What does the cortex layer of hair primarily contain?

The cortex layer of hair is primarily responsible for providing strength and elasticity. This middle layer of the hair shaft is composed of elongated cells and contains keratin, which is a fibrous protein that contributes significantly to the structural integrity of the hair. The arrangement and bonding of the keratin fibers in the cortex also play a crucial role in how hair can be styled and manipulated while maintaining its overall strength.

While color pigment, hair roots, and moisture do relate to hair structure and care, they are not primary features associated with the cortex. Color pigment is mainly found within the cortex but is not its primary content; this pigment influences the hair’s color. Hair roots are located beneath the surface of the skin and involve the hair growth process rather than the structure of the shaft itself. Moisture is vital for hair health, but it is not a defining characteristic of the cortex layer. Thus, focusing on the role of the cortex in providing strength and elasticity is essential for understanding the overall properties of hair.