An Overview of Skin

Your skin is the largest organ on your body, made up of several different components, including water, protein, lipids and different minerals and chemicals. If you're average, your skin weighs about six pounds. It's job is crucial: to protect you from infections and germs. Throughout your life, your skin will change constantly, for better or worse. In fact, your skin will regenerate itself approximately every 27 days. Proper skin care is essential to maintaining the health and vitality of this protective organ.

How Can I Keep My Skin Healthy?

It's easy to forget to drink that glass of water or to cleanse yourself at night when you're tired. But over time, those bad habits can take a toll on your skin. Each day, provide your skin with:

• Plenty of water.
• Thorough cleansing. You should perform this twice daily. At night, make sure you remove all your make-up and cleanse properly before going to bed.
• Balanced nutrition.
• Toning. After you cleanse with your bar soap or other cleanser, make sure you use a formulated toner or astringent to remove fine traces of oil, dirt and make-up that you may have missed when cleansing.
• Moisturizing. This is necessary even for those who have oily skin. There are plenty of moisturizers on the market that are oil-free.

Over the course of your life, you should pay attention to all parts of your skin. Familiarize yourself with it, so you'll notice any changes that might occur, such as different moles or patches that might indicate skin cancer. Whenever you have a question or concern, make sure you see your doctor.

How Does My Skin Work?

Medical terms for various parts of your skin are commonly used today to sell skin care products and procedures. Here's a rough guide to what those terms mean.

Epidermis: The Outer Layer of Skin

The epidermis is the thinnest layer in your skin, but it's responsible for protecting you from the harsh environment. The epidermis has five layers of its own: stratum germinativum, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum. The epidermis also hosts different types of cells: keratinocytes, melanocytes and Langerhans cells. Keratinocytes produce the protein known as keratin, the main component of the epidermis. Melanocytes produce your skin pigment, known as melanin. Langerhans cells prevent foreign substances from getting into your skin.

Dermis: The Middle Layer

This is the layer responsible for wrinkles. The dermis is a complex combination of blood vessels, hair follicles, and sebaceous (oil) glands. Here, you'll find collagen and elastin, two proteins necessary for skin health because they offer support and elasticity. Fibroblasts are the cells you'll find in this layer, because they synthesize collagen and elastin. This layer also contains pain and touch receptors.

Hypodermis: The Fatty Layer

Reduction of tissue in this layer is what causes your skin to sag. This layer is also known as the subcutis. It hosts sweat glands, and fat and collagen cells. The hypodermis is responsible for conserving your body's heat and protecting your vital inner organs.

Collagen

Collagen is the most abundant protein in the skin, making up 75% of your skin. This is also your fountain of youth, for it's responsible for warding off wrinkles and fine lines. Over time, environmental factors and aging diminish your body's ability to produce collagen.

Elastin

When you hear the word elastin, think elastic. This protein is found with collagen in the dermis, and is responsible for giving structure to your skin and organs. As with collagen, elastin is affected by time and the elements. Diminished levels of this protein cause your skin to wrinkle and sag.

Keratin

Keratin is the strongest protein in your skin. It's also dominant in hair and nails. Keratin is what forms the rigidity of your skin.

Reviewed by the doctors at The Cleveland Clinic, Department of Dermatology.
Edited by Michael W. Smith, MD, April 2003, WebMD.

Portions of this page ©The Cleveland Clinic 2000-2003.

QUESTION

An average adult has about ________ square feet of skin. See Answer