this page of your notes is titled connective tissue as a reminder of where we are in the big scheme of things the first thing let's put over here are the four major types of tissue in your body in other words every part of your body that you touch is one of these four kinds of tissues either epitheli those are the Linings or connective which are tendons and ligaments and fat and blood or muscle which contracts to help things move through the body or nervous which are cells that can fire electrical signals so in connective tissue of of course there are let's highlight connective before we move on focus of this page connective tissue is well known for the facts fact that it has scarce cells meaning not very much lots of Matrix which I'll explain to you in a second suffice it to say it's not cells though and usually scarce blood supply compared to other tissues like epithelial for example so let's Al go down to the bottom of the page and talk about Matrix so move your paper up like this Matrix usually has some kind of fibers most of the time those fibers are that's a c are collagen fibers collagen fibers are just a type of long fibrous protein and then they also contain what's called Ground substance and typically this is going to be something like in bone calcium salts for example e G is for example or uh something like glycoproteins glyco means sugar so these are proteins that have a sugar attached to them and the whole point of this and why I tell you about it it helps connective tissue hold water because of these glycoproteins water is attracted to the connective tissue and as we age these tend to break down so our connective tissue gets weaker and more brittle okay so we'll come back to that periodically throughout the quarter and kind of flush that out pun intended okay first let's talk about uh the different kinds of cartilage because cartilage is always connective tissue there are three kinds hyolin cartilage is the most common in your body and it's found for example articulations and this is articular cartilage that lines the ends of Bones and it should be smooth and glassy to reduce friction when you bend your knee for example so let's go ahead and color that on here this is a imaginary joint and the ends of the bones are always lined with articular cartilage some other places that you have articular or Highland cartilage sorry are for example in your trachea and this also makes up your larynx so your voice box and then your nose right nasal cartilages give us the unique shape we have to our nose and what do you think about this one costal word means rib and those are cartilages that connect your ribs to your sternum so highin cartilage is the most common it's not the only kind can see in this imaginary knee joint a couple of pads they would be over here too and those are called fibrocartilage pads and they are made of highin in typical terminology call this a meniscus so maybe You' heard of someone that has torn their medial or lateral meniscus in their knee and what they've really torn is a piece of fibrocartilage this is I would say the toughest of the cartilages the most or the least flexible but it gives good padding and so you find it in manisi for example in the knee to act as a cushioning and shock absorption and also uh in between each of your vertebrae something called an invertebral disc and that is made of fiber cartilage has kind of a pulpy interior and if you've heard of someone herting a disc then they have damaged a piece of fibrocartilage and then the other place you have that is the pubic symphysis this is where the anterior part of your pelvis is held together and if it were to come apart then the two sides of the hips actually could move freely it's really painful that can happen in someone that's had a lot of pregnancies all right so that is cartilage got hyolin cartilage and then fibro cartilage and then the last kind of cartilage is called a elastic cartilage you can tell in the name it is the most flexible and sure enough we find it in a flexible spot the ear notice it starts with an E just like elastic that's how you can remember and the other place that elastic cartilage is found is the epig glotus and this is a flap of cartilage that covers up the opening to your trachea when you swallow so it protects you from choking okay now let's look at a couple other kinds of connective tissue so so far we've only talked about cartilage and the three kinds hyolin fibro and elastic so these are all cartilage and next we'll look at ligaments and tendons so you can use an orange highlighter for a couple of ligaments on our imaginary knee sometimes they're actually in the well they are in the middle of the knee too the cruciate ligaments can't see that so ligaments connect one bone to another and they are strong collagen fibers I'm going to stop there for this page of your notes and we'll pick up in another video