What are the two ways to classify bones?
- the amount of movement
- structural binding
What are 2 factors that affect how mobile the joint is?
- bone congruency: how well the bones fit together
- binding tissues: capsules, ligaments, etc
Define diarthroses and the factors that create it. Give an example.
- mobile joint
- poor congruency and/or loose binding tissues
- ex: shoulder
Define synarthroses and the factors that create it. Give an example.
- stable joint
- good congruency and/or taut binding tissues
- ex: skull sutures
Define amphiarthroses and give an example.
- a somewhat stable joint because binding tissues is usually cartilage
- ex: pubic symphysis
What is one joint that does not really fall along the functional continuum?
-the hip
What are the 3 main structural categories of joints based on binding tissues?
- fibrous
- cartilaginous (from hyaline or fibrocartilage)
- synovial
Which is more stable- knee or elbow?
Elbow
What are the 3 subcategories of joints under fibrous joints?
- sutures: least amount of mobility b/c binding tissues is taut/short dense fibrous CT of collagen fibers
- syndesmoses: 2 joints are bound by dense fibrous regular CT, usually an interosseous membrane (not a ligament!)
- gomphoses: holds teeth in mandible/maxilla
Where are the 3 places synchondroses joints can be found in immature skeleton? and in mature skeleton?
- epiphyseal plates
- innominate fusion
- costal cartilage connecting ribs to sternum
- in mature skeleton, you only have the costal cartilage
What is synostosis?
-bone fusion: no longer have an epiphyseal disc, just a line of fusion due to hormonal changes that closed up the cartilage
What are the 2 subcategories of joints under cartilaginous joints?
- synchondroses
- symphysis
What are the 2 fibrocartilage/symphyses?
- intervertebral disks
- pubic symphsysis
List the 5 parts of a synovial joint
- fibrous joint capsule made of dense fibrous irregular CT (primarily collagen ) holds everything together with a joint cavity
- hyaline cartilage (articular cartilage) covers the bony ends (see other card for fxns)
- synovial membrane lines the joint capsule and produces synovial fluid as lubricant to reduce friction and nourish the joint during movement
- fibrocartilage pads (articular discs or menisci) to increase bone congruency and reduce compressional stresses by increasing area that force is placed (F/A=stress)
- 3 types of ligaments (intrinsic, extrinsic/bone-to-bone, capsular/joint-to-bone) to support the joint capsule by limiting ROM in specific directions
What is the function of articular cartilage covering the bony ends of synovial joints?
- provides smooth surface on ends of bones to reduce frictional forces and stresses associated w/ movement
- will deform when loaded to distribute forces amongst greater area to reduce compressional stress
What are the three types of ligaments found in synovial joints?
- intrinsic (within the joint)
- extrinsic (attaches bone to bone)
- capsular (most common; attaches joint to one bone)
What is an axis of rotation?
an imaginary rod, passing through the “center” of joint perpendicular to the plane of movement
What are the 3 joint motions in arthrokinematics?
- spinning: one bone turns about its axis of rotation (axis of rotation stays in the same place)
- translation/gliding: axis of rotation moves in one direction to new position
- rolling: joint distraction; bone is turning at different pivot point (not the axis of rotation)
What does it mean to be double-jointed?
increased ROM because either fibrous joint capsule/ligaments are loose or decreased bone congruency
What happens when we pop our knuckles?
trapped gas in synovial fluid escapes with extreme ROM increases pressure in joint
What is a synonym for dislocation and what is it? What is a less severe version?
- luxation; 2 articulating surfaces are out of place
- subluxation; not completely displaced
What is a sprain?
tearing of a joint capsule or ligament
What is a strain?
tearing of a muscle or tendon
What is arthritis? 2 types.
- joint inflammation
- rheumatoid: affects multiple synovial joints
- osteoarthritis: joint-specific
