Knowledge of Hair Structure

Understanding the structure of hair is very important in the Cosmetology trade, especially for treatments such as hair straightening, rebonding, smoothening, and hair coloring. Knowledge of hair structure helps cosmetologists understand how hair grows, how it reacts to different chemical products, and how to perform treatments safely without damaging the hair.

Each strand of hair is made up of several layers and is composed mainly of a protein called keratin. Hair grows from a root located inside the hair follicle in the scalp. The visible part of the hair above the skin is called the hair shaft.

Main Parts of Hair

Hair consists of two main parts:

• Hair Root: The part of the hair located below the scalp inside the hair follicle.
• Hair Shaft: The visible part of the hair that extends above the surface of the scalp.

Layers of the Hair Shaft

The hair shaft is made up of three main layers:

1. Cuticle

The cuticle is the outermost layer of the hair shaft. It is made up of thin, overlapping cells that protect the inner layers of the hair. The cuticle acts as a protective shield and controls the movement of moisture in and out of the hair.

Healthy cuticles lie flat and give the hair a smooth and shiny appearance. When the cuticle is damaged, hair may appear dull, dry, or rough.

2. Cortex

The cortex is the middle layer and the thickest part of the hair shaft. It contains the natural pigment called melanin, which determines the natural color of the hair. The cortex also gives hair its strength, elasticity, and texture.

Most chemical treatments such as hair coloring, rebonding, and perming affect the cortex because this layer controls the shape and structure of the hair.

3. Medulla

The medulla is the innermost layer of the hair shaft. It is made up of soft cells and air spaces. The medulla is not always present in every hair strand and is more commonly found in thick or coarse hair.

Hair Follicle

The hair follicle is a small pocket in the scalp from which hair grows. It contains the hair root and is connected to blood vessels that supply nutrients for hair growth. Healthy hair growth depends on proper nutrition and scalp health.

Hair Pigment

Hair color is determined by a pigment called melanin, which is produced by special cells in the hair follicle. There are two main types of melanin:

• Eumelanin: Responsible for dark shades such as black and brown.
• Pheomelanin: Responsible for lighter shades such as red and blonde.

The amount and combination of these pigments determine the natural color of a person's hair.

Importance of Understanding Hair Structure

• Helps cosmetologists perform chemical treatments safely.
• Prevents damage during hair coloring or straightening.
• Improves hair care and treatment techniques.
• Helps select suitable products for different hair types.

Conclusion

Knowledge of hair structure is essential for cosmetology students and professionals. Understanding the different layers of hair and their functions helps in performing hair treatments safely and effectively. Proper knowledge of hair structure ensures healthy hair care and successful beauty treatments.