The integumentary system consists of all of those tissues which create the external wrapping of the body (including skin, hair, fur, nails, etc.), as well as those glands of the skin (including sweat glands and oil glands). All of these structures are derived from the same primitive tissues, which differentiate to form these different components of the integumentary system.

The primary functions of these integumentary structures include protection of the internal organs of the body. The skin, in particular, serves as the body's largest organ, protecting it from physical, chemical, and infectious threats. The integumentary system also serves to help maintain appropriate body temperature, and prevents excess fluid loss. It guards the rest of the body against the threat of ultraviolet radiation, and is integral to the conversion of vitamin D. The integumentary system is involved in the acquisition of information from the external environment, including information on ambient temperature, pressure, and pain. Some fatty substances can be absorbed into the skin; other substances can be removed from the body by excretion through the sweat glands.