JOINTSIntroductionClassification of JointsFunctional ClassificationStructural ClassificationSummary of Joint ClassesFibrous JointsSuture JointSyndesmosisGomphosisCartilaginous JointsSynchondrosesSynchrondrosesSymphysesSynovial JointsStructures of Synovial JointArticular CartilageJoint (synovial) cavityArticular capsuleSynovial FluidReinforcing ligamentsFeatures of Select Synovial JointsBursae and Tendon SheathsBursaeBursae: AnomoliesTendon SheathsRetinaculumFactors Influencing Synovial Joint StabilityArticular SurfacesSlide 30LigamentsSupporting LigamentsMuscle ToneSlide 34Movements Allowed by Synovial JointsGliding MovementsFlexion/ExtensionFlexion/Extension/HyperextensionFlexionExtensionDorsiflexion and Plantar FlexionAb/Adduction/CircumductionRotationSupination and PronationInversion and EversionProtraction and RetractionElevation and DepressionOppositionTypes of Synovial JointsPlane JointPlane JointsHinge JointsSlide 53Pivot JointsSlide 55Condyloid JointsSlide 57Saddle JointsSlide 59Ball and Socket JointBall and Socket JointsPowerPoint PresentationSlide 63Slide 64Shoulder (Glenohumeral) JointSlide 66Slide 67Slide 68Slide 69Shoulder JointHip JointSlide 72Slide 73Elbow JointKnee JointSlide 76Slide 77Analysis of Knee MovementsSlide 79Analysis of Knee InjuriesOrthopedic Injuries to JointsDegenerative Conditions of JointsSlide 83End of ChapterJOINTSChapter 9Introduction Joints or articulations are sites where two or more bones meetJoints have two fundamental functions:–provide for skeletal mobility–hold the skeleton togetherWeakest parts of the skeleton, yet have a remarkable ability to resist the forces that tear them apartClassification of JointsStructural classification–focuses on the material binding the bones together and whether or not there is a joint cavity (fibrous, cartilaginous, synovial)Functional classification–based on the amount of movement allowed at the joint (synarthroses, amphiarthoroses, diarthroses)Functional ClassificationSynarthroses–Immovable jointsAmphiarthroses–Slightly movable jointsDiarthroses–Freely movable jointsStructural ClassificationFibrous–Joined by fibrous tissueCartilaginous–Joined by cartilageSynovial–The bones are joined and surrounded by a joint cavityNote:–Structural classification is the system used in your textSummary of Joint ClassesFibrous joints–Suture–Syndesmoses–GomphosesCartilaginous joints–Synchondroses–SymphysesSynovial–Gliding, hinge, pivot, condyloid, saddle, and ball and socketFibrous JointsIn fibrous joints the bones are joined by fibrous tissue; no joint is present. The three types of fibrous joints are. . . Sutures–Dense fibrous connective tissueSyndesmosis–A cord or band of connective tissueGomphosis–Peg-in-socket arrangement surrounded by fibrous tissue or peridontal ligamentSuture JointOccurs only between bones of the skullWavy articulating bone edges interlockJunction is filled by connective tissueRigid splices bind bones of the skull together tightlySyndesmosisLonger fibrous tissue occurs as a sheet or membraneLonger fibrous tissue permits the joint to “give” or flexTrue movement is not possibleGomphosisFibrous tissue holds teeth in their socketsTeeth embedded in sockets of boneAnchored by fibers of periodontal ligamentCartilaginous JointsIn cartilaginous joints, the articulating bones are united by cartilage, there is no joint cavitySynchondroses–Hyaline cartilage unites the bonesSymphyses–Fibrocartilage unites the bonesSynchondrosesHyaline cartilage unites the bonesEpiphyseal plates in growing childrenProvide for bone growthWhen growth ends all synchondroses become immovableEpipysealPlateSynchrondrosesSternocostal joint between the manubrium and rib 1 is a immovable hyaline cartilage jointSymphysesBone surfaces are covered with articular hyaline cartilage which is fused to a pad of fibrocartilageFibrocartilage is resilient and acts as a shock absorber and permits limited movementPubic SymphysisSynovial JointsIn synovial joints articulating bones are located within a fluid containing joint cavitySynovial joints permit substantial range of motionAll synovial joints have similar featuresStructures of Synovial Joint Articular cartilage–Hyaline cartilage on opposing bone surfacesJoint (synovial) cavity–Space filled with fluidArticular capsule–Capsule to confine fluidSynovial fluid–Fluid to lubricate jointsReinforcing ligaments–Maintain joint alignmentArticular Cartilage Hyaline cartilage covers the bone surfacesCartilage absorbs the compression placed on the jointCartilage keeps the bone ends from being crushedJoint (synovial) cavityJoint spaces are unique to synovial jointsJoint spaces are filled with synovial fluidArticular capsuleThe joint cavity is enclosed by a double layered articular capsuleThe external layer is a tough flexible fibrous capsuleThe inner synovial membraneSynovial FluidSynovial fluid fills the entire jointSlippery fluid lubricates jointWeeping lubrication squeezes synovial fluid into and out of the cartilage nourishing the cellsSynovialSynovialFluidFluidReinforcing ligamentsLigaments reinforce jointsIntrinsic ligaments reinforce capsuleExtracapsular are outside capsuleIntracapsular are inside capsuleExtracapsularExtracapsularLigamentLigamentIntracapsularLigamentFeatures of Select Synovial JointsCertain synovial joints have additional structural features–Fatty pads cushion the knee and hip joints–Fibrocartilage articular discs separates articular surfaces (menisci)–Articular discs improve the fit between the articulating surfaces (knee, jaw)Bursae and Tendon SheathsBursae and tendon sheaths are closely associated with synovial jointsEssentially sacs of lubricantFunction as “ball bearings” to reduce friction between adjacent structuresReduces friction during joint activityBursaeBursae are flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluidCommon at sites where ligaments, skin, muscles or tendons rub against a boneBursae: AnomoliesA bunion is an enlarged bursae at the base of the big toeFalse bursae may develop at any site where there is excessive motionFunction similar to a true bursaeTendon SheathsAn elongated bursa that wraps completely around a tendon subjected to