Our skin is a fascinating organ that protects us in an incredible number of ways through our three main layers called the epidermis, dermis and hypodermis.
These three layers are made up of functional layers of cells, immune cells, blood vessels, sebum and sweat glands. The cells in turn collaborate a host of beneficial bacteria and fungi that live in and on the skin. Together they determine your skin type (Normal, Dry, Oily, Combination) and whether you should have any skin condition such as psoriasis and what my research has shown is that this can change depending on the season and age.
The epidermis is the part of the skin that we can see and touch.
It is a very thin layer, no more than 0.1 millimetres, and acts as a protection and a barrier.
The outermost layer of the epidermis is called the stratum corneum and it protects the body from cold, UV rays, bacteria and viruses.
The cells contained in the stratum corneum are surrounded by a moisture-retaining film called the hydrolipidic film, which is made up of sebum, a mixture of the oils produced by the sebaceous glands, water and humectants. And the humectants are made up of salts and acids.
In the epidermis there are also two types of skin cells responsible for the renewal process of the epidermis, keratinocytes, which are the cells that migrate to the outermost layer of the skin, i.e. the stratum corneum, and melanocytes, which are pigment cells. They are the ones that build up your skin colour.
We leave the epidermis and move on to the next layer called the dermis.
The dermis, like the epidermis, has specific functions. It provides skin stability, controls our body temperature, supplies the epidermis with oxygen and nutrients, conducts signals from the sensory cells and backs up the immune system. It has very many and important functions.
The dermis is made up of collagen and elastin, two proteins that give the skin elasticity and resilience. These proteins are surrounded in the skin by a gel-like substance called hyaluronic acid and this is a substance that cosmetic companies are trying to add more and more to their products, especially in anti-ageing products as hyaluronic acid can add extra moisture to skin where collagen has started to diminish resulting in wrinkles and sagging of the skin.
The moisture content of the skin is important for creating elasticity and maintaining the skin's structure and elasticity. After the age of 25, we break down more collagen than we create. We lose about 1% of collagen each year and by adding hyaluronic acid, cosmetic companies are trying to counteract this. Hyaluronic acid is also a skin-building substance.
In addition to skin-bound ingredients, it is found in the dermis sebaceous glands and our hair roots. And if you recall, it is sebum from the sebaceous glands, together with water and salt from sweat and acid from bacteria, that forms the hydrolipid film in the epidermis.
If your sebaceous glands produce more sebum than your skin's pores can handle, you can get the skin type defined as oily. The T-zone - your forehead, nose and chin - can be most affected by this.
Then there are the hair roots. Where the hair roots are located are the melanocyte stem cells, the pigment cells that determine your skin colour that we talked about earlier. According to my research, the cells migrate from the hair follicles to the epidermis and then form pigment.
We also have 3 million sweat glands in the dermis and a network of blood vessels that supply the entire skin with oxygen and nutrients. The blood vessels are accompanied by lymphatic vessels.
If you were to cut yourself so badly that you started bleeding, you'd have dermis.
The last of the main layers of the skin is the hypodermis.
The hypodermis is often referred to as subcutaneous fat and insulates us from the cold. There are also important blood vessels that go up to the dermis, nerve fibres that go up to the dermis all the way up to the epidermis and lymphatic vessels.
The hypodermis is the thickest of the three layers.
In the depths of the hypodermis we find what many women find troublesome - cellulite. The appearance of cellulite is due to poor blood circulation in the skin, which causes fluid to accumulate in the tissue. These accumulations of fluid prevent the skin from getting rid of waste products. This, combined with pressure from swollen fat cells, forms cellulite.
Cellulite is incredibly common and completely natural. More common in women than in men.
There they are! The skin's three main layers and their functions.
Have a great day my green friend!
Julia