Joints

ARTHROLOGY (JOINTS) Joints: The place where two or more bones meet and permit some degree of movement. ARTHRO=JOINTS’

Types of joint: Structural Classification: Fibrous Joints Cartilaginous Joint Synovial Joint

Functional Classification: Synarthroses(immovable) Amphiarthroses(slightly movable) Diarthroses(free movable)

FIBROUS JOINTS (SYNARTHROSES) Joints with little or no movement, connected together by dense(fibrous) connective tissue TYPES: 1.SUTURE: eg sutures of skull

2. SYNDESMOSES : Bones are united by a ligament or a sheet of fibrous tissue Eg: yellow ligaments join the adjacent two vertebral arch, interosseouus membrane joints the radius and ulna

3.GOMPHOSES: joint found between teeth and maxilla or mandible

CARTILIGENOUS JOINTS (AMPHIARROSIS): Cartilage holds the joints together TYPES: 1.SYNCHONDROSIS: 2.SYMPHYSES:

TYPES: 1.SYNCHONDROSIS : hyaline cartilage connects the bone eg epiphysial plate between epiphysis and diaphysis

2.SYMPHYSES : fibrous cartilage connect the bones eg: joints between the bodies of vetebrae, pubic symphysis

SYNOVIAL JOINTS (DIARTHROSES): These joints are all freely mobile. STRUCTUREES OF A SYNOVIAL JOINTS 1Articular surface: they r usually covered by the hyaline cartilage,it is verry smooth 2Articular capsule: attached to peripheraly of the articular surface nad adjacnet bone surface. it encloses the joint cavity .it composed of two layer ...FIBROUS MEMBRANE(LAYER)is fomed by dense connective tissue and rich in blood vessela and nerves SYNOVIAL MEMEBRANE(LAYER)-The epithelium tissue is the SYNOVIAL MEMBRANE and it lines the CAVITY containing the SYNOVIAL FLUID. 3 Articular cavity:it is a closed cavity formed by the synovial membrane and the articular cartilage,it contain a proper amount of synovia.its pressure is negative to the atmosphere pressure. ACCESSORY STRUCTUREES OF THE SYNOVIAL JOINTS 1.Ligaments 2Articular disc or cartilage 3.Articular labrum (lip) eg labrum of glenoid cavity

Classification by movement: 1. Gliding 2. Angular 3. Rotation

1. Gliding

Angular

Rotation

Classification by Shape 1) UNIAXIAL: Movement only in one axis eg coronal axis,sagital axis or vertical axis a)HING JOINT: permit flexion and extention eg trochlear joints ,,ELBOW , ANGKLE,PHALANGES b)PIVOT JOINT: rotation around a long axis eg the proximal radioulnar joint,ATLAS-AXIS

2) BIAXIAL: Movement in two axes which meet at right angle to each other a)CONDYLOID JOINT(ELLLIPSOID JOINT): articular surfacees r ellipsoidal or oval in shape, permit flexion and extention,adduction and abduction,as well as circumduction eg radiocarpal joint,METACARPO-PHALENGEAL,KNEE b)SADDLE JOINT: articular surfacees r concave and convex ,opposit to each other,permit flexion,extention,abduction,adduction and circumduction eg 1st carpometacarpal joint,sternoclavicular

3) TRIAXIAL OR MULTIAXIAL: a) BALL AND SOCKET JOINT: most freely moving synovial joint. permit flexion and extention,adduction and abduction,medial and lateral rotation, circumduction eg the shoulder and hip joints b) PLAN JOINT: permit only a little of movement eg acromioclavicular joint,intercarpal,intertarsal,intervertebral