The five functions of the skin are protection, regulation of heat, secretion, excretion and absorption, according to Skin Genetix. There are two sections of the skin, the epidermis and the dermis, each of which aids in the functions in a different way.
The skin offers protection by telling the brain when it feels pain, hot or cold and by keeping out harmful organisms, explains Skin Genetix. It regulates heat by sweating or contracting. When palms or hands sweat, the skin releases moisture to keep cool. When blood cells contract, the skin retains heat.
Oil glands, also known as sebaceous glands, secrete sebum, a yellow, oily fluid that keeps the skin and hair lubricated, notes Skin Genetix. This lubrication prevents dehydration. Besides secreting sebum, the skin excretes sweat. Sweat provides a cooling effect but also gets rid of toxins in the body, such as excess salt and waste chemicals. Though skin is exposed to various products, such as soap, lotions, and perfumes, it only allows certain ingredients to be absorbed into the body.
The top layer of the skin is called the epidermis. Though there are five layers of the epidermis, it is very thin overall, states Skin Genetix. This is the layer that connects to the environment, and it contains many nerve endings. The dermis sits below the epidermis and is quite a bit thicker. It is made up of blood and lymph vessels, nerve endings, the oil and sweat glands, and hair follicles.