Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
21/04/36 Articulations Dr. Amjad El-Shanti MD,MPH, PhD Assistant professor of Public HealthEpidemiology 2014-2015 Articulations • Body movement occurs at joints (articulations) where 2 bones connect Joint Structure • Determines direction and distance of movement (range of motion) • Joint strength decreases as mobility increases 1 21/04/36 What are the major categories of joints, and the structure and function of each category? Functional Classification Table 9–1 2 21/04/36 Functional Classifications • Synarthrosis: • no movement • Amphiarthrosis: • little movement • Diarthrosis: • more movement Synarthroses • Also called immovable joints • Fibrous or cartilaginous connections • May fuse over time Amphiarthroses • Also called slightly moveable joints • Fibrous or cartilaginous connections 3 21/04/36 Diarthroses • Synovial joints • Also called freely moveable joints • Subdivided by type of motion Structural Classification Table 9–2 4 21/04/36 Structural Classifications • • • • Bony Fibrous Cartilaginous Synovial Synarthroses (Immovable Joints) • Are very strong • Edges of bones may touch or interlock 4 Types of Synarthrotic Joints • • • • 5 Suture Gomphosis Synchondrosis Synostosis 21/04/36 Suture • Bones interlocked • Are bound by dense fibrous connective tissue • Are found only in skull Gomphosis • Fibrous connection (periodontal ligament) • Binds teeth to sockets Synchondrosis • Is a rigid cartilaginous bridge between 2 bones: • epiphyseal cartilage of long bones • between vertebrosternal ribs and sternum Synostosis • Fused bones, immovable: • metopic suture of skull • epiphyseal lines of long bones 6 21/04/36 Amphiarthroses • More moveable than synarthrosis • Stronger than freely movable joint 2 Types of Amphiarthroses • Syndesmosis: • bones connected by ligaments • Symphysis: • bones separated by fibrocartilage What is the basic structure of a synovial joint, and what are the common accessory structures and their functions? 7 21/04/36 Synovial Joints (Diarthroses) • • • • Also called moveable joints At ends of long bones Within articular capsules Lined with synovial membrane Articular Cartilages • Pad articulating surfaces within articular capsules: • prevent bones from touching • Smooth surfaces lubricated by synovial fluid: • reduce friction 8 21/04/36 Synovial Fluid • Contains slippery proteoglycans secreted by fibroblasts Functions of Synovial Fluid 1. Lubrication 2. Nutrient distribution 3. Shock absorption Synovial Joints: Accessory Structures Cartilages • Cushion the joint: • fibrocartilage meniscus (articular disc) • Fat pads Cushion the joint: • fibrocartilage meniscus (articular disc) Accessory Ligaments • Support, strengthen joints • Sprain: • ligaments with torn collagen fibers 9 21/04/36 Synovial Joints: Accessory Structures • • • • Tendons Attach to muscles around joint Help support joint Bursae Pockets of synovial fluid Cushion areas where tendons or ligaments rub Synovial Joints: Stabilizing Factors • Prevent injury by limiting range of motion: • collagen fibers (joint capsule, ligaments) • articulating surfaces and menisci • other bones, muscles, or fat pads • tendons of articulating bones 10 21/04/36 Injuries • Dislocation (luxation): • articulating surfaces forced out of position • damages articular cartilage, ligaments, joint capsule • Subluxation: • a partial dislocation What are the dynamic movements of the skeleton? Types of Dynamic Motion • Linear motion (gliding) • Angular motion • Rotation 11 21/04/36 Linear Motion • Pencil maintains vertical orientation, but changes position Figure 9–2a, b Angular Motion • Pencil maintains position, but changes orientation Figure 9–2c 12 21/04/36 Circumduction & Rotation • Circular angular motion • Pencil maintains position and orientation, but spins Figure 9–2e Planes (Axes) of Dynamic Motion • Monaxial (1 axis) • Biaxial (2 axes) • Triaxial (3 axes) 13 21/04/36 Types of Movements at Synovial Joints • Terms describe: • plane or direction of motion • relationship between structures Linear Motion • Also called gliding • 2 surfaces slide past each other: • between carpal or tarsal bones 14 21/04/36 Flexion Angular motion Anterior–posterior plane Reduces angle between elements Figure 9–3a Extension • Angular motion • Anterior–posterior plane • Increases angle between elements Hyperextension • Angular motion • Extension past anatomical position 15 21/04/36 Abduction Figure 9–3b, c Abduction • Angular motion • Frontal plane • Moves away from longitudinal axis Adduction • Angular motion • Frontal plane • Moves toward longitudinal axis 16 21/04/36 Circumduction • Circular motion without rotation • Angular motion Figure 9–3d Rotation Figure 9–4 17 21/04/36 Rotation • Direction of rotation from anatomical position • Relative to longitudinal axis of body • Left or right rotation • Medial rotation (inward rotation): • rotates toward axis • Lateral rotation (outward rotation): rotates away from axis Pronation and Supination • Pronation: • rotates forearm, radius over ulna • Supination: • forearm in anatomical position 18 21/04/36 Inversion and Eversion Inversion: twists sole of foot medially Eversion: twists sole of foot laterally Figure 9–5a Dorsiflexion and Plantar Flexion • Dorsiflexion: flexion at ankle (lifting toes) • Plantar flexion: extension at ankle (pointing toes) Figure 9–5b 19 21/04/36 Opposition • Thumb movement toward fingers or palm (grasping) Figure 9–5c Protraction and Retraction Figure 9–5d 20 21/04/36 Protraction and Retraction • Protraction: • moves anteriorly • in the horizontal plane (pushing forward) • Retraction: • opposite of protraction • moving anteriorly (pulling back) Elevation and Depression • Elevation: moves in superior direction (up) • Depression: moves in inferior direction (down) Figure 9–5e 21 21/04/36 Lateral Flexion • Bends vertebral column from side to side Figure 9–5f What are the types of synovial joints, and the relationship of motion to structure? 22 21/04/36 Classification of Synovial Joints by Shape • • • • • • Gliding Hinge Pivot Ellipsoidal Saddle Ball-and-socket PLAY A Functional Classification of Synovial Joints Gliding Joints • Flattened or slightly curved faces • Limited motion (nonaxial) Figure 9–6 (1 of 6) 23 21/04/36 Hinge Joints • Angular motion in a single plane (monaxial) Figure 9–6 (2 of 6) Pivot Joints • Rotation only (monaxial) Figure 9–6 (3 of 6) 24 21/04/36 Ellipsoidal Joints • Oval articular face within a depression • Motion in 2 planes (biaxial) Figure 9–6 (4 of 6) Saddle Joints • 2 concave faces, straddled (biaxial) Figure 9–6 (5 of 6) 25 21/04/36 Ball-and-Socket Joints • Round articular face in a depression (triaxial) Figure 9–6 (6 of 6) KEY CONCEPT • A joint can’t be both mobile and strong • The greater the mobility, the weaker the joint • Mobile joints are supported by muscles and ligaments, not bone-to-bone connections 26 21/04/36 How do vertebrae in the vertebral column articulate? Intervertebral Articulations Figure 9–7 Intervertebral Articulations • C2 to L5 spinal vertebrae articulate: • at inferior and superior articular processes (gliding joints) • between adjacent vertebral bodies (symphyseal joints) 27 21/04/36 Intervertebral Discs • Intervertebral discs: • pads of fibrocartilage • separate vertebral bodies Disc Structure • Anulus fibrosus: • tough outer layer • attaches disc to vertebrae • Nucleus pulposus: • elastic, gelatinous core • absorbs shocks 28 21/04/36 Vertebral Joints • Also called symphyseal joints • As vertebral column moves: • nucleus pulposus shifts • disc shape conforms to motion Intervertebral Ligaments • Bind vertebrae together • Stabilize the vertebral column 29 21/04/36 6 Intervertebral Ligaments • Anterior longitudinal ligament: • connects anterior bodies • Posterior longitudinal ligament: • connects posterior bodies • Ligamentum flavum: • connects laminae 6 Intervertebral Ligaments • Interspinous ligament: • connects spinous processes • Supraspinous ligament: • connects tips of spinous processes (C7 to sacrum) • Ligamentum nuchae: • continues supraspinous ligament (C7 to skull) 30 21/04/36 Damage to Intervertebral Discs Figure 9–8 Damage to Intervertebral Discs • Slipped disc: • bulge in anulus fibrosus • invades vertebral canal • Herniated disc: • nucleus pulposus breaks through anulus fibrosus • presses on spinal cord or nerves 31 21/04/36 Movements of the Vertebral Column • Flexion: • bends anteriorly • Extension: • bends posteriorly • Lateral flexion: • bends laterally • Rotation Articulations and Movements of the Axial Skeleton Table 9–3 (1 of 2) 32 21/04/36 Articulations and Movements of the Axial Skeleton Table 9–3 (2 of 2) What are the structures and functions of the shoulder, elbow, hip, and knee joints, and what is the relationship between joint strength and mobility? 33 21/04/36 The Shoulder Joint Figure 9–9a The Shoulder Joint Figure 9–9b 34 21/04/36 The Shoulder Joint • Also called the glenohumeral joint: • allows more motion than any other joint • is the least stable • supported by skeletal muscles, tendons, ligaments Structure of the Shoulder Joint • Ball-and-socket diarthrosis • Between head of humerus and glenoid cavity of scapula 35 21/04/36 Socket of the Shoulder Joint • Glenoid labrum: • deepens socket of glenoid cavity • fibrocartilage lining • extends past the bone Processes of the Shoulder Joint • Acromion (clavicle) and coracoid process (scapula): • project laterally, superior to the humerus • help stabilize the joint 36 21/04/36 Shoulder Ligaments • • • • • Glenohumeral Coracohumeral Coracoacromial Coracoclavicular Acromioclavicular Shoulder Separation • Dislocation of the shoulder joint 37 21/04/36 Shoulder Muscles • Also called rotator cuff: • • • • supraspinatus infraspinatus subscapularis teres minor Shoulder Bursae • • • • 38 Subacromial Subcoracoid Subdeltoid Subscapular 21/04/36 The Elbow Joint Figure 9–10 The Elbow Joint • A stable hinge joint • With articulations between humerus, radius, and ulna 39 21/04/36 Articulations of the Elbow • Humeroulnar joint: • largest articulation • trochlea of humerus and trochlear notch of ulna • limited movement • Humeroradial joint: • smaller articulation • capitulum of humerus and head of radius Elbow Muscle • Biceps brachii muscle: • attached to radial tuberosity • controls elbow motion Elbow Ligaments • Radial collateral • Annular • Ulnar collateral 40 21/04/36 The Hip Joint Figure 9–11a The Hip Joint Figure 9–11b, c 41 21/04/36 The Hip Joint • Also called coxal joint • Strong ball-and-socket diarthrosis • Wide range of motion Structures of the Hip Joint • Head of femur fits into it • Socket of acetabulum • Which is extended by fibrocartilage acetabular labrum 42 21/04/36 Ligaments of the Hip Joint • • • • • Iliofemoral Pubofemoral Ischiofemoral Transverse acetabular Ligamentum teres The Knee Joint Figure 9–12a, b 43 21/04/36 The Knee Joint • A complicated hinge joint • Transfers weight from femur to tibia Articulations of the Knee Joint • 2 femur–tibia articulations: • at medial and lateral condyles • 1 between patella and patellar surface of femur 44 Figure 9–12c, d 21/04/36 Menisci of the Knee • Medial and lateral menisci: • • • • fibrocartilage pads at femur–tibia articulations cushion and stabilize joint give lateral support Locking Knees • Standing with legs straight: • “locks” knees by jamming lateral meniscus between tibia and femur 45 21/04/36 7 Ligaments of the Knee Joint • Patellar ligament (anterior) • 2 popliteal ligaments (posterior) • Anterior and posterior cruciate ligaments (inside joint capsule) • Tibial collateral ligament (medial) • Fibular collateral ligament (lateral) Articulations of the Appendicular Skeleton Table 9–4 (1 of 2) 46 21/04/36 Articulations of the Appendicular Skeleton Table 9–4 (2 of 2) What are the effects of aging on articulations, and the most common clinical problems? 47 21/04/36 Rheumatism • A pain and stiffness of skeletal and muscular systems Arthritis • All forms of rheumatism that damage articular cartilages of synovial joints Osteoarthritis • Caused by wear and tear of joint surfaces, or genetic factors affecting collagen formation • Generally in people over age 60 48 21/04/36 Rheumatoid Arthritis • An inflammatory condition • Caused by infection, allergy, or autoimmune disease • Involves the immune system Gouty Arthritis • Occurs when crystals (uric acid or calcium salts): • form within synovial fluid • due to metabolic disorders 49 21/04/36 Joint Immobilization • Reduces flow of synovial fluid • Can cause arthritis symptoms • Treated by continuous passive motion (therapy) Bones and Aging • Bone mass decreases • Bones weaken • Increases risk of hip fracture, hip dislocation, or pelvic fracture 50 21/04/36 Integration with Other Systems Figure 9–13 Bone Recycling • Living bones maintain equilibrium between: • bone building (osteoblasts) • and break down (osteoclasts) 51 21/04/36 Factors Affecting Bone Strength 1. 2. 3. 4. Age Physical stress Hormone levels Calcium and phosphorus uptake and excretion 5. Genetic and environmental factors Bones Support Body Systems • The skeletal system: • supports and protects other systems • stores fat, calcium, and phosphorus • manufactures cells for immune system 52 21/04/36 Body Systems Support Bones • Disorders in other body systems can cause: • • • • bone tumors osteoporosis arthritis rickets (demineralization) SUMMARY (1 of 5) • Joint classification by motion and structure • 4 types of synarthroses: • suture, gomphosis, synchondrosis, synostosis • 2 types of amphiarthroses: • syndesmosis, symphysis 53 21/04/36 SUMMARY (2 of 5) • Structures of diarthroses • 3 forms of dynamic motion: • linear or gliding, angular, rotation • 3 planes of motion: • monaxial, biaxial, triaxial SUMMARY (3 of 5) • Movements of synovial joints: • gliding, flexion, extension, abduction, rotation, pronation, inversion, dorsiflexion, opposition, protraction, depression, etc. 54 21/04/36 SUMMARY (4 of 5) • 6 structural types of synovial joints: • • • • • • gliding hinge pivot ellipsoidal saddle ball-and-socket SUMMARY (5 of 5) • Structures and movements of: • intervertebral articulations • shoulder joint • elbow joint • hip joint • knee joint • Effects of aging on joints • Relationship of the skeleton to other body systems 55