Final answer:
Free synovial fluid molecules provide lubrication to synovial joints, reducing friction and facilitating smooth bone movement. Articular cartilage and ligaments also play crucial roles in enabling joint mobility and stability.
Step-by-step explanation:
The student question is: Free synovial fluid molecules provide lubrication to joints between movable bones. In biology, synovial joints are known for their freedom of movement, facilitated by the presence of synovial fluid. This lubricating fluid is secreted by the synovial membrane and fills the synovial cavity of a joint, reducing friction between the articular cartilage of the connecting bones and allowing for smooth, lubricated motion.
Additionally, the articular cartilage, which covers the ends of the bones in the joint, acts like a Teflon coating, allowing the bones to glide over each other with minimal resistance. Ligaments support the joint by holding the bones together and preventing excess or abnormal motions. Thus, the synovial fluid, articular cartilage, and supporting ligaments collectively enable the wide range of motion seen in synovial joints such as the knees, elbows, and shoulders, which is essential for various bodily movements.