Which component of the IVD is primarily involved in providing tensile strength?

The annulus fibrosus is the component of the intervertebral disc (IVD) primarily responsible for providing tensile strength. It is composed of layers of collagen fibers arranged in a lamellar structure, which allows it to withstand tensile forces and maintain the structural integrity of the disc. The collagen fibers are oriented in a way that helps the annulus resist radial and compressive loads, effectively keeping the nucleus pulposus contained and maintaining intervertebral stability.

The nucleus pulposus, while important for cushioning and providing flexibility, primarily serves as a gel-like core that distributes pressure rather than contributing directly to tensile strength. The endplate cartilage plays a role in the nutrition of the disc and the connection between the discs and the vertebrae but does not significantly contribute to the tensile strength needed to withstand the mechanical loads placed on the spine.

Therefore, among the choices presented, the annulus fibrosus is recognized as the primary contributor to the tensile strength of the IVD.