Understanding Your Skin
Most of us know that the skin is considered to be an organ, and that it is the largest organ of the body. But we may not appreciate all that it does for us. The skin can:
- Protect us from the environment
- Keep our temperature regulated by conserving heat
- Keep moisture in
Skin Structure for Skin Cancer Screening
The skin has several layers. Various skin treatments deal with all of them. If you understand the layers of the skin, it is easier to understand how skin treatments will affect each layer.
- The outer layer is as the epidermis,
- the middle layer is the dermis
- and the inner layer is the subcutaneous layer.
Associated with these top layers are the accessory structures, including the hair follicles, sebaceous (oil) glands and sweat glands. Other structures involved with the skin are nerves, blood vessels, and lymphatic vessels.
Cross section skin anatomy diagram
The Epidermis of the Skin
This is the skin surface. It does a lot for only being 1/10th of a millimeter thick.
The skin at the surface is actually mostly dead cells. As the cells get to this point they start to slough away, which gives way for the cells beneath. The new cells are created in the deepest part of the epidermis and it takes about six weeks for them to migrate to the surface. They’re pushed to the surface as even more new cells get created.
The whole process is usually balanced as new skin cells are always forming and dead ones are always falling away. However, as we get older, this process slows. This means that there will be more dead cells present at a given time. This may create a dry, rough texture for the skin as we age. This can, of course, be treated—and doing so will improve the skin health. It will ensure the skin is not diseased. The cells we have been describing in this layer of skin are mostly keratinocytes.
Another cell type that is scattered throughout the epidermis is the melanocyte. The melanocytes produce the protective pigments called melanin granules of the skin. Their best function is to block some of the harmful effects of the sun (ultraviolet radiation) from getter into the deeper layers of the skin. When these cells have years of repeated UV radiation they can undergo a change and become diseased or ‘dysplastic’.
The UV light stimulates the melanocyte to becomes darker and this produces a color change in the skin. Sometimes an area can have an uneven response to UV radiation and this results in darker areas of skin color in an irregular distribution. This is known as hyperpigmentation. Other names used to describe this condition are age spots and melasma. These types of skin conditions can be treated with medicines and the IPL treatments. Conversely, when an area does not produce enough melanin, it is called hypopigmentation.
In these cell types of the skin, skin cancers may develop. Fortunately with proper skin cancer screening, most are diagnosed quickly.
Melasma or Hyperpigmentation
Melasma is a form of hyperpigmentation. The patches can range in color from light brown to dark red. Usually the spots darken with sun exposure and lighten again later. Melasma has several causes:
- UV exposure
- Hormone changes, such as those associated with oral contraceptive use or pregnancy
Age Spots on the Skin
Melasma photo example*
The melanocytes in the epidermis protect us from the harmful effects of UV rays. However, after years of UV exposure, these cells can become diseased. In normal melanocyte cells, UV rays will cause them to change color. The problem occurs when the color change becomes uneven. Some areas will appear darker than others and remain dark—these are often called age spots. These flat brown skin patches are also known as hyperpigmentation. (When too little melanin is produced, it is called hypopigmentation).
Age spots are the result of sun exposure rather than age. When these dark spots occur it means there are a lot of damaged melanocytes.
Dermis of the Skin
The dermis is the middle layer. It is made up of connective and elastic fibers. This layer provides the support structure for the outer skin layer. Most of the cells in this area are fibroblasts, which produce elastin and collagen. This network supports the epidermis. There are many blood vessels in this layer and these vessels nourish both the dermis and the epidermis. With aging and UV exposure, the fibroblasts diminish in size, they experience a slow down in metabolic activity and have a low turnover rate. The elastic fibers loose a lot of their natural recoil or elastic characteristics. The skin will become more lax and wrinkled. With sun exposure, the fibroblasts can grow erratically large and produce defective collagen. Quality topical medical skin care, will penetrate to this layer and improve it. These medical products used at The Loudoun Center for Plastic Surgery & Dermatology have been scientifically shown to be effective and have been validated by years of study and quality results.
The dermal layer is also where you’ll find:
- Sweat glands
- Oil glands
- The skin’s blood supply
- Hair follicles
- Lymph vessels
Subcutaneous Layer of the Skin
This is the deepest layer. It contains the fat cells and more nerves, glands, and blood vessels. This represents the border between the superficial skin layers and the rest of the body. If cancerous cells extend below this layer, they can begin to invade the body.
Each layer gets thinner as we age. This causes skin to sag, look less full, and wrinkle.
As we age our skin layers thin, this is what contributes to wrinkles and sagging of our skin.
George Washington University Professional Center
The Loudoun Center for Plastic Surgery
45155 Research Place, Suite 125
Ashburn, VA 20165