Human skin has the ability to recover even after severe damage. However, as a result of healing, scars always remain on it. Moreover, they can occur not only after injuries, but also in some other cases, for example, after surgery, infection, or even rapid body growth. But why do scars appear in the first place and do not disappear over time? To answer this question, you need to understand what human skin is and how damaged areas heal.
After the skin heals, scars remain on it. Photo source: middlepathspa.com.np
Contents
- 1 What is human skin made of
- 2 How is human skin restored
- 3 Why do scars appear on the skin
- 4 What types of scars are there on the human body
- 5 Can scars disappear
What is human skin made of
Human skin contains three main layers. The outer layer, called the epidermis, is the thinnest. It is formed by flattened, or epithelial, cells. It has a protective function, that is, it protects the body from the outside world – bacteria, mechanical impacts, ultraviolet radiation, etc.
The second layer of skin, located under the epidermis, is called the dermis. It is the thickest and contains blood vessels, nerves, hair follicles, and sweat and sebaceous glands. The dermis has a lot of collagen and elastin in the form of a large fibrous network of proteins. Thanks to them, our skin is elastic and able to maintain its structure.
Human skin contains three main layers. Photo source: sprosyvracha.ru
The third layer of skin, located under the dermis, is the hypodermis. It contains fatty tissue that performs several functions at once – it insulates the body, provides cushioning for internal organs and protection from injury. In addition, the fatty layer contains a reserve of energy for the body in fat cells.
How human skin is restored
The easiest layer of skin to restore is the top layer, the dermis. That's why small scratches don't leave scars. Also, if the dermis is damaged, for example by sunburn, the outer layer peels off, but a new one appears in its place. At the same time, the deeper layers of skin remain intact.
But if the injury is more serious and affects the dermis, more complex skin repair mechanisms are activated, which consist of several stages. First of all, a scab appears on the surface of the wound, which protects it. Then the inflammation process begins, which initiates healing, and the body begins to rebuild the tissue inside the wound.
Scars on the skin occur due to connective tissue. Photo source: bhub.com.ua
Why do scars appear on the skin
As mentioned above, the dermis contains a network of collagen fibers. This network is carefully structured and has a certain smooth pattern, that is, it resembles fabric. After skin damage, the injured areas cannot grow together, and therefore the collagen network cannot be restored either. Therefore, connective tissue appears between them.
Scientists do not yet know what this is connected with, but be that as it may, new collagen fibers appear in the wound, which fill the gap between the damaged skin. However, the formation of new tissue occurs unsystematically. Simply put, the body literally dumps the fibers “into a disorderly heap”, resulting in a sloppy “patch”.
Due to the fact that the accumulation of collagen inside the wound occurs unorganized, a scar appears. By the way, it is precisely because of the large amount of collagen that scar tissue does not look like normal skin. It is less elastic, and also does not have hair follicles and sweat glands.
A hypertrophic scar protrudes above the skin. Photo source: zentromed.com
What types of scars are there on the human body
In people with fair skin, the scar is initially pink or even red. Over time, the scar tissue begins to lighten and becomes lighter or, conversely, darker than the surrounding skin. In people with dark skin, scars look like dark spots.
During normal wound healing, the body stops filling the tissue gap with collagen in time, resulting in a small scar. But sometimes the body continues to deposit collagen even when it is no longer needed. This results in thick, raised scars called hypertrophic scars. They are red, pink, or purple.
Hypertrophic scars most often occur in adolescents and pregnant women. This may be due to hormonal changes, which result in increased inflammation in the body. Despite the fact that such scars are rough and protrude above the skin, they are the same size as a wound on the skin.
Keloids are caused by tissue proliferation. Photo source: juliasherbatova.ru
In some cases, a tumor-like growth of connective scar tissue occurs. As a result, the scars are larger than the wound and protrude above the skin more than hypertrophic scars. Such scars are called keloids. Most often, keloid scars occur in people with dark skin. Most likely, this is due to genetic factors.
Can scars disappear
Small scars, if they are not hypertrophic, and especially not keloids, can “disappear” over time. This is due to the fact that the disordered collagen fibers inside the tissue begin to align and smooth out. That is, structured connective tissue arises from disordered connective tissue. This usually takes more than a year.
Be sure to visit our Zen and Telegram channels, where you will find the most interesting news from the world of science and the latest discoveries!
However, the scar cannot disappear completely, since disordered connective tissue is fundamentally different from normal skin. Scientists cannot solve this problem yet. Theoretically, human skin can heal without a “pad” in the form of scar tissue. For example, it is known that during the first two trimesters of pregnancy, the fetus can completely regenerate wounded skin without connective tissue. However, for some reason, we lose this ability. Moreover, according to research, adult skin transplanted to a fetus still scars.
But at present, there are several technologies that allow you to get rid of scars. For example, these include laser resurfacing, cryotherapy, and some other methods. You can read more about them at the link.