Which layer of hair provides a protective outer coating?

The cuticle is the layer of hair that provides a protective outer coating. It consists of flat, scale-like cells that overlap like shingles on a roof, creating a barrier against environmental damage, moisture loss, and physical wear. This outer layer is essential for maintaining the hair's integrity and appearance, as it protects the inner layers of the hair shaft—specifically the cortex and medulla—from damage caused by heat styling, chemical processes, and UV exposure.

The function of the cuticle is crucial because it helps to keep the hair smooth and shiny, while also preventing the penetration of harmful substances. Proper care and maintaining the health of the cuticle can significantly impact the overall health and beauty of the hair.