Sweat duct in skin. Light micrograph of a section through the epidermis (upper layer) of the skin showing a sweat duct (upper centre). This is the stratum basale, the bottom layer of the epidermis, which is responsible for the production of new skin cells. Below the stratum basale is the dermis (blue/ white), the bottom layer of the skin. The dermis contains numerous sweat glands. These discharge their secretions onto the surface of the skin through long excretory ducts. Trichrome blue stain. Magnification unknown.