Pennsylvania Cosmetology Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

The three layers of hair are indeed the cuticle, cortex, and medulla.

The cuticle is the outermost layer, composed of overlapping flat, scale-like cells that protect the inner layers. It plays a crucial role in maintaining the integrity of the hair, providing a barrier against environmental damage and helping to retain moisture.

The cortex is the middle layer and is responsible for the majority of the hair's strength, elasticity, and color. It contains keratin (a protein) and melanin (which provides pigment). The structure of the cortex significantly influences the hair's texture and appearance, making it vital in cosmetic applications like dyeing and styling.

The medulla is the innermost layer and is often absent in fine or thin hair. It is made up of loosely packed cells and may play a role in the hair's overall structure and flexibility, although its function is less understood compared to the outer layers.

Understanding these layers is essential for cosmetology professionals, as it informs various hair treatments and techniques.