The Skin Functions

- Overview

Human skin is the largest organ in the body and is responsible for many critical functions that support survival, including thermoregulation, immune response, and barrier function. Thermal regulation occurs in two different ways. The first is a process called vasodilation and vasoconstriction, in which the control of blood flow is regulated by dilating and constricting blood vessels in the skin. This regulates internal body temperature, which releases heat to the environment, and also reduces inflammatory responses. In addition, temperature is regulated by sweat glands, which release sweat on the surface of the skin through the process of evaporative cooling. 

Viewed from a slightly different perspective, the skin's role in the immune system is crucial, involving the coordination of responses from many different cell types through complex molecular signaling pathways to mobilize an immune attack. Finally, the barrier function provided by the outermost layer of the epidermis (the stratum corneum) is essential to prevent the entry of foreign pathogens into the surviving epidermis and to prevent the loss of body water to the external environment. Skin is also the lens through which the outside world sees us. The health and physical condition of our skin plays a vital role in our mental health.