Skin 2, Layers of the skin

Structure of the skin
The skin is in two layers. Lining the outer skin surface is the epidermis with the dermis forming the layer below. The Epidermis is keratinised, stratified and is a squamous epithelium. Epidermal skin cells reproduce in the mitotic, or germinative, layer at the bottom of the epidermis and are gradually pushed upwards as new cell division takes place. The epidermis varies in thickness depending partly on the wear and tear the particular part of the body is exposed to. There are no blood or lymphatic vessels in the epidermis. Deeper layers of the epidermis are bathed in tissue fluid which keeps the cells alive but as the cells are pushed away from the mitotic layer they start to die. Epidermis also contains some melanocytes; these produce the dark coloured pigment melanin in response to exposure to sunlight.
The dermis contains loose connective tissue containing collagen with some yellow elastic fibres. It contains blood vessels, capillaries, sweat glands, sebaceous glands, hair follicles, hair erector muscles and peripheral sensory receptors; it also contains some lymphatic vessels.