STRUCTURE, FUNCTION

AND ILLNESSES OF

THE SKIN

STRUCTURE AND FUNCTION OF THE SKIN

Most people assume that the skin is just a smooth body covering. However, if you look at a cross section of the skin under a microscope, you will see three distinct layers: The EPIDERMIS; the DERMIS; and the SUBCUTANEOUS

Most people assume that the skin is just a smooth body covering. However, if you look at a cross section of the skin under a microscope, you will see three distinct layers: The EPIDERMIS; the DERMIS; and the SUBCUTANEOUS

THE EPIDERMIS

is the outer skin layer.

Papillae form a complex design on the finger tips. The eye can detect small opening in the skin surface called pores.

the top coat of the epidermis is composed of dead cell. This cell layer shields the body from sun, wind, harmful chemicals in the environment, and injuries. It also prevent moisture from leaving the body and forms a natural germ harrier. Beneath this surface, the inner cell layers of the epidermis are alive and active.

Melanin is made in the inner layers of the epidermis. Melanin protect the skin against the harmful ultraviolet ray of the sun. When exposed to the sun, the skin produces more melanin and tans. Freckles are small patches of melanin.

As new cells divide, older cells are pushed slowly to the surface. As they journey upward, they produce keratin. Keratin is a transparent, waterproof substance.

THE DERMIS

The middle layer of skin. It is called the true skin because it houses the skin’s

vital structures. It contains a dense network of blood vessels. Protein fibers called collagen run through the

dermis, giving the skin strength and elasticity.

The glands found around hair shafts secrete an oil, sebum. Sebum moves up through the duct around the hair shafts and out of the pore at the surface of the skin. It coats and lubricates the keratin layer of the epidermis. This makes the skin more waterproof and helps prevent water loss from the body.

Sweat glands secrete perspiration, ridding the body of excess water, salt, and other waste products from the blood.

THE SUBCUTANEOUS LAYER

The deepest of the skin layers is the subcutaneous layer. The body’s supplies of fat deposits are in this layer. Every one male or female, fat or thin has fat cells in the subcutaneous layer. This bottom layer naturally insulates the body against heat and cold. It also acts as an inner cushion to protect the body against injuries. As the body ages, some fat is lost from this layer. The skin shrinks unevenly and causes creases and wrinkles.

COMPLEXION COMPLAINTS

Are you bothered by skin problem ? Skin problems are among the most common complaints of adults and teenagers. Proper care can help correct various skin problems.

ACNE

Acne is one of the most common complexion complaints, specially among teenagers.

BLACKHEADS

PIMPLES

ACNE SCAR

Four Types of Acne Scars

BOILS

A deep, serious infection that invades all layers of the skin is called a boil. Boils can occur alone or in groups anywhere on the body. Like pimples, boils should never be squeezed. Boils require medical attention. A doctor can drain pus fro the boil and use antibiotics to control infection. Frequent or numerous boils can be a sign that the body has lost its ability to fight infection. Diabetes or other disease may be the cause of the problem.

WARTS

often warts appear as raised growths on the skin. Warts are caused by virus that can be picked up anywhere. At present there is no drug that will prevent warts. Warts can grow anywhere but are most common on the face and hands. Warts can spread from one person to another or from one area to another on the same persons body. They usually disappear spontaneously. However , if warts are irritating or if they begin to multiply rapidly, a doctor can remove them by a simple and painless produce.

The word plantar means on the sole of the foot. Plantar warts grow only one the sole of the foot. Plantar warts cannot grow out from the skin because your weight puts pressure on the sole of your feet. If they grow into nerves, plantar warts can be very painful. They can penetrate deeply and can be easily infected. They should be immediately treated by a doctor.

TYPES OF WARTS

SKIN SPOTS

White spots, called vitiligo are patches where the skin fails to produce melanin. The cause is unknown. Prescription drugs are available to treat this disorder. However, it may be easier and more practical to cover vitiligo with cosmetics

VITILIGO

MOLES

Are slight overgrowths of skin with excess pigment. Most brown moles range in color from light to dark brown. These moles are usually harmless. However, black or blue black moles can be dangerous. They can develop into a deadly skin cancer at any time. Skin growths that grow rapidly, change color, or bleed should be checked cat once. Of course, if you have any unusual skin condition, see a doctor.

MOLES

BURNS

If you are outdoor, you should avoid getting skin chaps & burns. Chaps and wind burns are caused by overexposure to wind & cold. This exposure dries the epidermis, causing it to become red & irritated.

SKIN SCALES

Psoriasis, is a skin that appears as patches of red, raised skin and silver scales of dead skin. It is most common on the scalp, elbow, knees & outer surface of the arms & legs. It can last & short for a long time, & it can occurs in cycles. Psoriasis seems less severe in summer than in winter. This is because the sun’s ultraviolet rays are stronger in the summer. Ultraviolet lights seems to improve this condition. The exact cause of psoriasis is unknown. There is no cure but medical treatment can control this condition.

ALLERGIES

Allergy is a reaction of the body to a certain substances. Allergies are highly individual. For example, strawberries can be a dessert delight for one person & the cause of an allergy for another .

Allergy reactions range from mild to severe. In a mild reactions, the skin & the soft tissues around the eyes & nose can become itchy, red & swollen. Nausea, vomiting & diarrhea can also be allergic reaction. Severe allergic reaction can cause swelling of the throat collapse of the circulatory system, heart failure & even death.

Most allergies develop gradually. When the body is first exposed to the substances, an allergic reaction does not usually occur. With repeated exposures, the body may develop a sensitivity. this means that three will probably be an allergic reaction each time the substance contacts the body if sensitive increases, the reactions become m ore severe. Some people are highly allergic to penicillin or other drugs.

ECZEMA

Many people refer to eczema as specific disease. But it is really an allergic reaction. Many substance can produce eczema, but the reactions to each one are similar. The skin becomes red, swollen, crusty and scaly. Small blister also form and ooze a clear fluid. Eczema often results when certain substance contact the skin directly. This condition is called contact dermatitis.

HIVES

Red, raised areas on the skin are an allergic reaction called hives. Hives vary size and depth and are usually very itchy. When severe reactions occur, giant hives sometimes appear these are deeper and less defined than ordinary hives. They can form on the skin and membranes of the lips, mouth, throat, and larynx. Giant hives in the throat and larynx can be very dangerous. They can block the airway and cause death by suffocation. The victim needs immediate medical attention. Cause of hives are numerous and hard to determine, hives are often caused by foods and other substances, such as sulfa drugs and aspirin. Hives can also caused by emotional states.

TEETH

Your teeth play an obvious role in appearance. They also have other important functions. Teeth are helpful for clear speech. Certain sounds, such as “s” and “th”, cannot be easily pronounced without front teeth. Teeth are also important for grinding food into small particles, so it can be more easily digested. Teeth and gum problems can cause unpleasant, ranging from bad breath to pain. If teeth become infected the infection ca be carried to other parts of the body.

STRUCTURES OF THE TEETH

The visible portion of a tooth are the heck and crown. Notice the crown appears above the gum and narrows to form the neck. A hard white protective layer of enamel cover the crown and neck. The root of the tooth lies in a socket in the jawbone. Its outer covering is called cementum. The tooth is anchored firmly in the jaw by the fibrous periodontal membrane. Lying beneath the enamel layer is a softer substances called dentin. It forms the actual body of the tooth, and it houses the pulp cavity. Blood vessels and nerves lie inside the pulp cavity. They join the jawbone’s larger nerves and blood vessels at the base of the roots.

PRIMARY TO PERMANENT TEETH

Primary teeth, commonly called the baby teeth, start arriving at about 6 months of age. They are lost gradually over period of years, starting at about age 6. the first tooth is usually a front tooth, or incisor. By age two and one half. Twenty primary teeth have arrived. Permanent tooth grow in the jaws beneath the roots of the primary teeth. When a permanent tooth’s root is well developed, the tooth is ready to emerge. By the, the root of the primary tooth is absorbed. As a rule, only the crown and neck remain when the primary tooth is lost.

Adults have 32 teeth of four types. Each types performs a separate job. The upper and lower permanent incisors cut food. Directly behind there are four pointed cuspid or canine teeth. They cut ant tear food. There are eight bicuspids two on each side of the upper and lower jaws. The bicuspid cut and crush food. Behind the bicuspid are the molars, which grind food. If all the molars developed, there 12 altogether, three on each side of the upper and lower jaws. Molars first appear at age 6 or 7, they do not replace primary teeth. They grow behind them. At about age 12 the second molars develop behind the first ones. Third molars known as wisdom teeth usually appear sometime between ages (18 and 21).

DENTAL PROBLEMS

DENTAL DAMAGE. Dental caries, known as tooth decay, is a common dental disease procedures holes, called cavities, in teeth. Tooth decay can start close to the gum line, or between teeth. Tooth decay can start close the gum line, or between teeth or on the biting surface of the molar. Tooth decay is not communicable disease. It is caused by bacteria that are always in the mouth. Bacteria, food residues, and saliva form a sticky colorless film on the teeth called plaque (plak). The bacteria in plaque use the sugar in food to form acids and other byproducts that destroy tooth enamel and irritate gums.

decay penetrates the enamel and spreads to the dentin: as the cavity grows toward the pulp, the tooth becomes more sensitive. When the decay reaches the pulp and exposes a nerve, a toothache starts. In the stage of decay, the bacteria in the verve canal destroy the pulp. An abscess or pus collection, forms at the base of the tooth. If not treated, the infection can spread to other parts of the body. A decayed tooth can be saved by cleaning, medicating, and filling the cavity.

when tooth decay penetrates deeply into the pulp, a tooth can often still be saved. Endodontics , commonly called root canal therapy, is required. The dentist removes the diseased nerve canal contests, cleans out the infection, and sterilizes and fills in the canal. If possible, teeth should always be saved. Although root canal therapy removes the nerves and blood vessels in the root canal, the tooth looks almost the same. However, it may become brittle due to the loss of its pulpal blood supply. For this reason, your dentist may crown the tooth with gold or porcelain to help protect it.

PERIODONTAL DISEASE

Periodontal disease. This disease, which can begin as early as age five, is mainly caused by plaque formation. When plaque is not removed daily, its harmful products collect along the gums, irritating the gums. They become red, swollen or tender, and bleed easily. As plaque builds up, it hardens into a limelike substance called tartar which pushes against the gums. Pocket form between the gums and teeth where more plaque can grow and further damage the tooth root. As periodontal disease spreads, gum recede and pus forms. Eventually the bony structures supporting the teeth are destroyed. Then, teeth looosen and fall out.

STAGES OF PERIODONTAL DISEASES

MALOCCLUSION

More and more adults, teenagers, and young children are wearing braces because they look forward to the improvement that braces produce in the positioning of their teeth. Orthodontics is the dental specialty that corrects malocclusion, which ia an irregularity in the position and bite of teeth.

BEFORE AND AFTER

ORAL HYGIENE

Proper oral hygiene requires flossing and brushing the teeth each day. A thorough cleaning removes food particles and helps eliminate plaque before it hardens into tartar. This is why a thorough cleaning of the teeth at least once a day is essential

METHODS OF BRUSHING TEETH

PROFESSIONAL HELP

Good dental care includes dental checkups at least twice a year. Most cavities develop over several months. Do not wait for a toothache before seeing a dentist. The dentist can spots prolems before serious trouble develops. To prevent periodontal disease, a professional tooth cleaning called prophylaxis is usually needed. It removes tartar build up. The dentist may take an X ray of the teeth to locate hidden trouble.

X-RAY OF A CAVITIES