What component is primarily responsible for the mechanical properties of tendons?

Collagen is the primary component responsible for the mechanical properties of tendons. It provides tensile strength, which allows tendons to withstand the high forces experienced during muscle contraction and movement. The specific type of collagen most abundant in tendons is type I collagen, which is organized in a parallel structure that aligns with the direction of tensile forces. This organization enhances the tendon's mechanical performance, enabling it to effectively transmit forces between muscles and bones while also contributing to the overall structural integrity of tendons.

Other components like elastin, fibroblasts, and proteoglycans play roles in the overall function and health of tendon tissue. Elastin contributes to elasticity and is more prevalent in tissues that require stretch, while fibroblasts are the cells that produce collagen and other extracellular matrix components. Proteoglycans contribute to the hydration and nutrient transport within the tissue but do not provide the primary tensile strength. Thus, collagen is the key player in defining the mechanical properties of tendons.