1. Joints
Chapter 8

2. Classifying Joints Functions Classification Flexibility for movement
Hold bones together
Structural
Functional
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
(immovable)
Amphiarthroses
(slightly movable)
Diarthroses
(freely movable)
Examples
Sutures
Syndesmoses
Gomphoses
Synchondroses
Symphyses
Joints of limbs

3. Fibrous Joints Sutures Syndemoses Gomphoses Only b/w skull bones
Bind, but allow growth
As an adult CT ossifies = synostoses
Syndemoses
Longer than sutures
Length of ligament determines mov’t
E.g interosseous membrane and tibia-fibula distal ends
Gomphoses
Tooth in alveolar socket
E.g periodontal ligament

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

5. Synovial Joint Structure
Synovial cavity filled w/ synovial fluid
Viscous, but thins with mov’t
Articular capsule enloses cavity
Fibrous capsule (ext-) DICT
Synovial membrane (int-) LCT
Articular cartilage (hyaline)
Reinforcing ligaments
Double jointed = looser/stretchier
ligaments and capsule

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

7. Synovial Joint Shapes Plane - intercarpal and –tarsals
Slip 1 or 2 ways (A)
Hinge – elbow and interphalengeal
1 plane of mov’t (B)
Pivot – C1 & C2 or radius & ulna (C)
1 plane of mov’t
Condyloid - metacarpophalangeal (knucles)
2 planes of mov’t (D)
Saddle – carpometacarpal joint (thumb)
2 planes of mov’t (E)
Ball and socket – shoulder or hip joint
3 planes mov’t (F)

8. Synovial Joint Movements
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
Rotation/circumduction
Turning on an axis/ making small circles
Inversion/eversion
Turn sole medially/ turn sole laterally
Dorsiflexion/plantar flexion (foot and wrist)
Flex/ point
Protraction/retraction
Jaw out/jaw in
Elevation/depression
Lift superiorly/move inferiorly

9. 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 attachment)
ACL: runs up posteriorly & laterally; prevents forward tibia mov’t
PCL: runs up anteriorly & medially; prevents backward tibia & forward femur mov’t
Lateral and medial meniscus
anterior
cruciate
ligament

10. Temporomandibular Joint (TMJ)
Mandibular condyle and fossa mismatched shape
Shallow socket = easy dislocation
Reset: thumbs in molars, push inferior and posterior
Pain and disorders from muscles tension
Lateral exclusion, side to side mov’t, unique to mammals
Grinding, clenching, biting

11. 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;