Hairs are threads of fused (i.e. attached together), dead, keratinized cells.
The hair bulb is the bulb-shaped structure at the base of the hair follicle of which it is a part.
Each hair bulb includes:
- several layers of different types of cells that extend up through the hair follicle
- a region of cells called the germinal matrix
(the area of cells that produces new hairs by mitosis)
- an indentation called the papilla of the hair
(containing many blood vessels that supply nutrients to nourish the growing hair)