Joints Flashcards
(87 cards)
Structural Classifications of Joints
Fibrous, Cartilaginous, Synovial
Functional Classification of Joints
Synarthroses, amphiarthroses, diarthroses
Synarthroses
Immovable Joints
Amphiarthroses
Slightly movable joints
Diarthroses
Freely movable joints
Fibrous Joints
Bones joined by fibrous tissue. No joint cavity present.
Amount of movement allowed depends on length of connective tissue fibres.
Mostly synarthroses. Some amphiarthroses.
Includes sutures, syndesmoses, and gomphoses.
Sutures
Fibrous joints occurring only in the skull.
Wavy articulating bone edges interlock and the junction is completely filled by a minimal amount of very short connective tissue fibres.
Synostoses
Sutures which are ossified, fused.
Syndesmoses
Fibrous joint in which bones are connected by a ligament.
Synarthroses and amphiarthroses.
Gomphoses
Articulations of the teeth with bony alveolar sockets.
Fibrous joints joined by the periodontal ligaments.
Synarthroses.
Cartilaginous Joints
Articulating bones are united by cartilage. Lack joint cavity.
Synarthroses and amphiarthroses.
Includes synchondroses and symphyses.
Synchondroses
Cartilaginous joints joined by a bar or plate of hyaline cartilage.
Almost all synarthrotic.
Symphyses
Cartilaginous joints in which the articular surfaces of the bones are covered with articular cartilage, which in turn is fused to an intervening plate of fibrocartilage.
Amphiarthrotic.
Synovial Joints
Joints in which the articulating bones are separated by a fluid-containing joint cavity.
All are diarthroses.
Distinguishing Features of Synovial Joints (5)
Articular cartilage, joint cavity, articular capsule, synovial fluid, reinforcing ligaments.
Articular Cartilage
Glassy-smooth hyaline cartilage which covers the opposing bone surfaces in a synovial joint.
Joint Cavity
Potential space of synovial joint that contains a small amount of synovial fluid.
Articular Capsule
Two-layered capsule enclosing the synovial joint cavity.
Consists of the fibrous capsule and the synovial membrane.
Fibrous Capsule
External layer of the articular capsule of a synovial joint, composed of dense irregular connective tissue. Strengthens the joint.
Synovial Membrane
Inner layer of the synovial joint capsule which is composed of loose connective tissue. Covers all internal joint surfaces that are not hyaline cartilage and secretes synovial fluid.
Synovial Fluid
Lubricating fluid derived by filtration from blood flowing through the capillaries in the synovial membrane of a synovial joint.
Provides a weight-bearing film that reduces friction between cartilages.
Also contains phagocytic cells that rid the joint cavity of microbes and debris.
Reinforcing Ligaments
Bandlike structures which reinforce and strengthen synovial joints.
Bursae
Flattened sacs lined with synovial membrane and containing a thin film of synovial fluid.
Common where parts of synovial joints rub together.
Factors Effecting the Stability of a Synovial Joint
Shapes of the articular surfaces, number/positioning of ligaments, muscle tone