The hair cortex, also called the hair cortex, is the main part of the hair shaft and lies between the outer layer (Cuticle) and the inner core (Medulla(if present). The cortex makes up the largest part of the hair's volume and is responsible for its strength, color, and texture. It consists mainly of long keratin-Protein fibers arranged parallel to the growth direction of the hair, and is interspersed with Melanin, the pigment that gives hair its color.
Structure and functions of the hair cortex
- Keratin : The hair cortex consists primarily of keratin, a protein-rich fibrous substance that gives hair its strength and elasticity. Keratin molecules are linked together by disulfide bonds, which are responsible for the physical properties of hair, such as frizz and resistance to chemical treatments.
- Melanin : There are two types of melanin in hair – eumelanin (which gives hair brown or black color) and pheomelanin (which gives hair red or blonde color). The amount and type of melanin in the hair cortex determine the natural hair color.
- Moisture : The hair bark plays a vital role in regulating hair moisture. Keratin absorbs water, which gives the hair flexibility. A lack of moisture can lead to dry and brittle hair.
Importance of hair bark for hair treatments
- Dyeing and bleaching : Chemical processes that change hair color act on the melanin molecules in the hair cortex by removing them (bleaching) or replacing them with artificial dyes.
- Hair straightening and perming : These treatments alter the disulfide bonds between the keratin molecules in the hair cortex to temporarily or permanently change the hair structure.
- Hair care products : Many hair care products aim to nourish and strengthen the hair cortex by moisturizing, repairing damage, or protecting against future damage.
Damage to the hair cortex
- Chemical treatments : Excessive dyeing, bleaching or perming can damage the structure of the hair cortex, leading to hair breakage and dryness.
- Heat damage : Frequent styling with heat (blow-drying, straightening, curling) can weaken the keratin structure and cause moisture loss.
- Environmental factors : UV radiation, salt water and chlorine can also damage the hair cortex and impair hair color and health.
To preserve the health of the hair cortex and thus the entire hair, it is important to use gentle styling methods, protective care products and to protect the hair from extreme environmental influences.
Similar terms
