and cells like spread out all over the place. That's what connective tissue looks like. That's everything. The last, and that's almost everything. That's everything except for this last thing I'm going to tell you, which is that connective tissues. Holy diverse. I'm going to put it in capital diverse letters so that you remember, dude, connective tissues are crazy. They're so diverse that you'll be surprised that that thing is a connective tissue and that thing's a connective tissue. They don't even look remotely the same. But we will see how they are similar. So let's look closer at the structures that are found in connective tissues and then we'll start classifying them.