Which structure primarily provides cushioning and reduces friction in joints?

The correct answer is cartilage because it plays a crucial role in joint function by providing cushioning between bones and reducing friction during movement. Cartilage is a type of connective tissue that is smooth and resilient, allowing it to absorb shock and distribute load evenly across the joint surfaces. This property is essential for maintaining joint health and function, particularly in weight-bearing joints such as the knees and hips, where excessive friction could lead to wear and tear.

The synovial membrane, while important in producing synovial fluid that lubricates joints, does not itself provide cushioning. Tendons connect muscles to bones and facilitate movement but do not function to cushion joints. The joint capsule surrounds the joint and helps keep the joint structure intact, but it does not directly provide the cushioning effect that cartilage does. Thus, in the context of cushioning and friction reduction in joints, cartilage is the primary structure responsible for these functions.