Your Skin

The largest organ in the body. Your skin protects you from ultraviolet radiation, bacteria, toxic chemicals, and tissue damage caused by physical impact from the surrounding environment. During strenuous exercise your body can produce enough heat to boil several cups of coffee. The 2 to 5 million sweat glands and capillary beds in your skin are responsible for cooling you down. Your skin breathes oxygen.

Resembling roof tiles, your tightly overlapping skin cells create a waterproof seal. It senses the wind direction and the movement of a bug on the skin via 5 million hair follicles. It removes toxins from metabolic waste and other ingested or absorbed substances. It synthesizes proteins and Vitamin D, which is crucial for mineral metabolism. It's 5 million touch receptors provide many sensations. These sensations can bring two people emotionally closer through intimate human interaction, or can cause a protective reflex when burned. Your skin is your body's vessel.

Your skin has an incredible ability to heal equal only to your liver and mucous membranes. From a single cut, around 106 blood vessels are severed. Quickly, tiny cells in the blood called platelets latch together forming a clot that plugs the severed vessels. Threads of protein and collagen form a tight mesh trapping blood cells within the damaged area. This combination of mesh and blood cells forms a protective scab over the wound. The scab contracts as new skin grows underneath. The scab falls off leaving a new strip of skin. The only trace of previous damage is the slight discoloration of the new skin.

Do not suntan or go to tanning booths or you will look like a leathery John Rivers by the time you're 22.

Be aware of your skin's normal features. If you notice a mole that changes texture, or grows larger, darker or more irregular, have your doctor check it out for skin cancer. Do the same for sores that don't heal or persistently reoccur.

Splinter? If the splinter has not drawn blood, there is no need to visit the emergency room. Grab some Scotch tape and apply it to the splinter and surrounding skin. Press it firmly against the skin to insure it is adhered to the splinter. Slowly pull off the tape. This theoretically should pull out the splinter. If it doesn't, maybe duck tape will. If that doesn't, resort to good old fashion tweezers. When using tweezers, be careful to pull the splinter out in the opposite direction as it went in, in order to avoid breaking off the end. If these techniques fail miserably, don't worry. Your skin is constantly generating new skin cells. Your body sheds 500 million dead skin cells a day. In less than a week, the movement of new skin cells toward the surface will push the splinter to the surface as well.

For information on a long list of skin conditions, their prevention and treatment read our Appearance: Skin page.

• Your skin is the largest organ of the body weighing in at 9 pounds.
• Your skin has a surface area on average of 20 square feet.
• The average head has 100,000 hairs each living for about 2 to 4 years.
• There are over 5 million hair follicles on the body.
• No hair exists on the lips, palms or soles of the feet.
• 50 to 100 scalp hairs fall out daily.
• There are more than 650 sweat glands in one square inch of skin
• Under normal conditions and strenuous exercise you can secrete 2 pints of sweat per hour.
• Under severe heat and stress adult males can secrete 1 to 2 liters of sweat per hour.
• The collagen strands, which give skin its strength and structure, are stronger than steel wires of the same size.
• Skin grafts, not taken from oneself, are usually grown from the circumcised foreskins of babies. The cells from a baby's foreskin can generate enough skin cells to cover a football field.
• Fingernails grow four times faster than toenails.
• Fingerprints form 6 to 8 weeks before birth.
• 500 million dead skin cells fall off daily due to ordinary wear and tear.
• A single pea-sized bead of sweat can cool about 1 quart of blood by 1 degree F.
• Americans spend spend about 750 million on anti-perspirants and deoderants a year.
• Eccrine sweat glands open directly to the skin. You have from 2 to 5 million eccrine glands on your body.
• Apocrine sweat glands open into a hair follicle on your scalp, armpits, and external genitals, and are mostly responsible for body odor since sweat from these glands collects on hair where bacteria breaks it down releasing a foul odor.
• Sweat is mainly water, salt and electrolytes. Electrolytes are molecules that help regulate the body's fluids.

Appearance-Skin
(For information on a long list of skin conditions, their prevention and treatment as well as piercing and other issues read this section.)

Male Surface Anatomy
Female Surface Anatomy