Epidermis
Epidermis is formed from five layers, including a surface layer, keratinize (keratinization process).This corneal layer, along with sebaceous gland secretions, protects against biological and chemical external influences, while melanin protects against ultraviolet radiation.
Epidermis also contains many special cells, such as keratinocytes and melanocytes. Keratinocytes are a major skin cells, they represent up to 95% of all cells in human skin. Melanocytes produce melanin, which is a pigment giving us the colour of our skin. This layer is continuously shed and replaced, every 15–30 days.