1. Articulations – where two bones connect
a. Synarthrosis (immovable joint)
Very strong - edges of bone may touch or interlock
i. Suture (fibrous) – only in bones of the skull
ii. Gomphosis (fibrous) – only between tooth and socket
iii. Synchondrosis (cartilaginous-rigid) – end of first pair of rib to sternum
iv. Synostosis (bony fusion) – epiphyseal lines & coronal suture
b. Amphiarthrosis (slightly movable Joint)
i. Syndesmosis (fibrous) – connection by ligament – distal tibia & fibula
ii. Symphysis (Cartilaginous) – uses wedge or pad of fibrocartilage – like pubic symphysis
c. Diarthrosis (freely movable joint) (Synovial)
Movable joints – at ends of long bones – within articular capsules – lines with synovial membrane. synovial fluid, hyaline cartilage at ends of bone.
i. Monoaxial – Movement in one plane
ii. Biaxial – movement in two planes
iii. Triaxial – movement in three planes
1. Synovial Fluid
a. Lubrication
b. Shock absorption
c. Nutrient distribution
2. Accessories
a. Cartilages
i. Cushion the joint
ii. A fibrocartilage pad is a MENISCUS
b. Fat pads
i. Superficial to joint capsule
ii. Protect articular cartilages
c. Ligaments
i. Support and Strengthen
ii. Sprain=ligament with torn collagen fibers
d. Tendons
i. Attach to muscle around joint
ii. Help support joint
e. Bursae – (singular = bursa)
i. Pockets of synovial fluid
ii. Cushion where ligaments or tendons might rub.
3. Factors That Stabilize Synovial Joints
a. Prevent injury by limiting ROM
i. Collagen fibers (joint capsule, ligaments)
ii. Articulating surfaces and menisci
iii. Other bones, muscles or fat pads
iv. Tendons of articulating bones.
4. Injuries
a. Dislocation (luxation ) – Forced out of position
b. Subluxation – partial dislocation
5. Types Of Articular Movement
a. Gliding movement – Between carpals or tarsals
b. Angular Movement
c. Circumduction
d. Rotation
6. Angular Movement
a. Flexion (reduces angle in ant/post plane)
b. Extension (increases angle in ant/post plane)
c. Hyperextension – extension past anatomical position
d. Abduction – (away from longitudinal axis in frontal plane)
e. Adduction – (Toward longitudinal axis in frontal plane)
f. Circumduction
g. Rotation (left, right, medial, lateral
h. Pronation
i. Supination
j. Inversion
k. Eversion
l. Dorsiflection (lifts toes)
m. Plantar flection (points toes)
n. Oposition
o. Reposition
p. Protraction
q. Retraction
r. Elevation
s. Depression
t. Lateral flection
iv. Types Of Synovial Joints By Shape
1. Gliding – limited motion
a. Acromioclavicular and claviculosternal joints
b. Intercarpal and intertarsal joints
c. Vertebrocostal joints
d. Sacro-illiac joints
2. Hinge – monoaxial
a. Elbow joint
b. Knee joint
c. Ankle joint
d. Interphalangeal joint
3. Pivot – rotation only (monoaxial)
a. Atlanto-axial joint
b. Proximal radio-ulnar joint
d.
e.
f.
g.
h.
4. Condylar – biaxial – oval articular face within depression
a. Radiocarpal join
b. Metatarsal phalangeal joints
c. Metacarpophalangeal joints 2 – 5
5. Saddle
a. First carpometacarpal joint
6. Ball-and-socket
a. Shoulder joint
b. Hip joint
The greater the mobility, the weaker the joint
Intervertebral Discs
i. Nucleus pulposis – inner layer – elastic gelatinous core
1. Absorbs shock
2. Can conform to motion
ii. Anulus fibrosis – outer layer – tough
1. attaches disc to vertebrae
Slipped Disc
i. Bulge in annulus fibrosus
ii. Invades vertebral canal
Herniated Disc
i. Nucleus pulposus breaks through annulus fibrosus
ii. Presses on spinal cord or nerves
Six Intervertebral Ligaments
i. Anterior longitudinal ligament – Connects anterior bodies
ii. Posterior longitudinal ligament – Connects posterior bodies
iii.
iv.
v.
vi.
Ligamentum Flavum – Connects laminae
Interspinous ligament – connects spinous processes
Supraspinous ligament - tips of spinous processes (C7 to sacrum)
Ligamentum nuchae – (C7 to skull)