Skin structure

This chapter outlines the structure of the skin and the clinical significance of this structure. The skin is the largest organ in the body and has the essential role of providing barrier protection to the host. The four-layer structure of the epidermis (stratum basale, stratum spinosum, stratum granulosum and stratum corneum) and the two-layer dermis (papillary dermis and reticular dermis), in addition to the skin appendages make up the components of skin. The complex signalling that triggers the formation of the protective outer stratum corneum in the embryo and adult is addressed. Clinically, connective tissue diseases of the dermis and epidermis illustrate how breakdown of skin components can result in significant morbidity for the patient. Novel cures for these diseases await through protein, cell or stem cell transfer.