Hair Structure

Knowledge is power, which is why the deeper you understand the structure of
hair, the more resources you will have. Today we grab paper, pencil, and the notebook to
take notes from this master class on hair.

What is the structure of the hair?

The first step to understanding the structure of hair is to delve into the hair fiber, which is nothing more than a cylindrical filament made of keratin that is born and grows in the scalp. This filament is composed of proteins, lipids, trace elements, water, and pigments, and its function is to protect us from external aggressions. That’s why they are distributed throughout the entire body, except for the palms of the hands and the soles of the feet, although on the head is where they grow in the greatest size and abundance.

Regarding the structure of hair, we can divide it into the following parts:
• Dermal Papilla: Formed by dermal cells and blood vessels full of nutrients, it is located at the base of the hair bulb and its mission is to transport the necessary food and oxygen for hair growth and structure.
• Hair Bulb: It is the most vascularized area and the center of hair production, where mitosis and pigmentation occur. Additionally, the bulb provides the necessary nutrients for the hair to grow strong and healthy.
• Root: The root begins in the hair follicle. We can find it in the skin of the scalp. In this area are located the sebaceous glands in addition to the dermal papilla which is responsible for providing nutrients from the blood to the hair.
• Sebaceous Gland: It is responsible for keeping the hair lubricated and preventing dryness, but an excess of sebum can cause your hair to look oily.
• Hair Shaft: This is where we see hair growth and can determine the structure of the hair and the stage of its life cycle.

 

What do we find in the internal structure of the hair?

If we could see a cross-section of a hair shaft under a microscope, we could differentiate, in turn, three parts: the medulla, the cortex, and the cuticle. This is what we call the internal hair structure.

 

• Medulla: It is found in the core of the hair, formed by soft keratin cells bonded together.
• Cortex: It contains melanin which is seen through the cuticle which is transparent. The cortex contains fibrous substances made of keratin and provides the shape and elasticity of the hair. For the bonds between the keratin and the fibers to be established, it is essential that water or other moisturizing agents pass through the cuticle into the cortex. The elasticity and resistance of the cortex depend on this.
• Cuticle: Formed by layers of hard keratin with a tile or scale-like appearance, it is the outer layer of the hair that protects the hair fiber.