SKIN HISTOLOGY & THE EPIDERMIS:

The skin is composed of two layers, the outer epidermis, or epithelium (E), and the underlying dermis. The epithelium has two basic layers: stratum corneum and stratum germinativum. The stratum corneum (SC) is the layer of dead epithelial cells and keratin that forms a protective barrier over the underlying living cells. The stratum germinativum (SG) is the living, growing part of the epidermis; as the cells mature, they gradually move up towards the surface of the skin where they die and become part of the stratum corneum.

SKIN HISTOLOGY & THE DERMIS: The upper image shows the relatively thin epidermis (E) (the darker pink outermost layer) and the very thick dermis. The dermis contains much connective tissue that forms a foundation for the blood vessels and nerves and various glands (sweat and sebaceous) that are within this supportive layer. In this slide there is a hair follicle (F), minus the hair itself, diving down into the dermis. The lower image shows the rest of this hair follicle embedded within the dermis. Near the base of the follicle are several large sebaceous glands (SG). These glands secrete the fatty material that lubricates the skin and hair. The sebaceous gland cells look very pale because fat (lipid) does not take up the stain red stain that was used.