Understanding the skin
The skin is the intermediary between the body and the outside world. Its condition and appearance are evocative elements of the general state of health and well-being of an individual. When skin is healthy, it protects the body against bacteria and viruses and regulates its temperature. In addition, she looks rested, hydrated, and her complexion is even.
Many internal and external factors have consequences on the health of the skin and its appearance.
In order to remedy this, you need to take care of your skin. It is essential to know its composition, its functioning as well as its needs in order to choose the right products, the right care routines , and adopt appropriate actions.
What is skin made of?
The skin is considered an organ of the human body. It is the largest in terms of size and weight, in fact, skin tissue represents 16% of the total weight.
For example, for an adult man who weighs 70kg, it extends over 1.8 m² and weighs approximately 3kg.
Skin thickness can vary in different areas of the body. It is thicker at the hands and feet (around 4.7 millimeters), and thinner at the face (around 0.12 millimeters).
The skin is made up of 70% water, 25% proteins, 2% fats and 0.5% mineral salts and trace elements. All these components are distributed over three layers of tissues: the epidermis, the dermis and the hypodermis.
What is the structure of the skin?
The skin is divided into three layers (epidermis, dermis, hypodermis):
- The epidermis : this is the upper layer of the skin which is in direct contact with external aggressions. This epidermis is covered with a protective film called a “hydrolipidic film”. It is made up of sweat, sebum and lipids secreted every day by the skin. Its role is to retain skin hydration and prevent water evaporation. On this epidermis, there are also micro-organisms which guarantee the good balance of the skin, we call this the “cutaneous flora”. Finally, the epidermis is made up of blood vessels, which explains why during a small cut, only a small layer of skin is removed and there is no trace of blood.
- The dermis: it is the thickest and strongest layer of the skin. It also contains much more water and is more flexible. In this dermis, there are hairs, sweat glands which create sweat, sebaceous glands which produce sebum as well as blood vessels which provide nutrients and defense cells. In addition, it protects the body thanks to its presence of different types of white blood cells. Also, the dermis helps nourish and supply the epidermis.
- The hypodermis : it represents the deepest and thickest layer of the skin. The hypodermis is the protective interface between the dermis and the different organs. It contains fat cells and adipocytes. Since fat is considered a natural insulator, the hypodermis acts as a thermal regulator to protect against the cold. Thanks to its significant thickness, it protects and absorbs the shocks suffered by the body.
What are the different functions of the skin?
It is important to know the different functions of the skin in order to better understand the purpose of each element:
- The secretory function: it rejects, thanks to the sebaceous and sweat glands, all elements likely to destabilize the internal balance (toxins, sebum, residues linked to drug treatment, etc.).
- Sensory function: the skin is made up of a large number of nerve receptors which give it a sensory function. These react to different stimuli such as cold, heat, touch or even pain.
- The protective function: it protects the body from all external attacks (shocks, friction, aggressive products, pollution, extreme temperatures, etc.) of daily life. It helps maintain the body at a temperature of 37 degrees through perspiration. It also forms a barrier against viruses, bacteria and microbes by stimulating certain lymphocytes and white blood cells to guarantee good immune defense.
- The emotional function: we don't know it but the skin serves as a means of communication, in fact, it can inform us about our state of health and our emotions. It can turn red in the event of discomfort, turn white in the event of illness, be dull due to fatigue, or even reveal dark circles or imperfections.
What are the different skin types?
There are 4 different skin types: dry skin, normal skin, combination skin and oily skin. As mentioned previously, skin type depends in particular on genetic heritage.
- Dry skin: it does not secrete enough sebum. It therefore lacks essential lipids to preserve its hydrolipidic film and thus protect itself well against external aggressions.
- Normal skin: this is the most “balanced” skin, it is neither too oily nor too dry. However, the T zone (forehead, chin, nose) may be a little oily.
- Combination skin: we recognize it by the fact that the skin type is different depending on the areas of the face. In general, the T-zone is oily and the rest of the face is normal or dry. The T zone produces too much sebum while the rest of the face, on the contrary, lacks it.
- Oily skin: this is the type of skin that overproduces sebum, we call it “seborrhea”. The skin shines more, then the pores are dilated and more visible.
When it comes to sensitive skin, it's not actually a skin type. It can be dry or oily. But it is more reactive and prone to irritation and redness because the epidermis is not able to sufficiently protect it from external aggressions.
Whatever the skin type, you should know that its state of health can vary depending on various factors it faces.
What are the main factors that affect the skin?
- Genetic heritage: it determines the type of skin as well as its biological aging. It may also imply a predisposition to skin diseases.
- Hormones: hormonal changes can lead to acne during puberty, or increase the production of melanin and create a form of hyperpigmentation (melasma) during pregnancy. As for osteogenic hormones, they have a beneficial effect on the skin's moisture balance. However, when they decrease during menopause, the skin loses its structure. Finally, stress makes the skin much more sensitive, more fragile, and less resistant to free radicals. It causes the production of cortisol, a hormone that affects the immune system of the epidermis. This can damage the protective function of the skin and cause allergic reactions, skin aging, dryness, the appearance of wrinkles or pigment spots.
- Climate and environment: first of all, UV radiation has a significant impact on the skin. Free radicals are aggressive molecules that are responsible for the process of tissue oxidation damaging cells. They can therefore lead to premature aging of the skin. Then, the skin is also sensitive to temperatures and their variations. Cold causes the phenomenon of vasoconstruction (thermal regulation of peripheral cutaneous arterioles which directs blood flow towards the deep venous system). The cold prevents the secretion of the sebaceous glands but causes drying of the skin. On the contrary, when it is hot and humid, the sweat glands produce more perspiration. The skin then becomes moist and shiny.
- Chemical attacks: slightly acidic (pH 5), the skin is sensitive to aggressive cleansing agents (for example sodium lauryl sulfate) which excessively tax its natural neutralization capabilities. Its cells are damaged and its protective barrier function (at the level of the epidermis) loses its effectiveness. The skin can then become very dry and hypersensitive.
- Diet: when balanced, it helps maintain healthy skin. Indeed, certain imbalances can cause, for example, acne. Water also plays an important role for the elasticity and hydration of the skin. Taking food supplements can be effective in helping to maintain normal skin. Délicure offers a range of vegan and natural gummies, rich in vitamins (B6, B8, B9, B12 and E) and minerals ( zinc , selenium), which targets hair, nails and skin.
What are the main skin diseases?
The factors stated above can cause skin diseases. Almost all individuals, during their life, have faced the appearance of spots, redness or itching on the skin.
Here are the most common skin diseases:
- Eczema: This is the most common skin disease. It can affect all parts of the body and manifests itself with itching, redness, blisters or blisters. This disease is favored by dry skin.
- Rosacea: quite common, it only affects the face. This disease can manifest itself with redness, tiny broken blood vessels, small pink-colored bumps full of pus, swelling around the eyes, painful eyelids or even thickening of the skin of the nose.
- Skin fungal infections: These are characterized by a scaly, itchy (itchy) rash, inflammation and discoloration of the skin . These include athlete's foot, ringworm and intertrigo .
- Psoriasis: it is an autoimmune disease that is recognized by the appearance of red, scaly patches. It causes pain and swelling in the affected joint(s) .
- Shingles: it is diagnosed following a red, spotted and painful rash. It is often visible on the chest and stomach, or the face, eyes and genitals. The rash may appear as blisters that itch and ooze.
- Acne: recognized by the appearance of pimples, this disease is linked to inflammation of the sebaceous glands under the skin . It most often appears on the face, chest and back. It can affect all ages but is more often due to puberty and its hormonal variations.
If symptoms suggestive of a skin disease appear, you should quickly go to a doctor or dermatologist who will prescribe appropriate treatment.