Transcript Joints
Chapter 8 Classifying Joints Functions Flexibility for movement Hold bones together Structural Classification (binding tissue and cavity) Fibrous Cartilaginous Synovial Functional Classification (amount of movement) Synarthroses – immovable; axial skeleton Amphiarthroses - slightly movable; axial skeleton Diathroses - freely moveable; limbs Organizing Joints Fibrous Joints Cartilaginous Joints Synovial 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 Sutures Syndesmoses Gomphoses Synchondroses Symphyses Joints of limbs Fibrous Joints Sutures Only b/w skull bones Bind, but allow growth Complete as an adult (synostoses) Syndemoses Longer than sutures Length determines mov’t* Interosseous membrane and tibiafibula distal ends Gomphoses Tooth in alveolar socket Periodontal ligament Cartilaginous Joints Synchondroses Temporary, become synostoses Epiphyseal plates and coastal cartilage Symphyses Cartilage fused to fibrocartilage pad/plate Strength with flexibility Intervetevbral discs and pubic symphysis Synovial Joints Articular cartilage Joint (synovial) cavity Articular capsule Fibrous capsule (ext-) DICT Synovial membrane (int-) LCT Synovial fluid Viscous, but thins with mov’t Reinforcing ligaments Double jointed = looser/stretchier ligmanents and capsule Rich blood and nerve innervation Fatty pads for cushioning (hip and knee) Menisci divide cavity and improve fit (knee and jaw) Synovial Joints Preventing friction Bursae are flattend fibrous synovial sacs Tendon sheaths are elongated bursa wrapped around a tendon Stability Articular surface shape Determine mov’t & some stability Ligaments Prevent excessive/undesirable mov’t Inadequate than stay stretched (taffy) = snapping Muscle tone Tendons stay taut so reactive Joint Articular Shapes Plane - articular surface is flat, nonaxial Intercarpal and –tarsals; slip 1 or 2 ways Hinge – cylindrical projection to a trough Elbow and interphalengeal; 1 plane of mov’t Pivot – rounded end into ring or “sleeve” C1 & C2 or radius & ulna; 1 plane of mov’t Condyloid - oval surface into a depression Metacarpophalangeal (knucles); 2 planes of mov’t Saddle – concave and convex surface Carpometacarpal thumb joint; 2 planes of mov’t Ball and socket – spherical end with a cup- like socket Shoulder or hip joint; 3 planes mov’t Synovial Movements Gliding 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/circumduction Turning on an axis/ making small circles Inversion/eversion Turn sole medially/ turn sole laterally Dorsiflexion/plantar flextion Flex/ point Protraction/retraction Jaw out/jaw in Elevation/depression Lift superiorly/move inferiorly Knee Joint Single cavity w/ 3 joints Capsule partially encloses Strong vertical force, weak lateral Patellar ligament (knee-jerk) Prevent hyperextension anterior cruciate ligament Fibular and tibial collateral ligaments Prevent lateral and medial rotation w/ extension Anterior and posterior cruciate ligaments (tibial attach) Prevent forward sliding of tibia; back displacement of tibia or forward femur Posteriorly, medially, up; anteriorly, laterally, up Lateral and medial meniscus Temporomandibular Joint (TMJ) Mandibular condyle is egg-shaped Temporal bone is knob forward, concave fossa Side-to-side is lateral exclusion, unique to mammals Shallow socket = easy dislocation Reset: thumbs in molars, push inferior and posterior Pain from muscles tension Clinical Terms Sprain: stretching/tearing of a ligament Dislocation (luxation): bones forced out of position Bursitis: inflammation on bursa; blow or friction Arthritis: synovial membrane thickens, production decrease Osteoarthritis – degenerative; tissue thickens & bone spurs formed Rheumatoid arthritis - autoimmune Gouty arthritis – uric acid accumulation in soft tissue joints Synovitis: inflammation of synovial membrane Tendinitis: inflammation of tendon sheaths, overuse;