Synovial Joints • Typically Found at the Ends of Long Bones • Examples of Diarthroses • Shoulder Joint • Elbow Joint • Hip Joint • Knee Joint
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Chapter 8 The Skeletal System Articulations Lecture Presentation by Steven Bassett Southeast Community College © 2015 Pearson Education, Inc. Introduction • Bones are designed for support and mobility • Movements are restricted to joints • Joints (articulations) exist wherever two or more bones meet • Bones may be in direct contact or separated by: • Fibrous tissue, cartilage, or fluid © 2015 Pearson Education, Inc. Introduction • Joints are classified based on: • Function • Range of motion • Structure • Makeup of the joint © 2015 Pearson Education, Inc. Classification of Joints • Joints can be classified based on their range of motion (function) • Synarthrosis • Immovable • Amphiarthrosis • Slightly movable • Diarthrosis • Freely movable © 2015 Pearson Education, Inc. Classification of Joints • Synarthrosis (Immovable Joint) • Sutures (joints found only in the skull) • Bones are interlocked together • Gomphosis (joint between teeth and jaw bones) • Periodontal ligaments of the teeth • Synchondrosis (joint within epiphysis of bone) • Binds the diaphysis to the epiphysis • Synostosis (joint between two fused bones) • Fusion of the three coxal bones © 2015 Pearson Education, Inc. Figure 6.3c The Adult Skull Major Sutures of the Skull Frontal bone Coronal suture Parietal bone Superior temporal line Inferior temporal line Squamous suture Supra-orbital foramen Frontonasal suture Sphenoid Nasal bone Temporal Lambdoid suture bone Lacrimal groove of lacrimal bone Ethmoid Infra-orbital foramen Occipital bone Maxilla External acoustic Zygomatic bone meatus Mastoid process Styloid process Mandible Zygomatic process Zygomatic of temporal bone Mental foramen arch Temporal process Mental protuberance of zygomatic bone Coronal suture Parietal bone Frontal bone Sphenoid Supra-orbital foramen Superior temporal line Ethmoid Frontonasal suture Squamous suture Nasal bone Lacrimal groove Squamous part of of lacrimal bone temporal bone Infra-orbital foramen Lambdoid suture Zygomatic bone Occipital bone Maxilla External occipital protuberance Temporal process of zygomatic bone External acoustic meatus Zygomatic process of temporal bone Mastoid process Mantal foramen Styloid process Mental protuberance c Lateral view of the bones of the adult skull © 2015 Pearson Education, Inc. Table 8.1 Function and Structural Classification of Articulations © 2015 Pearson Education, Inc. Figure 6.12a The Maxillae Frontal process Zygomatic process Lacrimal groove Orbital surface Infra-orbital foramen Anterior nasal spine Body Alveolar process a Right maxilla, anterior and lateral surfaces © 2015 Pearson Education, Inc. Figure 5.3a Anatomy of a Representative Bone Epiphysis Metaphysis Diaphysis (shaft) Metaphysis Epiphysis a The femur, or thigh bone, in posterior and sectional views. The femur has a diaphysis (shaft) with walls of compact bone and epiphyses (ends) filled with spongy bone. A metaphysis separates the diaphysis and epiphysis at each end of the shaft. The body weight is transferred to the femur at the hip joint. Because the hip joint is off center relative to the axis of the shaft, the body weight is distributed along the bone so that the medial portion of the shaft is compressed and the lateral portion is stretched. © 2015 Pearson Education, Inc. Figure 7.10a The Pelvic Girdle Ilium POSTERIOR ANTERIOR Pubis Ischium Lateral view © 2015 Pearson Education, Inc. Classification of Joints • Amphiarthroses (Slightly Movable Joints) • Syndesmosis (ligaments that connect two bones but limit their motion) • Between the radius and ulna • Between the tibia and fibula • Symphysis (bones are separated by a wedge or pad of cartilage) • Between the pubic bones of the two coxal bones © 2015 Pearson Education, Inc. Table 8.1 Function and Structural Classification of Articulations © 2015 Pearson Education, Inc. Figure 7.7d The Radius and Ulna ULNA RADIUS Interosseous membrane d Anterior view of the radius and ulna © 2015 Pearson Education, Inc. Figure 7.11a The Pelvis (1 of 2) Hip Bone Ilium Pubis Ischium Pubic symphysis a Anterior view © 2015 Pearson Education, Inc. Classification of Joints • Diarthroses (Freely Movable Joints) • Also called synovial joints • Typically found at the ends of long bones • Examples of diarthroses • Shoulder joint • Elbow joint • Hip joint • Knee joint © 2015 Pearson Education, Inc. Table 8.1 Function and Structural Classification of Articulations © 2015 Pearson Education, Inc. Classification of Joints • Synovial Joints • All synovial joints have six basic characteristics • A joint capsule • The presence of articular cartilages • A joint cavity with synovial fluid • A synovial membrane • Accessory structures (cartilage, ligaments, tendons, bursae) • Sensory nerves and blood vessels © 2015 Pearson Education, Inc. Figure 8.1a Structure of a Synovial Joint Medullary cavity Spongy bone Periosteum Components of Synovial Joints Joint capsule Synovial membrane Articular cartilages Joint cavity containing synovial fluid Compact bone a Diagrammatic view of a simple articulation © 2015 Pearson Education, Inc. Figure 8.1b Structure of a Synovial Joint Quadriceps tendon Accessory Patella Structures of Joint capsule Femur a Knee Joint Synovial Bursa membrane Joint cavity Fat pad Articular Meniscus cartilage Ligaments Tibia Extracapsular ligament (patellar) Intracapsular ligament (cruciate) b A simplified sectional view of the knee joint © 2015 Pearson Education, Inc. Classification of Joints • Joints can be classified based on their histological structure • Bony fusion (fusion of the frontal bone) • Fibrous joint (skull sutures) • Cartilaginous joint (pubic symphysis) • Synovial joint (ball-and-socket joints and hinge joints) © 2015 Pearson Education, Inc. Table 8.1 Function and Structural Classification of Articulations © 2015 Pearson Education, Inc. Classification of Joints • Synovial Fluid • Lubricates the surfaces of the articular cartilages and reduces friction • Nourishes the chondrocytes by entering and exiting the articular cartilages due to the forces acting on the joint • Acts as a shock absorber © 2015 Pearson Education, Inc. Classification of Joints • Accessory Structures of Synovial Joints • Accessory structures are: • Menisci • Ligaments • Tendons • Bursae © 2015 Pearson Education, Inc. Figure 8.15b The Knee Joint, Part I Knee extensors (Quadriceps femoris muscles) Femur Suprapatellar bursa Plantaris muscle Quadriceps tendon Synovial Patella membrane Prepatellar bursa Articular capsule Infrapatellar fat pad Popliteus muscle Anterior cruciate ligament Lateral meniscus Gastrocnemius Infrapatellar bursa muscle Patellar ligament Soleus muscle Tibial tuberosity Tibia Tibialis posterior muscle b A diagrammatic parasagittal section through the extended right knee © 2015 Pearson Education, Inc. Figure 8.16c The Knee Joint, Part II Articular Patellar surface Patellar cartilage surface Articular cartilage Ligaments that Stabilize the Knee Joint Posterior cruciate ligament Lateral Lateral Menisci Medial Medial condyle condyle condyle condyle Anterior cruciate ligament Medial Lateral meniscus Medial Tibial collateral ligament Lateral Tibial collateral Fibular collateral Fibular collateral ligament meniscus ligament ligament Cut tendon of Patellar ligament (cut) Tibia biceps femoris muscle Fibula Fibula Tibia c Anterior views of the right knee at full flexion after removal of the joint capsule, patella, and associated ligaments © 2015 Pearson Education, Inc. Classification of Joints • Strength versus Mobility • A highly mobile joint is not very strong • Diarthrosis • A fairly immovable joint is strong • Synarthrosis • Limited mobility reduces the chance of injury © 2015 Pearson Education, Inc. Articular Form and Function • Types of Movement • Linear movements • Angular movements • Circumduction • Rotation • Special movements © 2015 Pearson Education, Inc. Articular Form and Function • Linear Movements • Two bones gliding past each other • Carpal/carpal • Tarsal/tarsal • Clavicle/sternum • Angular Movements • Abduction/adduction • Flexion/extension © 2015 Pearson Education, Inc. Figure 8.2 Joint Motion (5 of 10) Gliding joint Description: Examples: Gliding joints, or planar joints, Monaxial • Sternoclavicular and acromioclavicular joints have flattened or slightly curved Movement: • Intercarpal and intertarsal surfaces that slide across one Slight linear Manubrium joints another, but the amount of motion • Vertebrocostal joints movement is very slight. • Sacro-iliac joints © 2015 Pearson Education, Inc. Figure 8.3a Angular Movements Abduction Abduction Adduction Adduction Abduction Adduction Abduction Adduction a Abduction/adduction © 2015 Pearson Education, Inc. Figure 8.3b Angular Movements Flexion Extension Flexion Flexion Extension Extension Flexion Extension b Flexion/extension © 2015 Pearson Education, Inc. Articular Form and Function • Rotational Movements • Pronation/supination • Circumduction Movements • Moving the joint in a circular manner © 2015 Pearson Education, Inc. Figure 8.4 Rotational Movements Head rotation Right Left rotation rotation Lateral (external) Medial Supination Pronation rotation (internal) rotation Supination Pronation © 2015 Pearson Education, Inc. Figure 8.3d Angular Movements d Circumduction © 2015 Pearson Education, Inc. Articular Form and Function • Special Movements • Inversion/eversion • Dorsiflexion/plantar flexion • Lateral flexion • Protraction/retraction • Opposition • Depression/elevation © 2015 Pearson Education, Inc. Figure 8.5a Special Movements Eversion Inversion a Eversion/inversion © 2015 Pearson