all right let's take a look at chapter 8 chapter deals with joints are also known as articulations an articulation is a functional Junction with between bones so this is showing an MRI of the knee so if we go to this that's a good picture to start off with there are two functions in terms of joints one is that they hold the skeleton together and secondly some joints are going to allow the skeleton to have mobility all right so let's take a look at the classification in joints we're gonna start off with fibrous joints so a fibers showing is a type of joint in which two more bonds are joined by fibrous tissue what we see here is there is no joint cavity with these guys so the first or sutures so we see sutures in the skull so a suture is an immovable fibrous joint it's gonna attach bones of the skull as I said it's no movement a lot there next is a syndesmosis this joint in which the bones are united by a ligament or sheet of fibrous tissue so this showing syndesmosis between the ulna and radius here we also find a syndesmosis between the tibia and the fibula next is a gong ptosis a GaN pose is a joint which a cone-shaped process is fastened in a bony sound so here's a cone-shaped process there's the bony socket and we have fibers attaching those there so this is what we see with teeth into the mandible or teeth into the maxilla all right the next type are called cartilaginous joints cartilage is join a type of joint in which two of our bones are joined by cartilage and this produces a slightly movable joint so the first type is called a Sinkin grossest this joint in which the bones are you know by hyaline cartilage and so this is what we see here between the sternum and the ribs here these are the costal cartilage and this allows for movement of the ribcage all right so next these are not Somu moveable here but you know the they upsell plates or another synchondrosis we actually lose our pelvis which is made of three bones that fuse together and we have a synchondrosis before the fusion of those all right next is synthesis so a synthesis is a joint in which the bones are connected by fiber cartilage so the intervertebral discs are actually synthesis all right once again they've provided a little bit of movement but since we have so many vertebrae this you can get some good movement there as well also the pubic symphysis between the pelvises is another one of these synthesis all right 500 partners do lastly our synovial joints a synovial joint is typically what we think of a joint this is a freely movable joint exhibiting a joint cavity so let's take a look at the general structure of a snowgo joint so first we see articular cartilage which we've talked about before this protects the ends of the bones there next we have a joint cavity so we have a cavity there this is so this space is filled with synovial fluid we'll talk about that in a minute it is enclosed by the joint capsule so this is the joint capsule here so that joint capsule the inner layer is synovial membrane the outer layer is made of tenon all right so I'm sorry it's made of ligament not tendon sorry about that the fluid in here just like serous membrane that's Noble so like serous fluid this synovial fluid reduces friction between the bones all right so that's no avail membranes gonna produce that synovial fluid which fills that cavity and so we move our bones we're not having bone against bone it's hyaline cartilage gets high on the carbs but not really a whole lot because we have that synovial fluid and so this really reduces a friction in here so that when we have articular cartilage against articular cards with that synovial fluid in there this is 40 times slicker than ice against ice all right so the next few here are not found in all synovial joints Sonax are reinforcing the ligaments these are ligaments other than those in the joint capsule now unfortunately I don't have pictures of these but like the anterior cruciate ligament the posterior cruciate ligament found in the knee right there there's the anterior cruciate ligament alright so those are reinforcing ligaments the knee also shows the Nisus the sky is plural meniscus is singular and these are pads of fiber cards for shock absorption also what we can see in the knee are these versa so Bursa our fluid-filled sacs synovial fluid that's fills in those there they're lined by synovial membranes they actually aid the movement of tendons and they are shock displacer so spreading the shock over more than one area if you have a bursa is so yeah if you have a bunion a bunion is an enlarged bursa all right let's take a look at types of synovial joints the first are ball in the socket so in a ball and socket basically you have a one bone that it's kind of the ball shaped structure and then you have kind of a cup like structure in the other boat this is found in like the shoulder and the hip all right next is a lip side joint so lip side you have one curvature of a bone and the other one has a complementary shape to that curvature this is what we see between the Atlas that's our first vertebrae in the occipital condyles of the skull next is a plane joint that's where you have two flat bones next to each other all right so we see this between the ankle between carpals between tarsals we also have two between vertebrae next is a hinge joint so in a hinge joint it moves just like the hinge on a door so this is what we see with it elbows knees next is a pivot joint so pivot joint is where moves around access so we see this between the radius and all to us we get this movement we also see between the Atlas and the axis of giving us this movement lastly is a saddle joint so we find this at the base of our thumb there is basically both bones have a shape of a sound and so this gives us a variety of movements which we see down here at the base of that bone alright let's look at a look at types of Sinovel movements alright so the first is the flexion a flexion is a decreasing joint angle so when she brings our arm up that's a flexion there's a joint angle there would you bring that arm back down that's an extension so an extension is an increase in joint ankle so showing a few of these flexions and extensions a hyperextension is the excessive extension of the parts of the joint typically we associate that with damaging that joint somehow next are the two with the foot so one is dorsiflexion is a flexion of the foot upwards towards the body so if you take your foot off the gas it's a dorsiflexion put your foot onto the gas that's a plantar flexion this is a flexion of the foot downwards away from the bumping okay some people just say like if you plant your foot you know that's a plantar flexion all right all right next is abduction and adduction abduction is moving a body part away from the midline so you bring your arm up that's an abduction you bring it back down so up abduction bring it back part back down that's an abduction that's a movement of a body part towards the midline so abduction towards but midline abduction abduction is away from the midline I know it's getting those you think about like if you're abducted you're taken away so that's an abduction you can also do this with the hands so this is an abduction abduction alright next is a rotation alright so rotation is movement apart around an axis like this like this you know this is showing that rotation of the arm there as well next is a circumduction circumduction is a movement part in a wide circle alright so moving your arm like so alright specific rotations for the lower arm here one is pronation there's a rotation of the lower arm where the palm is up sorry where the palm is down is pronation rotation in the arms of the palm is down supination is a rotation of the alarm so the palm is up so that supination pronation alright next deals with a couple with the feet so aversion and inversion e-version is a turning of the foot so the sole faces laterally and inversions turning the foot so the sole face is medially next is elevation depression elevation Israeli body part depression is a lowering of a body part so elevation raising those shoulders depression lowering those shoulders ah so this is showing a protraction and retraction so protraction here is move park forward retraction is a moving part faculties alright so you can also do this show protraction retraction alright next our excursion so lateral excursions are moving the mandible to either the right or left side of the midline so the lateral exertion is moving off to the side medial excursion is returning the mandible to the neutral position so I've gone from this back to the middle okay next opposition right so opposable thumbs alright so this is a moving the font thumb towards the other fingers so that's a opposition and reposition is moving the thumb to the neutral position back to there