Louisiana Cosmetology Board Practice Exam

The three primary layers of the hair are the cuticle, cortex, and medulla. The cuticle is the outermost layer, made up of overlapping, scale-like cells that serve as protective armor for the inner layers of the hair. It plays a crucial role in shielding the hair structure from damage and retaining moisture. Beneath the cuticle lies the cortex, which is the thickest layer of the hair. The cortex contains long keratin fibers that give hair its strength, elasticity, and color. Finally, the innermost layer is the medulla, which is often described as a soft, spongy core. Although not always present in every hair type, when it is, it can contribute to the overall thickness and insulation of the hair strand.

This understanding of the hair structure is essential for cosmetologists as it informs how different hair types should be treated, how products interact with the hair, and the impact of chemical processes like coloring and perming on its health. The other choices mention elements that do not accurately convey the primary structure of the hair.