Epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the body's surface and is made up of stratified squamous epithelium with an underlying basement membrane. It contains no blood vessels, and is nourished by diffusion from the dermis. The main type of cells which make up the epidermis are keratinocytes, with melanocytes and Langerhans cells also present. Epidermis is divided into several layers where cells are formed through mitosis at the innermost layers. They move up the strata changing shape and composition as they differentiate and become filled with keratin. They eventually reach the top layer called stratum corneum and become sloughed off, or desquamated. This process is called keratinization and takes place within weeks. Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system composed of a layer of tissues that protect underlying muscles and organs. ... In zootomy, epithelium is a tissue composed of a layer of cells. ... ... The arterial system The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... Diffusion, being the spontaneous spreading of matter (particles), heat, or momentum, is one type of transport phenomena. ... The dermis is the layer of skin beneath the epidermis, that consists of connective tissue and cushions the body from stress and strain. ... The keratinocyte is the major cell type of the epidermis, making up about 90% of epidermal cells. ... Melanocytes are cells located in the bottom layer of the skins epidermis. ... Langerhans cells are immature dendritic cells containing large granules called Birbeck granules. ... Light micrograph of a newt lung cell in early anaphase of mitosis. ... Micrograph of stained α-keratin from mouse liver Keratins are fibrous structural proteins; tough and insoluble, they form the hard but nonmineralized structures found in reptiles, birds and mammals (vertebrates), and also the silk of insects and spiders (invertebrates). ...

Epidermis is divided into the following 5 sublayers or strata:

• Stratum corneum
• Stratum lucidum
• Stratum granulosum
• Stratum spinosum
• Stratum germinativum also called stratum basale

A mnemonic that is good for remembering the layers of the skin is: "Corn Lovers Grow Several Bales"
The stratum corneum (the horny layer) is the outermost layer of the epidermis, and comprises the surface of the skin. ... The Stratum Lucidum is one of the layers of the Epidermis. ... It contains 3 to 5 rows of flattened cells whose cytoplasm contains small granules. ... It is a multiple-layered arrangement of cuboidal cells containing molecular bridges that conect them to adjacent cells. ... Stratum germinativum or stratum basale is the layer of keratinocytes that lies at the base of the epidermis immediately above the dermis. ... A mnemonic (pronounced in American English, in British English) is a memory aid. ...