Surgical anatomy of the skin

Abstract

The skin is the largest organ in the body and forms the interface between the body and the environment. Its structure is highly adapted to protect the body from many forms of noxious agents, to maintain homeostasis in several physiologic domains and to allow the individual to appreciate various modalities of sensation. The skin is divided into three layers – the epidermis, dermis and hypodermis (or subcutaneous tissue). The epidermis is a continually regenerating structure formed mainly from keratinocytes which account for the majority of cells in the epidermis. The pigment melanin, produced in the melanocyte cells of the epidermis is a major factor in determining skin colour. The dermis supports and gives strength and flexibility to the epidermis. It contains multiple blood vessels, lymphatics and nerves within its connective tissue architecture. The hypodermis is composed of various amounts of subcutaneous fat which plays a role in thermoregulation and water storage. It is essential that surgeons have a good knowledge of the structure of skin in order to choose the optimum site for surgical incisions, to understand the best methods of wound closure and to anticipate potential problems with wound healing. Furthermore, recognizing the role of specialist advice from plastic, reconstructive, or trauma surgeons is crucial for managing wounds that are complex, large, involve underlying structures, or are located on exposed skin such as the face and neck.