Surface, barrier, and interface zone: Comparative aspects of the skin

Abstract

The skin is the main body barrier of vertebrates covering the entire body. Via the evolution, this outer layer underwent substantial changes; moreover, different structures and derivatives were developed as a consequence of adaption to the lifestyles of different animal species. In general, the skin is the largest organ and the first barrier, therefore being important to interfacing with the environment and protecting the body against heat, dehydration, light, injury, and infections. For these functions also several substances are secreted, like salts or different organic molecules.