What is the stratum corneum layer of the skin?

Dr. Ellen Marmur, MD
There are four epidermal layers, the first of which is the stratum corneum. When you touch your skin, what you're feeling is almost thirty layers of dead keratin cells (a protein that also makes up hair and nails). All these inert cells, called keratinocytes, overlap like thin shingles on a roof, with pores (the ducts for hair follicles and sweat glands) interspersed among them. These tough keratinocytes shed approximately every twenty-eight days, depending on your skin's regenerative process. New cells that are formed in the lowest level of the epidermis push upward to the surface, constantly replacing the old ones. When your skin flakes, what's coming off are thousands of those dead cells. In fact, every minute we shed about forty thousand keratinocytes. 
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.