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The Articular System. Joint. Connection between two bones Joints allow motion Bear body weight Provides stability. Types of Joints. Fibrous Cartilaginous Synovial. Fibrous joint. Has thin layer of periosteum between the bones e.g. – sutures of skull. 3 types of fibrous joints:
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Joint • Connection between two bones • Joints allow motion • Bear body weight • Provides stability
Types of Joints • Fibrous • Cartilaginous • Synovial
Fibrous joint Has thin layer of periosteum between the bones e.g. – sutures of skull
3 types of fibrous joints: • Synarthrosis thin layer of fibrous periosteum between two bones no motion between bones • Syndesmosis great deal of fibrous tissue small amount of twisting or stretching e.g.- distal tibiofibularjint distal radio ulnar joint • Gomphosis between tooth & wall of its dental socket in mandible & maxilla
Cartilaginous joint • Hyaline or fibrocartilage is present between bone surfaces Vertebral joints: disc of fibro cartilage directly connect bones 1st sternocostal joint: direct connection made by hyaline cartilage
Synovial (diarthrodial) joint • No direct union between bone ends • Joint surfaces covered with hyaline (articular) cartilage • Outer layer of capsule by strong fobrous tissue
Diarthroidal Joint Classification • Nonaxial • Uniaxial • Biaxial • Triaxial
Nonaxial • Linear movement • Flat surfaces of bone glide over each other
Uniaxial • Angular movement (hinge) • One plane around one axis
Biaxial • Movement in 2 different directions allowed
Triaxial(multiaxial) • Motion occurs at 3 axes
Joint Structure • Bone • Ligament- bands of fibrous tissue • Hold ends of bones together • Flexible, but not elastic
Joint Capsule • Surrounds • Protects • 2 layers: • Outer fibrous layer • Inner layer • Synovial membrane • Synovial fluid http://www.allaboutmydoc.com/surgeonweb/surgeonId.2729/clinicId.1432/theme.theme3/country.US/language.en/page.article/docId.20262
Cartilage – 3 Types • Hyaline (articular) cartilage • Fibrocartilage • Meniscus • Intervertebral discs • Labrum • Elastic cartilage • Ear
Tendon • Connects muscle to bone • Tendon sheaths • Aponeurosis • Flat tendinous sheet • Linea alba
Bursa • Fluid filled sac • Located in areas of friction • Lined with synovial membrane • Natural vs. Acquired
PLANES of the BODY • Sagittal plane • Divides body into left and right halves • Flexion/extension • Frontal plane • Divides body into front and back halves • Adduction/abduction • Transverse (Horizontal) plane • Divides body into top and bottom halves • Rotation • Cardinal Planes – divide the body equally
Axis • Point through center of joint around which the body part rotates • Movement Occurs In a Plane, Around an Axis
Sagittal axis • Frontal axis • Vertical axis
Degrees of Freedom • Number of planes in which a joint can move • Uniaxial joint – one degree of freedom, motion at one axis • Biaxial joint – 2 degrees of freedom, motion at 2 axes • Triaxial joint – 3 degrees of freedom, motion at 3 axes