SKIN, ILLUSTRATION. SKIN, ILLUSTRATION Anatomical cutaway view of the epidermis with from the top to the bottom, in brown : the layer of the pavimentous epithelial cells, in blue, the layer of keratinocytes, in purple, the layer of the basal cells. In red, the dermis. The blue structures present in the layer of keratinocytes are Langerhans cells, involved in the immune defense. The pink structures inserted in the layer of basal cells are melanocytes.