The many functions of our skin
By: David Luehr, M.D.
It protects you from injury, regulates temperature, keeps your internal organs in place, gives you a rosy glow and keeps you from getting sick. What is this medical miracle? It’s something you see everyday. In fact it’s all around you – literally. This medical miracle is your skin.
Beyond moisturizers and sunscreen, you might not give your skin too much thought. But it truly is a remarkable organ. With a total weight of about 24 pounds, the skin is considered the largest organ in the body.
Skin contributes to our appearance and shape, but it also serves numerous other important functions.
One is regulating body temperature. The skin contains a blood supply far greater than its requirements. When the blood vessels in the skin dilate, more blood circulates and heat loss increases (body temperature decreases). When vessels constrict, blood flow is reduced to conserve heat.
When you are cold, the hairs on your skin rise up under goose bumps. When this happens, the air close to your skin acts as an insulator, preserving heat. The skin has another tool for maintaining body temperature: sweat. When the body gets too warm, the sweat glands work to cool the body by excreting sweat, which is made up of 99 percent water. The sweat evaporates off your skin, causing a cooling effect.
Sweat helps to cool you off. It also releases waste substances such as salt, ammonia and urea from the body.
Your skin provides a protective barrier from the outside world. It serves as a cushion and protects internal organs from injury. The skin is relatively waterproof. This keeps most bacteria, viruses and other pathogens from entering the body.
This waterproof quality also serves to keep moisture and nutrients from leaving the body and evaporating too quickly. This helps to keep the body from becoming dehydrated.
Melanin in your skin protects it from ultra violet (UV) radiation. Your skin utilizes other light from the sun – ultra B light – and converts it to vitamin D, which is used by the body to aid in the absorption of calcium as well as maintain normal levels of calcium and phosphorus.
The skin’s ability to detect touch is our fifth sense. Nerve endings in the skin tell you when you feel heat, cold, pressure and pain, protecting the skin and body from injury.
What else can the skin do? It can heal itself. When injured with a cut, scrape or burn, the skin seals off broken blood vessels and fills the hole created by the injury with a scab. The scab prevents blood and other bodily fluids from being lost. It also acts as a shield to prevent bacteria, dirt and other substances from entering the body. Under the scab, the skin is healing itself. Once healing is complete, the scab will fall off.
To keep skin healthy: Keep it hydrated. This is best done from the inside out. Drink plenty of liquids – water is best. Keep it clean. Cleaning your skin does not require harsh soaps or abrasive detergents. A mild soap, rinsed well with lots of warm water works best. Keeping your hands clean is especially important, as they can transfer germs to other parts of the body. If you have dry skin, a gentle moisturizer made without dyes or perfumes may make your skin feel less itchy. Protect your skin from the sun with a sunscreen that contains an SPF of at least 30. Apply it at least 20 minutes before going out in the sun, and reapply every two hours and after swimming or sweating.
Your skin – from maintaining body temperature to warding off illness to protecting us from injury – its jobs are varied and important. At 20-plus pounds, it is the largest organ in the body, and one that none of us could live without.
|Dr. Luehr is a board certified family practice physician at Raiter Clinic.|