Lecture 10 Flashcards
What features do all synovial joints have? What additional features can they have?
Bone ends, articular cartilage, capsule, cavity, synovial membrane and capsular ligaments. Additional features are intracapsular ligaments and bursae (bursa).
What are bursa?
A small fluid filled sac lined by synovial membrane which provides cushioning between bones and tendons or muscles between joints.
What is the relationship between stability and mobility in joints? Why?
A joint with high stability can not be highly mobile and vice versa, this means there is a trade off between the to.
This occurs because high stability is given by high bone congruence and as such this restricts movement. In synovial joints mobility is often more favoured.
What terms describe movements?
Planes e.g sagittal, coronal or transverse. The amount of axes moved through, this can be uniaxial, biaxial or multiaxial. The range of movement.
What determines the range of movement?
The bone end shapes, ligament location and length and body surface contact.
What are the different synovial joint shapes?
Hinge, pivot, saddle, ellipsoid, condylar, plane and ball and socket
What are the uniaxial joints? What do they do and where can they be found?
Hinge joint: can either undergo flexion or extension e.g ankle, elbow (humerus with ulna) and interphalangeal joints.
Pivot joint: Allows rotation of one bone around another, a good example of this is the radioulnar joint (supination and pronation) or the C1-C2 vertebrae joint.
What are the biaxial joints? What do they do and where can they be found?
Saddle joint: flexion, extension, abduction, adduction (circumduction), leads to obligatory rotation (allowing for opposition), the only example of this is the carpometacarpal joint at the base of the thumb.
Ellipsoid joint: allows flexion, extension, abduction and adduction (circumduction), has no rotation and a good example of this is the wrist/radiocarpal joint.
Condylar joint: allows for flexion, extension and rotation (only when the knee is bent and only slight).
What are the multiaxial joints? What do they do and where can they be found?
Plane joint: Allows for sliding and gliding in all directions via flat articulated surfaces, the best example of this is the intercarpal and intertarsal joints.
Ball and socket: flexion, extension, abduction, adduction (circumduction) and rotation, examples of this are the shoulder or the hip.
What does opposition refer to in regard to joints?
The ability of the thumb to touch all other digits of the hand.
