Which three layers compose the hair shaft?

The hair shaft is composed of three distinct layers: the cuticle, cortex, and medulla. Each of these layers plays a vital role in the structure and function of the hair.

The cuticle is the outermost layer, consisting of overlapping, scale-like cells that protect the inner layers from damage and environmental factors. This layer also contributes to the overall shine and smoothness of the hair.

Beneath the cuticle lies the cortex, which is the thickest layer of the hair shaft. The cortex contains fibrous proteins and is responsible for the strength, elasticity, and color of the hair. It's where the majority of the hair's mass is located, making it critical for its overall integrity.

The innermost layer, the medulla, is not present in all types of hair, but when it is, it can influence the hair’s overall characteristics and can contribute to its flexibility.

Understanding these layers is crucial for professionals in the beauty industry, especially in practices such as waxing and hair care, as they need to consider how treatments may interact with these structures. Other options include layers or components that do not comprise the actual hair shaft or mix different types of proteins and structures not directly related to hair anatomy.