Which features are components of a synovial joint?

• A. Joint cavity, synovial membrane, synovial fluid, articular cartilage, fibrous joint capsule, and supporting ligaments.
• B. Bones with periosteum and marrow.
• C. Cartilaginous joints only.
• D. Synovial joints do not have capsules.

Answer: (A)

What defines a synovial joint is its enclosed, movable structure that includes a cavity and protective coverings with lubrication and cushioning for smooth motion. The joint cavity provides a space between the bones, while the fibrous joint capsule forms the tough outer enclosure. Inside this capsule lies the synovial membrane, which secretes synovial fluid to lubricate the joint and reduce friction as the bones move. The ends of the bones are covered with articular cartilage, a smooth surface that minimizes wear and helps with easy gliding. Ligaments reinforce the joint by tying bone to bone and guiding movement. Together, these features—joint cavity, synovial membrane, synovial fluid, articular cartilage, joint capsule, and ligaments—define the components of a synovial joint.

The other options don’t fit because they describe aspects not specific to synovial joints: bones with periosteum and marrow are features of bone tissue rather than the joint’s lubricated, capped interface; cartilaginous joints refer to a different type of joint lacking a synovial cavity and fluid; and the idea that synovial joints lack capsules contradicts the very structural hallmark that enables their mobility and stability.