Joints & Joint Features Flashcards
Joints are formed where?
2 or more separate bones connect
Joints are designed for?
Movement
Amount of movement depends on?
Type of joint
Fibrous
-Joint is connected by fibrous tissue
-Degree of movement at a given joint is determined by the amount of fibrous tissue between the two joint surfaces
Sutures
-Only Occur in the skull
-Limited Movement
Syndesmosis
Bones are connected by a sheet of fibrous tissue
Cartilaginous
Joint is connected by cartilage or a combination of cartilage and fibrous tissue
Synovial
Most common joint type
3 Features of Synovial Joints
- Joint Cavity
- Articular Cartilage
- Joint Capsule
Joint Cavity
Space between the 2 joint surfaces
Articular Cartilage
- Shiny, whitish connective tissue
-Protects underlying bone
-Designed to absorb shock, allow movement, and to last
-usually hyaline cartilage
Joint Capsule
-Surrounds and lines the joint
-Does not cover the articular cartilage
-Makes the synovial fluid contained within the joints
-friction between the 2 joint surfaces is minimized by lubrication from the synovial fluid and by the articular cartilage
Condyloid
-Biaxial
-Flexion/extension and abduction/adduction
Saddle
-Biaxial
-Opposing surfaces are shaped like saddles
-Concave and convex articulate with eachother
Ball and Socket
-Multiaxial
-Spheroidal surface articulates with socket of other surface
Plane
-Gliding or sliding movements
-Joint surfaces are flat or almost flat
-Most are uniaxial
Pivot
-Uniaxial
-Rotation
-Rounded process rotates within a sleeve or ring
Hinge
-Uniaxial
-Flexion and extension only
Bursa
Sacs filled with synovial fluid that decrease the friction generated by the motion of one tissue over another
Where is bursa located between?
-Tendons and bony prominences
-Tendons and other tendons
-Bone and overlying skin
Ligaments
-Connect bone to bone
-Prevent excessive movement in a specified direction
Is movement at a joint normal?
Movement at a joint is normal - but excessive movement at a joint is potentially dangerous/can cause injury
Close-Packed Position
-Ligaments and joint capsule are tight
-Joint has maximal articular surface contact
-Increase in stability - decrease in mobility
Loose-Packed Position
The ligaments and joint capsule are loose
-Joint has maximal space and available movement
-Increase in mobility - decrease in stability
