Chapter 8 Classification of Joints Joints of the Skeletal System • Fibrous Joints • dense connective tissues connect bones • Articulations • between bones in close contact • synarthrotic • Functional junctions between bones • immovable • Bind parts of skeletal system together • amphiarthrotic • Make bone growth possible • slightly movable • Cartilaginous Joints • Permit parts of the skeleton to change shape during • diarthrotic • hyaline cartilage or childbirth • freely movable fibrocartilage connect bones • Enable body to move in response to skeletal muscle contraction • Synovial Joints • most complex • allow free movement 1 2 Fibrous Joints Fibrous Joints 3 Types Suture • Held together by • Syndesmosis • between flat bones dense connective • Suture • synarthrotic tissue • Gomphosis • thin layer of connective • Interosseous tissue connects bones membrane • Interosseous ligament Gomphosis Syndesmosis • cone-shaped bony • a sheet or bundle of process in a socket fibrous tissue connects • tooth in jawbone bones • synarthrotic • amphiarthrotic • lies between tibia and fibula 3 4 1 Cartilaginous Joints Cartilaginous Joints Connected by • 2 Types Symphysis hyaline cartilage or • Synchondrosis • pad of fibrocartilage between bones fibrocartilage • Symphysis • pubis symphysis • joint between bodies of adjacent vertebrae Synchondrosis • amphiarthrotic • bands of hyaline cartilage unite bones • epiphyseal plate (temporary) • between manubrium and first rib • synarthrotic 5 6 General structure of a synovial Synovial Joints joints • Articular cartilage • Most common type • Joint (articular) capsule of joint • Outer layer • diarthrotic • ligaments • More complex • Inner layer - synovial structurally membrane • synovial cavity • synovial fluid- lubricates and protects joint • Menisci-pad of cartilage • bursae-fluid filled sac 7 8 2 Types of Synovial Joints Types of Synovial Joints Ball-and-Socket Joint Condyloid Joint Gliding Joint Hinge Joint • hip • between metacarpals • between carpals • elbow • shoulder and phalanges • between tarsals • between phalanges • Allow the greatest degree of movement 9 10 Types of Synovial Joints Types of Joint Movements • abduction/adduction-moving away Pivot Joint Saddle Joint from midline/moving toward the • between proximal • between carpal and midline of the body ends of radius and metacarpal of thumb • dorsiflexion/plantarflexion-moving ulna toes toward shin/pointing toes down • flexion/extension/hyperextension- decreasing the angle between two bones/increasing the angle between two bones/extending the joint past the anatomical position 11 12 3 Types of Joint Movements Types of Joint Movements • eversion/inversion-rotating toes inward/rotating toes outward • rotation/circumduction-rotating • protraction/retraction-moving a structure anteriorly/moving a structure around a point/moving a posteriorly structure in a circle • elevation/depression-moving a structure superiorly/moving a structure • supination/pronation-rotating a inferiorly structure laterally/rotating a structure medially 13 14 Clinical Application Life-Span Changes Joint Disorders • Fontanels close at 2, 3, 12, 18 - 24 months Sprains • Fibrous joints strength with age • damage to cartilage, ligaments, or tendons associated • Joint stiffness is an early sign of aging with joints • Fibrous joints first to change; can strengthen • forceful twisting of joint over a lifetime Bursitis • Changes in symphysis joints of vertebral • inflammation of a bursa column diminish flexibility and decrease • overuse of a joint height • Synovial joints lose elasticity Arthritis • Disuse hampers the blood supply • inflamed, swollen, painful joints • Rheumatoid Arthritis • Activity and exercise can keep joints • Osteoarthritis functional longer 15 • Gout 16 4 Clinical Application Joint Disorders Dislocations • bones in a joint are displaced from their normal position Torn Cartilage • meniscus tares 17 5 .