New York State Cosmetology Practice Exam

The cortex of hair is the middle layer of the hair shaft, and it is responsible for giving hair its strength and texture. While sebum is a natural oil produced by the scalp to keep hair moisturized, it is found on the outer layer of the hair, the cuticle. Keratin and fats are also important components of hair, but they are found in the outer layers as well. Sweat, on the other hand, is produced by the sweat glands in the skin and is not related to hair at all. Therefore, the cortex contains hair pigment, or melanin, which gives hair its color and helps protect it from UV rays.