The Structure of Skin
Skin is amazing! Did you know it is the largest organ of your body and the only one you can see! Your skin is made up essentially 3 layers:
- The Stratum Corneum – or ‘the barrier’ as we call it.
- The Epidermis – we like to call this the ‘middle layer'
- The Dermis – the ‘bottom layer'
Let’s start with the top bit and the bit you can see ‘The Barrier’. It is actually made up of dead epidermal cells stuck together with special waterproof cement, a bit like overlapping bricks and mortar. It is very strong and waterproof. But just like a wall it can crack and leak if it is not looked after properly or if something damages it. If the barrier does get damaged, you may well experience signs of sensitive skin.
Luckily our body replaces the barrier roughly once a month.
Next is the ‘middle layer’ The Epidermis. New cells are produced by the bottom layer of the epidermis. These cells called keratinocytes, go through a process called ‘terminal differentiation’ – this sounds grim, but it is perfectly natural. It’s a process of change from a normal cell into the special ‘bricks’ that make up the Barrier. During this process they even make their own cement!
Finally the ‘bottom layer’, the Dermis. Making the Barrier takes a lot of energy. The Barrier and the Epidermis have no blood supply of their own, so all their needs are provided by the Dermis. Tiny blood vessels called capillaries carry blood very close to the Epidermis; here they deliver nutrients and oxygen.
Whereas the Epidermis is nearly all cells packed tightly together, the Dermis is nearly all a matrix. This matrix is made by cells called fibroblasts and it is this dermal matrix that gives the skin support, plumpness and flexibility. It is made of proteins including collagen and elastin with lots of water.
The three layers of the skin sit on a layer of fat. We don’t usually think of having a layer of fat as a good thing, but when it comes to your skin, this layer is vital! Even the thinnest people have a layer of fat under their skin which with the dermis helps to provide support and cushioning.