Redseal Hairstyling License Practice Test

What is the function of the cortex layer in the hair?

1. Provides moisture to the hair

2. Acts as a protective barrier

3. Provides strength and elasticity

4. Regulates the hair's temperature

The correct answer is: Provides strength and elasticity

The cortex layer of the hair serves a crucial role in providing strength and elasticity. It is the thickest layer of the hair shaft and is located between the cuticle (the outer layer) and the medulla (the innermost layer, which is not always present). The cortex is made up of long, fibrous proteins called keratin, which give the hair its structure and durability. Additionally, the cortex contains melanin, which contributes to the hair's color. This layer is fundamental for the hair's overall integrity and flexibility, allowing it to withstand various stresses, such as tension and manipulation. When hair is subjected to styling techniques, like curling or straightening, the cortex's properties enable it to change shape temporarily without breaking. Therefore, the function of the cortex directly relates to maintaining the hair's physical properties and resistance to damage.