Joints PDF

 Joints Stability of joint wy Depends on: 1. Shape of the bones “hip joint is stable while knee joint is instable” 2. Contraction of the surrounding muscles....

 Joints Stability of joint wy Depends on: 1. Shape of the bones “hip joint is stable while knee joint is instable” 2. Contraction of the surrounding muscles. da 3. Strength of the ligaments Hilton law en The nerve supplying the joint also supply the muscle acting on this joint and the skin covering it H R. D Anatomist “Joint”  Classification of joints 1. Fibrous “synarthrosis” joints Bones: Separated from each other by fibrous tissue. wy Types:  Sutures: as skull bones  Syndesmosis: as Inferior tibio-fibular & middle radio-ulnar “inter-osseous membrane” da  Gomphosis: as Joints between teeth & jaw en H R. D Anatomist “Joint”  2. Cartilaginous “amphiarthrosis” joints Bones are separated from each other by cartilage wy Primary Cartilaginous:  Type of cartilage: hyaline da  Ossification: occur with age “temporary joint”  Movement: no movement en  Example:  Epiphyseal plate H  1st sterno-costal joint R. D Anatomist “Joint” Secondary Cartilaginous:  Type of cartilage: fibro-cartilage wy  Ossification: never ossify “permanent joint”  Movement: limited movement  Example: da  Symphysis pubis en  Inter-vertebral disc  Joints between parts of sternum H R. D Anatomist “Joint”  3. Synovial “diarthrosis” joints wy  Freely movable joints.  The articular surfaces of bones are covered by hyaline cartilage da  Synovial joints are surrounded by a fibrous capsule  The capsule is lined by Synovial membrane "produces synovial fluid" en  Synovial fluid:  Shock absorption  Lubrication of articular cartilage  H Provides nutrition of articular cartilage. R D Anatomist “Joint” Number Shape of Axis & Movements allowed Example of axes articulating bones o Elbow joint. o Ankle joint wy Synovial Hinge Transverse axis allow Flexion & extension Uni- o Inter-phalangeal joint axial o Superior & inferior radio-ulnar joints. Synovial Pivot Vertical axis allow Rotation da o Median atlanto-axial joint. Synovial Condyloid / Transverse axis allow Flexion & extension o Knee joint Bi- Bicondylar/ Condylar & Vertical axis allow Rotation o Metacarpo-phalangeal joint en axial Synovial Ellipsoid Transverse axis allow Flexion & extension o Wrist joint Synovial Saddle & antero-posterior allow adduction & abduction o Carpometacarpal joint of thumb Poly- Synovial H Transverse axis allow Flexion & extension & Vertical axis allow Rotation o Shoulder joint R. axial Ball and Socket o Hip joint & antero-posterior allow adduction & abduction Non No specific axis o Inter-carpal joint Synovial Plane D The movement is Sliding o Inter-tarsal joint axial o Superior tibio-fibular joint Anatomist “joint”. wy da en H R. D Anatomist “joint”