File
advertisement
Chapter 8 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 8.1: Introduction • Are known as articulations • Functional junctions between bones • Bind parts of skeletal system together • Make bone growth possible • Permit parts of the skeleton to change shape during childbirth • Enable body to move in response to skeletal muscle contraction • Three (3) classifications of joints will be considered 2 8.2: Classification of Joints • (1) Fibrous joints • Dense connective tissues connect bones • Between bones in close contact • (2) Cartilaginous joints • Hyaline cartilage or fibrocartilage connect bones • These joints are also known as: • Synarthrotic joints • Considered immovable • Amphiarthrotic joints • Slightly movable • Diarthrotic joints • Freely movable • (3) Synovial joints • Most complex • Allow free movement 3 Fibrous Joints • There are three (3) types of fibrous joints (synarthroses): • Syndesmosis • Suture • Gomphosis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Interosseus membrane of leg • Syndesmosis: • A sheet or bundle of fibrous tissue connecting bones • Lies between tibia and fibula (interosseous membrane) Fibula Anterior tibiofibular ligament (interosseus ligament) Tibia Medial malleolus Lateral malleolus 4 Fibrous Joints Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Suture: • Between flat bones • See teeth-like projections • Thin layer of connective tissue connects bones • Skull Parietal bone Margin of suture Sutural bones Suture Occipital bone (a) (b) Courtesy of John W. Hole, Jr. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Crown of tooth • Gomphosis: • Cone-shaped bony process in a socket • Tooth in jawbone Alveolar process of mandible Periodontal ligament Root of tooth 5 Cartilaginous Joints • There are two (2) types of cartilaginous joints (amphiarthroses): • Synchondrosis • Symphysis First rib Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thoracic vertebra Costal cartilage • Synchondrosis: Manubrium • Bands of hyaline cartilage unite bones • Epiphyseal plate (temporary) • Between manubrium and the first rib (costal cartilages) 6 Cartilaginous Joints • Symphysis: • Pad of fibrocartilage between bones • Pubic symphysis • Joint between bodies of adjacent vertebrae Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Gelatinous core Band of fibrocartilage Spinous process Body of vertebra Pubis Intervertebral discs Fibrocartilage disc of symphysis pubis (a) 7 (b) 8.3: General Structure of a Synovial Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Synovial joints are freely moveable (diarthroses) • There are three (3) types of diarthroses • There are specific parts of a diarthroses: • Articular cartilage Joint cavity • Joint cavity filled with synovial • Joint capsule fluid • Synovial membrane • Synovial fluid • Meniscus • Bursae Spongy bone Joint capsule Articular cartilage Synovial membrane 8 8.4: Types of Synovial Joints • Uni-axial • Hinge joint • Pivot or trochoid joint • Bi-axial • Saddle or sellar joint • Condylar or ellipsoidal joint • Multi-axial • Ball and socket joint • Gliding or plane joint 9 Types of Synovial Joints • Pivot Joint • Between atlas (C1) and the dens of axis (C2) • Hinge Joint • Elbow joint • Between phalanges Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Dens Transverse ligament Humerus Radius Atlas Axis Ulna (e) Pivot joint (d) Hinge joint 10 Types of Synovial Joints • Saddle Joint • Between carpal and 1st metacarpal (of thumb) • Condylar Joint • Between metacarpals and phalanges • Between radius and carpals Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Metacarpal First metacarpal Trapezium Phalanx (f) Saddle joint (b) Condylar joint 11 Types of Synovial Joints • Ball-and-Socket Joint • Gliding Joint • Hip joint • Shoulder joint • Between carpals • Between tarsals • Between facets of adjacent vertebrae Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hip bone Head of femur in acetabulum Femur Carpals (a) Ball-and-socket joint (c) Plane joint 12 8.5: Types of Joint Movements • Movement at a joint occurs when a muscle contracts and its fibers pull its moveable end (insertion) towards its fixed end (origin). 13 Types of Joint Movements • Abduction/adduction • Dorsiflexion/plantar flexion • Flexion/extension/hyperextension • Lateral flexion Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hyperextension Extension Flexion Flexion Abduction Extension Adduction Dorsiflexion Plantar flexion © McGraw-Hill Companies / Womack Photography Ltd. 14 Types of Joint Movements • Rotation • Circumduction • Supination/pronation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Circumduction Supination Medial rotation Lateral rotation © McGraw-Hill Companies / Womack Photography Ltd. Pronation 15 Types of Joint Movements Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Eversion/inversion • Protraction/retraction • Elevation/depression Inversion Eversion Protraction Retraction Elevation Depression © McGraw-Hill Companies / Womack Photography Ltd. 16 8.6: Examples of Synovial Joints • The shoulder, elbow, hip, and knee are large, freely moveable joints. 17 Shoulder Joint • Ball-and-socket • Head of humerus and glenoid cavity of scapula • Loose joint capsule • Bursae • Ligaments prevent displacement • Very wide range of movement (circumduction) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Clavicle Acromion process Subdeltoid bursa Synovial membrane Joint capsule Joint cavity Humerus Articular cartilage Scapula (a) 18 Shoulder Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Joint capsule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Joint cavity Head of humerus Articular cartilage Scapula Acromion process Clavicle Coracohumeral ligament Transverse humeral ligament Coracoid process Joint capsule Clavicle Coracoid process Acromion process Subscapular bursa Glenohumeral ligaments Tendon of biceps brachii (long head) Glenoid labrum Glenoid cavity Humerus Humerus (a) Articular capsule (glenohumeral ligaments hidden) Scapula Scapula Triceps brachii (long head) (b) 19 (b) © Paul Reimann Elbow Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Hinge joint • Trochlea of humerus • Trochlear notch of ulna Humerus Joint capsule • Gliding joint Synovial membrane Joint cavity • Capitulum of humerus • Head of radius Articular cartilage Coronoid process • Flexion and extension • Many reinforcing ligaments • Stable joint Anular ligament Radius Ulna (a) Olecranon process Trochlea 20 Elbow Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Humerus Humerus Tendon of biceps brachii muscle Medial epicondyle Lateral epicondyle Radius Anular ligament Anular ligament Radius Ulna (a) Coronoid process Ulnar collateral ligament Olecranon process Radial collateral ligament (b) 21 Ulna Hip Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Ball-and-socket joint • Head of femur and acetabulum of coxa • Heavy joint capsule • Many reinforcing ligaments • Less freedom of movement than shoulder joint • Circumduction Hip bone Joint cavity Articular cartilage Synovial membrane Ligamentum capitis Joint capsule Femur (a) 22 Hip Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hip bone Ilium Ilium Articular cartilage Joint cavity Pubofemoral ligament Head of femur Iliofemoral ligament Greater Joint capsule trochanter Pubis Femur Ischium Femur (a) Iliofemoral ligament Ischiofemoral ligament Lesser trochanter Femur (b) (b) © Paul Reimann 23 Knee Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Largest joint • Most complex • Medial and lateral condyles of distal end of femur and • Medial and lateral condyles of proximal end of tibia and • Femur articulates anteriorly with patella • Strengthened by many ligaments and tendons • Menisci separate femur and tibia • Bursae Femur Synovial membrane Suprapatellar bursa Quadriceps femoris tendon (patellar tendon) Patella Prepatellar bursa Joint cavity Articular cartilage Patellar ligament Menisci Infrapatellar bursa Joint capsule Tibia (a) 24 Knee Joint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Femur Tendon of adductor magnus (cut) Joint capsule Gastrocnemius muscle (cut) Femur Anterior cruciate ligament Femur Lateral condyle Posterior cruciate ligament Medial condyle Lateral meniscus Articular cartilage Lateral condyle Head of fibula Tibia Lateral condyle Lateral meniscus Lateral condyle Fibular collateral ligament Fibula Tibia Fibula (a) (b) Anterior cruciate ligament Medial meniscus Medial condyle Tibial collateral ligament Patellar ligament (cut) Plantaris muscle (cut) Tendon of semimembranosus (cut) Oblique popliteal ligament Tibial collateral ligament Fibular collateral ligament Popliteus muscle cut) Arcuate popliteal ligament Tibia Fibula (b) © Paul Reimann 25 8.1 Clinical Application Replacing Joints 26 8.2 Clinical Application Joint Disorders 27 8.7: Lifespan Changes • Joint stiffness is an early sign of aging • Fibrous joints first to change; can strengthen however over a lifetime • Changes in symphysis joints of vertebral column diminish flexibility and decrease height (remember water loss from the IVDs) • Synovial joints lose elasticity • Disuse hampers the blood supply • Activity and exercise can keep joints functional longer 28
