The skin is the outer covering of the human body. It is the largest organ system of the body. No matter how you think of it, the skin is very important. It covers and protects the insides of our body and has many other functions such as providing a anatomical barrier from pathogens and damage between internal organs. It also helps the body maintain a normal temperature. Its pigments protect us from the damaging ultraviolet rays of the sun. We also get the natural vitamin D from the sun through our skin.
Some people may be surprised that the skin is an organ. Many people go to wellness centers and spas to take good care of their skin and body shape. A lot of people consider their skin as the utmost important part of their body and would invest on many skin care products and dermatological treatments to make them look and feel good. Some people would even have their skin tanned or have whitening treatments for aesthetic purposes. Some people would even have their skin inked for cultural and artistic purposes or to express themselves through tattoos. The skin color and appearance tells a lot about our race, and well being. Many diseases can be assessed through the signs symptoms that are appreciated on the skin. For an example, a person with hepatitis will have a manifestation of yellowish colored skin. Many diseases have different lesions as first sign of the disease. Stress and aging can be seen on skin integrity that is why anti-aging creams and treatments are very popular nowadays because everybody wants to have a soft, youthful skin.
The skin is composed of three layers—the epidermis, dermis and subcutaneous or fat tissue.
The epidermis is the outermost layer of the skin. The thickness of the epidermis ranges from 0.1 millimeter on the eyelids, which is the thinnest to about 1 millimeter on the palms and soles of the feet which has the thickest. Some people may even have thicker soles and feet due to callous formation on the skin. This thickening of the skin generates more protection for the skin on these parts that require more contact—our hands and feet handle the most physical contact to the environment and is bound to pressure and friction. The melanocytes are the special cells of the epidermis that are primarily involved in producing the pigment melanin, which gives the color of our skin. The more melanin in the tissue, the darker is the color. Normal skin color depends on the race and varies from pale, almost ivory to deep brown and almost pure black. A lot of other factors such as diseases and low oxygen perfusion also affect the color of the skin.
The next layer of the skin is the dermis which makes up the largest portion of the skin, providing strength and structure. The papillary dermis lies directly under the epidermis and is composed of fibroblast cells that is capable of producing collagen. Under the papillary dermis lies the reticular dermis which produces collagen and elastic bundles for strength and structure. The dermis contains blood vessels, lymph vessels, nerves, sweat and sebaceous glands, and hair roots. The dermis is considered the “true skin.” These parts give integral protection in our everyday lives. When we come in contact with something that is hot, we immediately feel pain and then it is a reflex or automatic thing that in an instant, we take off the body part that came in contact with the hot thing, thus preventing a burn on the skin. Sweat and sebaceous excretions have also lubricating and protective properties. The skin hair acts like antennas that when the hairy part comes in contact with something, we can feel it immediately before it comes in contact directly to the skin. Blood vessels provide blood that gives the pinkish glow on the skin and also brings nutrients to the skin and in times wherein the skin barrier is damaged with an abrasion or a wound, it brings the necessary nutrients to heal the wound.
Subcutaneous tissue or hypodermis is the innermost layer of the skin. It is primarily adipose tissue, which provides protection by cushion between the layers of the skin, muscles and bones. It promotes skin mobility, molds body contours and insulates the body from heat and cold. Some people make it necessary to reduce fat by burning fat in the gym and exercising because it adds to their self confidence when their preferred body shape is attained. Some thin persons make it necessary for them to add more fat to make them look and feel good because the fat in the body adds more shape to their bodies.