Several structures are involved in the waterproofing of tissues:
Keratinocytes: These cells, found in the epidermis, produce keratin, a fibrous protein that provides strength and water resistance. Stratum Corneum: This is the outermost layer of the epidermis, composed mainly of dead keratinocytes filled with keratin. It acts as a primary barrier against water loss. Lipid Bilayers: Intercellular lipids, mainly ceramides, cholesterol, and free fatty acids, form a barrier that prevents water loss between cells in the stratum corneum. Tight Junctions: These are specialized connections between keratinocytes that prevent the passage of water and solutes through the paracellular route.
