The integumentary system is the set of organs that forms the external covering of the body and protects it from many threats such as infection, desiccation, abrasion, chemical assault and radiation damage. IN humans the integumentary system includes the skin – a thickened keratinized epithelium made of multiple layers of cells that are largely impervious to water. Layers of skin include epidermis, dermis, and hypodermis. Differentiating features between thick skin and thin skin are also discussed in this chapter. Clinical images are also provided in the chapter.