Pennsylvania Cosmetology Practice Exam

The three primary layers of the hair are indeed the cuticle, cortex, and medulla. The cuticle is the outermost layer, consisting of a protective layer of overlapping, scale-like cells that help keep moisture in and protect the inner layers from damage. The cortex is the middle layer, which provides strength, color, and texture to the hair due to its fibrous protein structure; it contains most of the hair's pigment. The medulla is the innermost layer and can vary in size, presence, and structure across different hair types, but generally serves as a soft, spongy core.

Understanding the structure and function of these layers is essential in cosmetology, as they influence hair characteristics and determine how hair responds to various treatments and products. The other options do not accurately reflect the three primary layers of hair, as they reference components or characteristics that do not align with the foundational structure of hair.