Hair roots. Time-lapse light microscopy footage of blood (red) flowing through capillaries at the roots of hairs. The hair roots are bulb-shaped, with the hair shaft (black) also visible. The base of a hair is known as the hair bulb and is the site of hair growth. It is usually located in a hair follicle in the skin, at the base of which is an area called the dermal papilla. This region is supplied with blood, which gives nourishment for the production of new hair.