What is the cuticle in terms of hair structure?

The cuticle is indeed defined as the outermost layer of the hair structure. It plays a crucial role in protecting the underlying layers of the hair shaft, which include the cortex and medulla. The cuticle is made up of flat, overlapping cells that resemble scales, and its primary function is to shield the delicate inner layers from environmental damage, such as UV light, chemical exposure, and mechanical abrasion. This protective layer also helps to retain moisture within the hair shaft, contributing to the overall health and appearance of the hair.

In addition, the condition of the cuticle can significantly affect the hair's overall texture and shine. Healthy cuticles lie flat, which leads to a smooth surface that reflects light effectively, giving hair a shiny look. When the cuticle is damaged or roughened, it can result in dull, frizzy hair. Understanding the role of the cuticle is essential for effective hair care, as treatments that target the cuticle can help improve hair's health and appearance.