150 ch8 joints

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  • Anatomy and Physiology, Seventh EditionRod R. Seeley Idaho State UniversityTrent D. Stephens Idaho State UniversityPhilip Tate Phoenix CollegeCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.*See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes.Chapter 08Lecture Outline*

  • Articulations or Joints

    Articulation or JointPlace where two bones (or bone and cartilage) come togetherArthrology = study of the jointsKinesiology = study of musculoskeletalFunctions of jointsGive the skeleton mobilityHold the skeleton togetherStructure correlated with movement

  • Classification of JointsStructural classes: based on type of connective tissue type that binds bones and whether or not a joint cavity is presentFibrousCartilaginousSynovialFunctional classes: based on degree of motion Synarthrosis: non-movableAmphiarthrosis: slightly movableDiarthrosis: freely movable

  • Fibrous JointsCharacteristicsUnited by fibrous connective tissueHave no joint cavityMove little or noneTypes: SuturesSyndesmosesGomphoses

  • Fibrous Joints: Sutures Types of suturesSerrated: Opposing bones interdigitate (Sagittal suture)Lap: Overlapping beveled edges (Squamosal suture) Plane: Straight, non-overlapping edges (Intermaxillary suture) Periosteum of one bone is continuous with the periosteum of the other.In adults may ossify completely: synostosis. Fontanels: membranous areas in the suture between bones. Allow change in shape of head during birth and rapid growth of the brain after birth.

  • Types of Sutures

  • Fibrous Joints: SyndesmosesTwo bones joined by ligamentInterosseous membraneMost moveable of fibrous jointsExamples: radioulnar joint and tibiofibular joints

  • Fibrous Joints: GomphosesSpecialized jointsPegs that fit into socketsPeriodontal ligaments: hold teeth in placeInflammationsGingivitis leads toPeriodontal disease

  • Cartilaginous JointsBones are joined by cartilageLack a joint cavityTypesSynchondroses: bound by hyaline cartilageSymphyses: bound by fibrocartilage

  • Cartilaginous Joints: SynchondrosesJoined by hyaline cartilageLittle or no movementSome are temporary and are replaced by synostosesSome are permanentSome like costochondral joints develop into synovial jointsExamples: Epiphyseal plates, 1st sternocostal

  • Cartilaginous Joints: SymphysesFibrocartilage uniting two bonesSlightly movableExamples: symphysis pubis, between the manubrium and the body of the sternum, intervertebral disks.

  • Synovial JointsContain synovial fluid in a joint cavity called the synovial cavityAllow considerable movement (diarthroses)Most joints that unite bones of appendicular skeleton reflecting greater mobility of appendicular skeleton compared to axial

  • Structure of Synovial JointsArticular cartilage: hyaline; provides smooth surface on epiphysisJoint cavity: synovial; encloses articular surfacesArticular Capsule encloses joint cavityFibrous capsule: dense irregular connective tissuecontinuous with periosteum. Portions may thicken to form ligaments.Synovial membrane and fluid:Thin, delicate membrane lines inside of joint capsule. Synovial fluid: complex mixture of polysaccharides, proteins, fat and cells. Hyaluronic acid- slippery. No blood vessels or nerves in articular cartilages; nutrients derived from nearby blood vessels and synovial fluidNerves in capsule help brain know position of joints (proprioception)

  • Accessory StructuresBursaePockets of synovial membrane and fluid that extend from the joint. Found in areas of frictionBursitisLigaments and tendons: stabilizationArticular discs: temperomandibular, sternoclavicular, acromioclavicularMenisci: fibrocartilaginous pads in the knee.Tendon sheaths: synovial sacs that surround tendons as they pass near or over bone

  • Synovial Joints: Friction-Reducing StructuresFigure 8.4

  • Types of MovementGliding: in plane joints; slight movementAngularFlexion and ExtensionHyperextensionPlantar and DorsiflexionAbduction and AdductionCircularRotationPronation and SupinationCircumduction

  • Flexion and ExtensionFlexion: movement of a body part anterior to the coronal planeExtension: movement of a body part posterior to the coronal plane

  • Dorsiflexion and Plantar FlexionExceptions to definitionPlantar flexion: standing on the toesDorsiflexion: foot lifted toward the shin

  • Abduction and AdductionAbduction: movement away from the midlineAdduction: movement toward the midline

  • Circular Movements: Rotation, Pronation and SupinationRotation: turning of a structure on its long axisExamples: rotation of the head, humerus, entire bodyMedial and lateral rotation; example, the rotation of the armPronation/Supination: refer to unique rotation of the forearmPronation: palm faces posteriorlySupination: palm faces anteriorly

  • Circular Movement: CircumductionCombination of flexion, extension, abduction, adductionAppendage describes a cone

  • Special MovementsUnique to only one or two jointsTypesElevation and DepressionProtraction and RetractionExcursionOpposition and RepositionInversion and Eversion

  • Elevation and DepressionElevation: moves a structure superiorDepression: moves a structure inferiorExamples: shrugging the shoulders, opening and closing the mouth

  • Protraction and RetractionProtraction: gliding motion anteriorlyRetraction: moves structure back to anatomic position or even further posteriorlyExamples: scapulae and mandibles

  • ExcursionLateral: moving mandible to the right or left of midlineMedial: return the mandible to the midline

  • Opposition and RepositionOpposition: movement of thumb and little finger toward each otherReposition: return to anatomical position

  • Inversion and EversionInversion: turning the ankle so the plantar surface of foot faces mediallyEversion: turning the ankle so the plantar surface of foot faces laterally

  • Movements at Synovial jointsMonoaxial: occurring around one axisBiaxial: occurring around two axes at right angles to each otherMultiaxial: occurring around several axesSee Table 8.2 in text

  • Types of Synovial Joints:Plane JointsPlane or gliding jointsMonaxial. One flat bone surface glides or slips over another similar surfaceSometimes considered an amphiarthrosisExamples: intervertebral, intercarpal, intertarsal acromioclavicular, carpometacarpal, tarsometatarsal,

  • Hinge and Pivot JointsHinge jointsMonaxialConvex cylinder in one bone; corresponding concavity in the otherExample: elbow, ankle, interphalangealPivot jointsMonaxial. Rotation around a single axis.Cylindrical bony process rotating within a circle of bone and ligamentExample: articulation between dens of axis and atlas (atlantoaxial), proximal radioulnar

  • Saddle joints Each articular surface is shaped like a saddle; Trapeziometacarpal joint at base of the thumb

    Types of Synovial Joints:

  • Ball-and-Socket and Ellipsoid JointsBall-and-socketSmooth heispherical head fits within a cuplike depressionMultiaxialExamples: shoulder and hip jointsCondyloid (ellipsoid) jointOval convex surface on one bone fits into a similarly shaped depression on the nextAtlantooccipital joint (C1-C2)Metacarpophalangeal joints

  • Shoulder (Glenohumeral) JointMost freely moveable joint in bodyShallowness and loosenessStability is reducedDeepened by glenoid labrum, a rim of cartilage built up around glenoid cavitySupported by rotator cuff musculaturetendons fuse to joint capsule Stabilize and strengthen itsupraspinatus, infraspinatus, teres minor and subscapularis,Bursae: subacromial and subscapularTendon of biceps brachii passes through the joint capsuleFlexion/extension, abduction/adduction, rotation, circumduction

  • Tendons of Rotator Cuff Muscles

  • The Knee JointMost complex diarthrosis patellofemoral = gliding jointtibiofemoral = gliding with slight rotation and gliding possible in flexed positionJoint capsule anteriorly consists of patella and extensions of quadriceps femoris tendonCapsule strengthened by extracapsular and intracapsular ligaments

  • Knee, cont.Cruciate ligaments: extend between intercondylar eminence of tibia and fossa of the femurAnterior cruciate ligament (ACL). Prevents anterior displacement of tibiaPosterior cruciate ligament (PCL). Prevents posterior displacement of tibiaCollateral and popliteal ligaments: along with tendons of thigh muscles strengthen the jointBursae: may result in slow accumulation of fluid in the joint (water on the knee)

  • Knee Joint Anterior and Posterior ViewsAnterior and lateral cruciate ligaments limit anterior and posterior sliding movementsMedial and lateral collateral ligaments prevent rotation of extended knee

  • Knee Joint Superior ViewMedial and lateral meniscus absorb shock and shape joint

  • Knee Injuries and DisordersFootball injuries: often tear the tibial collateral ligament, the anterior cruciate ligament, and damage the medial meniscus BursitisChondromalacia: softening of cartilage due to abnormal movement of the patella or to accumulation of fluid in fat pad posterior to patellaHemarthrosis: acute accumulation of blood in joint

  • Effects of Aging on JointsTissue repair slows; rate of new blood vessel development decreasesArticular cartilages wear down and matrix becomes more rigidProduction of synovial fluid declinesLigaments and tendons become shorter and less flexible: decrease in range of motion (ROM)Muscles around joints weakenA decrease in activity causes less flexibility and decreased ROM

  • SprainsThe ligaments reinforcing a joint are stretche