Skin Science & Anatomy

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 unique; it’s your protection and armour.

It is also the first thing you notice about someone.

Think about it: glowing, vibrant skin suggests vitality.

Yet sallow, dry skin indicates poor health.

This is why a basic understanding of skin functions is critical.

That is if you want to keep your skin youthful and healthy.

Your Skin Layers

The layers of skin are made up of the following:

  • The epidermis
  • The dermis
  • The subcutaneous

All of these skin layers play an essential 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 a waterproof covering; it is also where melanocytes, the pigmented skin cells that give our skin colour, are housed.

There are five skin layers within the epidermis.

Cells go on a 28-day migration towards the surface and are continually pushed up through these layers until they are shed.

This shedding is called desquamation, a natural exfoliating process that your skin goes through; this process does slow down as we age, which is why exfoliation is an essential step in your home care routine.

The Dermis

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

It is a constant hive of activity; lymph vessels and nerve endings are found in the dermis, which gives you your sensitivity to touch, pain, pressure, and hot and cold sensations.

Elastin and Collagen

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

  • Elastin gives skin its snapback 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 in your skin. Both elastin and collagen are encased in glycosaminoglycans (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 essential anti-ageing ingredient; it’s a humectant with a fantastic 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 secreted through the hair follicles and delivered to your skin; this keeps your outer layer of skin, the epidermis, well-lubricated, thus preventing dryness and dehydration.

Subcutaneous Layer

This is also called the hypodermis, 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 fatty cushioning and insulation, helping keep everything encased while protecting your internal organs.

It plays a vital role in drawing nutrients from the blood supply to feed your skin, keeping it nice and healthy.

To conclude: The naked truth

Your skin, the body’s largest organ, performs many functions.

And it’s the first thing people notice about us, which is why we are responsible for looking after it.

Three skin layers help it achieve these; they play a major role in protecting 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 primary function of your skin is temperature regulation.

The layers of skin contain around 2 million sweat glands, and we can sweat about 10 litres daily 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 skin layers and their role in skin health in more detail.