A Guide to the Physiology of the Skin Layers

This is my skin. This is not your skin
Yet you are still under it!

Your skin is amazing; it’s your protection and armour.

It is also the first thing you notice about someone.

Think about it: A glowing, vibrant skin suggests vitality, whilst sallow, dry skin indicates poor health.

This is why having a basic understanding of how your skin functions on a cellular level are key, that is if you want to keep it healthy.

Skin layers

Your skin consists of three layers; the epidermis, dermis and subcutaneous, all of which play an important role in the health of your skin.

The epidermis

This makes up the skin layers that are visible to the naked eye.

The epidermis offers protection and provides us with a waterproof covering; it is also where melanocytes are housed, the pigmented skin cells that give our skin colour.

There are five skin layers within the epidermis; Cells go on a 28-day migration towards the surface and are continually being pushed up through these layers until they are shed, this is referred to as desquamation, a natural exfoliating process that your skin goes through; this process does slow down as we age, which is why exfoliation is an important step in your home care routine.

The dermis

This layer sits just below our epidermis; the dermis is known as the living or true layer because a lot is going on here.

It is a constant hive of activity, lymph vessels and nerve endings are found in this layer, which gives us our sensitivity to touch, pain, pressure, hot and cold sensations.

Elastin and Collagen

The dermis is also where your all-important collagen and elastin is found, our internal scaffolding.

  • elastin gives skin its snap back and elasticity.
  • collagen, which is not quite as flexible as elastin helps to give your skin its firmness, keeping everything taut and in place.

Next to water, collagen is one of the most abundant substances found within your skin. Both elastin and collagen are encased in glycosaminoglycan’s (GAGS), a jelly-like fluid which keeps your skin soft and supple.

One of the components we use in cosmetic chemistry to mimic this valuable ingredient is hyaluronic acid, an important anti-ageing ingredient; it’s a humectant that has an amazing ability to bind water to the layers of the skin, keeping it plump, healthy and supple.

Sebaceous glands

Within the dermis, there are also sebaceous glands, which secrete sebum on the surface of your skin.

Sebum is an oily mixture, that is secreted up through the hair follicle to deliver oil to your skin, this keeps your outer layer of skin the epidermis, well-lubricated, thus preventing dryness and dehydration.

Subcutaneous layer

This is also referred to as the hypo-dermis, which means beneath the tissue; it is the most internal layer of your skin, which lies below the dermis.

This subcutaneous fat layer gives your skin it’s fatty cushioning and insulation, helping to keep everything encased whilst also protecting your internal organs, it plays an important role, drawing nutrients from the blood supply to feed your skin, keeping it nice and healthy.

Conclusion

Your skin the body’s largest organ performs many functions, and its the first thing people notice about us, which is why we have a responsibility to look after it.

It has three distinct layers to help it achieve these; a major role is for protection against physical aggressors such as UV, environmental pollutants, friction, chemicals and infection.

It is also your largest sensory organ; you receive lots of information about the world through the nerve endings in your skin, including heat, cold and pain.

Another major function of your skin is temperature regulation. The skin contains around 2 million sweat glands, and we can sweat around 10 litres per day in hot environments, to help keep our body cool, when it’s cold, the sweat production and blood supply to your skin are reduced, to help conserve heat.

For more in-depth reading, this article looks at the skins layers and their role in skin health in more detail.