C8 1-11 Flashcards
Explain the inverse relationship between mobility and stability within a joint.
When mobility increases, stability decreases and vice versa.
Joint/articulation
The junction of two or more bones
Structural classification of joints
Fibrous, cartilaginous, synovial
Fibrous joints characteristics
Bones are joined together by fibrous tissue (dense/reg ct) and lack a joint cavity
Cartilaginous joints characteristics
Bones are joined together by cartilage and lack a joint cavity
Synovial joints (basic) characteristics
Articulating bones separated by a fluid containing joint cavity
Functional classification of joints
Synarthroses, amphiarthrosis, diarthrosis
Synarthroses characteristic
Immovable joint
Amphiarthosis characteristic
Slightly moveable joint
Diarthrosis characteristic
Freely moveable joint
Fibrous joint types
Sutures (skull, dr/ct holds together), syndesmoses (fibula/tibia, dr/ct/ligament, slight movement), gomphoses (pegs in sockets, teeth held by ligament)
Cartilagenous joint types
Synchondrosis, Symphysis
Synovial joint characteristics 6
- articular (hyaline) cartilage on bone ends
- joint cavity filled with synovial fluid.
- joint capsule encloses the joint cavity (two-layered fibrous dr/ct and synovial membrane areolar)
- synovial fluid fills free space within the joint cavity
- reinforcing ligaments dr/ct cross the synovial joints to strengthen the joint
- sensory nerves, blood vessels and tendons (in dr/ct but not part of joint)
Bursae
Flattened, fibrous sac lined with synovial membrane and containing a thin film of synovial fluid. Occur where ligaments, muscles, skin, tendons or bones rub together. Reduce friction
Tendon sheath
Essentially an elongated bursa that wraps completely around a tendon that is subject to friction. Reduce friction.
What are three factors that stabilize synovial joints?
1. Shape of articular surfaces (plays more of a role in determining movement type, but does some stabilizing) 2. Ligaments - prevent excessive or unwanted movements (the more ligaments, greater the stability) 3. Muscle tone - keeps tendons crossing joints taut (most important factor!)
Flexion
Decreases the angle of the joint between two bones
Extension
Increases the angle of the joint between two bones
Abduction
Movement of a limb away from the midline
Adduction
Movement of a limb toward the midline
Circumduction
Moving a limb so that it describes a cone
Supination
rotating the forearm laterally so that the palm faces anteriorly or superiorly
Pronation
Rotating the arm medially so that the palm faces posteriorly or inferiorly
Inversion
Turns sole of foot so that it faces medially
Eversion
Turns sole of foot so that it faces laterally
Opposition
Touching thumb to fingers on the same hand
Knee joint - tibiofemoral
Articulating bones: Tibia/femur
Joint type: Synovial hinge w/ articular discs
Functional type: Diarthrotic with flexion/extension movement
Joint stability: shape of condyles and menisci, ligaments ACL PCL MCL LCL
Knee joint - femoropatellar
Articulating bones: Femur/patella
Structure type: Synovial-plane
Functional/movement type: Diarthrotic-gliding of patella
Joint stability: patellar ligament, bursa anterior and posterior
Osteoarthritis
Wear/tear, articular cartilage, bigger joints, unilateral
Rheumatoid arthritis
Autoimmune response, synovial membrane + articular cartilage, smaller joints, bilateral
Gouty arthritis
Uric acid deposited in soft tissues of the joints
Synchondrosis
have a bar or plate of hyaline cartilage uniting bone - epiphyseal plate. (Sternum/first rib)
Symphysis
articular surfaces are covered with articular cartilage that is fused to an intervening pad or plate of fibrocartilage (pubic symphysis, between vertebra)
Which stuctural types of joints are synarthosis?
Suture, gomphosis, synchondrosis
Which stuctural types of joints are amphiarthrosis?
symphysis
Which structural type of joint is both amphiarthrosis and synarthrosis?
Syndesmosis
