Basic Skin Information - How Skin Works

Skin is the largest organ in your body, and one of the most important. It keeps your entire body safe from infection - and provides a way to detect pain, pressure, heat and cold problems. It lets you give off sweat to help cool yourself if you are overheating. It turns darker if exposed to sunlight, to help protect you against cancerous rays. 

There are three main layers to your skin. 

Epidermis

The top layer is the epidermis. This is the outer layer that you see. It does not have any blood vessels in it. It simply provides the 'barrier' between your body and the outside world. This layer is about as thin as a sheet of paper. The very top of the epidermis is formed by a layer of dead skin cells. As they fall off, the newer, live skin cells are exposed to the air, die off, and the cycle continues.

The epidermis layer is what people see - it is the part of your skin that beauty products are meant to work on. When you are young, this layer replaces itself every 16 days or so, giving you fresh, healthy looking skin. By the time you hit 35, the layer is only replacing itself about once a month. Your skin begins to look more tired and worn. 

Dermis

The next layer down is the dermis layer. This layer has blood vessels, which provide blood to that upper epidermis layer. It also provides some of the 'padding' in your skin. The dermis is a permanent layer of skin - it does not replenish. It can NOT be reached by lotions and creams and such. Those items only work their way in to the epidermis. That is the function of skin - to keep foreign substances out of your body's system. 

The dermis also contains the elastin and collaging, forming the 'structure' of your skin. It is this layer that stays elastic or gets saggy, to cause wrinkles or firmness in your skin's look. If you get a tan too many times, you destroy that elasticity in your skin, and make it look old and wrinkly. 

Hypo dermis

The lower layer of your skin is the hypo dermis. It is here that the main sweat glands, hair follicles, and main blood vessels of your skin layer lives. If you take hold of a hair with a tweezers and yank it out, that hair follicle you see at the end of your hair just came from your hypo dermis. 

Each layer of skin has its own life cycle. The top layer - or epidermis - exfoliates normally. That means that the top cells wear away, new cells grow beneath to replace them, and so on. This is just how the hair on your head works, too. However, the dermis is a much more permanent layer. When people get tattoos, the tattoo needles go THROUGH the epidermis and inject the ink into the dermis. That is why, even though the top layer of skin constantly renews, the tattoo stays there for a person's entire life.