What is the outermost layer of the hair shaft called?

The outermost layer of the hair shaft is called the cuticle. This layer is crucial because it serves as the protective barrier for the hair; it consists of overlapping cells that scale like shingles on a roof. The purpose of the cuticle is to shield the inner structures of the hair, namely the cortex and the medulla, from environmental damage and moisture loss. A healthy cuticle is vital for shiny, strong hair, as it reflects light and protects against elements such as pollution and heat styling.

The other components of the hair shaft serve different functions. For example, the cortex is the thickest layer, providing strength, color, and texture, while the medulla is the innermost layer that can be absent in some hair types. The follicle, on the other hand, is not part of the hair shaft itself but rather the structure in the skin from which the hair grows. Understanding the roles of these layers enhances one’s knowledge of hair structure and health, contributing to effective hair care practices.