Light micrograph of a vertical section through the human scalp, showing several hair follicles. The outer layer of the skin, the epidermis, (dark red band at top) is supported by an underlying dermis. Beneath the dermis is a subcutaneous layer of connective tissue & fat. The epidermis grows down to form the lining of the hair shaft or follicle. Hairs are rooted in a bulb", where actively dividing cells make the hair grow. Three hair bulbs are just out of view at bottom left. The swelling at the sides of the hair follicle in centre is a sebaceous gland, which secretes sebum, an oily, waterproofing substance, onto the hair surface. Magnification: x25 at 6x6cm size."