The skin belongs to the integumentary system. It is an organ designed to protect the body from outside harm and is the largest organ system in the human body.
The skin has several functions in addition to serving as a barrier from the external environment. It protects underlying tissues, regulates body temperature and excretes wastes. The surface of the skin contains sensory receptors.There are three layers of skin: the epidermis, dermis and hypodermis. The epidermis is the topmost layer and serves to protect the skin. The lower two layers house connective tissue and adipose tissue, serving to cushion the body and provide energy.