Chapter 8
Chapter 8
Classifying JointsFunctions
Flexibility for movement Hold bones together
Structural Classification (binding tissue and cavity)Fibrous CartilaginousSynovial
Functional Classification (amount of movement)Synarthroses – immovable; axial skeletonAmphiarthroses - slightly movable; axial skeletonDiathroses - freely moveable; limbs
Organizing JointsFibrous Joints Cartilaginous
JointsSynovial Joints
Binding material
Joined by fibrous tissue
Joined by articular (hyaline) cartilage
Separated by synovial fluid cavity
Cavity Present No No Yes
Functional Type
Synarthroses Amphiarthroses Diarthroses
Examples SuturesSyndesmosesGomphoses
SynchondrosesSymphyses
Joints of limbs
Fibrous JointsSutures
Only b/w skull bonesBind, but allow growthComplete as an adult
(synostoses)Syndemoses
Longer than suturesLength determines mov’t*Interosseous membrane and
tibia-fibula distal endsGomphoses
Tooth in alveolar socketPeriodontal ligament
Cartilaginous Joints
SynchondrosesTemporary, become
synostosesEpiphyseal plates and
coastal cartilageSymphyses
Cartilage fused to fibrocartilage pad/plate
Strength with flexibilityIntervetevbral discs and
pubic symphysis
Synovial JointsArticular cartilageJoint (synovial) cavityArticular capsule
Fibrous capsule (ext-) DICTSynovial membrane (int-) LCT
Synovial fluidViscous, but thins with mov’t
Reinforcing ligamentsDouble jointed = looser/stretchier ligmanents and
capsuleRich blood and nerve innervationFatty pads for cushioning (hip and knee)Menisci divide cavity and improve fit (knee and jaw)
Synovial JointsPreventing friction
Bursae are flattend fibrous synovial sacs
Tendon sheaths are elongated bursa wrapped around a tendon
StabilityArticular surface shape
Determine mov’t & some stabilityLigaments
Prevent excessive/undesirable mov’t
Inadequate than stay stretched (taffy) = snapping
Muscle tone Tendons stay taut so reactive
Joint Articular ShapesPlane - articular surface is flat, nonaxial
Intercarpal and –tarsals; slip 1 or 2 waysHinge – cylindrical projection to a trough
Elbow and interphalengeal; 1 plane of mov’tPivot – rounded end into ring or “sleeve”
C1 & C2 or radius & ulna; 1 plane of mov’tCondyloid - oval surface into a depression
Metacarpophalangeal (knucles); 2 planes of mov’t
Saddle – concave and convex surfaceCarpometacarpal thumb joint; 2 planes of mov’t
Ball and socket – spherical end with a cup-like socketShoulder or hip joint; 3 planes mov’t
Synovial MovementsGliding
Slips surfaces across one another
Flexion/extension Reduces angle of joint/
increases angle
Abduction/adduction Away from center/ toward
midline
Pronation/supination Face or palm down/ face or
palm up
Rotation/circumductionTurning on an axis/ making
small circles
Inversion/eversionTurn sole medially/ turn sole
laterally
Dorsiflexion/plantar flextionFlex/ point
Protraction/retraction Jaw out/jaw in
Elevation/depressionLift superiorly/move
inferiorly
Knee JointSingle cavity w/ 3 jointsCapsule partially enclosesStrong vertical force, weak lateralPatellar ligament (knee-jerk)
Prevent hyperextensionFibular and tibial collateral ligaments
Prevent lateral and medial rotation w/ extensionAnterior and posterior cruciate ligaments (tibial
attach)Prevent forward sliding of tibia; back displacement of
tibia or forward femurPosteriorly, medially, up; anteriorly, laterally, up
Lateral and medial meniscus
anteriorcruciateligament
Temporomandibular Joint (TMJ)Mandibular condyle is egg-shapedTemporal bone is knob forward, concave fossaSide-to-side is lateral exclusion, unique to
mammalsShallow socket = easy dislocation
Reset: thumbs in molars, push inferior and posteriorPain from muscles tension
Clinical TermsSprain: stretching/tearing of a ligamentDislocation (luxation): bones forced out of positionBursitis: inflammation on bursa; blow or frictionArthritis: synovial membrane thickens, production
decreaseOsteoarthritis – degenerative; tissue thickens & bone spurs
formedRheumatoid arthritis - autoimmuneGouty arthritis – uric acid accumulation in soft tissue joints
Synovitis: inflammation of synovial membraneTendinitis: inflammation of tendon sheaths, overuse;