Colorado Cosmetology Written Practice Exam

The outermost layer of the skin is the epidermis. This layer serves as the primary barrier protecting the underlying structures of the skin and the body from environmental factors such as bacteria, pollutants, and UV radiation. The epidermis is composed of multiple layers of cells, primarily keratinocytes, which continually renew themselves. As new cells are produced, older cells are pushed towards the surface, where they eventually shed off. This process is vital for maintaining healthy skin.

In contrast, the dermis lies beneath the epidermis and contains connective tissue, blood vessels, and nerve endings, supporting the epidermis while providing strength and elasticity. The cuticle refers more specifically to the outer layer of the hair shaft or the area of skin around the nail, rather than a layer of skin itself. The subcutaneous layer, or hypodermis, is located beneath the dermis and mainly consists of fat and connective tissue that insulates the body and aids in shock absorption.