The integumentary system is one of the least complex body systems, but it is just as important. Also known under the generic term, the skin, the integumentary system regulates body temperature, protects the body from pathogens and harmful materials, shields organs from ultraviolet rays, slows the rate of water loss, and allows the body to feel the texture of objects of sense temperature.
The integumentary system is composed of:
The skin is made up of three layers: the epidermis, the dermis, and the subcutaneous tissues. The epidermis, mainly made up of dead skin cells, has two major purposes: to shield the body from damaging materials and the sun and to slow the evaporation of water from the body. The dermis, which contains glands and nerves, acts as a sensory organ and is responsible for thermoregulation. Through the process of thermoregulation, the dermis keeps the body's temperature within a healthy range. By dilating and contracting blood vessels, the rate of heat loss is hastened or slowed. In addition, sudiferous glands in the dermis produce sweat which carries additional heat away from the body as it evaporates through pores in the epidermis. Nerves within the dermis sense heat, pain, pressure, and other physical sensations. Finally, the subcutaneous tissues beneath the dermis store "fuel" in fat cells, assist in thermoregulation, and cushion delicate innards against impact.
Sweating is one the body's ways of regulating its temperature. Thermal perspiration is produced during exercise. As the body heats up, eccrine glands secrete sweat.