2IntroductionJoints, or articulations, are connections between bones that may or may not permit movement.Cartilage, fluid, or dense connective tissues is usually involved in holding joints together.Joints maybe classified structurally or functionally
3Classification of Articulations - Structural Structural Classification1) Fibrous – No joint cavity – fibrous tissuea) Suture – very thin fibrous tissueif fused – synostosesb) Syndesmosis – broader fibrous tissuefontanelc) Gomphosis – peg in coneexample: tooth in jaw2) Cartilaginous – No joint cavity – Cartilagea) Synchondrosis – hyaline cartilageepiphyseal plateb) Symphysis – fibrocartilagesymphysis pubis and intervertebral disks3) Synovial – Joint (Synovial) cavitya) Gliding – intertarsalb) Hinge – knee and anklec) Pivot – atlantoaxiald) Condyloid or Ellipsoidal – wriste) Saddle – thumbf) Ball and Socket – should and hip
4Classification of Articulations Functional Functional Classification of Joint1) Synarthroses – Immovable Jointsa) Sutureb) Gompohsisc) Synchondrosis2) Amphiarthrosis – Slightly movable jointsa) Symphysis – pubic symphysisb) Syndesmosis - tibia and fibula3) Diarthrosis – Freely movablea) Gliding – glidingb) Hinge – flex and extend (1 plane)c) Pivot – rotation – 1 planed) Condyloid or Ellipsoidal – 2 planesflex, extend, abduct and adducte) Saddle – – 2 planesf) Ball and Socket – (3 planes)flex, extend; abduct adduct; and medial and lateral rotation
5Synarthroses (Immovable Joints) Sutures are joints found only in the skull.Bony edges interlock and short dense connective tissue fiber hold the bones together.A gomphosis is the joint between a tooth and the alveolar fossa of the maxillae or mandible.Periodontal ligaments (PDL) hold the tooth to the bone in the gomphosis.A synchondrosis is a joint in which hyaline cartilage separates the ends of the bones involved in the joint.A synostosis occurs if bones fuse together to form one bone.
6Amphiarthroses (Slightly Movable Joints) A syndesmosis occurs when to bones are connected by relatively long connective tissue ligaments.Connecting bones using a fibrocartilage pad forms a symphysis.
7Diarthroses (Freely Movable Joints) Synovial joints are typically found at the ends of long bones in the upper and lower limbs.All synovial joints have six basic characteristics:A joint capsuleArticular cartilagesA joint cavity filled with synovial fluidA synovial membrane lining the joint capsule
8Synovial JointsFigure 8.1 Structure of a Synovial Joint
9Synovial fluid has three functions: Lubricates the surfaces of the articular cartilages on the ends of the bones.Nourishes the chondrocytes by entering and exiting the articular cartilages due to the forces acting on the joint.Acts as a shock absorber.
10Types of MovementsAngular movementsRotationPLAYMovements
11Movements at the ankle include: Special MovementsMovements at the ankle include:Eversion/inversionDorsiflexion/plantar flexionMovement of the vertebral column includes:Lateral flexionMovement of the pollex (thumb):Opposition/reposition
12Movements that occur at many joints include: Special MovementsMovements that occur at many joints include:Protraction: anterior movement in the horizontal planeRetraction: posterior movement in the horizontal planeElevation: cranial movement in the vertical axisDepression: caudal movement in the vertical axis
13Structural Classification of Synovial Joints Plane joints: Nonaxial or multiaxialHinge joints:flexion and extensionPivot joints:rotational movementsPLAYJoint Structure
14Structural Classification of Synovial Joints Condylar joints:flexion/extension and abduction/adductionSaddle joints:biaxial joints that also allow circumductionBall and socket joints:triaxial joints
15The Temporomandibular Joint Figure 8.7a,b The Temporomandibular Joint (TMJ)
17There are four possible movements of the vertebral column: Vertebral MovementsThere are four possible movements of the vertebral column:Anterior flexion, or bending forwardExtension, or bending backwardLateral flexion, or bending to the sideRotation–twisting
18The Sternoclavicular Joint Figure The Sternoclavicular Joint
19The Shoulder Joint Figure 8.11a The Anterior Shoulder Figure 8.11b The Lateral Shoulder