Skin. Light micrograph of a section through healthy human skin. The uppermost skin layer is the epidermis (orange & pink). The stratum corneum (orange), a cornified layer composed of flattened, fused keratin-rich cell remnants, forms the surface of the epidermis. The dead cells from this layer are continuously being shed and replaced by cells from the living epidermal layers below (pink). These layers contain keratinocytes, specialized cells that synthesize keratin. Below the epidermis is the dermis (blue), a thick layer of fibrous connective tissue which supports and nourishes the epidermis. The dermis contains blood vessels and sweat glands. Magnification unknown.