The whole story of skin Skin has pigmentation, provided by melanocytes, which absorbs some of the potentially dangerous radiation in sunlight. It also contains DNA repair enzymes which reverse UV damage, and people who lack the genes for these enzymes suffer high rates of skin cancer. One form predominantly produced by UV light, malignant melanoma, is particularly invasive, causing it to spread quickly, and can often be deadly. Human skin pigmentation varies among populations in a striking manner. This has sometimes led to the classification of people on the basis of skin color. See the article on human skin color. The skin on a person's face is seen by people that person interacts with. For some people, therefore, facial skin care is of particular importance, and they often use cosmetics to deal with the appearance of the face and condition of the skin, such as those for pore control and black head cleansing. Skin is composed of the epidermis and the dermis. Below these layers lies the hypodermis(subcutaneous adipose layer), which is not usually classified as a layer of skin. The outermost epidermis is consists of stratified squamous epithelium with an underlying basement membrane. It contains no blood vessels, and is nourished by diffusion from the dermis. The main type of cells which make up the epidermis are keratinocytes, with melanocytes and Langerhans cells also present. The epidermis can be further subdivided into the following strata (beginning with the outermost layer): corneum, lucidum, granulosum, spinosum, basale. Cells are formed through mitosis at the innermost layers. They move up the strata changing shape and composition as they differentiate, inducing expression of new types of keratin genes. They eventually reach the corneum and become sloughed off (desquamation). This process is called keratinization and takes place within about 30 days. This layer of skin is responsible for keeping water in the body and keeping other harmful chemicals and pathogens out. Blood capillaries are found beneath the epidermis, and are linked to an arteriole and a venule. Arterial shunt vessels may bypass the network in ears, the nose and fingertips. The dermis lies below the epidermis and contains a number of structures including blood vessels, nerves, hair follicles, smooth muscle, glands and lymphatic tissue. It consists of loose connective tissue otherwise called areolar connective tissue - collagen, elastin and reticular fibres are present. Erector muscles, attached between the hair papilla and epidermis, can contract, resulting in the hair fibre pulled upright and consequentially goose bumps. The hypodermis is not part of the skin, and lies below the dermis. Its purpose is to attach the skin to underlying bone and muscle as well as supplying it with blood vessels and nerves. It consists of loose connective tissue and elastin. The main cell types are fibroblasts, macrophages and adipocytes (the hypodermis contains 50% of body fat). Fat serves as padding and insulation for the body. The constantly peeling off dead cells of the epidermis mix with the secretions of the sweat and sebaceous glands and the dust found on the skin to form a filthy layer on its surface. If not washed away the dirt and dead skin slurry begins to decompose emitting a foul smell. The skin supports its own ecosystems of microorganisms, including yeasts and bacteria, which cannot be removed by any amount of cleaning. In general these organisms keep one another in check and are part of a healthy skin. When the balance is disturbed, e.g., by antibiotics which kill bacteria, there may be an overgrowth and infection by yeasts. The skin is continuous with the inner epithelial lining of the body at the orifices, each of which supports its own complement of flora.
Ways to care for your skin In fact, skin care and protection should be an essential part of your health, fitness, and beauty regime. If you take care of your skin, your skin will take care of you! If your stuck in a skin care rut, or if you are just looking to learn a bit more about the basics of skin care, read on to learn more about this important step in your daily activities. You are never too young or too old to start taking care of your skin. In fact, skin care and protection should be an essential part of your health, fitness, and beauty regime. If you take care of your skin, your skin will take care of you! But with all of the lotions, creams, and potions on the market, it can be difficult to know which product will work for you. Many products claim to remove wrinkles or heal dry skin. Others claim to contain expensive ingredients that they say will improve the effects of the product. The first step to taking care of your skin is preventing damage. Sun, wind, pollutants, and simply aging can degrade the condition of your skin. Common complaints include dry and itchy skin, wrinkles, sagging, color changes, and age spots. There are steps that you can take to keep you skin looking and feeling its best. The most important way to care for your skin is to protect it from the damaging rays of the sun. Ultraviolet radiation damages the skin and can lead to wrinkles, premature aging, age spots, and cancer. Take extra precautions to make sure your skin is not exposed to the sun's rays. Use a natural sunscreen, or a moisturizer that contains sunscreen (at least SPF 15) everyday. Your skin does need some sunlight 10-15 minutes of direct exposure daily. When you do use soap, try using a natural very mild soap that does not contain any dyes, parabens or perfumes. Follow up the bath with a moisturizing lotion, concentrating on problem dry areas. A good all natural moisturizer is one of the foundations for a healthy skin care regimen. Continue moisturizing throughout the day to keep skin healthy. Your hands and face are particularly susceptible to daily damage, and may need to be moisturized several times. Wash your skin thoroughly on a daily basis to remove the dirt, debris, pollutants, and perspiration that accumulates on a daily basis. If you have dry or sensitive skin, use only warm water to wash your skin and use a mild natural cleanser every few days. If you have normal or oily skin, be sure to wash with a gentle cleanser on a daily basis. Be sure to brush your teeth before washing your face, as toothpaste residue can irritate sensitive facial skin. Experts say that the amount of wrinkles that a person will develop through the years also depends on the genetic make up of this individual. However, smoking, sun exposure, dry skin, and repetitive facial expressions and mannerisms such as frowning, can all enhance the creation of wrinkles that may or may not be permanently present.
Definition interpretationAcne
- An inflammatory disease of the sebaceous glands and hair follicles of the skin that is marked by the eruption of pimples or pustules, especially on the face.
Bacteria
- Microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles.
Dermis
- The sensitive connective tissue layer of the skin located below the epidermis, containing nerve endings, sweat and sebaceous glands, and blood and lymph vessels.
Epidermis
- The outer, protective, nonvascular layer of the skin of vertebrates, covering the dermis.
Hypodermis
- A subcutaneous layer of loose connective tissue containing a varying number of fat cells.
Pimples
- A small swelling of the skin, usually caused by acne; a papule or pustule.
Ultraviolet radiation
- Invisible electromagnetic radiation between visible violet light and X rays.
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