Illinois Cosmetology Practice Exam

The cuticle is the most visible part of the hair strand. It is the outermost layer that serves as a protective barrier for the inner structures of the hair. The cuticle consists of overlapping, scale-like cells that resemble shingles on a roof, which help minimize damage to the cortex and medulla underneath. When hair is viewed, whether in natural light or under a microscope, the cuticle is what is prominently seen. This layer plays a crucial role in the texture and shine of the hair, as it affects how light reflects off the hair surface.

In contrast, the cortex is located beneath the cuticle and is responsible for the hair's strength, texture, and color because it contains the pigment melanin. While it is essential to the hair's overall characteristics, it is not directly visible from the outside. The medulla, which is the innermost layer, is present in some hair types but is not typically visible as it often consists of a soft, spongy keratin. Finally, the bulb is found at the base of the hair strand, embedded in the scalp, and is responsible for hair growth but is not visible in a strand of hair. Thus, the cuticle being the outer layer is why it is the most