Flashcards in Lecture 10: Movement of Synovial Joints Deck (17)
What determines the amount and direction of movement?
- Joint Structure
What is the structure of synovial joints?
- Bone ends
- Articular Cartilage (covering bone ends)
Purpose: Smooth, shiny, frictionless
Purpose: To keep two bony ends together, made of DFCT, sleeve-like continuation of periosteum
Allows actual movement of joints, allowing space for it to occur
- Synovial Membrane
Fluid that fills joint space and helps create frictionless environment, articular cartilage does not have blood supply so can not heal quickly, it gets rid of its waste through synovial fluid
So close together with capsule that we can't dissect them out, made out of DFCT, purpose is to resist separation of bone ends
Any additional features of Synovial Joints?
- Articular Cartilage
- Ligaments on outside of joint AND inside joint - intracapsular (cruciate) ligaments to prevent movement of tibia in one direction and femur in the other
Made of fibrocartilage, little shock absorbers, crescent like discs. Top of tibia is like a plate, distal end of femur is like a ball - would make a poor joint. Meniscus cups condyles of femur and gives a better fit / bony congruence.
How do we see things using camera inside body?
Fluid is injected in
What is Bursa / House Maid Knee?
Tiny little fluid filled sacs, located behind (quadriceps) tendon, sometimes they become inflamed
What is the joint design principle?
There has to be a trade-off between stability and mobility
How many axes are there?
What determines range of movement?
- Bone end shape
- Body Surface Contact
How much movement is possible?
By using a big protractor,
What are the different synovial joint shapes?
- Ball and Socket
What does the hinge joint do? Give examples
- Allows movement in one plane (uniaxial)
- Ankle, elbow (humerus + ulna)
What does the pivot joint do? Give examples
- Rotation in transverse plane
- eg. proximal and distal radioulnar joint
Fibrous on the inside, keeps bones together
What does the saddle joint do? Give an example
- Biaxial (+) : circumduction
- Obligatory rotation (because of opposition
- Looks like two saddles
- eg. Base of first metacarpal + first carpal bone (carpometacarpal)
What does the ellipsoid joint do? Give examples
- Convex and concave surfaces, radius + carpal, radiocarpal joint
- Biaxial : circumduction
- NO rotation
What does the condylar joint do? Give examples
- Biaxial : flexion / extension
- e.g. knee, TMJ (jaw + skull joint)
What is a plane joint? Give examples
- Multiaxial: sliding and gliding can occur in any direction
- Flat articular surfaces
- e.g. intercarpal and intertarsal joints