What is the primary function of the hair cuticle?

The primary function of the hair cuticle is to protect the inner layers of the hair. The cuticle is the outermost layer of each hair strand, composed of overlapping, scale-like cells that lie flat against each other. This structure helps to create a barrier against environmental damage, chemical exposure, and physical wear, thereby safeguarding the more delicate inner layers of the hair, which include the cortex and medulla. By maintaining the integrity of these inner layers, the cuticle plays a crucial role in preserving the overall health, strength, and appearance of the hair.

While other elements play roles in hair characteristics and health, such as volume or nourishment to the scalp, these functions do not pertain to the hair cuticle specifically. The cuticle itself does not contribute to hair color; that function is primarily due to the presence of melanin in the cortex.