What is the primary function of cartilage in the joints?

The primary function of cartilage in the joints is to cushion and reduce friction between bones. Cartilage is a smooth, flexible tissue that covers the ends of bones where they meet at a joint, allowing for easier movement and articulation. This smooth surface helps to minimize wear and tear on the bones during movement, effectively acting as a shock absorber. By reducing friction, cartilage enables joints to move freely and comfortably, preventing damage that could lead to conditions such as arthritis.

In contrast, the other options pertain to different functions within the musculoskeletal system. For example, while structural support to muscles is important, it is primarily the role of tendons, not cartilage. Additionally, the storage of calcium and phosphorus is a function associated with bone tissue, not cartilage, and blood supply to bones is managed by the vascular system, rather than being a direct role of cartilage. Thus, the role of cartilage as a cushioning agent in joints is vital for maintaining joint health and facilitating movement.