Anatomy And Physiology

Anatomy Physiology

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The next time you are relaxing on a beautiful beach, enjoying the cool breezes and working on that suntan, remember to take care of the largest and one of the most important organs of your body—your skin. 

This amazing, complex part of the body serves many functions, not the least of which is to hold everything else together!. As the primary organ exposed to the environment and all its elements, it stands as the first guard against infection, disease and illness, enclosing all the interior organs, muscles, nerves and blood vessels. It assists in maintaining the homeostasis or equilibrium of the body's temperature.. Since the skin houses some of then many nerves of the body, it serves as the main conductor for the sense of touch. Another role sees the skin as part of the body's elimination system and, last but not least, it contributes mightily to an individual's appearance. 

As a player in so many different functions of the human body, the skin is a complex organism comprised of many different elements, including blood vessels, muscles, nerves, enzymes, glands, as well as the large variety of cell structures and all their make-up material. 

When the medical community talks of degrees of burns to the skin, they are talking about the three layers that make up skin. First degree burns, for instance, involve the outer layer of skin which is called the epidermis. Second degree burns have penetrated this layer and gone to the second layer of the skin called the dermis. Third degree burns, the most serious, involve the subcutaneous, or third level of skin. Each level has it's own main function which contributes to the overall body functions. 

The epidermis primarily performs the protection role, but also contributes to regulating the body temperature and the elimination process. This layer is also responsible for the skin color through the production of melanin a chemical which influences the skin's pigment. Since the epidermis is constantly exposed to the outer elements, it makes sense that this layer contains few, if any nerves or blood supply. 

Actually, what the epidermis does have is a lot of dead cells! As a living organism, the body is constantly producing new cells. As old cells die, they are pushed to the body's surface and sloughed off through washing and/or rubbing with external surfaces. One light scratch with a fingernail will produce some of those dead cells. This is one way the skin helps to eliminate some of the body wastes. Some of the liquid body wastes are eliminated through epidermis from the sweat glands which are found in the second level of the skin. 

The dermis, or second layer of skin is the working area for the body's ability to feel sensation, the provision of nourishment to the epidermis and the muscles which allow the skin to contract and expand. It also acts as further back-up to the epidermis to contain and protect the inner organs of the body. 

The ability to feel sensations is one of the communication lines to the outside world. Of the five senses, sensation comes primarily through the skin. The nerve endings found in the dermis can distinguish heat, cold, pressure, vibration, soft and hard. Human fingers, which have some of the most sensitive nerves in the body, can distinguish between micro-sensations, such as discerning whether one has one coffee filter or two! The skin on the fingers and feet also feature ridges which allow a better grip, like tread on tires. These ridges, by the way, are always unique, which allows for identification of one individual from another. 

The dermis contains many of the small blood vessels (capillaries) which carry oxygen and nourishment to cells, help to remove toxic waste from them and expand and contract to control blood flow influencing temperature levels. This skin layer also contains miniscule muscles which control the opening and closing of the skin's pores and the material which enables the skin to stretch as needed. Finally, the dermis is the home of the hair follicles. All of these elements work together to enable the skin to aid in regulating the body temperature by the control of air and liquids entering and leaving the body. 

The last and deepest level of skin is the subcutaneous layer. This level is the “last stand” of the skin for protection. It contains many of the same elements as the dermis. In addition to the function of protection, it serves as a storage area for the skin's food and the fatty area which helps to insulate the body interior. 

Last, but not least, skin plays a large role in an individual's appearance. The color, texture and contours of skin literally define looks, which, in turn, affects the personality and self esteem. 

Wonderful stuff, skin. It not only comprises about 15% of the total body weight, it probably accounts for that much or more of human health, overall well being and psyche. Remember that, out there in the sun and be sure it gets its fair share of tender, loving, care.

More about this author: Martha Leonard

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