Wyoming State Board Cosmetology Practice Exam 2026 - Free Cosmetology Exam Questions and Study Guide

The cuticle is the outermost layer of the hair shaft and is typically the most damaged part due to its exposure to environmental factors, heat styling, chemical treatments, and everyday wear and tear. The cuticle consists of overlapping scales that protect the inner layers of the hair, primarily the cortex, which contains the majority of the hair's strength and color. When the cuticle is compromised, it can lead to frizz, split ends, and a loss of shine, making it crucial for maintaining healthy hair.

In contrast, the cortex lies beneath the cuticle and is less directly impacted by surface damage. While it can also suffer from chemical damage and heat exposure, the cuticle provides the first line of defense against these harmful elements. The medulla is the innermost part of the hair shaft and is often absent in finer hair types; its role does not directly relate to the damage experienced on the hair's surface. Lastly, the bulb is located at the base of the hair follicle and is responsible for the hair's growth; it is not involved in the structural integrity of the hair shaft itself and therefore not associated with damage related to external factors.