Flo Hyman had at all times been a tall lady. I imply… actually tall. By her twelfth birthday, she was already six ft, and by 17 she’d topped out at simply over 6’5’’. Initially self-conscious about her stature, she realized to make use of it to her benefit when she began enjoying volleyball. She attended the College of Houston as the varsity’s first feminine scholarship athlete, and on the age of 21, she was competing in World Championships. 9 years later she made it to the 1984 Olympics and helped her crew win the silver medal. After the Olympics, Hyman moved to Japan the place she gained fame enjoying skilled volleyball. However all of that led to 1986 when out of nowhere, she collapsed and died throughout a sport. She was 31 years previous. Hyman’s preliminary explanation for loss of life was regarded as a coronary heart assault, however an post-mortem revealed that she died from a tear in her aorta, brought on by an undiagnosed situation referred to as Marfan Syndrome. Marfan Syndrome is a genetic dysfunction of the connective tissue. Folks affected by it have a defect of their connective tissue that considerably weakens it over time. And also you’ve acquired connective tissue just about in all places in your physique, so it could trigger large issues. Outwardly, these with Marfan’s are inclined to to be particularly tall and skinny, like Flo Hyman, with unfastened, versatile joints and noticeably longer limbs and fingers. These lengthy fingers and flexible joints have truly helped some athletes and musicians do issues that the remainder of us can’t — well-known blues guitarist Robert Johnson, piano virtuoso Sergei Rachmaninov, and Italian violinist Niccolo Paganini are all believed to have had Marfan Syndrome. However these skills come at an amazing price — as folks with Marfan’s become old, their weakening tissue may cause critical issues within the joints, eyes, lungs, and coronary heart. The truth that a single genetic mutation can have an effect on your bones, cartilage, tendons, blood vessel partitions, and extra, exhibits that every one of these buildings are intently associated, irrespective of how totally different they could appear. We’ve lined the fundamental properties of nervous, muscle, and epithelial tissue, however we haven’t gotten to essentially the most plentiful and various of the 4 tissue sorts — our connective tissue. That is the stuff that retains you trying younger, makes up your skeleton, and delivers oxygen and vitamins all through your physique. It’s what holds you collectively, in additional methods than one. And if one thing goes unsuitable with it, you’re in for some havoc. And meaning we’re gonna be talkin’ about Jello right now. Uh…we’ll get to that in a minute. The springiness right here? That’s connective tissue. So is the construction in right here, and the stuff inside right here, and the tendons coming out right here Connective tissue is just about in all places in your physique, though how a lot of it exhibits up the place, varies from organ to organ. For example, your pores and skin is generally connective tissue, whereas your mind has little or no, because it’s nearly all nervous tissue. You’ve acquired 4 fundamental lessons of connective tissue — correct, or the type you’d discover in your ligaments and supporting your pores and skin, together with cartilage, bone, and blood. Whaaaa? Sounds a little bit bizarre, however your bones and your blood are simply kinds of connective tissue! So, regardless of the title, your connective tissues do far more than simply join your muscle tissues to your bones. Your fats — which is a sort of correct connective tissue — offers insulation and gas storage — whether or not you prefer it or not — but it surely additionally serves structural functions, like holding your kidneys in place, and holding your eyeballs from coming out of your cranium. Your bones, tendons, and cartilage bind, help, and shield your organs and offer you a skeleton so that you could transfer with a goal, as an alternative of blobbing round like an amoeba. And your blood transports your hormones, vitamins, and different materials throughout your physique. There’s no different substance in you that may boast this type of variety. But when they’re so totally different, how do we all know that something is a connective tissue? Properly, all connective tissues have three components in widespread that set them aside from different tissue sorts. First, they share a typical origin: All of them develop from mesenchyme, a unfastened and fluid sort of embryonic tissue. Not like the cells that go on to kind, say, your epithelium, that are mounted and neatly organized in sheets, mesenchymal cells may be located any-which-way, and might transfer from place to position. Connective tissues even have totally different levels of vascularity, or blood movement. Most cartilage is avascular, for instance, which means it has no blood vessels; whereas different kinds of connective tissue, just like the dense irregular tissue in your pores and skin, is brimming with blood vessels. Lastly — and as unusual as it might sound — all connective tissues are largely composed of nonliving materials, known as the extracellular matrix. Whereas different tissue sorts are primarily made from dwelling cells packed collectively, the inert matrix between connective-tissue cells is definitely extra essential than what’s contained in the cells. Mainly, your connective tissue, if you see it up shut, appears to be like and acts lots like this. Yeah. Probably the most plentiful and various tissue in your physique, that makes all your actions and features potential? Seems it’s not that totally different from the dessert that Aunt Frances brings to each vacation social gathering. The jello that offers this confection its construction is like that extracellular matrix in your connective tissue. The precise cells are simply intermittent little goodies floating round contained in the matrix — just like the little marshmallows. And though it might not appear to be it on this specific edible mannequin, the extracellular matrix is generally made from two parts. The primary half is the bottom substance — a watery, rubbery, unstructured materials that fills within the areas between cells, and — just like the gelatin on this dessert — protects the fragile, scrumptious cells from their environment. The bottom substance is versatile, as a result of it’s largely made of massive ol’ starch and protein molecules combined with water. The anchors of this framework are proteins known as proteoglycans. And from every one sprouts heaps and plenty of lengthy, starchy strands known as glycosaminoglycans, or GAGs, radiating out from these proteins like brush bristles. These molecules then clump collectively to kind large tangles that lure water, and in the event you’ve ever made glue out of flour, you understand that starch, protein and water could make a powerful and gooey glue. However operating all through the bottom substance is one other essential element: fibers, which present help and construction to the in any other case shapeless floor substance. And right here, too, are numerous differing types. Collagen is by far the strongest and most plentiful sort of fiber. Powerful and versatile, it’s primarily a strand of protein, and stress exams present that it’s truly stronger than a metal fiber of the identical dimension. It’s a part of what makes your pores and skin look younger and plump, which is why generally we inject it into our faces. As well as, you’ve additionally acquired elastic fibers — that are longer and thinner, and kind a branching framework throughout the matrix. They’re made out of the protein elastin which permits them to stretch and recoil like rubber bands; they’re present in locations like your pores and skin, lungs, and blood vessel partitions. Lastly, there are reticular fibers — brief, finer collagen fibers with an additional coating of glycoprotein. These fibers kind delicate, sponge-like networks that cradle and help your organs like fuzzy nets. So, there’s floor substance and fibers in all connective tissue, however let’s not overlook concerning the cells themselves. With a tissue as various as this, naturally there are every kind of connective tissue cells, every with its distinctive and important job — from constructing bone to storing vitality to holding you from bleeding to loss of life each time you get a paper lower. However every of those signature cell sorts manifests itself in two totally different phases: immature and mature. You may acknowledge the immature cells by the suffix all of them share of their names: -blast. “Blast” sounds kinda damaging, however actually it means “forming” — these are the stem cells which are nonetheless within the strategy of dividing to copy themselves. However every type of blast cell has a specialised operate: specifically, to secrete the bottom substances and fiber that kind its distinctive matrix. So chondroblasts, for instance, are the blast cells of cartilage. Once they construct their matrix round them, they’re making the spongy tissue that types your nostril and ears and cushions your joints. Likewise, osteoblasts are the blast cells of bone tissue, and the matrix they lay down is the nexus of calcium carbonate that types your bone. As soon as they’re achieved forming their matrix, these blast cells transition right into a much less lively, mature section. At that time, they commerce in -blast for the suffix -cyte. So an osteoblast in your bone turns into an osteocyte — ditto for chondroblasts changing into chondrocytes. These cyte cells preserve the well being of the matrix constructed by the blasts, however they’ll generally revert again to their blast state if they should restore or generate a brand new matrix. So, the matrices that these cells create are just about what construct you — they assemble your bone and your cartilage and your tendons and all the things that holds the remainder collectively. Not unhealthy for a bunch of marshmallows floating in jello. BUT! There’s one other class of connective tissue cells which are answerable for an equally essential function. And that’s: defending you, from just about all the things. These are cells that perform lots of your physique’s immune features. I’m speaking about macrophages, the large, hungry guard cells that patrol your connective tissues and eat micro organism, international supplies, and even your individual lifeless cells. And your white blood cells, or leukocytes that scour your circulatory system preventing off an infection, they’re connective tissue cells, too. You may see how pervasive and essential connective tissue is in your physique. So a situation that impacts this tissue, like Marfan Syndrome, can actually wreak havoc. Top-of-the-line methods of understanding your physique’s buildings, in spite of everything, is finding out what occurs when one thing goes unsuitable with them. Within the case of your connective tissue, Marfan Syndrome impacts these fibers we talked about, that lend construction and help to the extracellular matrix. Most frequently, it targets the elastic fibers, inflicting weak spot within the matrix that’s the root of lots of the situation’s most critical signs. About 90 % of the folks with the illness expertise issues with the center and the aorta — the largest and most essential artery within the physique. When the elastic fibers round the aorta weaken, they’ll’t present the artery with sufficient help. So, over time, the aorta begins to enlarge — a lot in order that it could rupture. That is in all probability what occurred to Flo Hyman. She was bodily exerting herself, and her artery — with out the help of its connective tissue — couldn’t take the stress, and it tore. There’s SO MUCH occurring together with your connective tissue — so many variations inside their bizarre variety — that we’re going to spend one final lesson on them subsequent week, exploring the subtypes that come collectively to make you potential. However you probably did be taught lots right now! You realized that there are 4 kinds of connective tissue — correct, cartilage, bone, and blood — and that all of them develop from mesenchyme, have totally different levels of blood movement, and are largely made from extracellular matrix filled with floor substance and fibers. We touched on totally different blasts, and cyte, and immune cell sorts, and mentioned how Marfan Syndrome can have an effect on connective tissue. Thanks for watching, particularly to our Subbable subscribers, who make Crash Course potential for themselves and likewise for the remainder of the world. To seek out out how one can turn into a supporter, simply go to subbable.com. This episode was written by Kathleen Yale, edited by Blake de Pastino, and our marketing consultant, is Dr. Brandon Jackson. Our director and editor is Nicholas Jenkins, the script supervisor and sound designer is Michael Aranda, and the graphics crew is Thought Café.