Hair follicle. Light micrograph of a section through a hair follicle & sweat (sebaceous) gland. The hair is a tubular structure that is formed from concentric layers of epithelial cells, with an enlarged \hair bulb\" at its base (lower left). The cells of the hair are dead, except in the region within the bulb, where actively dividing cells push the older, keratinised cells outward, making the hair grow. Magnification unknown."