What is the function of the cuticle in hair?

The cuticle plays a crucial role in the structure of hair by serving as a protective layer. It is the outermost layer composed of overlapping, scale-like cells that guard the inner layers of the hair shaft, including the cortex and medulla. This protection is essential because it helps minimize damage from external factors such as environmental elements, chemical treatments, and physical wear. By safeguarding the inner layers, the cuticle contributes to the overall health and integrity of the hair, preventing moisture loss and maintaining the hair's strength and shine.

In contrast, the other options do not accurately describe the primary function of the cuticle. While the cortex is where natural color is found, the cuticle itself does not provide color. Although the hair can absorb moisture, this is mainly due to the inner layers rather than the cuticle's function. Adding volume is typically attributed to the hair's natural texture and styling techniques, not the cuticle's role.