What is the primary function of the bursae?

The primary function of the bursae is to reduce friction between tissues, particularly in areas where there is movement between bones, tendons, and muscles. Bursae are small, fluid-filled sacs that act as cushions, providing a smooth surface for the movement of these structures against each other. This reduction of friction helps to prevent wear and tear on the tissues and allows for smoother and more efficient movement at the joints.

In contrast, other options focus on different aspects of musculoskeletal function. Providing structural support to bones relates more to the role of skeletal components and ligaments. Storing calcium is primarily associated with the bones themselves, which serve as a reservoir for calcium vital for other bodily functions, including muscle contraction and nerve signaling. Facilitating muscle contraction refers to the role of muscles and their interactions with the nervous system, rather than the protective and lubricating function of bursae. Therefore, the role of the bursae as friction reducers highlights their importance in maintaining joint health and mobility.