When you look at your skin, you really only see one layer. And, that’s your first line of defense against different pathogens in the air. Basically, without the skin, your inner body wouldn’t be protected from germs. This outer layer is called the epidermis, and it has no blood supply of its own. And, that’s why when you shave, you don’t bleed, unless you cut the next layer where the blood supply is. The underlying skin structure is complicated and elegant, and helps keep us safe from a ton of environmental factors. Let’s get into skin structure.
Underlying Skin Structure
The epidermis or skin is actually divided into four or five layers, with the fifth only present in some parts of the body. These five layers that comprise the skin structure are; Stratum Basale, Stratum spinosum, Stratum granulosum, Stratum lucidum, Stratum corneum. And, below we’ll discuss each of them in turn.
This is the base layer of your epidermis, and it’s one of the most important ones in your skin. Because, it contains the only cells in the skin that can actually divide and produce more of themselves. So, your skin grows from this layer. And, this layer makes Keratin, one of the most important proteins in the epidermis. Keratin makes our skin tough and helps add protection from the outside world.
Stratum Spinosum and Granulosum
Stratum spinosum gets its named from the shape of the cells that comprise it. The cells in this layer are spiny-shaped. And, these cells help give the skin its strength and overall flexibility. So, without this layer, your skin would puncture a lot easier and you wouldn’t be able to move the way you do. Then, the next layer is the Stratum Garnulosum, called that because the cells contain little granules. Under a microscope, these cells look like little dots of sand clustered together. This layer has a lot of keratin to keep your skin strong and healthy.
This layer is mostly made up of dead keratinocytes from the layers below it. And, keratinocytes travel all the way to this layer to die. They die here because they’re so far away from the blood supply of the first few layers. Then, these keratinocytes are devoid of nutrients and oxygen, and they’re pushed up toward the surface of the skin. This layer gets its name because the cells look translucent under a microscope. And, this layer is most often found on the hairless parts of our bodies, and is usually the thickest. For example, it’s on our hands and feet.
Finally, the keratinocytes that have worked their way through every layer of skin reach this final layer. And, this is basically your skin as you know it. In other words, it’s the skin you can see with your naked eye. Now, in this layer, the keratinocytes are called corneocytes. And, they don’t have any water or any living part of the cell left. Basically, this layer is just dead skin cells filled with tough keratin. So, they can keep out different germs and illnesses from your body. And, they overlap and keep skin airtight.
The cells in this layer also help protect you from environmental trauma. For example, if you hit your skin on something, it protects you from abrasions. Then, it also keeps out light, heat, chemicals, and germs. The cells in this layer are also water resistant. In other words, they help keep water out of your system that shouldn’t be there. And, that’s why water beads on your skin instead of soaks in. Eventually, the cells making up this layer shed into the environment. The entire life cycle of a skin cell is only around 25-45 days long, as it makes its way through all the different layers.
Looking to keep your skin looking fresh?