The purpose of my skin

DID YOU know that the skin has many functions? The skin is the largest organ of the body, measuring 1.5-2 square metres. Like the other organs of the body, the skin is designed to play its role in maintaining proper functioning of the human body.

BARRIER

A major role of the skin is protection of the internal organs and the environment that they need to function. It cushions the internal organs from external trauma and has the capacity to repair itself when damaged.

It is often described as the first line of defence, the barrier that chemicals and organisms must first breach in order to cause harm to the body. The structure of the outermost layer of the skin, the epidermis, is designed for this role. It is composed of keratinocytes which replicate, mature and migrate towards the surface of the skin, where the cells die but stick together to form a waterproof layer. This layer of dead cells prevents entry of fluids and noxious chemicals into the body and maintains the water and salts within the body.

IMMUNE ROLE

In addition to keeping out chemicals, the epidermis is equipped to resist invasion by microorganisms such as bacteria and fungi. Cells within the epidermis are able to recognise and initiate defensive mechanisms to repel the invaders. When the integrity of the barrier is compromised, microorganisms are able to enter the skin, multiply and cause skin infection such as boils, ringworm and warts.

UV PROTECTION

Within the epidermis are melanocytes which produce a pigment called melanin. Melanin absorbs ultraviolet light produced by the sun which may cause sunburn, skin cancer and skin ageing. It is present in all races, but is packaged and distributed differently in dark skin, affording more protection from uv rays. Albinos who are unable to produce melanin develop multiple skin cancers on exposed skin.

TEMPERATURE REGULATION

During and after physical exertion, we produce sweat from the sweat glands located in the middle layer of the skin, the dermis. Evaporation of the sweat from the skin cools the surface of the skin, lowering body temperature. The blood vessels in the dermis also relax and increase in size, aiding heat loss. In cold environments, the skin raises the hair follicles in the dermis to trap a layer of air next to the skin to keep us warm. The blood vessels in the skin constrict or narrow, minimising heat loss.

COMMUNICATION AND SOCIAL INTERACTION

We use our skin to communicate with our environment and to interact with other living things. Nerves in the dermis detect temperature differences, itch, pain, pressure and touch. We utilise these sensations of itch, temperature changes and pain to warn us of possible danger. When diabetes damages the nerves, individuals who are unable to feel toe-pinching shoes or sharp objects on the ground develop ulcers on their feet.

Touch is used to differentiate between objects and to learn about the environment. It is an important method of communication between humans and other animals, conveying feelings including comfort, happiness and pleasure.

Like other species, our outer covering is important in attraction and social interaction. Although beauty may vary from culture to culture, smooth, even-toned and wrinkle-free skin appear to be important elements/features of attractiveness. Man is able to supplement these attractive features through application of make-up, tattoos, wearing of jewellery and hair extensions, and the use of cosmetic procedures such as botox, fillers, platelet-rich plasma, lasers and cosmetic surgery. Skin that is lacking the required elements of beauty, whether due to trauma, skin disease or ageing, may result in social isolation with psychological consequences and an impaired quality of life.

NUTRITION

The skin also plays a role in nutrition, harnessing ultraviolet light to begin the production of vitamin D in the skin. This vitamin is essential for strong bones and teeth.

INTERDEPENDENCE

The skin is an essential organ of the body, acting interdependently with the other organ systems of the body to ensure normal structure and function of the individual as a whole, and facilitating communication and social interaction with our society.