Anatomy and Physiology of Connective Tissues

Hey everybody! Welcome to Professor Long's lectures on anatomy and physiology. I'm Professor Bob Long. If you're watching these videos, you know we're in the coronavirus shutdown, so I've moved everything to YouTube for my students. These videos are intended for students who are enrolled in my class, and I want you to learn the material the way that I teach it. If you're not enrolled in my class and you found these videos on YouTube or someone shared them with you, great. I hope you find them helpful, but know this. I cover the material the way that I want my students to learn it at this particular time. I know that when we go into chapters, I was a student too, instructors cover every little detail on every page and every chapter and you get these PowerPoints with 9,000 bits of information. Nobody can learn all of that. It becomes too overwhelming. So my style is a little different. I teach you some fundamentals, leaving certain information out or not going into the nth level of detail until the time is appropriate. We're building a foundation. We'll add detail later on. If you're not in my class and your instructor covers more material or covers it. it differently, please learn it the way that your instructor wants you to learn it. This should at least still help you set a foundation and understand it, okay? If you're in my class, this is my part one class, biology 2401, we've been covering tissues or histology. We've gone through a general introduction into tissues, we've gone through epithelial tissues, and we've been going through connective tissues. We did all the connective tissue proppers that I want you to know. We've even completed the fluid connective tissues. And if you're following along... in my note set. I don't actually have my note set on me, but I did print out some pages to follow along with the notes just to make sure I'm doing things and I can refer to certain information for my students. We're on page 33. We've already completed the top of page 33 with fluid connective tissues. We're starting with supportive connective tissues. So let's get started with them, okay? Excuse me, I have a little frog in my throat. So now, when it comes to the connective tissues, one of the things I started off with is... is that the connective tissues are probably one of the most varied of the tissues in their organization, in their appearance, in their cells. And when we looked at connective tissue proper, most of the cells were fibroblasts. We find them in loose, dense, and reticular tissue. Now, some fibroblasts modify their development and become adipocytes. So adipocytes are simply modified fibroblasts. And then we went through the blood cells. Well now we're about to go through the support of connective tissues when it comes to the support of connective tissues One of the things that we learned is that there are two different types of supportive connective tissue there's cartilage and Anytime we're talking about cartilage. You're gonna see the root word conjure Chandra this Chandra that and then there's bone and For bone you're gonna see the term osteo But bone tissue is very often referred to as osseous tissue. So osseous tissue is bone tissue. Okay. Now, if you speak Spanish, you know, the word for bone is vessel and it looks like a lot like osseous or it's related to osteo. Now, the cells found in cartilage are called chondroblasts and chondrocytes. The cells found in bone are called osteoblast osteocytes and osteoclasts, but they're another cell altogether. One of the things that I want to get out and get across to you guys is this, okay? When I have a cell that is in the embryonic state, so as you guys know, we start off as a single cell. That cell divides by mitosis to make two cells, those make four, those will divide, and we will continually double the amount of cells in the human body. for a number of cell divisions, we end up looking like a little ball of cells. At this stage of development, all of the cells are genetically identical. They're clones of each other because of the way that DNA replication and mitosis occurs. And what's also true about each cell is that, you know, if I mark two cells, I'm going to pick this cell right here, cell number one, and this one over here and call it cell number two, and let's just pick another one. This one's cell number three. cells. We have all these long pieces of DNA called chromosomes and there are genes on those chromosomes. Not all the genes are on making proteins through transcription and translation. In this cell, let's say on a particular chromosome only specific genes are turned on and are producing proteins. All the other genes are turned off. We're not transcribing them into proteins. Well, Whatever genes are on in this cell are also on in this cell and this cell and all the other cells. All of the cells are making the exact same proteins performing the exact same functions behaving identically. At some point in development this cell might decide I'm going to on some new genes and turn off some of the old genes that used to be on so that it starts making different proteins and performing different functions this cell might turn on a whole different cell set of genes and turn off some that are completely different than this. So now these two cells are making different proteins not only from each other but from all the other cells. They're behaving differently. We call that differentiation. When the cells differentiate they start behaving differently. Okay and this cell might turn on a whole different set of genes and so what we end up having is and we might end up having three groups of cells that differentiate, excuse me, sorry about that. One group of cells is going to become certain types of tissues in the body. Another group of cells will be different tissues and the third group of cells will be the basis of all the other tissues in the body. And when we get to embryology in part two A&P at the very end, we get into development, we'll talk about the germ layers and gastrulation and, you know, which cells become which, but essentially all the tissues of the body are going to be developed from one of these three groups of cells. And in one of these groups of cells will come some of the connective tissues. So knowing that these cells are differentiating, at some point when we have a cell that has not developed into anything else, we call that a stem cell. Or sometimes we'll use the term mesenchymal cells. So mesenchym is embryonic tissue that's undeveloped. So mesenchymal cells are stem cells. And we call them that because these are the cells, like in that ball of cells that I just erased, those are the cells that will... that all the tissues and organs of your body stem from. They are undifferentiated or not very well differentiated. Some of those stem cells will start to grow up to become what we call a fibroblast. Now that fibroblast can stay a fibroblast its entire life. If it's going to stay a fibroblast, it's going to stay in connective tissue proper. And sometimes those fibroblasts will branch off and become an adipocyte for adipose tissue, which is a modified fibroblast. Some of the fibroblasts, as they differentiate and turn on different genes, actually go on to become a chondroblast, which will grow up to become a chondrocyte. So they're going to become cartilage cells and some of these fibroblasts as they grow up become an osteoblast which then grows up to become an osteocyte. So somewhere during development some stem cell matures into some kind of cell that's going to end up becoming all the different types of connective tissue cells. There are some steps in here that I've skipped because it's not super important to us at this point but essentially what I want you to see is look connective tissue proper and the support of connective tissue cells are all stemming from fibroblasts At some point in development, the fibroblast leaves their genes on and stays a fibroblast, or it can turn on different genes and become an adipocyte, or alter their genetic function, which proteins are being transcribed and become a chondroblast, or become an osteoblast. But all of these cells have a common relative or common ancestor, which are fibroblasts. So a lot of your connective tissues are derived from the same stem cell group. Okay? Now knowing that is going to help us understand some stuff that's going to happen in cartilage and bone. So now I'm going to focus on cartilage right now because it is the first one on our page. So when it comes to the support of connective tissues, some of the information here that's written is going to explain to you some things that I've also talked about in lab. But what I want you to know is this. There is a membrane that develops. And this... This membrane would be called the perichondrium, which literally means membrane around the cartilage. In that perichondrium, there are some cells in here called fibroblasts. And the perichondrium really is made out of dense connective tissue. Okay, now if these fibroblasts migrate out here and decide that they want to start making cartilage tissue, they start laying down the matrix of the cartilage. and as long as they are not trapped in the cartilage, these cells can divide by mitosis, and the new cells can move on, but eventually they all continue to lay down cartilage between each other, and some of the cells get trapped in the cartilage. They're completely trapped in the matrix. And eventually, I'm not going to color this all in purple, but you get the idea that all of these cells would be surrounded by a lacuna and buried or encapsulated with the matrix of the tissue. And then we would have our other membrane over here. piece of perichondrium. As long as the cell is not trapped in a lacuna and can divide by mitosis and build the tissue, we would call it a chondroblast. We went over this when we went over the suffixes at the end of the cell name. And if the chondroblast builds cartilage all the way around itself It's trapped in a space called a lacuna the little space around the cells and then the cell would become a chondrocyte Okay, well, that's how cartilages form So the membrane that surrounds the cartilage is called the perichondrium It's filled with cells called fibroblasts and some of those fibroblasts develop in the chondroblasts They migrate out into the tissue and start building cartilage around themselves and they actually build the cartilage in which they live. In the matrix of the cartilage, depending on which cartilage we look at, there are different substances. And by the way, the substances found in the matrix that is not part of the fibers, but all the fluid or the gel that's around there is sometimes referred to as ground substance. Okay. So anyway, so now if I start to look at the different cartilages, they all kind of form this way. So when it comes to the cartilage, cartilages, we looked at three different cartilages. And one of the cartilages we looked at was called hyaline cartilage. And what you need to know for the test is you need to know the structure of the cartilage and the cells found in there, but you need to know the location and the function of each one of these cartilages. So now we're just adding to that. If you watched my previous video, you should be able to make an outline of the four major tissues, the different types of epithelial tissues, the different types of connective tissue, proper, fluid, and supportive, and the different subtypes, okay? So now, when we start talking about hyaline cartilage, you need to know the location. and the function. Now in lab I described the hyaline cartilage as the smooth cartilage because the way the matrix is set up is it's very slick and smooth and hyaline cartilage is very often referred to as articular cartilage. Now to articulate means to communicate and an articulation in anatomy and physiology is where two bones communicate or rub together. We form a joint. So anytime you hear the term articulation or articular and A and P, what you're talking about usually is some kind of joint where two bones meet. Now, if I took two pieces of bone tissue and I rubbed them together, bone tissue is very similar to a seashell or a stuff called caliche. If you live in South Texas, you know what that is. But if I took two oyster shells, which are very similar in many instances to bone, and I start to rub them together, they will grind on each other and make a very... fine powdery dust and eventually grind it down. Well, if we did that with our bones, by the time we reach our 40s, our bones would be little nubs. They would be ground down from all the activity. And when you rub bone on bone, there are some nerve fibers that are found in what's called the periosteum, the membrane that surrounds the bone. And when you rub those, it hurts. It's painful. That's what we call arthritis, rubbing bone on bone. So wherever we we have a joint a movable joint especially for example in the knee the top bone or femur up here and the tibia one of the lower leg bones where they would rub each other as we walk mother nature Took a very thin layer of hyaline cartilage and covered the surface, the articular surface of the bone and it's on both bones. So that would be where we find hyaline cartilage. It is found on the location of articular of hyaline cartilage is on the articular surfaces of bones. And any bones in your body that move, your fingers, your wrist bones, your elbow, your shoulder, your hip, your knee, your toes, your ankles, your vertebrae, the way that we move, your mandible right here. Any two bones that rub on each other have articular cartilage on the surface. And since we have so many joints in the body, hyaline cartilage is actually the most abundant cartilage in the human body. We have more hyaline cartilage than we do elastic and fibro cartilage. So that's where we find it on all the articular surfaces of the bone We also find it in two other places actually before I move on to elastic cartilage we do find it in part of our nose the flexible part of your nose and right here in the sternum where our ribs can attach, we have a lot of hyaline cartilage there, okay? So, but this is the main location, the articular surfaces of our bones. Its function is that it assists in joint movement. It almost acts like it facilitates joint movement in that it prevents bone from rubbing on bone. It does sort of a protection of the bone tissue. Okay, so it also does the attachment of our ribs to our sternum. That's why attachments in the notes, but that's what I want you to know about hyaline cartilage It's got that real slick smooth appearance so that it our bones glide across each other and sometimes when people damage the cartilage in a joint and means they've started to damage this cartilage and if you continue to damage and eat it away then you end up with what's called osteoarthritis you're rubbing bone on bone okay anyway all right we're done with hyaline cartilage the second cartilage we're going to look at is going to be called elastic cartilage if you remember in lab I called elastic cartilage the fuzzy cartilage because it has a very fuzzy appearance so when it comes to elastic cartilage The matrix of elastic cartilage looks real fuzzy because in the ground substance, mixed in that ground substance, it is filled with elastic fibers. And you should know what elastic fibers do. They provide elasticity or flexibility. So this is a very flexible cartilage. We don't have a whole lot of elastic cartilage in the human body. There's only a few locations. One of those locations for elastic cartilage is what we call the pinna, which is also called the auricle of the ear. That's the part of your ear that we think of when we see the ear. This outer part here is called the pinna or auricle. If I flex it and let go, it snaps back. It's very elastic. So it has its function is flexibility and maintain shape. So the function of elastic cartilage is flexibility to maintain shape and support of certain structures. Okay, a second location though that we find this cartilage is called the epiglottis. Now we haven't done part 2 A&P yet, but we'll refer back to this when we do part 2 A&P. The epiglottis is a little piece of tissue in your throat. Let me erase this information. You already have that down. and let me explain to you what I'm talking about okay so if I were to look at a person's nose and their mouth these cavities are separated by some bone and some soft tissue we have the cavity where you would breathe air in and you have the oral cavity where you would take food in and where those two meet up for a little ways they share the same tube that tube by the way happens to be called the pharynx a lot of people say pharynx but anyway so now the pharynx and the oral and the nasal cavity share the pharynx for a short distance but very quickly that is going to branch in the two separate tubes One of the... These tubes is called the esophagus and the esophagus eventually leads to your stomach. So when you have food or drink come in through the mouth, they're going to go all the way down into your stomach. The other tube, there's going to be your voice box and there's going to be what we call the trachea. The trachea is your windpipe and it's going to lead to the lungs through what we call the bronchial tree or the respiratory tree that we talked about last time. Now, when it comes to swallowing food or drink, I do not want any food or drink making it down into my lungs. So Mother Nature in her grand design, there's a little opening here to this. called the larynx or your voice box and that opening leads to this tube. If that opening stayed open then anytime you swallow food or drink it could go down into your lungs. You've done that on accident sometimes and you end up having to have that out it could damage your lungs and damage breathing. So Mother Nature put a little flap of connective tissue here called elastic cartilage and that little flap is called the epiglottis. And it gets its name because this opening is called the glottis and it's right above it. And when you swallow, the epiglottis will cover the glottis so that food and drink can only go down into your stomach. There's a muscle that... contracts and closes this off. When you're done swallowing, that muscle relaxes, the elastic cartilage pops it open. Every time you swallow, it closes and it pops open. Now, it is a low level of consciousness, but it is under... conscious control so sometimes if we're distracted or we inhale something it'll go back it'll go food or drink can make it down in here and you end up having to hack it or cough it out but I wanted you to know that that's one of the main places that we find elastic cartilage in the body okay so By the way, one of the things I did not tell you, and I should, it just dawned on me. The entire windpipe or trachea, don't press on it, it's not comfortable, but if you feel it, it's pretty hard, but it's not made out of bone. It's made out of a... series of little C-shaped cartilages that go all the way down. And it's almost like a microphone stand that you can flex and bend around so that when we move our head around, we don't pinch off our breathing tube. The trachea is made up, the cartilage and the trachea. trachea is hyaline cartilage. It's another place that we find it. So we have three places we can talk about hyaline cartilage, actually four. We find it in our nose, the flexible part of our nose. We find it in our windpipe or part of the respiratory tree. We find it connecting our ribs to the sternum, but mostly we find it in the articular parts of the body. Elastic cartilage, we got two places, the pinna of the ear and the epiglottis, and it does flexibility to maintain some. or shape of things. Finally the last type of cartilage we can talk about is called fibrocartilage. Fibrocartilage is the most tough, it's the toughest of the three cartilages and it's filled with lots of collagen fibers which makes it very very strong. So fibrocartilage The ground substance or the matrix is filled with collagen fibers. It makes it very, very strong and tough. And there are several locations for fibrocarbonage. One is called the meniscus of the knee. And the other main one that I want to talk about, although there's a few other examples, the two that I really want to discuss are the meniscus of the knee and what we call the intervertebral disc. Okay, now. If we look at certain joints, many of our joints don't take a real hard pounding unless, you know, you have some special activity that you do. Like if you were a carpenter and you're hammering all the time, then your wrist and your elbow and your shoulder are going to take a lot more pounding than most people. But most of our joints, if I were to look at the bones of my fingers, the little bones here. fit together like this, okay, and in between right here on the surface there is some hyaline or elastin. hyaline cartilage, okay? All the movable surfaces of our body are lined with hyaline cartilage. But if I look at a couple of the joints that take a severe pounding, particularly the knee, which takes the most pounding of any joint in the human body, I mean we beat on our knees all day every day as we walk as we run as we play sports so the end of the femur of the knee and the top of the tibia Where these two bones meet? have a little bit thicker layer of hyaline cartilage here. But hyaline cartilage is not real tough stuff. You know, I've seen this in surgery. I work for orthopedic surgeons. You can reach in with an instrument, and you can scrape that cartilage off. If you take the end of a chicken bone, if you're eating a chicken leg, you can scratch the cartilage off that you see on the end of the bone, or it's the chewy stuff you get in your mouth. That's going to be the elastic cartilage. The hyaline cartilage is the stuff stuck on the bone, and you can scratch it off. It's pretty soft stuff. Because our knees take such a tremendous pounding, Mother Nature put a pad of fibrocartilage in here that sits on top of the tibia and between the femur and the tibia, and that is called the meniscus. Now, I don't know how many of y'all have taken chemistry, but when you're looking in a cylinder and you're trying to measure how many milliliters of something you have, the water hugs the edges. of the glass a little bit through adhesion. So you usually read the bottom of the meniscus. So meniscus describes a certain shape and that's why they call this that. It's called the meniscus and the knee. And the meniscus itself is a fibrocartilage pad. So then as we run or jump and land on our knees, the highland cartilage doesn't get beat up. It's got a little cushion in there. We're going to talk more about the meniscus, its shape and function when we do bones and joints in the future. Now, in between our vertebrae, if we were to take the vertebrae out, which we're about to do in lab when we do bones, the body of the vertebrae are stacked on top of each other, and very often our vertebrae have these little bony pieces that stick off. We're going to learn all that when we do bones in lab. But some of these little pieces will articulate. That's not the best drawing of one, but nonetheless. Now... These little openings are a hole between the vertebrae where nerves can exit. So I'm going to put a big red thing or brownish looking thing here. That's where a nerve would come out of your spine. In between the discs of the vertebrae, there's a thin layer of hyaline cartilage on all the surfaces where your vertebrae are going to slide across each other. As you twist your body or as you flex and under... flex, flex and extend, we have highland cartilage there. But because if you jump or if you're carrying something heavy the vertebrae get pushed down on each other, mother nature also put a pad in between the vertebrae. And if we pull that out it's a little disc shape. That is called the intervertebral disc, the disc of fibrocartilage between the vertebrae. And when someone hurts their back and they've slipped or herniated a disc, it's that that thing that gets damaged. When that gets damaged and the vertebrae compress together, very often it can pinch a nerve and cause things like sciatica or nerve pain and numbness and tingling and other problems. So we often look at our spine when we have a pinched nerve and nerve issues to see if the intervertebral discs are still healthy in there. If they're not, the discs collapse, I mean the vertebrae collapse onto each other and cause some problems. So I need you to know these are the locations of fibrocartilage. In both places they act like a padding and a shock absorber. Okay so so we're done with page 33 we're going to move on to page 34 we're going to talk a little bit about bone tissue. I'm not going to spend a lot of time on bone tissue because in my class the way that I do it we're going to have an entire exam dedicated to bone tissue. bone tissue. So I'm going to do the bare minimum on bone and then we're going to move on and talk about some other things so we can finish up this unit. So when it comes to bone, bone is set up very, very similarly to cartilage. And what we have around bone is we also have this connective tissue covering. It's dense connective tissue. And this is called the periosteum. The only thing that's different is that it's surrounding bone instead of cartilage. There are some cells that live in the periosteum. And really these cells are like modified fibroblasts. Those cells were once fibroblasts that have decided they're going to start moving out into the tissue and building bone. When these cells migrate out... They can divide by mitosis and make a whole bunch of themselves and then in between the cells they start spitting out all the tissue that's going to make bone and as they build the bone around them they get trapped in a little space called a lacuna. As long as the cells can move along, they're not trapped in a lacuna and they can divide by mitosis. We call those osteoblasts. Once they're trapped in a lacuna, they become an osteoblast. osteocyte. They can maintain the bone tissue around themselves, but they cannot go build big swaths of bone, okay? So bone develops very similarly to cartilage, and the membrane would wrap all the way around the bone tissue in all three dimensions, or all directions, I should say, okay? So I would have a big swath of bone tissue here with osteoblasts and osteocytes, but the matrix of bone is very hard. hard and solid. It's made up of a lot of calcium salts. It's almost similar to cement in that there's this powdery salts that if I mix them with the right chemicals will have a chemical reaction and solidify and become very hard and solid. It has a membrane like cartilage, but the membrane is called periosteum. It has osteoblasts and osteocytes. Now osteoclasts, we'll talk about later on when we study bone tissue, they're not related to these cells. They're from your immune system. They're actually modified white blood cells. cells. Now right now I think that's all I want you to know about bone tissue. Let me make sure, let me double check my notes. And the only reason I'm double checking these things so much is because I'm in the process of rewriting my note set for the next fall. and I've changed some things up so I want to make sure I'm covering the way that it's in the old notes that you guys have. Yeah that's it. So now for now that's all you need to know about bone tissue. We're going to talk about membranes of the body. So when it comes to the membranes of the body There are four major membranes. One is called the cutaneous membrane. The cutaneous membrane is also referred to as the skin. Another one is the serous membranes. The serous membranes we've learned earlier in the semester for lecture test one, the visceral and parietal pleura, the visceral and parietal pericardium, the visceral and parietal peritoneum. And I actually think I'm doing these out of order from my notes, but a third one is the mucous membranes. And the fourth one is what we call synovial membranes. These are the four major membranes of the body. You should know the location of each one and the function of each one. The cutaneous membrane is our skin. Our skin is our barrier and our boundary to the outside world, for the most part. And so it provides protection, it controls permeability, it does some secretion and isolation. We're going to talk about the functions of the skin in the next video. But ultimately, it's called the cutaneous membrane. It's your skin. It covers the external surfaces of the body. So I like to do a picture like this, okay? If I drew a little person here. That's the cutaneous membrane covering all of the external surfaces of the body, our skin, the epidermis and dermis. Now, I'm going to skip to mucous membranes next, and I'm going to do them in green. Mucous membranes line up. some of the internal cavities of the body but they line those cavities that are exposed to the outside world the ones that have an opening like the oral cavity ah and all of those membranes leading down towards the lung and the digestive tract and actually if I swallowed a piece of string and flossed myself, it would be a mucous membrane all the way through the entire digestive tract. Because whether we like to think about it or not, you could reach into the digestive tract from the other end. The urinary opening called the urethra, and it's an opening to the outside world, and there are instruments. When they have to dislodge a stone or a blocked kidney, sometimes they can run a wire into the urethra. So those are cavities, the urinary system, and the vagina and the uterus are empty spaces that are open to the outside world. So these lines... internal cavities are lined with mucous membranes they're all moist and snotty or mucusy so we will do the nasal cavity and the oral cavity the respiratory tract and the digestive tract all the way through you, and the urinary and reproductive tracts are lined with mucous membranes. So these line cavities that are open to the external environment. I abbreviated the word environment. Respiratory cavities and tract, digestive tract, urinary and reproductive tracts are all lined with mucous membranes. The serous membranes, I tend to do those in a different color, but the serous membranes, one of the things that we know about these is they line the closed internal cavities. Those cavities that are closed off to the outside world. So, for example, there's a serous membrane that surrounds the lungs, and it has two layers. There's a visceral and parietal pleura. pericardial cavity of visceral parietal peritoneum and some of our I'm sorry the visceral parietal pericardium and then some of the digestive system is lined with these membranes called the visceral and parietal Serotonin. So you need to know that they line the sealed internal cavities or the closed internal cavities. Mucus membranes line those cavities that are open to the outside world. Finally, there's the synovial membranes. Synovial membranes line what we call, well, we'll just say they line the joints of the body. And they really line what we call synovial joints. And they're called synovial joints because of the synovial membrane. All of the freely moving... movable joints in the body, your knee, your hip, your toes, your ankle, your wrist, your vertebrae are called synovial joints. So if I drew the end of the femur here and the tibia and the ankle and some of these little bones down here in your ankles, all of those joints are sealed off with the membrane that are called synovial membranes. So synovial membranes line or seal off the joints of the body. And they actually secrete... create a fluid called synovial fluid or synovium. Well, synovium is the membrane, but the synovial fluid actually lubricates the joint and fills it with a certain amount of this viscous fluid that acts literally like motor oil that lubricates the joint so that everything moves around nice and easy. So all of the movable joints have a synovial membrane that seals the joint off. Part of it's um... Part of its job is to seal the joint off so that if you do have some little float or a piece of tissue that gets torn off, it can't make it into the joint and then it starts to grind. Like if you got a rock in your shoe, it would create damage. Okay? So those are the four membranes of the body. the cutaneous membrane which is your skin, the mucous membranes which line the openings that are the cavities that are open to the external environment or external world, the serous membranes which line these sealed internal cavities. and the synovial membranes, which seal off our joints and fill with the fluid that lubricates the joints. By the way, if you damage the cartilage in that joint, your body tries to lubricate it even more and you secrete more synovial fluid and the joint gets swollen. Some people refer to it as water on the knee or removing some fluid from your shoulder when they pulls the fluid off. It's actually synovial fluid. It's not really water. Anyway, we're going to stop there. I hope that you have a great day. you had as much fun as I did. I hope you learned something. Please do this stuff until you can't stand it. Do it till you understand it and then do it five more times. Work through the material over and over and over until you can teach this. You should be able to do an outline of all the tissues and put some bullet points of where do we find each one and what its function is. If you can do that, you're going to do very well on the next exam. Thanks for watching. I hope you had as much fun as I did. See you next time. Thank you.

Hey everybody! Welcome to Professor Long's lectures on anatomy and physiology. I'm Professor Bob Long.

If you're watching these videos, you know we're in the coronavirus shutdown, so I've moved everything to YouTube for my students. These videos are intended for students who are enrolled in my class, and I want you to learn the material the way that I teach it. If you're not enrolled in my class and you found these videos on YouTube or someone shared them with you, great. I hope you find them helpful, but know this.

I cover the material the way that I want my students to learn it at this particular time. I know that when we go into chapters, I was a student too, instructors cover every little detail on every page and every chapter and you get these PowerPoints with 9,000 bits of information. Nobody can learn all of that.

It becomes too overwhelming. So my style is a little different. I teach you some fundamentals, leaving certain information out or not going into the nth level of detail until the time is appropriate. We're building a foundation.

We'll add detail later on. If you're not in my class and your instructor covers more material or covers it. it differently, please learn it the way that your instructor wants you to learn it.

This should at least still help you set a foundation and understand it, okay? If you're in my class, this is my part one class, biology 2401, we've been covering tissues or histology. We've gone through a general introduction into tissues, we've gone through epithelial tissues, and we've been going through connective tissues.

We did all the connective tissue proppers that I want you to know. We've even completed the fluid connective tissues. And if you're following along... in my note set.

I don't actually have my note set on me, but I did print out some pages to follow along with the notes just to make sure I'm doing things and I can refer to certain information for my students. We're on page 33. We've already completed the top of page 33 with fluid connective tissues. We're starting with supportive connective tissues. So let's get started with them, okay?

Excuse me, I have a little frog in my throat. So now, when it comes to the connective tissues, one of the things I started off with is... is that the connective tissues are probably one of the most varied of the tissues in their organization, in their appearance, in their cells. And when we looked at connective tissue proper, most of the cells were fibroblasts.

We find them in loose, dense, and reticular tissue. Now, some fibroblasts modify their development and become adipocytes. So adipocytes are simply modified fibroblasts.

And then we went through the blood cells. Well now we're about to go through the support of connective tissues when it comes to the support of connective tissues One of the things that we learned is that there are two different types of supportive connective tissue there's cartilage and Anytime we're talking about cartilage. You're gonna see the root word conjure Chandra this Chandra that and then there's bone and For bone you're gonna see the term osteo But bone tissue is very often referred to as osseous tissue.

So osseous tissue is bone tissue. Okay. Now, if you speak Spanish, you know, the word for bone is vessel and it looks like a lot like osseous or it's related to osteo. Now, the cells found in cartilage are called chondroblasts and chondrocytes. The cells found in bone are called osteoblast osteocytes and osteoclasts, but they're another cell altogether.

One of the things that I want to get out and get across to you guys is this, okay? When I have a cell that is in the embryonic state, so as you guys know, we start off as a single cell. That cell divides by mitosis to make two cells, those make four, those will divide, and we will continually double the amount of cells in the human body. for a number of cell divisions, we end up looking like a little ball of cells.

At this stage of development, all of the cells are genetically identical. They're clones of each other because of the way that DNA replication and mitosis occurs. And what's also true about each cell is that, you know, if I mark two cells, I'm going to pick this cell right here, cell number one, and this one over here and call it cell number two, and let's just pick another one.

This one's cell number three. cells. We have all these long pieces of DNA called chromosomes and there are genes on those chromosomes.

Not all the genes are on making proteins through transcription and translation. In this cell, let's say on a particular chromosome only specific genes are turned on and are producing proteins. All the other genes are turned off. We're not transcribing them into proteins. Well, Whatever genes are on in this cell are also on in this cell and this cell and all the other cells.

All of the cells are making the exact same proteins performing the exact same functions behaving identically. At some point in development this cell might decide I'm going to on some new genes and turn off some of the old genes that used to be on so that it starts making different proteins and performing different functions this cell might turn on a whole different cell set of genes and turn off some that are completely different than this. So now these two cells are making different proteins not only from each other but from all the other cells.

They're behaving differently. We call that differentiation. When the cells differentiate they start behaving differently.

Okay and this cell might turn on a whole different set of genes and so what we end up having is and we might end up having three groups of cells that differentiate, excuse me, sorry about that. One group of cells is going to become certain types of tissues in the body. Another group of cells will be different tissues and the third group of cells will be the basis of all the other tissues in the body.

And when we get to embryology in part two A&P at the very end, we get into development, we'll talk about the germ layers and gastrulation and, you know, which cells become which, but essentially all the tissues of the body are going to be developed from one of these three groups of cells. And in one of these groups of cells will come some of the connective tissues. So knowing that these cells are differentiating, at some point when we have a cell that has not developed into anything else, we call that a stem cell.

Or sometimes we'll use the term mesenchymal cells. So mesenchym is embryonic tissue that's undeveloped. So mesenchymal cells are stem cells.

And we call them that because these are the cells, like in that ball of cells that I just erased, those are the cells that will... that all the tissues and organs of your body stem from. They are undifferentiated or not very well differentiated.

Some of those stem cells will start to grow up to become what we call a fibroblast. Now that fibroblast can stay a fibroblast its entire life. If it's going to stay a fibroblast, it's going to stay in connective tissue proper.

And sometimes those fibroblasts will branch off and become an adipocyte for adipose tissue, which is a modified fibroblast. Some of the fibroblasts, as they differentiate and turn on different genes, actually go on to become a chondroblast, which will grow up to become a chondrocyte. So they're going to become cartilage cells and some of these fibroblasts as they grow up become an osteoblast which then grows up to become an osteocyte. So somewhere during development some stem cell matures into some kind of cell that's going to end up becoming all the different types of connective tissue cells.

There are some steps in here that I've skipped because it's not super important to us at this point but essentially what I want you to see is look connective tissue proper and the support of connective tissue cells are all stemming from fibroblasts At some point in development, the fibroblast leaves their genes on and stays a fibroblast, or it can turn on different genes and become an adipocyte, or alter their genetic function, which proteins are being transcribed and become a chondroblast, or become an osteoblast. But all of these cells have a common relative or common ancestor, which are fibroblasts. So a lot of your connective tissues are derived from the same stem cell group. Okay?

Now knowing that is going to help us understand some stuff that's going to happen in cartilage and bone. So now I'm going to focus on cartilage right now because it is the first one on our page. So when it comes to the support of connective tissues, some of the information here that's written is going to explain to you some things that I've also talked about in lab.

But what I want you to know is this. There is a membrane that develops. And this...

This membrane would be called the perichondrium, which literally means membrane around the cartilage. In that perichondrium, there are some cells in here called fibroblasts. And the perichondrium really is made out of dense connective tissue. Okay, now if these fibroblasts migrate out here and decide that they want to start making cartilage tissue, they start laying down the matrix of the cartilage. and as long as they are not trapped in the cartilage, these cells can divide by mitosis, and the new cells can move on, but eventually they all continue to lay down cartilage between each other, and some of the cells get trapped in the cartilage.

They're completely trapped in the matrix. And eventually, I'm not going to color this all in purple, but you get the idea that all of these cells would be surrounded by a lacuna and buried or encapsulated with the matrix of the tissue. And then we would have our other membrane over here. piece of perichondrium. As long as the cell is not trapped in a lacuna and can divide by mitosis and build the tissue, we would call it a chondroblast.

We went over this when we went over the suffixes at the end of the cell name. And if the chondroblast builds cartilage all the way around itself It's trapped in a space called a lacuna the little space around the cells and then the cell would become a chondrocyte Okay, well, that's how cartilages form So the membrane that surrounds the cartilage is called the perichondrium It's filled with cells called fibroblasts and some of those fibroblasts develop in the chondroblasts They migrate out into the tissue and start building cartilage around themselves and they actually build the cartilage in which they live. In the matrix of the cartilage, depending on which cartilage we look at, there are different substances. And by the way, the substances found in the matrix that is not part of the fibers, but all the fluid or the gel that's around there is sometimes referred to as ground substance. Okay.

So anyway, so now if I start to look at the different cartilages, they all kind of form this way. So when it comes to the cartilage, cartilages, we looked at three different cartilages. And one of the cartilages we looked at was called hyaline cartilage.

And what you need to know for the test is you need to know the structure of the cartilage and the cells found in there, but you need to know the location and the function of each one of these cartilages. So now we're just adding to that. If you watched my previous video, you should be able to make an outline of the four major tissues, the different types of epithelial tissues, the different types of connective tissue, proper, fluid, and supportive, and the different subtypes, okay?

So now, when we start talking about hyaline cartilage, you need to know the location. and the function. Now in lab I described the hyaline cartilage as the smooth cartilage because the way the matrix is set up is it's very slick and smooth and hyaline cartilage is very often referred to as articular cartilage.

Now to articulate means to communicate and an articulation in anatomy and physiology is where two bones communicate or rub together. We form a joint. So anytime you hear the term articulation or articular and A and P, what you're talking about usually is some kind of joint where two bones meet.

Now, if I took two pieces of bone tissue and I rubbed them together, bone tissue is very similar to a seashell or a stuff called caliche. If you live in South Texas, you know what that is. But if I took two oyster shells, which are very similar in many instances to bone, and I start to rub them together, they will grind on each other and make a very...

fine powdery dust and eventually grind it down. Well, if we did that with our bones, by the time we reach our 40s, our bones would be little nubs. They would be ground down from all the activity. And when you rub bone on bone, there are some nerve fibers that are found in what's called the periosteum, the membrane that surrounds the bone. And when you rub those, it hurts.

It's painful. That's what we call arthritis, rubbing bone on bone. So wherever we we have a joint a movable joint especially for example in the knee the top bone or femur up here and the tibia one of the lower leg bones where they would rub each other as we walk mother nature Took a very thin layer of hyaline cartilage and covered the surface, the articular surface of the bone and it's on both bones. So that would be where we find hyaline cartilage.

It is found on the location of articular of hyaline cartilage is on the articular surfaces of bones. And any bones in your body that move, your fingers, your wrist bones, your elbow, your shoulder, your hip, your knee, your toes, your ankles, your vertebrae, the way that we move, your mandible right here. Any two bones that rub on each other have articular cartilage on the surface.

And since we have so many joints in the body, hyaline cartilage is actually the most abundant cartilage in the human body. We have more hyaline cartilage than we do elastic and fibro cartilage. So that's where we find it on all the articular surfaces of the bone We also find it in two other places actually before I move on to elastic cartilage we do find it in part of our nose the flexible part of your nose and right here in the sternum where our ribs can attach, we have a lot of hyaline cartilage there, okay?

So, but this is the main location, the articular surfaces of our bones. Its function is that it assists in joint movement. It almost acts like it facilitates joint movement in that it prevents bone from rubbing on bone. It does sort of a protection of the bone tissue. Okay, so it also does the attachment of our ribs to our sternum.

That's why attachments in the notes, but that's what I want you to know about hyaline cartilage It's got that real slick smooth appearance so that it our bones glide across each other and sometimes when people damage the cartilage in a joint and means they've started to damage this cartilage and if you continue to damage and eat it away then you end up with what's called osteoarthritis you're rubbing bone on bone okay anyway all right we're done with hyaline cartilage the second cartilage we're going to look at is going to be called elastic cartilage if you remember in lab I called elastic cartilage the fuzzy cartilage because it has a very fuzzy appearance so when it comes to elastic cartilage The matrix of elastic cartilage looks real fuzzy because in the ground substance, mixed in that ground substance, it is filled with elastic fibers. And you should know what elastic fibers do. They provide elasticity or flexibility. So this is a very flexible cartilage.

We don't have a whole lot of elastic cartilage in the human body. There's only a few locations. One of those locations for elastic cartilage is what we call the pinna, which is also called the auricle of the ear. That's the part of your ear that we think of when we see the ear.

This outer part here is called the pinna or auricle. If I flex it and let go, it snaps back. It's very elastic.

So it has its function is flexibility and maintain shape. So the function of elastic cartilage is flexibility to maintain shape and support of certain structures. Okay, a second location though that we find this cartilage is called the epiglottis. Now we haven't done part 2 A&P yet, but we'll refer back to this when we do part 2 A&P. The epiglottis is a little piece of tissue in your throat.

Let me erase this information. You already have that down. and let me explain to you what I'm talking about okay so if I were to look at a person's nose and their mouth these cavities are separated by some bone and some soft tissue we have the cavity where you would breathe air in and you have the oral cavity where you would take food in and where those two meet up for a little ways they share the same tube that tube by the way happens to be called the pharynx a lot of people say pharynx but anyway so now the pharynx and the oral and the nasal cavity share the pharynx for a short distance but very quickly that is going to branch in the two separate tubes One of the...

These tubes is called the esophagus and the esophagus eventually leads to your stomach. So when you have food or drink come in through the mouth, they're going to go all the way down into your stomach. The other tube, there's going to be your voice box and there's going to be what we call the trachea. The trachea is your windpipe and it's going to lead to the lungs through what we call the bronchial tree or the respiratory tree that we talked about last time.

Now, when it comes to swallowing food or drink, I do not want any food or drink making it down into my lungs. So Mother Nature in her grand design, there's a little opening here to this. called the larynx or your voice box and that opening leads to this tube.

If that opening stayed open then anytime you swallow food or drink it could go down into your lungs. You've done that on accident sometimes and you end up having to have that out it could damage your lungs and damage breathing. So Mother Nature put a little flap of connective tissue here called elastic cartilage and that little flap is called the epiglottis. And it gets its name because this opening is called the glottis and it's right above it.

And when you swallow, the epiglottis will cover the glottis so that food and drink can only go down into your stomach. There's a muscle that... contracts and closes this off.

When you're done swallowing, that muscle relaxes, the elastic cartilage pops it open. Every time you swallow, it closes and it pops open. Now, it is a low level of consciousness, but it is under...

conscious control so sometimes if we're distracted or we inhale something it'll go back it'll go food or drink can make it down in here and you end up having to hack it or cough it out but I wanted you to know that that's one of the main places that we find elastic cartilage in the body okay so By the way, one of the things I did not tell you, and I should, it just dawned on me. The entire windpipe or trachea, don't press on it, it's not comfortable, but if you feel it, it's pretty hard, but it's not made out of bone. It's made out of a... series of little C-shaped cartilages that go all the way down.

And it's almost like a microphone stand that you can flex and bend around so that when we move our head around, we don't pinch off our breathing tube. The trachea is made up, the cartilage and the trachea. trachea is hyaline cartilage. It's another place that we find it. So we have three places we can talk about hyaline cartilage, actually four.

We find it in our nose, the flexible part of our nose. We find it in our windpipe or part of the respiratory tree. We find it connecting our ribs to the sternum, but mostly we find it in the articular parts of the body. Elastic cartilage, we got two places, the pinna of the ear and the epiglottis, and it does flexibility to maintain some. or shape of things.

Finally the last type of cartilage we can talk about is called fibrocartilage. Fibrocartilage is the most tough, it's the toughest of the three cartilages and it's filled with lots of collagen fibers which makes it very very strong. So fibrocartilage The ground substance or the matrix is filled with collagen fibers. It makes it very, very strong and tough.

And there are several locations for fibrocarbonage. One is called the meniscus of the knee. And the other main one that I want to talk about, although there's a few other examples, the two that I really want to discuss are the meniscus of the knee and what we call the intervertebral disc. Okay, now. If we look at certain joints, many of our joints don't take a real hard pounding unless, you know, you have some special activity that you do.

Like if you were a carpenter and you're hammering all the time, then your wrist and your elbow and your shoulder are going to take a lot more pounding than most people. But most of our joints, if I were to look at the bones of my fingers, the little bones here. fit together like this, okay, and in between right here on the surface there is some hyaline or elastin.

hyaline cartilage, okay? All the movable surfaces of our body are lined with hyaline cartilage. But if I look at a couple of the joints that take a severe pounding, particularly the knee, which takes the most pounding of any joint in the human body, I mean we beat on our knees all day every day as we walk as we run as we play sports so the end of the femur of the knee and the top of the tibia Where these two bones meet?

have a little bit thicker layer of hyaline cartilage here. But hyaline cartilage is not real tough stuff. You know, I've seen this in surgery.

I work for orthopedic surgeons. You can reach in with an instrument, and you can scrape that cartilage off. If you take the end of a chicken bone, if you're eating a chicken leg, you can scratch the cartilage off that you see on the end of the bone, or it's the chewy stuff you get in your mouth.

That's going to be the elastic cartilage. The hyaline cartilage is the stuff stuck on the bone, and you can scratch it off. It's pretty soft stuff. Because our knees take such a tremendous pounding, Mother Nature put a pad of fibrocartilage in here that sits on top of the tibia and between the femur and the tibia, and that is called the meniscus.

Now, I don't know how many of y'all have taken chemistry, but when you're looking in a cylinder and you're trying to measure how many milliliters of something you have, the water hugs the edges. of the glass a little bit through adhesion. So you usually read the bottom of the meniscus.

So meniscus describes a certain shape and that's why they call this that. It's called the meniscus and the knee. And the meniscus itself is a fibrocartilage pad.

So then as we run or jump and land on our knees, the highland cartilage doesn't get beat up. It's got a little cushion in there. We're going to talk more about the meniscus, its shape and function when we do bones and joints in the future. Now, in between our vertebrae, if we were to take the vertebrae out, which we're about to do in lab when we do bones, the body of the vertebrae are stacked on top of each other, and very often our vertebrae have these little bony pieces that stick off. We're going to learn all that when we do bones in lab.

But some of these little pieces will articulate. That's not the best drawing of one, but nonetheless. Now... These little openings are a hole between the vertebrae where nerves can exit. So I'm going to put a big red thing or brownish looking thing here.

That's where a nerve would come out of your spine. In between the discs of the vertebrae, there's a thin layer of hyaline cartilage on all the surfaces where your vertebrae are going to slide across each other. As you twist your body or as you flex and under...

flex, flex and extend, we have highland cartilage there. But because if you jump or if you're carrying something heavy the vertebrae get pushed down on each other, mother nature also put a pad in between the vertebrae. And if we pull that out it's a little disc shape.

That is called the intervertebral disc, the disc of fibrocartilage between the vertebrae. And when someone hurts their back and they've slipped or herniated a disc, it's that that thing that gets damaged. When that gets damaged and the vertebrae compress together, very often it can pinch a nerve and cause things like sciatica or nerve pain and numbness and tingling and other problems.

So we often look at our spine when we have a pinched nerve and nerve issues to see if the intervertebral discs are still healthy in there. If they're not, the discs collapse, I mean the vertebrae collapse onto each other and cause some problems. So I need you to know these are the locations of fibrocartilage.

In both places they act like a padding and a shock absorber. Okay so so we're done with page 33 we're going to move on to page 34 we're going to talk a little bit about bone tissue. I'm not going to spend a lot of time on bone tissue because in my class the way that I do it we're going to have an entire exam dedicated to bone tissue.

bone tissue. So I'm going to do the bare minimum on bone and then we're going to move on and talk about some other things so we can finish up this unit. So when it comes to bone, bone is set up very, very similarly to cartilage. And what we have around bone is we also have this connective tissue covering.

It's dense connective tissue. And this is called the periosteum. The only thing that's different is that it's surrounding bone instead of cartilage. There are some cells that live in the periosteum. And really these cells are like modified fibroblasts.

Those cells were once fibroblasts that have decided they're going to start moving out into the tissue and building bone. When these cells migrate out... They can divide by mitosis and make a whole bunch of themselves and then in between the cells they start spitting out all the tissue that's going to make bone and as they build the bone around them they get trapped in a little space called a lacuna. As long as the cells can move along, they're not trapped in a lacuna and they can divide by mitosis. We call those osteoblasts.

Once they're trapped in a lacuna, they become an osteoblast. osteocyte. They can maintain the bone tissue around themselves, but they cannot go build big swaths of bone, okay?

So bone develops very similarly to cartilage, and the membrane would wrap all the way around the bone tissue in all three dimensions, or all directions, I should say, okay? So I would have a big swath of bone tissue here with osteoblasts and osteocytes, but the matrix of bone is very hard. hard and solid. It's made up of a lot of calcium salts. It's almost similar to cement in that there's this powdery salts that if I mix them with the right chemicals will have a chemical reaction and solidify and become very hard and solid.

It has a membrane like cartilage, but the membrane is called periosteum. It has osteoblasts and osteocytes. Now osteoclasts, we'll talk about later on when we study bone tissue, they're not related to these cells.

They're from your immune system. They're actually modified white blood cells. cells. Now right now I think that's all I want you to know about bone tissue.

Let me make sure, let me double check my notes. And the only reason I'm double checking these things so much is because I'm in the process of rewriting my note set for the next fall. and I've changed some things up so I want to make sure I'm covering the way that it's in the old notes that you guys have.

Yeah that's it. So now for now that's all you need to know about bone tissue. We're going to talk about membranes of the body. So when it comes to the membranes of the body There are four major membranes.

One is called the cutaneous membrane. The cutaneous membrane is also referred to as the skin. Another one is the serous membranes.

The serous membranes we've learned earlier in the semester for lecture test one, the visceral and parietal pleura, the visceral and parietal pericardium, the visceral and parietal peritoneum. And I actually think I'm doing these out of order from my notes, but a third one is the mucous membranes. And the fourth one is what we call synovial membranes.

These are the four major membranes of the body. You should know the location of each one and the function of each one. The cutaneous membrane is our skin. Our skin is our barrier and our boundary to the outside world, for the most part.

And so it provides protection, it controls permeability, it does some secretion and isolation. We're going to talk about the functions of the skin in the next video. But ultimately, it's called the cutaneous membrane. It's your skin.

It covers the external surfaces of the body. So I like to do a picture like this, okay? If I drew a little person here. That's the cutaneous membrane covering all of the external surfaces of the body, our skin, the epidermis and dermis.

Now, I'm going to skip to mucous membranes next, and I'm going to do them in green. Mucous membranes line up. some of the internal cavities of the body but they line those cavities that are exposed to the outside world the ones that have an opening like the oral cavity ah and all of those membranes leading down towards the lung and the digestive tract and actually if I swallowed a piece of string and flossed myself, it would be a mucous membrane all the way through the entire digestive tract. Because whether we like to think about it or not, you could reach into the digestive tract from the other end. The urinary opening called the urethra, and it's an opening to the outside world, and there are instruments.

When they have to dislodge a stone or a blocked kidney, sometimes they can run a wire into the urethra. So those are cavities, the urinary system, and the vagina and the uterus are empty spaces that are open to the outside world. So these lines... internal cavities are lined with mucous membranes they're all moist and snotty or mucusy so we will do the nasal cavity and the oral cavity the respiratory tract and the digestive tract all the way through you, and the urinary and reproductive tracts are lined with mucous membranes.

So these line cavities that are open to the external environment. I abbreviated the word environment. Respiratory cavities and tract, digestive tract, urinary and reproductive tracts are all lined with mucous membranes. The serous membranes, I tend to do those in a different color, but the serous membranes, one of the things that we know about these is they line the closed internal cavities. Those cavities that are closed off to the outside world.

So, for example, there's a serous membrane that surrounds the lungs, and it has two layers. There's a visceral and parietal pleura. pericardial cavity of visceral parietal peritoneum and some of our I'm sorry the visceral parietal pericardium and then some of the digestive system is lined with these membranes called the visceral and parietal Serotonin. So you need to know that they line the sealed internal cavities or the closed internal cavities. Mucus membranes line those cavities that are open to the outside world.

Finally, there's the synovial membranes. Synovial membranes line what we call, well, we'll just say they line the joints of the body. And they really line what we call synovial joints. And they're called synovial joints because of the synovial membrane.

All of the freely moving... movable joints in the body, your knee, your hip, your toes, your ankle, your wrist, your vertebrae are called synovial joints. So if I drew the end of the femur here and the tibia and the ankle and some of these little bones down here in your ankles, all of those joints are sealed off with the membrane that are called synovial membranes.

So synovial membranes line or seal off the joints of the body. And they actually secrete... create a fluid called synovial fluid or synovium.

Well, synovium is the membrane, but the synovial fluid actually lubricates the joint and fills it with a certain amount of this viscous fluid that acts literally like motor oil that lubricates the joint so that everything moves around nice and easy. So all of the movable joints have a synovial membrane that seals the joint off. Part of it's um...

Part of its job is to seal the joint off so that if you do have some little float or a piece of tissue that gets torn off, it can't make it into the joint and then it starts to grind. Like if you got a rock in your shoe, it would create damage. Okay? So those are the four membranes of the body.

the cutaneous membrane which is your skin, the mucous membranes which line the openings that are the cavities that are open to the external environment or external world, the serous membranes which line these sealed internal cavities. and the synovial membranes, which seal off our joints and fill with the fluid that lubricates the joints. By the way, if you damage the cartilage in that joint, your body tries to lubricate it even more and you secrete more synovial fluid and the joint gets swollen. Some people refer to it as water on the knee or removing some fluid from your shoulder when they pulls the fluid off.

It's actually synovial fluid. It's not really water. Anyway, we're going to stop there.

I hope that you have a great day. you had as much fun as I did. I hope you learned something. Please do this stuff until you can't stand it. Do it till you understand it and then do it five more times.

Work through the material over and over and over until you can teach this. You should be able to do an outline of all the tissues and put some bullet points of where do we find each one and what its function is. If you can do that, you're going to do very well on the next exam. Thanks for watching. I hope you had as much fun as I did.

See you next time. Thank you.

Transcript for:Anatomy and Physiology of Connective Tissues

Transcript for:
Anatomy and Physiology of Connective Tissues