Final answer:
The articular cartilage is a thin layer of hyaline cartilage that covers the articulating surfaces of bones at a synovial joint. It prevents friction between the bones, allowing smooth movement. The presence of the articular cartilage and synovial fluid reduces friction and nourishes the cartilage.
Step-by-step explanation:
Friction between the bones at a synovial joint is prevented by the presence of the articular cartilage, a thin layer of hyaline cartilage that covers the entire articulating surface of each bone. Lining the inner surface of the articular capsule is a thin synovial membrane. The cells of this membrane secrete synovial fluid, a thick, slimy fluid that provides lubrication to further reduce friction between the bones of the joint. This fluid also provides nourishment to the articular cartilage, which does not contain blood vessels. Each synovial joint is functionally classified as a diarthrosis due to its ability to allow smooth movement between bones within the joint cavity.