THE SKIN(our armor)

June 18, 2022

In as much as the armor protects one from being hurt during a fight, so does the skin protects us from varieties.

Our inner Organs, tissues and cells depend on a source of protection, without this source their functions are impaired and the wellbeing of an individual is at risk, Guess what? This source is the SKIN, how much do you know about your skin, do you actually know the functions it performs? You do not have to be science-knowledged before you know major things about your skin. Ride with me to know basic and complex things about the skin, this context is as simple and understandable as possible.

Do you know the skin is the largest organ of the body? Yes! it is, with a total area of about 20 square feet. The skin protects us from microbes (minute foreign particles that can't be seen with naked eyes) and the elements. The skin also covers all the parts of our body (face, eye, hand, leg among others).

LAYERS OF THE SKIN

The skin has three layers:

The epidermis

Outermost layer of the skin, which provides a waterproof barrier and creates our skin tone (that radiant look on our skin). In the epidermis, we have various cells such as MELANOCYTES (these cells are responsible for producing the skin's pigment melanin: the skin color that absorbs ultraviolet radiation to protect us from its harmful effects), KERATINOCYTES (major building block of the epidermis and produces the protein keratin which is responsible for the formation of the epidermal water barrier by making and secreting lipids), LANGERHANS CELLS (they are part of the body's immune system, they are the skin's first line defenders that look out for antigens, trap them and present them for destruction in our system) and MERKEL CELLS (these cells are present in minute numbers and play a role in sensation especially in areas like palms, soles, fingertips). The epidermis is avascular (contains no blood vessels), for this reason it is entirely dependent on the underlying dermis for nutrient delivery and waste disposal through the basement membrane.

The prime function of the epidermis is to act as a physical and biological barrier to the external environment, preventing penetration of irritants and allergens. At the same time, it prevents the loss of water and maintains internal homeostasis (a constant environment).

The dermis

Beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands. The dermis forms the inner layer of the skin and is much thicker than the epidermis (1-5mm). The primary role of the dermis is to sustain and support the epidermis, the main functions of the dermis are:

Protection;
Cushioning the deeper structures from mechanical injury;
Providing nourishment to the epidermis;
Playing an important role in wound healing.
Blood vessels in the dermis form a complex network and play an important part in thermoregulation (maintenance of a constant core temperature).

The hypodermis (subcutaneous tissue)

Made of fat and connective tissue. It provides the main structural support for the skin, as well as insulating the body from cold and aiding shock absorption. It is interlaced with blood vessels and nerves.

FUNCTIONS OF THE SKIN

Each layers of the skin contribute their respective functions, these roles are accumulated as the functions of the skin and they include;

Protection

The skin acts as a protective barrier from:

Mechanical, thermal and other physical injury;
Harmful agents;
Excessive loss of moisture and protein;
Harmful effects of UV radiation.

Thermoregulation

One of the skin’s important functions is to protect the body from cold or heat. This is achieved by alterations to the blood flow through the cutaneous vascular bed. During warm periods, the vessels dilate, the skin reddens and beads of sweat form on the surface. In cold periods, the blood vessels constrict, preventing heat from escaping. The secretion and evaporation of sweat from the surface of the skin also helps to cool the body.

Sensation

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 patients with a skin condition, as pain and itching can be extreme for many and cause great distress. Also touch is important for many patients who feel isolated by their skin as a result of color, disease or the perceptions of others as many experience the fact that they are seen as dirty or contagious and should not be touched.

Biochemical functions

The skin is involved in several biochemical processes. In the presence of sunlight, a form of vitamin D called cholecalciferol is synthesized from a derivative of the steroid cholesterol in the skin. The liver converts cholecalciferol to calcidiol, which is then converted to calcitriol (the active chemical form of the vitamin) in the kidneys. Vitamin D is essential for the normal absorption of calcium and phosphorous, which are required for healthy bones. The skin also contains receptors for other steroid hormones (oestrogens, progestogens and glucocorticoids) and for vitamin A.

Social and sexual function

How an individual is perceived by others is important. People make judgements based on what they see and may form their first impression of someone based on how that person looks. Throughout history, people have been judged because of their skin, for example, due to its color or the presence of a skin condition.