"Cutis" is a word derived from Latin, and the original meaning was "skin". Today, the term is used in the fields of anatomy and physiology to refer to the two outermost layers of the skin, which are the epidermis and the dermis. Together, these two layers serve many functions for the human body, including protection against the elements, heat regulation, water resistance and evaporation control. The cutis contains melanin, which provides our bodies with additional protection against the sun and accounts for skin color. The subcutis, or subcutaneous tissue, lies beneath the cutis.
One of the primary functions of the cutis is to act as the body's barrier against the outside environment. This is necessary to protect the body from microorganisms, bacterial infection and physical damage. The epidermis acts as a waterproof, protective wrap, and the dermis acts as a cushion, protecting the body against stress and strain.
Thermoregulation is another important function performed by the cutis. The term "thermoregulation" refers to the control and adjustment of the temperature of the body. In order to do this, the body must be able to perceive and respond to the temperature of its environment. The cutis houses nerve receptors that allow for perception of the temperature outside the body. It also houses sweat glands and hair follicles that respond to changes in the outside temperature, allowing the skin to regulate the amount of heat or cold that penetrates to the body.
Yet another function of the cutis is to control evaporation from the body. The skin acts as a semi-impermeable barrier between the body and its environment in order to reduce fluid loss and control fluid absorption. When additional moisture is needed, the skin adjusts to decrease the amount of fluids lost through the skin and allow an increased amount of fluids to penetrate. This is something a person takes advantage of when he or she applies skin moisturizer.
The cutis also contains melanin. Melanin protects the body against sun damage by converting the sun's most damaging rays into heat. When the skin is exposed to more of the sun's rays, the body produces more melanin. This darkening of the skin, or tanning, is an indication that the body is fighting DNA damage caused by the sun in an effort to reduce the possibility that skin cancer will develop.