Skin forms the largest organ of the body, comprising of almost 20 square feet (in most adults) and accounting for about 16 per cent of a person’s weight. Apart from the startling facts we also need to understand the important functions that our skin performs round the clock:
- It performs many vital roles as both as a shield and a regulating influence between the outside world and the controlled environment within our bodies.
- It regulates the body temperature. Internal body temperature is controlled through several processes, including the combined actions of sweat production and the rate of blood flowing through the network of blood vessels within the skin.
- It helps in eliminating the toxic waste products and water from the body. Poor elimination leads to sallow and dull complexion, swelling all over the body and aggravation of acne.
- In very cold conditions skin blood flow drops very low, retaining heat in the center of the body and preserving the flow of warm blood to the vital organs within the chest and abdomen and to the brain.
- The physical toughness of the skin prevents the intrusion of harmful chemicals and invading organisms such as bacteria and viruses.
- Maintains the moisture level of the skin by discharging perspiration and the oily sebaceous material that is the skin's best lubricant.
- It also provides resistance to shocks for the more sensitive tissues underneath. At the same time however skin needs to be supple and be able to stretch to accommodate movement.
- Skin exposed to sunlight is the main site of manufacture of vitamin D, which is essential for the growth and maintenance of our bones.
The nerve ending under the skin makes us aware of heat, cold, pain and pleasurable sensations. Sensation helps us to react. How? The extensive network of nerves within the skin feeds continuous information to the brain concerning our surroundings.
Phew! Quite an awesome task for the layering we call skin, but how does it handle all these tasks - you ask? Here’s how:
- The skin comprises of three layers-the epidermis, the dermis and the hypodermis. A detailed description will help us understand these important layers of the skin:
- The outer layer is the epidermis - the part we see and touch. It is composed of the main skin cell called the keratinocyte, thus named because it produces a tough protein called keratin and a basal cell layer underneath where the new cells are manufactured. The new cells move upwards to the surface where they expire and then are exfoliated. Melanin cells, which are responsible for freckles and darkening the skin's color due to the ultraviolet rays in sunlight, are also in the dermis. The epidermis has no blood vessels or nerves.
- The dermis is made up of connective tissues, which include collagen protein and elastic fibers (elastic type protein). The connective tissues form a valuable support system to the skin. It is in this layer that the majority of the skin's aging process takes place. The sweat glands, the oil glands, the nerve endings and receptors, blood vessels, arrector pili muscles and a major portion of hair follicles are also located in the dermis.
- The hypodermis or sub-dermis is a subcutaneous tissue or fatty layer situated below the dermis. It influences the quality of our skin's appearance. A dramatic loss of weight causes the skin to sag and too much fat or water retention in the skin's tissue makes the skin stretch and dimple. The hypodermis is a cushion for the skin. It acts as a shock absorber to protect the bones and to help support the delicate structures, such as blood vessels, nerve endings and hair bulbs. The layer gives contour and shape to the body and acts as an emergency reservoir of food and water.
- There are two sets of glands found in the dermis the sweat glands and the oil glands. The sweat glands are employed in the elimination of the water-soluble cellular waste. The oil glands secrete oil, which lubricates the skin surface. This prevents the skin from excessive dryness and chapping. Blockages, congestion, over activity or under activity of these two sets of glands are considered the primary causes of our numerous skin problems.
source : skin-care-at-home.com