Structure of Hair

Structure of Hair

Hair consists of a protein called keratin, which is extremely resistant to breakage and abrasion. Keratin is also the main structural unit of our nails and it is composed of smaller building blocks named amino-acids. Keratin provides resistance to even the thinnest hair.

Hair follicle has three vertical segments;

1 - Upper portion – Infundibulum: The part between the exit of hair fiber to the part that sebaceous gland is attached to the hair follicle.

2 - Middle portion – Isthmus: The portion between the attachment point of the sebaceous gland and the Arrector pili muscle. The point, which the Arrector pili muscle is attached to the hair follicle, is called “bulge region”. The bulge region has the utmost importance in hair follicle stem cell research.

3 - Lower portion – Inferior: The region spanning the Arrector pili attachment and the basal part of the hair follicle. A hair bulb, which consists of hair matrix and dermal papillae cells, is found at the base of the hair follicle.