Hair anatomy: the bulb and the root

Today we discover how hair is made ... and also some curiosity.
The "invisible" part of the hair, under the skin, is composed of the root and the hair bulb. Both are contained in the hair follicle, which is an extension of the epidermis.

The one under the skin is the only "living" part of the hair: in the depth of the bulb, that envelops a series of blood vessels, new cells are produced, which will gradually be pushed upwards towards the keratinization process. Keratin is a fibrous protein, responsible for the strength and stiffness of the hair.
This is how the cells produced by the hair bulb stiffen and transform, while moving towards the surface of the skin ... in the hair we see.Above the hair follicle, but always under the skin, there is the sebaceous gland: which secretes sebum (an oily and acid substance), whose production is directly responsible for the type of hair: fat, dry, normal.  

Read also:
Hair anatomy: the shaft