Hair is a filamentous biomaterial that grows from follicles found in the dermis. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class. (Definition askoxford. Com). The word “hair” often refers to two distinct structures: the part beneath the skin, called the bulb. This organ is located in the dermis and maintains stem cells which not only regrow the hair after it falls out but also are recruited to regrow skin after a wound.