let's say that you want to build a human body from scratch in this crazy hypothetical scenario there's gonna be some store you can visit and you can shop for the tissues you need what you'd be shopping for are essentially four basic tissues that comprise your entire body so we have muscle tissue epithelial tissue nervous tissue and connective tissue now muscle epithelial and nervous are pretty intuitive you could probably figure out where those are for the most part but connective tissue tends to be a little more mysterious what is it connecting where do you find it and what's its purpose all good questions and hopefully I have a few answers for you in this video let's do this [Music] [Applause] okay so let's start by figuring out the different types of connective tissue because there are four different subtypes you have cartilage bone general connective tissue and blood blood these days is actually kind of on the fence as to whether or not we're gonna keep classifying it as a connective tissue and depending on the textbook you're looking at you might see something different but for our purposes we're gonna consider it a connective tissue for the time being let's start with cartilage because there are different types of cartilage and we also find it in different locations in the bottom so there are three different types of cartilage found in the body first is called hyaline cartilage also sometimes referred to as Highline so whatever makes you happy you can go ahead and call it that fibrocartilage and elastic cartilage each of these are gonna have their own unique functions so we'll take a look at them individually so let's start off with hyaline cartilage and in front of us I have a trachea or windpipe and you can kind of see how I'm able to accordion it back and forth that's because there's a lot of flexibility in this structure which you're gonna want especially when you start coughing or respirating in general but if you look closely you're gonna see there are these things called cartilaginous rings and then there's gonna be other little bits of connective tissue connecting those rings these cartilaginous rings don't form a full circle and if I turn this around and scoop this esophagus to the side you can see that it doesn't form a complete circle on the backside so you'll often hear these be referred to as C shaped rings or U shaped rings to just reinforce the idea that it doesn't form a complete circle but they're made of hyaline cartilage hyaline is the most common type of cartilage found in the body you find this on the end of long bones your nose is made of hyaline cartilage in fact when you were an embryo still inside a mom's uterus your entire skeleton was made of hyaline cartilage but again its main purpose is to reduce friction which is why it's also really glassy and smooth which is why you find this inside of joints at the end of bones because it makes for a nice and efficient surface for the bones to articulate with the next type of cartilage is called fibrocartilage and you're going to find this in areas of the body that require a good amount of shock absorption so in front of us we're looking at the spine or vertebral column right here and these light colored bands are going to be the inner vertebral discs and then these darker color bands are going to be the vertebrae or backbones so these inner vertebral discs here are made of fibro cartilage and again this is all about shock absorption you can kind of picture that these are cushions for all of these vertebrae which are stacked on top of each other without these intervertebral discs cushions just try and imagine this for a second what would happen if you went like that you can just picture all those backbones slamming into each other so it makes sense you'd need to have a cushion the problem is there gonna be a vascular which means they don't have a good amount of blood supply and makes it very difficult to heal from injuries like a bulging or ruptured disc but that's a separate topic for a completely different video but still it's all about shock absorption you find fibrocartilage in places such as your temporal mandibular joint where your mandible is connecting up into your cranium we're also in the knee you may have heard of a meniscus the menisci are types of fibrocartilage and they are just helping to absorb shock between the femur and the tibia the last type of cartilage is called elastic cartilage and this is the most rare type in the body you only find it in two places the external ear or your oracle and then also your voice box or your larynx and it's called the epiglottis now the thing about elastic cartilage is it's all about retaining its shape if I were to just sit and pinch my ear for like five minutes or so and then release it it would snap back and that's because it's made of elastic cartilage if I did that to my nose which is made of hyaline cartilage it would just be bent because it's not designed to retain its shape so the question is why is it important to retain the shape well for the ear it comes down to the reliability of sound you see if you just go ahead and pinch and move your outer ear around while I'm talking you're gonna hear my voice start to be distorted and it's gonna be a little difficult to get the exact location of where my voice is at this could be a big problem if you're in the wild being chased by a tiger or maybe if you're just trying to find somebody in there out there yelling Marco and you just have no idea where the sound that's coming from in terms of the epiglottis I can actually help you out here because I have one here so what you're gonna notice is that I have I can kind of get this going for you right lung that is going to be connected to the trachea and if I bring this closely we can see the outside of the larynx or your voice box here now what I want to do is turn this around and what we can see is inside of that voice box and you see this little flap right here this is called the epiglottis and that's that elastic cartilage structure and it's job is going to be to protect the airway so as I push it down it's going to be blocking off the entryway into the respiratory tract and making it so whatever is being swallowed goes down this posterior tube called the esophagus so as you're swallowing food and drink this is going to slam down and block off the airway it makes sense that you'd want this made out of elastic cartilage so it always does its job because if it doesn't even just once well you're choking [Music] the next type of connective tissue is probably the most intuitive and that's going to be bone tissue so in front of you I have a real human skeleton now bone tissue serves a variety of different functions including calcium and mineral storage blood cell formation fat storage and also as an attachment site for muscles in fact if you didn't have bone tissue you just be this puddle of soft tissue on the floor it's extremely important it's also very much alive I know a lot of times at least in my eyes it's easy to think of bone as like almost these rocks inside of your body but that's not true your bones aren't fossilized your bones are very much alive and if you were to microscopically zoom in on this bone well not this one but a living bone you would find that there are cells that are very much alive this next one is probably the least intuitive of all the different types of connective tissue it's called general connective tissue and there are three different subtypes of it you have what's called connective tissue proper reticular tissue and adipose tissue now in a later video we're gonna be going into the specifics of general connective tissue in all of its many nuances but for now we're gonna keep it simple and generalize things and just say it's kind of like the soft fatty and protein dense tissue that wraps and connects all the different structures in the body now the thing I want you to understand about this is that it is everywhere so what I have in front of you is going to be a chest plate so you can see the umbilicus but you see all this white stuff on top of the ab muscles that is all general connective tissue those are collagen proteins and collagen is extremely tough I believe it is rated up to about 17,000 pounds per square inch in its tensile strength which means it is really good at resisting getting pulled apart so if you have a tough tissue like this you're gonna want to put it pretty much everywhere in fact collagen is inside of bones it wraps around the outside of bones collagen wraps the outside of nerves of muscle cells of blood vessels collagen is absolutely everywhere here and I can even show you this really cool view you can see just all that kind of looks like spider webs or cobwebs those are all just collagen spindles between the oblique muscles so you may have even heard the term fashio and that is a type of general connective tissue so in my eyes general connective tissue while at first glance may be the least intuitive once you know what it is it's probably the most intuitive because it is what literally connects everything in your body and lastly we have blood now as I mentioned earlier anonymous are currently discussing reclassifying this saying that it's no longer connective tissue but as of this moment most textbooks are still saying that it's a connective tissue so we're just gonna go ahead and keep it that way but this probably makes sense to you blood is literally everywhere I mean this is the life force for cells blood is what carries oxygen and nutrients and also removes the waste that the cells produce so it makes sense that you'd have blood pretty much everywhere in the body there are very few structures that are called a vascular meaning they don't have a blood supply so again this one probably makes a lot of sense okay so now that we know all the different types of connective tissues I want you to know that I'm a big fan of what are called mnemonic devices these are memory tricks that help you kind of consolidate and put a lot of information into an easy to digest package so the one that I've been teaching my students for years is the CBGB's it's kind of like saying the heebie-jeebies and so CBGB's stands for cartilage bone general connective tissue and blood you can actually switch around the B's if you want to put blood first and then bone early doesn't matter it's whatever makes you happy because this is just a tool for you to be able to remember all the different types of connective tissues again I find mnemonic devices to be extremely useful so I really recommend taking this one hard thanks for watching everybody but before you go do you want to look as amazing as I do wearing an Institute of human anatomy shirt you do we are selling merchandise and you'll find a link to that down below so be sure to check out our store and then you can show everybody just how much anatomical knowledge you have or just how cool you are but thanks again for watching and I will see you in the next video [Music] you