Like HowStuffWorks on Facebook!

How Your Skin Works

        Health | Skin Anatomy

Skin as It Ages
Laugh lines are the kind of wrinkles that are worth it.
Laugh lines are the kind of wrinkles that are worth it.
Ryan McVay/Photodisc/Getty Images

We've all marveled at the softness of babies' skin, which is so much smoother than our own. There are several structural differences that give babies their soft skin. For one thing, their dermis layer is about 20 to 30 percent thinner than adult skin, which makes it less adaptable and more in need of sheltering [source: Johnson & Johnson]. Babies take in and lose water much more quickly than adults and, because they don't sweat as much, they aren't able to regulate their body's temperature like adults, either. Their skin is also very tender and prone to rashes when irritated. All of that softness comes with a price.

As children grow older, their skin becomes less sensitive. Adolescence is the next step, bringing with it a rush of hormones. Acne is often quick to follow, and may persist into adulthood. The next stop on the timeline of your skin is adulthood.

As we grow older, our skin ages in two ways: intrinsic and extrinsic. Intrinsic aging is what naturally happens to us due to our genes. The epidermis produces new skin cells more and more slowly as our skin cell layer decreases from a wall 20 cells deep to one that's only two skin cells deep [source: Roizen]. The proteins in our skin that give it firmness and elasticity ease up -- our bodies make less collagen, and elastin loses some of its strength. This is why our skin gets thinner and looser.

Intrinsic aging can be affected by external factors, such as smoking. This is known as extrinsic aging. The nicotine in cigarettes, for example, constricts the blood vessels to your skin, which results in less oxygen and fewer vitamins getting where they need to be. Other chemicals in cigarettes break down the collagen and elastin we mentioned earlier.

Another big part of extrinsic aging is sun exposure. Everyone gets wrinkles, little patchworks of lines that crisscross all over our skin. Genetics partly determines just how wrinkly you'll be, but you can help keep lines to a minimum by taking care of your skin. If you're a smoker or a tanning bed enthusiast, it's likely you'll have more wrinkles than someone who isn't.

Photoaging is what dermatologists call the effects of too much skin on your skin. Wrinkles, pigmentation and changes in skin texture are a natural part of intrinsic aging, but they can be made worse by all the UV rays you've soaked up. Two people may be exactly the same age as far as birth date and yet have skin that makes them look a decade apart. Age spots, for example, also known as liver spots, are a common sight on the skin of older people. These brown, gray or black flat spots are found on the parts of your body that have seen the most sun. Less sun equals less of a chance of age spots.

And just because your skin looks great and healthy in your 20s and bounces back quickly from a summer burn doesn't mean you've seen the last of that willful decision to go without sunblock at the beach. Damage to the skin happens long before you can actually see it.

Read on for some easy tips on how to help your skin care for itself.