Its is produced in hair follicles from cells originating in the matrix: a vascularized niche of stem cells.
When sectioned, hair shapes can be elliptical (short curly hair),ovoid (wavy hair) or round (straight hair).
Each strand of hair is made up of the medulla, cortex, and cuticle.
The cortex is the thickest part, giving the hair its strength and color (contains melanin).
Hair disorders can be classified into scarring and non-scarring alopecia, in the latter case hair is absent but hair follicles remain mostly intact (common baldness, alopecia areata)
Sometimes the hair is damaged by external techniques (hair decolorization, hair straightening…)