1. Joints
Chapter 8

2. Classifying Joints Functions
Flexibility for movement
Hold bones together
Structural Classification (binding tissue and cavity)
Fibrous
Cartilaginous
Synovial
Functional Classification (amount of movement)
Synarthroses – immovable; axial skeleton
Amphiarthroses - slightly movable; axial skeleton
Diathroses - freely moveable; limbs

3. Organizing Joints Fibrous Joints Cartilaginous Joints Synovial Joints
Binding material
Joined by fibrous tissue
Joined by articular (hyaline) cartilage
Separated by synovial fluid cavity
Cavity Present No
Yes
Functional Type
Synarthroses
Amphiarthroses
Diarthroses
Examples
Sutures
Syndesmoses
Gomphoses
Synchondroses
Symphyses
Joints of limbs

4. Fibrous Joints Sutures Syndemoses Gomphoses Only b/w skull bones
Bind, but allow growth
Complete as an adult (synostoses)
Syndemoses
Longer than sutures
Length determines mov’t*
Interosseous membrane and tibia-fibula distal ends
Gomphoses
Tooth in alveolar socket
Periodontal ligament

5. Cartilaginous Joints Synchondroses Symphyses
Temporary, become synostoses
Epiphyseal plates and coastal cartilage
Symphyses
Cartilage fused to fibrocartilage pad/plate
Strength with flexibility
Intervetevbral discs and pubic symphysis

6. Synovial Joints Articular cartilage Joint (synovial) cavity
Articular capsule
Fibrous capsule (ext-) DICT
Synovial membrane (int-) LCT
Synovial fluid
Viscous, but thins with mov’t
Reinforcing ligaments
Double jointed = looser/stretchier ligmanents and capsule
Rich blood and nerve innervation
Fatty pads for cushioning (hip and knee)
Menisci divide cavity and improve fit (knee and jaw)

7. Synovial Joints Preventing friction Stability
Bursae are flattend fibrous synovial sacs
Tendon sheaths are elongated bursa wrapped around a tendon
Stability
Articular surface shape
Determine mov’t & some stability
Ligaments
Prevent excessive/undesirable mov’t
Inadequate than stay stretched (taffy) = snapping
Muscle tone
Tendons stay taut so reactive

8. Joint Articular Shapes
Plane - articular surface is flat, nonaxial
Intercarpal and –tarsals; slip 1 or 2 ways
Hinge – cylindrical projection to a trough
Elbow and interphalengeal; 1 plane of mov’t
Pivot – rounded end into ring or “sleeve”
C1 & C2 or radius & ulna; 1 plane of mov’t
Condyloid - oval surface into a depression
Metacarpophalangeal (knucles); 2 planes of mov’t
Saddle – concave and convex surface
Carpometacarpal thumb joint; 2 planes of mov’t
Ball and socket – spherical end with a cup-like socket
Shoulder or hip joint; 3 planes mov’t

9. Synovial Movements Rotation/circumduction Inversion/eversion
Turning on an axis/ making small circles
Inversion/eversion
Turn sole medially/ turn sole laterally
Dorsiflexion/plantar flextion
Flex/ point
Protraction/retraction
Jaw out/jaw in
Elevation/depression
Lift superiorly/move inferiorly
Gliding
Slips surfaces across one another
Flexion/extension
Reduces angle of joint/ increases angle
Abduction/adduction
Away from center/ toward midline
Pronation/supination
Face or palm down/ face or palm up

10. Knee Joint Single cavity w/ 3 joints Capsule partially encloses
Strong vertical force, weak lateral
Patellar ligament (knee-jerk)
Prevent hyperextension
Fibular and tibial collateral ligaments
Prevent lateral and medial rotation w/ extension
Anterior and posterior cruciate ligaments (tibial attach)
Prevent forward sliding of tibia; back displacement of tibia or forward femur
Posteriorly, medially, up; anteriorly, laterally, up
Lateral and medial meniscus
anterior
cruciate
ligament

11. Temporomandibular Joint (TMJ)
Mandibular condyle is egg-shaped
Temporal bone is knob forward, concave fossa
Side-to-side is lateral exclusion, unique to mammals
Shallow socket = easy dislocation
Reset: thumbs in molars, push inferior and posterior
Pain from muscles tension

12. Clinical Terms Sprain: stretching/tearing of a ligament
Dislocation (luxation): bones forced out of position
Bursitis: inflammation on bursa; blow or friction
Arthritis: synovial membrane thickens, production decrease
Osteoarthritis – degenerative; tissue thickens & bone spurs formed
Rheumatoid arthritis - autoimmune
Gouty arthritis – uric acid accumulation in soft tissue joints
Synovitis: inflammation of synovial membrane
Tendinitis: inflammation of tendon sheaths, overuse;