The Cuticle. It is made of different patches, narrowly interlocked with each other, just like fish scale. They are connected by ceramide, which is an oily substance mainly constituted of essential fatty acids.
The ceramides seals scales just like ciment does with bricks. The assembled cuticle has a waterproof and smooth surface, which enables the hair to reflect light (shine effect), to preserve its internal hydration and to protect itself from external aggressions.
The Cortex.It makes for 90% of the hair’s weight. It contains keratin and sulphured protein, made of multiple longitudinal fibrillas. They determine the hair’s resistance and elasticity. In the case of abusive aggression (brushing, straightening or colouring…), the fibrillas lose their cohesion and the hair breaks and has split-ends.
The cortex is hydrophiclic: despite its cuticle waterproof scales, the hair is permeable to water and to cosmetic manipulations. In order to dye a hair, its scales must be raised in order for the colouring product to penetrate the cortex. If the procedure is repeated too often, the cuticle deteriorates and the hair becomes dull, excessively hydrophilic and porous.
The Marrow. Made of coreless cells stacked on top of each other. |
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