Hair and scalp

How is the hair formed?>

The hair follicles are obliquely rooted in the scalp, and the hair has two parts: the hair bulb and the hair shaft.

It is in the bulb, located at the base of the hair root, that the cells proliferate, thanks to the essential provision of oxygen, nourishing substances and mineral salts transported by the tiny capillaries.

Gradually pushed upwards, these cells become loaded with keratin, a protein rich in sulphurous amino acids (cysteine and methionine) to form the hair shaft. The latter is composed of three concentric layers of cells:

• The medulla, in the centre, is formed of cells with no nucleii and very little pigment.

• The cortex is composed of cells with plenty of keratin and pigments which determine the hair colour. It guarantees the hair’s rigidity and strength.

• The cuticle, the outer layer, is composed of flattened cells, superimposed like the tiles on a roof. It protects the hair’s internal structure: it plays a barrier role that enables the hair to combat external attack and maintain a satisfactory level of moisturisation. It is therefore vital for the hair to remain healthy.