A joint is where two or more bones meet, providing movement and holding the skeleton together.
What are the two main classifications of joints?
Joints are classified structurally as fibrous, cartilaginous, or synovial, and functionally as synarthroses (immovable), amphiarthroses (slightly movable), or diarthroses (freely movable).
What characterizes fibrous joints?
Fibrous joints have dense fibrous connective tissue, no joint cavity, and allow little to no movement.
Name the three types of fibrous joints.
The three types are sutures (skull joints), syndesmoses (bones connected by ligaments), and gomphoses (tooth in socket).
What defines cartilaginous joints?
Cartilaginous joints have bones united by cartilage, no joint cavity, and allow limited movement.
What are the two types of cartilaginous joints?
Synchondroses (hyaline cartilage, immovable) and symphyses (fibrocartilage, slightly movable).
What are the key features of synovial joints?
Synovial joints have a fluid-filled joint cavity, are freely movable, and include structures like articular cartilage, synovial fluid, and ligaments.
List the main structures of a synovial joint.
Articular cartilage, joint (synovial) cavity, articular capsule (fibrous and synovial layers), synovial fluid, ligaments, nerves, and blood vessels.
What additional structures may be found in synovial joints?
Bursae and tendon sheaths help reduce friction around synovial joints.
What factors contribute to the stability of synovial joints?
Stability depends on the shape of articular surfaces, ligament strength, and especially muscle tone.
Name the types of motion at synovial joints.
Nonaxial, uniaxial, biaxial, and multiaxial motions.
What are the main categories of movement at synovial joints?