It would be right to describe the stratified squamous cells of the stratum corneum as many layers of thin, flat, tightly packed dead/keratinized cells which will eventually shed off. As the first layer of the epidermis and closest layer to the environment, the stratum corneum is the first “port of entry” for chemicals that comes in contact with the body surface and serves as a barrier for the other layers of the skin.
It is the protective covering of the other layers of the epidermis, dermis and sub-cutaneous layer. Dermal absorption is the process through …show more content…
Substances can enter the body via the skin by chemical diffusion in which the chemical diffuses from a region of higher concentration (outer the surface) to one of lower concentration (inside the layers of the skin). Three mechanisms by which chemicals diffuse into the skin have been proposed:
Intercellular lipid pathway
As the name implies this process involves the movement of the hazardous chemical through a lipid pathway. The spaces of the corneocytes (cells of the stratum corneum) is the pathway through which the substances navigate through. These spaces are composed of fats, oils and lipids, as a result chemicals with a high lipo-affinity or with a lipophilic chemical nature will pass through these layers with ease compared to lipophobic or hydrophilic substances. This process relies on the lipid composition of the corneocytes for entry into the dermal layers of the skin.