The skin is the body’s largest organ.
It can measure up to about 1.5 - 2m² in adults and can weigh about 15% of your total body weight. It is home to about three million micro-organisms per cm², which feed on its keratinised debris (dead skin cells) and secretions.
Understanding this fascinating and complex organ will help us to know our skin better and evaluate its potential for healing following injury, trauma or disease.
The skin holds the contents of our body together. It consists of two layers, the epidermis and the dermis, which work closely together.
The epidermis, or outer layer, has up to five separate layers of cells but no blood vessels or nerve endings of its own. Most regions of the body have four layers except the soles of the feet and the palms of the hands which have a fifth flexible layer to provide durability for friction (the stratum lucidum).
The dermis, or deeper layer, forms an elastic structure of connective tissue that nourishes, provides strength and supports the epidermis and the hair, sweat glands, nerve endings, blood vessels and lymph glands within it.
Different collagens found in this layer work to:
- Provide strength
- Provide elastin which allows the skin to stretch (though this can break when overstretched. This results in silvery lines known as stretch marks)
The following functions of the skin work in synergy -
Your skin secretes an oil known as sebum. Sebum is created in the sebaceous gland which is attached to every tiny little hair follicle on our bodies. This secretion of sebum is important as it keeps the skin soft and supple, ensures moisture from the deeper layers does not evaporate and it provides an invisible “layer” on the skin’s surface which works daily to control & stop the invasion of foreign microbes (i.e. bacteria), this layer of oil is also referred to as the acid mantle.
The acid mantle provides the skin with an acidic pH (the skin has a healthy pH of between 4.5 - 5.5). As this layer is the first line of defence, barrier protection, it is most important to keep this barrier intact. Problems arise when sebum production is overactive, this is largely due to hormonal changes and leads to conditions like acne, breakouts, excessive oiliness and underlying congestion. On the opposite side of the scale, when the gland does not produce enough oil, the skin becomes dry and flaky.
We are able to control and maintain some of the production of oils by using the correct products to use on our skins don’t exacerbate either dryness or oiliness. Sometimes medical intervention is needed to help control the production of oils - this would be in the case of acne.
Your skin regulates your body temperature through blood vessels and through the process of sweating. This is also known as Thermoregulation. When you are exposed to hot conditions, sweating is one of the primary methods your body uses to control its temperature. Sweat on the surface of the skin evaporates and this helps cool the body. Blood vessels feeding the skin also dilate, helping the body to cool down quickly.
Sweat is created in the Apocrine glands. Apocrine glands are located next to tiny hair follicles all over the body. A large concentration of these glands are located in the skin under the armpits, in the groin, and in the area around the nipples of the breast. Apocrine glands in the skin are known as scent glands, and as the name suggests, in the areas where they are largely concentrated their secretions usually have an odour.
Being a regulatory organ, the skin is therefore able to expel and absorb substances equally.
When it comes to absorption of substances there are certain criteria that need to be followed for it to enter the skin’s deeper layers (i.e. the skin cannot just accept or allow any substance applied onto its surface into the deeper layers, just as it cannot expel or excrete any substance from the inside), simply put our skins have a large task to monitor what leaves and what is allowed to enter.
This is important for us as consumers when we are looking at skincare. We can all be confused by the fancy names and advanced ingredient technologies product companies offer us.
What actually enters the skin and makes a difference and what doesn’t? This is a very large subject matter with conflicting opinions. One way to explain it would be to say that there are many variables that affect the skin’s ability to accept active skincare ingredients into its deeper layers, and this is where a consultation with a skin care professional is imperative. The integrity of the skin plays a role just as much as the current health of the skin and body, and this can and will affect the outcome of any skin treatments.
The main function of the skin at large is protection. It serves as a physical barrier to the outside world but also offers some internal protection. Melanocytes are a peculiar looking little cell that resembles an octopus, found in the Epidermis and upper Dermis. This cell grouping is responsible for creating pigment that gives our skins their own unique shade of beauty. Producing pigment or creating a “tan” is actually a protective response to external factors. Although this is aesthetically appealing, it is not a positive response in the long run (as we all very well know - everything in moderation).
The skin may also produce pigment on the back of injuries, this is the skin’s way of recruiting all the protective mechanisms available to protect vulnerable skins (for those skins that are a little darker in colour, you may find dark spots where the skin has had some lesions and these dark spots may stay for a while after the lesions have healed). It is very important to understand your skin’s unique response to healing as this will help you choose the right treatments in the future.
Your skin also disposes of waste through excretion - by producing sweat. Sweating eliminates excess water and salts and a small amount of urea, a by-product of protein catabolism.
Our skin is the 'sense-of-touch' organ that triggers a response if we touch or feel something, including things that may cause pain. This is important for all of us when suffering with skin challenges, as the pain, itching and discomfort allows a skincare professional to identify what the cause may be as well as the exact treatment and management plan long term.
Sensations also allow skincare professionals insight into how tolerant each individual’s skin may be. As mentioned before, our body’s mechanisms are unique, and an individual approach is needed to treat skin effectively as well as safely.
When it comes to the physiological health of the skin it is important to know where these changes are originating from. Skincare professionals are then able to manage the symptoms, treat the causes and work together with you to prevent further damage and discomfort while giving you optimal results.
In order to manage your skin health and achieve your desired results it is not always possible to navigate the skincare realm alone, regardless of the challenge it is always advisable to seek a professional’s advice. With over 25 years’ experience, Tracie Giles is a global leader in Permanent Cosmetics & Aesthetics and is available to guide you to make the best decisions regarding skincare and aesthetic treatment possibilities.