Hairfollicle: small cavity made up of keratinocytes and melanocytes that extend in dermis.
From this organ, the hair root develops with a progressive accumulation of keratinocytes continuously dividing in the hair matrix of the bulb.
Melanocytes located in the bulb produce melanin and transfer it to the surrounding keratinocytes. It will provide the constitutive hair color.
Hairshaft: visible part above skin consist of an accumulation of keratinized pigmented keratinocytes of hair follicle (cells gradually lose their nucleus and become filled with keratin, a hard protein). The melanin is in the cortex.
Pigmentation starts in the bulb
at the same time as hair grows
Why Hair Varies From Blonde to Black?
Why Does Hair Turn Grey?
Greying Hair Process = Gradual Loss of Melanin