 Hey everybody, Dr. O here, I think we've covered everything we need to about epithelial tissue. Now we're going to move into connective tissue. So what is fat and blood and a ligament have in common? Well they are all classified as connective tissues. So what makes something a connective tissue? Number one, it has to have specialized cells. Number two, there's going to be what's called a ground substance. So it's a liquid ground substance, obviously like blood's going to have more of a liquid ground substance than bone but they both do have some and they're going to have some sort of protein fibers. So those are the three things that make something a connective tissue. Specialized cells, ground substance, and then some protein fibers. Most common cell type you're going to see in connective tissue is the fibroblast. So fibroblast, they make connective tissues like collagen, they're responsible for scar tissue, these kind of things as well. Your connective tissues do have this extracellular matrix so they make all the stuff that fills in between the cells in your body and then there are three major types. That's what I really want to focus on here. So the three major types of connective tissue are going to be what is called connective tissue proper, supportive connective tissue, and fluid connective tissue. So your connective tissue proper is going to be broken down and we'll do videos in each of these three categories. It's going to be broken down to loose and dense connective tissue. So loose connective tissue, we think like fat tissue, like adipose tissue, we'll cover reticular tissue and all those. Dense, we have dense regular and dense irregular so I'll do a separate video on those as well. Your supportive connective tissues, we have cartilage and bone. I won't do a video on this chapter about bone, excuse me, real itchy today. I won't do a video about bone right now because bone tissue has its own chapter coming up. But I do want to talk about bone versus cartilage, key difference because bone used to be cartilage. We'll cover that later. But bone is vascular, meaning it has blood supply and cartilage is avascular. So in this chapter, I'll cover those three types of cartilage, hyaline, fibrocartilage, and elastic cartilage. And then we have our fluid connective tissues, blood and lymph. I also won't cover that yet in this chapter because they each will have their own videos when we get to blood and the lymphatic system in A and P2. All right. So those are, that's what makes something in connective tissue and those are the examples that you will be expected to know throughout the course of this year. I hope this helps. Have a wonderful day. Be blessed.