Which layer is the outermost layer of the hair?

• A. Cuticle
• B. Cortex
• C. Medulla
• D. Dermis

Answer: (A)

The outermost layer is the cuticle. It is made up of overlapping, scale-like cells that form a protective, slick outer covering around the hair shaft. This positioning is what makes the cuticle the first line of defense against damage from brushing, chemical treatments, and environmental conditions. A smooth, intact cuticle helps hair look shiny and feel soft, and it also helps control how much moisture and chemicals can enter the inner layers.

Beneath the cuticle lies the cortex, which provides most of the hair’s strength, elasticity, and color because it contains the hair’s pigment cells. Inside the cortex is the medulla, the hair’s innermost core, which isn’t always present, especially in finer hair. The dermis is skin, not part of the hair shaft, so it isn’t involved in the hair’s structure.