Joints and Articulations Flashcards
Fibrous joints
Bones held together by fibrous tissue with no joint cavity
Sutures
Non-mobile (fibrous) joints found in the skull
Syndesmoses
Fibrous joint in which bones are connected by ligaments; e.g. distal end of tibia and fibula
Gomphoses
Joint of the tooth and its socket
Cartilaginous joints
Bones joined together by a cartilaginous plate
Synchondroses
Bones jointed by a cartilaginous plate. Provides sources of growth in youth (usually ossified after puberty). e.g. joint between first rib and manubrium, epiphyseal plate of long bones
Symphyses
Pad between bones composed of fibrocartilage sandwiched between hyaline cartilage. Allows movement and acts as shock absorber. e.g. intervertebral joints and pubic symphysis
Synovial joints
Articulating bones separated by fluid filled joint cavity
General structure of synovial joints
1) Articular cartilage
2) Joint cavity and articular capsule
3) Synovial membrane
4) Synovial fluid
5) Reinforcing ligaments: intrinsic (part of fibrous capsule), extracapsular (found outside capsule), and intracapsular (just deep to capsule)
Bursae
Flattened sacs containing synovial fluid. Common where bones, tendons and/or ligaments rub together
False bursae
Develop at sites of excessive motion (typically within soft tissue)
Bursitis
Inflammation of a bursa. Could be due to overuse, injury, infection, continual microtrauma, etc
Tendon sheaths
Elongated bursae that wraps around a tendon subjected to friction
Factors that influence synovial joint stability
1) Articular surface: most determine range of motion rather than stability. e.g. deep ball and socket (such as hip joint) provides much stability
2) Ligaments: function to direct bone movement and prevent excessive range
3) Muscle tone: tendons crossing joint are important in stabilizing the joint; important in shoulder and knee joints
