cartilaginous joints are joints that are made out of cartilage they lack a synovial cavity and again structurally they're held together by cartilage there are two types of cartilaginous joints synchondrosis remember that anytime you see the word Kandra it's basically telling us cartilage sin means together so this joint is held together by cartilage specifically hyaline cartilage and then syntheses these are joints that are held together by fiber cartilage now synchondrosis are going to be found in two major areas of your body if you remember synchondrosis i have it in red so red means what about the functional aspect of the joints if you said no movement you're correct synchondrosis are going to be joints that are sin arthritic the first spot that we find synchondrosis is going to be in your epiphyseal plates also known as the growth plates these growth plates are composed of Highland cartilage but we don't have a joint there our entire life instead what will happen is when the epiphyseal plates close and become the epiphyseal line this original cartilaginous joint will just become bone and at this point it's basically two separate areas of bone fused together and we call this a sin as ptosis so as soon as these epiphyseal plates are gone and become a line it is now known as a sin osto --ss again when it's two bones fused together there is not going to be any movement either so it would still be considered sin arthritic now the next synchondrosis is gonna be found where your costal cartilage is located but it's very specific and where it is so between the sternum and the ribs we're gonna have costal cartilage we have 12 pairs of ribs and we can see that all of this that's brown in this picture is costal cartilage but not all of this is considered synchondrosis the only part that's considered synchondrosis is the first pair this is the only place that will consider this costal cartilage to be a synchondrosis so when we look at it it's the first costal cartilage between the rib and the sternum no other pairs of costal cartilage are considered SantaCon Josie's just this again there's gonna be no movement between the first pair of ribs and the sternum just the first this again is Highland cartilage so just to recap synchondrosis are going to be made out of hyaline cartilage - examples of the epiphyseal plate and the first pair of costal cartilage where the ribs and sternum connect next cartilaginous joint is the syntheses these are going made out of fibrocartilage if you remember fiber cartilage is the only cartilage without a perichondrium so it doesn't have that dense irregular tissue surrounding it which helps promote growth as well as we pear now there are two syntheses in the body they're the intervertebral discs so we have quite a few of those between every single vertebrae and there's the pubic symphysis which is found between the two pubic bones both of these are composed of fibrocartilage and since it's in yellow syntheses are going to allow what type of movement if you said a little bit exactly right and we term that antfee arthritic okay so if you think about it these fibrocartilage discs both between their inner both between the vertebra and the pubic bones are gonna allow a little bit of movement because you're not that stiff but they're great at absorbing shock and if you think about movement in our body we put a lot of shock on our back on our hips and on our knees all places that do have fibrocartilage having that strong collagen within the fiber cartilage helps to absorb the shock and distribute the weight throughout the structure so one of the things that happens is during pregnancy your body starts producing higher amounts of a hormone called relaxin and what relaxin does is it basically reshapes the pubic symphysis making it a little bit softer to actually widen your hip girdle so your pelvic brim what that does is it helps with the birth canal making it a little bit bigger for an easier natural childbirth now with intervertebral discs something that you often hear about as a slip disc which is also known as a herniated disc and those fiber cartilage discs are made out of two parts the outer part which is the annulus which is going to be very fibrous it's tons and tons of collagen collagen fibers within the fiber cartilage and then the inner portion which is the nucleus which is more about the chondroitin sulfate so more ground substance with not as much collagen when you have a slip disc or herniated disc basically the nucleus starts to break through the annulus that outer fiber cartilage and when that happens it starts to put pressure on spinal nerves and you've either become numb in certain areas so you get severe pain most often herniated discs are gonna occur in the lumbar region so the lower region of the back so in this picture right here this is showing your lower three lumbar out of the five and this is the most common place that you have slipped a herniated disc so just to recap we have our synchondrosis which are composed of hyaline cartilage we find them in the epiphyseal plates as well as that first pair of costal cartilage where the ribs connect with the sternum both are going to be sin arthritic unmovable then we have the syntheses which are going to be found in your intervertebral discs as well as the pubic symphysis between the two pubic bones they're both going to be composed of fibrocartilage and they are going to be an theoretic slightly movable