ARTICULAR SYSTEM(ARTHROLOGY)BAGIAN ANATOMI

DYAH PURNANING

A joint (articulation or arthrosis) is a point of contact between two or more bones, between cartilage and bones, or between teeth and bones.The scientific study of joints is called arthrology.Joints hold bones together but permit movementPoint of contact between 2 bones between cartilage and bone between teeth and bones Arthrology = study of joints Kinesiology = study of motionDefinition

Joints by Functional Classification

TypeMovementExampleSynarthrosisNone (minimal)Sutures, Teeth,Epiphyseal plates,1st rib and costal cart.AmphiarthrosisSlightDistal Tibia/fibulaIntervertebral discsPubic symphysisDiarthrosisGreatGlenohumeral jointKnee jointTMJ

Joints by Structural Classification

StructureTypeExampleCartilagenousSynchondrosisSymphysisEpiphyseal platesIntervertebral discsFibrousSuturesSyndesmosesGomphosisSkullDistal Tibia/fibulaTeeth in socketsSynovialGlenohumeral jointKnee jointTMJ

Cartilaginous Joint -- SynchondrosisBones are joined by hyaline cartilagerib attachment to sternumepiphyseal plate in children binds epiphysis and diaphysis

Cartilaginous Joint -- Symphysis2 bones joined by fibrocartilagepubic symphysis and intervertebral discsOnly slight amount of movement is possible

Immovable fibrous jointsbind skull bones together

Fibrous Joint -- Sutures

Fibrous Joint -- GomphosesAttachment of a tooth to its socket Held in place by fibrous periodontal ligamentcollagen fibers attach tooth to jawboneSome movement while chewing

Two bones bound by ligament onlyinterosseus membraneMost movable of fibrous jointsInterosseus membranes unite radius to ulna and tibia to fibulaFibrous Joint -- Syndesmosis

General AnatomyArticular/ joint capsule encloses joint cavitycontinuous with periosteumlined by synovial membraneSynovial fluid (in the joint cavity) = slippery fluid; feeds cartilagesArticular cartilage = hyaline cartilage covering the joint surfacesArticular discs and meniscijaw, wrist, sternoclavicular and knee jointsabsorbs shock, guides bone movements and distributes forcesTendon attaches muscle to boneLigament attaches bone to bone

Synovial Joint

Synovial JointJoint in which two bones are separated by a space called a joint cavityMost are freely movable

Types of Synovial Joints

Ball-and-Socket JointsSmooth hemispherical head fits within a cuplike depressionhead of humerus into glenoid cavity of scapulahead of femur into acetabulum of hip boneMultiaxial joint

Condyloid (ellipsoid) JointsOval convex surface on one bone fits into a similarly shaped depression on the nextradiocarpal joint of the wrist metacarpophalangeal joints at the bases of the fingersBiaxial joints

Saddle JointsEach articular surface is shaped like a saddle, concave in one direction and convex in the othertrapeziometacarpal joint at the base of the thumbBiaxial jointmore movable than a condyloid or hinge joint forming the primate opposable thumb

Gliding JointsFlat articular surfaces in which bones slide over each otherLimited monoaxial jointConsidered amphiarthroses

Hinge JointsOne bone with convex surface that fits into a concave depression on other boneulna and humerus at elbow jointfemur and tibia at knee jointfinger and toe jointsMonoaxial joint

Pivot JointsOne bone has a projection that fits into a ringlike ligament of anotherFirst bone rotates on its longitudinal axis relative to the otheratlantoaxial joint (dens and atlas)proximal radioulnar joint allows the radius during pronation and supination

The Humeroscapular JointMost freely movable joint in the bodyshallowness and looseness deepened by glenoid labrumSupported by ligaments and tendons glenohumeral (superior, middle, inferior), coracohumeral, transverse humeral and biceps tendon are important joint stabilizerSupported by rotator cuff musculaturetendons fuse to joint capsule and strengthens itsupraspinatus, infraspinatus, teres minor and subscapularis, 4 Bursae associated with shoulder joint

Stabilizers of the Shoulder Joint

Tendons of Rotator Cuff Muscles

Shoulder JointShoulder DisordersThe shoulder is the most commonly dislocated joint in the body. The major ligaments cross the superior part of the shoulder joint, and no major ligaments or muscles are associated with the inferior side. As a result, dislocation of the humerus is most likely to occur inferiorly into the axilla. Because the axilla contains very important nerves and arteries, severe and permanent damage may result from attempts to relocate a dislocated shoulder using inappropriate techniques. Chronic shoulder disorders include tendonitis (inflammation of tendons), bursitis (inflammation of bursae), and arthritis (inflammation of joints).

The Elbow JointSingle joint capsule enclosing the humeroulnar and humeroradial jointsHumeroulnar and humeroradial joint is supported by collateral ligaments.Radioulnar joint is head of radius held in place by the anular ligament encircling the head

Elbow Joint

The Coaxal (hip) JointHead of femur articulates with acetabulumSocket deepened by acetabular labrumBlood supply to head of femur found in ligament of the head of the femur (round ligament)Joint capsule strengthened by ligaments

Hip JointJoint capsule strengthened by ligamentspubofemoralischiofemoraliliofemoral

Hip Joint

Dissection of Hip Joint

HIP JOINTHip DislocationDislocation of the hip may occur when the hip is flexed and the femur isdriven posteriorly, such as when a person sitting in an automobile isinvolved in an accident. The head of the femur usually dislocatesposterior to the acetabulum, tearing the acetabular labrum, the fibrouscapsule, and the ligaments. Fracture of the femur and the coxa oftenaccompany hip dislocation.

The Knee JointMost complex diarthrosis patellofemoral = gliding jointtibiofemoral = gliding with slight rotation and gliding possible in flexed positionJoint capsule anteriorly consists of patellar ligament and extensions of quadriceps femoris tendonCapsule strengthened by extracapsular and intracapsular ligaments

Knee Joint Sagittal Section

Knee Joint Anterior and Posterior ViewsAnterior and posterior cruciate ligaments limit anterior and posterior sliding movementsMedial (tibial) and lateral (fibular) collateral ligaments prevent rotation of extended knee

Knee Joint Superior ViewMedial and lateral meniscus absorb shock and shape joint

Dissection of Knee Joint

ANKLE JOINTThe distal tibia and fibula form a highly modified hinge joint with the talus called the ankle, or talocrural joint

ANKLE JOINT

ANKLE JOINT

Ankle InjuryThe ankle is the most frequently injured major joint in the body. The most common ankle injuries result from forceful inversion of the foot. A sprained ankle results when the ligaments of the ankle are torn partially or completely. The calcaneofibular ligament tears most often, followed in frequency by the anterior talofibular ligament. A fibular fracture can occur with severe inversion because the talus can slide against the lateral malleolus and break it.

ANKLE JOINT

Artificial Joints~ Arthroplasty is replacement of diseased joint with artificial device called prosthesis

Range of MotionDegrees through which a joint can moveDetermined bystructure of the articular surfacesstrength and tautness of ligaments, tendons and capsulestretching of ligaments increases range of motiondouble-jointed people have long or slack ligamentsaction of the muscles and tendonsnervous system monitors joint position and muscle tone

Axes of RotationShoulder joint has 3 degrees of freedom = multiaxial jointOther joints monoaxial or biaxial

Types of MovementGliding MovementsGliding movements are the simplest of all the types of movement. These movements occur in plane joints between two flat or nearly flat surfaces where the surfaces slide or glide over each other. These joints often give only slight movement, such as between carpal bones.

Angular MovementsThe most common angular movements are flexion and extension and abduction and adduction.

Flexion, Extension and HyperextensionFlexion decreases the angle of a jointExtension straightens and returns to the anatomical positionHyperextension = extension beyond 180 degrees

Flexion, Extension and Hyperextension

Abduction and AdductionAbduction is movement of a part away from the midline hyperabduction raise arm over back or front of headAdduction is movement towards the midlinehyperadduction crossing fingers

Elevation and DepressionElevation is a movement that raises a bone verticallymandibles are elevated during biting and clavicles during a shrugDepression is lowering the mandible or the shoulders

Protraction and RetractionProtraction = movement anteriorly on horizontal planethrusting the jaw forward, shoulders or pelvis forwardRetraction is movement posteriorly

CircumductionMovement in which one end of an appendage remains stationary while the other end makes a circular motionSequence of flexion, abduction, extension and adduction movementsbaseball player winding up for a pitch

RotationMovement on longitudinal axisrotation of trunk, thigh, head or armMedial rotation turns the bone inwardsLateral rotation turns the bone outwards

Supination and PronationIn the forearm and footSupination rotation of forearm so that the palm faces forwardinversion and abduction of foot (raising the medial edge of the foot)Pronationrotation of forearm so the palm faces to the reareversion and abduction of foot (raising the lateral edge of the foot)

Movements of Head and TrunkFlexion, hyperextension and lateral flexion of vertebral column

Rotation of Trunk and HeadRight rotation of trunk; rotation of head

Movements of MandibleLateral excursion = sideways movement Medial excursion = movement back to the midlineside-to-side grinding during chewingProtraction retraction of mandible

Movement of Hand and DigitsRadial and ulnar flexionAbduction of fingers and thumbOpposition is movement of the thumb to approach or touch the fingertipsReposition is movement back to the anatomical position

Movements of the FootDorsiflexion is raising of the toes as when you swing the foot forward to take a step (heel strike)Plantarflexion is extension of the foot so that the toes point downward as in standing on tiptoeInversion is a movement in which the soles are turned mediallyEversion is a turning of the soles to face laterally

Description of Selected JointsShoulder Joint

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