Understanding your skin : Functions of the skin

In Clear Words

Did you know — the outer part of our body, our skin, qualifies as a sensory organ? Our eyes, ears, nose, tongue, and skin are the five sensory organs of our body. It communicates the sense of touch.

It is fascinating that there is barely any part of our external body that our skin doesn’t cover. Our skin feels, behaves, and performs differently in different areas. It is unfathomable to imagine the human body without skin.

Our skin has 3 main layers, with each layer made up of different types of cells. These cells form various tissues and become home to a massive network of tiny nerves, blood vessels, and special glands.

With such a diverse composition, it would be interesting to know the actual functions of our skin.

Our skin made up of three distinct layers (epidermis, dermis, and hypodermis) perform a variety of functions-

• Protective: By means of a physical barrier and a physiological membrane.
• Secretory: By ensuring the production of liquid-like substances needed for control, protection, and nourishment.
• Excretory: By removing unwanted elements through sweat, and shedding layers of dead skin.
• Regulatory: By controlling the temperature, and balancing the various elements such as sodium, potassium, and chloride.

Together, across various sites on the body, our skin helps us with the following functions explained in detail in the upcoming sections

Our skin acts as the first layer in contact with the outside environment. Irrespective of the temperature outside, our skin tries to keep our core body temperature constant via two mechanisms :

Blood vessels and their supply

The various layers of skin contain a network of blood vessels that can change their size as required. These blood vessels are arteries and veins. Arteries carry fresh blood from the heart to all the tissues. The veins carry this blood back to the lungs for oxygen infusion. The arteries and veins can modify the size of their channel to control the flow of blood. When the blood vessels dilate, more blood flows through, allowing loss of heat. For reduction of loss of heat, these blood vessels constrict and become narrower.

Sweat is a fluid secreted by the sweat glands in the dermis layer of the skin. By releasing this secretion, the skin creates a fluid layer above its surface. This fluid comes in contact with the air around and evaporates. During this evaporation process, the heat on the skin decreases. When it is hot, the skin sweats more to keep things cool inside and vice versa. Thus, by sweating process, our skin achieves thermoregulation and maintains the inner body temperature.

Our skin forms a protective layer around our inner tissues and muscles. The skin protects our body and its internal organs when we step into the water.

It acts as a barrier and does not allow any fluid to permeate our bodies. Not just the fluid, it does not allow any particles or chemicals present in the fluid to pass through. Our skin acts as a membrane and ensures that there is no absorption of harmful chemicals and foreign particles into our bodies.

On the outer surface of our skin, there are openings known as pores. These pores can communicate directly with blood vessels in the epidermis of the skin. These microscopic openings, known as pores, act as a channel between the lower layer of the skin and the outer surface of the skin. Through these pores, the skin reacts to the outside environment.

Our skin has an auto-regulatory function that inhibits the absorption of certain elements and chemicals. Due to the size of the pores, it also reduces the chances of most foreign particles crossing through the external layer. The skin primarily protects our bodies externally. It also ensures that the organs inside stay protected.

Beneath our skin, there are many blood vessels. The elasticity and rigidity of our skin across various surfaces ensure that this blood does not leak out or spill out. The only time we can see the loss of fluid from the skin is when there is a break or cut or tear in our skin.

While we welcome sunshine and go out to the beach to tan our skin, the sun rays can be a cause of concern too. Regular sun rays contain ultraviolet light that is very harmful to our bodies and our skin.

The light emitted from the sun travels through many layers of our atmosphere before it reaches us here, on Earth, on our skin. When this sunlight or sun rays are not filtered through, they carry a high frequency of light known as UV rays or Ultraviolet rays.

UV rays can cause changes in the cells that form the tissue of the skin. These rays can cause the tissue to change its appearance and size. This abnormal change is known as melanoma or skin cancer.

The melanin pigment present in our skin counteracts these harmful UV rays that come along with sunlight. Those with higher melanin, ergo darker skin, are less prone to the harmful effects of these rays. Those with lighter skin due to less melanin pigment must protect themselves with an appropriate sunscreen lotion.

Sunlight and our skin are not all bad news. While some parts of sunlight may be harmful to our skin, it also brings along a vital element needed for our body. The sunshine vitamin or Vitamin D. Vitamin D technically is a hormone but is also considered a fat-soluble vitamin. Vitamin D is synthesized naturally when our skin absorbs sunlight. When our skin receives the sunlight, the epidermis layer photolyzes it to a form of D3 that our body can well absorb.

There is a chemical conversion of the available form of D3 into a form that our liver can process. After being processed by our liver, it can be used by our bones to increase the binding and absorption of calcium to build stronger bones.

Based on your location, the distance from the equator, and the year’s season, the optimal time for exposure to sunlight can vary. Exposure to sunlight during these specific time zones would result in an optimal conversion to Vitamin D3 used by the body. This conversion is not sustained throughout the day. One must keep track of this before stepping out in the sun to soak in the goodness.

Increased melanin content in our skin is inversely proportional to its capability of converting sunlight to vitamin D3. The importance of our skin as a source of nutrition for the body is a revelation.

Summary

Our skin acts as a barrier membrane against fluids and chemical changes, but before that, it acts as a physical barrier against pathogens. Our skin covers and protects the inner tissues, organs, and blood vessels from direct contact with pathogens. The skin blocks pathogens like germs, bacteria, and fungi to avoid infection. It also protects the underlying tissues and organs from being affected.

It is essential to wash our skin surface regularly. Washing helps clear the residual pathogens and dead cells, keeping our skin as healthy as possible.

It is not without reason that our skin is known as the largest sensory organ of our body. Our skin conveys the most vital sensory functions — touch, pain, and temperature.

When the skin comes in contact with any other surface, it can convey the sensation to our brain. While the epidermis has many blood vessels, the dermis has multiple nerve endings. Each hair follicle and pore has a nerve ending at its base. This network of nerve endings can detect and communicate the sensation.

Touch: The sensation of feeling another human skin, fur, cloth, hard or soft surface, rough or smooth texture is conveyed by the skin’s nerve endings.

Temperature: We can judge and react to whether the water is cold or the coffee mug is hot by the virtue of our skin. Sometimes, we can anticipate the temperature without actually touching the other surface due to the heightened nerve endings in the skin.

Pain: Any touch that exceeds certain pressure or is applied unfavourably is communicated as a pain stimulus by our skin to our brain. The brain then decides the appropriate action for such a stimulus.

Many of these functions of our skin deteriorate with age and time. It is essential to take good care of our skin. Sunscreen helps prevent skin cancer. Other creams and gels help replenish the collagen and keratin. An adequate amount of collagen helps decrease or delay wrinkles. It is vital to clean them regularly for our skin to be able to breathe freely. Hence, taking good care of our skin is vital, not just to look good but to also feel good and let our bodies perform better.

Originally published at https://enclaire.in.