The stratified epithelium cells cover mainly those surfaces, which experience mechanical, chemical, thermal or osmotic stresses. Due to this, the outer cells whether living or dead are regularly slaughed off. In the skin, keratinised stratified-epithelium occurs where the outermost cells become hard and dead. These are exposed to drying and mechanical stresses.
These glands are located in the skin. They are epidermal in origin but pass into the dermi from which they receive nourishment. The sweat glands have long coiled tubes, which open over the skin’s surfaces through the sweat pores. The sebaceous or oil glands open into the hair follicles.