The outer ear consists of the auricle, auditory canal, and eardrum. The auricle is the visible section of the ear. It funnels sound waves into the auditory canal. The auditory canal is a passageway lined with hair that amplifies the sound as it passes. It also contains wax-producing glands that help to protect the eardrum. The eardrum is a thin membrane at the end of the auditory canal that vibrates to send sound waves into the middle ear.

The middle ear consists of the ossicles and air cavities between the bones of the ossicles. The ossicles consist of the three bones of the middle ear--malleus, incus, and stapes. The malleus (hammer) is a tiny bone connected to the eardrum. The eardrum's vibration starts movement in the malleus, which then moves the second bone of the middle ear, the incus. When the incus (anvil) moves, it causes movement in the third bone of the middle ear, the stapes. The stapes (stirrup) strikes the oval window, which is the covering over the opening of the cochlea. The mastoid consists of the air-filled spaces in the bones of the middle ear. The eustachian tube connects the nasal cavity in the back of the throat with the middle ear. It equalizes pressure on the two sides of the eardrum.

The inner ear is called the labyrinth. It contains the structures that maintain balance and detect sound. The vestibule consists of the utricle and saccule. It is lined with hair cells that play a role in maintaining balance. The semicircular canals are three fluid-filled canals containing hair cells. One end of the canals forms a pouch-like structure. The hair cells are attached to nerve endings for balance. The cochlea is a shell-shaped structure with three ducts. One of the ducts contains the basilar membrane. The basilar membrane contains the Organ of Corti, which has 15 thousand hair cells that act as hearing receptors.

The auditory nerve consists of fibers that extend to each hair cell in the Organ of Corti. It sends the sound impulses to the brain for interpretation.

Cleaning the Ears

The auricle should be cleaned with a cotton swab, but nothing should ever be put into the auditory canal. Serious permanent damage can occur if the eardrum is punctured. Also wax can be pressed against the eardrum, inhibiting its ability to vibrate. If the ear "tickles," you should wiggle the outer ear passage, but never "dig" into the ear canal.

Protecting the Ears

The ears should be protected against extremes in cold and noise. Extreme cold (even cold drafts) can make the ear more vulnerable to ear infections. If you are going to be outdoors in extreme cold weather, make sure that your ears are completely covered. If you must be in an environment where there are cold drafts, place cotton in the outer ear to block the opening of the ear canal.

If your ears are going to be exposed to loud noise, you should wear ear plugs suitable for blocking some of the sound waves. The eardrum and the tiny hair cells of the inner ear can be seriously damaged by high-intensity noise. CAUTION: Be especially careful with noise from earphones. Because earphones funnel noise directly into the auditory canal, even relatively "quiet" noise can do serious damage.

Short-term Effects

Relaxation--Alcohol is a depressant, so it causes the nervous system to slow down, creating a sense of relaxation.

Dilation of blood vessels--The face becomes flushed and the body gets a warming sensation because the blood vessels close to the skin's surface dilate, causing more blood flow.

Frequent urination--The body tries to eliminate the alcohol as quickly as possible, so it becomes necessary to urinate frequently.

Change in brain function--Alcohol impairs emotional and behavioral brain function. People who have been drinking may have memory lapses. Alcohol also causes a loss of inhibitions and self-control, often resulting in poor judgment. In addition, alcohol can cause extreme mood swings, which may result in excessive emotional responses. Alcohol greatly affects the portion of the brain that controls coordination, so intoxication results in a lack of coordination for movement and speech.

Hangover--After becoming seriously intoxicated, most people suffer from a hangover. They may have headaches, nausea, and dizziness even hours after drinking alcohol.

Long-term Effects

Liver damage--The liver can be damaged from the use of alcohol. Alcohol leaves fatty deposits on the liver cells.

• Hepatitis is an inflammation or infection of the liver.

• Cirrhosis results in liver cells being replaced by scar tissue, causing digestive problems. Once cirrhosis occurs, the victim has less than a 50 percent chance of survival for five years, if he/she continues drinking alcohol.

Heart damage--Alcohol leaves fat deposits on the heart muscle, making it more vulnerable to disease.

Brain damage--Alcohol kills brain cells, and brain cells cannot regenerate. Permanent memory impairment and loss of existing memory can occur with prolonged alcohol usage.

Cancer--Alcohol increases the risk of cancer of the liver, esophagus, pharynx, and larynx.

Fetal Alcohol Syndrome--Alcohol drunk by an expectant mother passes through the bloodstream of the fetus. Therefore, a baby can be born with fetal alcohol syndrome, a problem that can cause low birth weight, premature birth, mental retardation, facial deformities, and long-term behavioral problems.

1. Violent Crime--Drug abuse is a leading contributor to all violent crime, including child abuse and domestic violence.
2. Accidents--Being under the influence of drugs sharply increases the risk of motor vehicle accidents. Injuries from falls and other accidents increase as well when under the influence of illicit drugs.
3. Impaired Mental Capacities--Illegal drugs also are responsible for decreased mental capabilities: decreased concentration and attention span; impaired judgments; decreased long- and short-term memory; increased depression and anxiety; and decreased ability to function appropriately.
4. Addiction--Addiction refers to the body's dependency on the drug. The body becomes so accustomed to the presence of the drug that it cannot seem to function without it. Psychoactive drugs are especially likely to create an addiction. A psychoactive drug is any drug that affects the central nervous system, altering brain function.
   • Physical dependence refers to the process in which the body has such a dependence on the drug that it goes through a physical withdrawal without it. Some withdrawal symptoms are relatively minor, such as slight shaking or headaches. But some drug withdrawals are so serious that they can lead to hallucinations, loss of consciousness, and even suicide. The more dramatic the effects of the drug, the more serious the withdrawal.
   • Psychological dependence causes a constant craving for the drug. It is especially pronounced in drugs that affect mood. Often the person believes that he/she cannot get the desired feelings without the drug.

1. The dose is the amount of the drug that is to be taken for treatment. Over-the-counter drugs have dosage information on the package or label. The dosage is usually standard for everyone, or it is divided by adults' dosage and children's dosage. The dosage for prescription drugs is set by the prescribing doctor; it will be individualized based on the individual patient's needs and characteristics.
2. Administration--Drugs can be taken orally, inhaled, or injected. Medicines that are taken orally usually are absorbed into the bloodstream either through the stomach lining or the small intestine, depnding upon the pH of the drug. Food in the stomach can delay the absorption. Food also can help protect the stomach when you are taking medication, such as aspirin, that may irritate the stomach. Drugs that are inhaled enter the bloodstream through the mucous membrane in the nasal cavity or the lining of the lungs. Drugs that are injected enter the bloodstream directly; therefore, they usually have the quickest results.
3. Drug interaction refers to the effect that can occur when drugs are mixed. The overall effect of each of the drugs involved may be altered. Many drug interactions are dangerous. You should not mix medications without checking with a doctor or pharmacist. Therefore, always tell your doctor what medications you are taking, so that he/she can avoid prescribing a medication that may have a harmful drug interaction. Even common over-the-counter drugs can be deadly for some people if they are combined.
4. Side effects are any effects that the drug has that occur in addition to the desired effect. Most packages or labels will outline possible side effects from the medication.
5. Some people have allergies to certain drugs. Their immune system mistakes the medicine for a pathogen and rejects it. Some drug allergies can be very serious and even fatal. Make sure to notify your doctor and pharmacist of any known drug allergies.

• Cavities--Cigarette smoking damages teeth and gums, making teeth more vulnerable to cavities. In addition, sores or injuries that occur in the mouth take longer to heal.

• Gum ulcers--Smokeless tobacco creates unsightly open sores along the gum line.

• Gingivitis--Gingivitis is gum disease, in which the gums become irritated and swollen, leaving the base of the teeth exposed. Cigarette smoking and the use of smokeless tobacco increase the risk of gingivitis, the leading cause of tooth loss in adults.

• Halitosis--Halitosis is another name for bad breath. Tobacco use causes bad breath that cannot be covered with breath fresheners or mouth washes.

• Laryngeal cancer--The poisons present in tobacco smoke pass through the larynx, voice box, on their way to the lungs. Many of these poisons cause cancer, leading to the need to remove the voice box. A person whose voice box has been removed must use a voice simulator to communicate verbally.

• Leukoplakia--Leukoplakia is characterized by white patches that appear in the mouth. These patches usually lead to malignant tumors in the mouth.

• Oral cancer--Oral cancers cover all of the cancers of the mouth. All uses of tobacco increase the risk of oral cancer, leading to the need to remove the tongue, lips, and/or portions of the jaw and cheek.

• Wrinkles--The poisons in cigarette smoke age and dry the skin, causing premature wrinkling.

Aerobic Fitness

Aerobic exercise is necessary for physical fitness even if your primary reason for exercising is weight loss, not cardiovascular or respiratory health.

Weight Control

Exercise is important to the success of any weight loss program. It decreases appetite, increases metabolism, and helps lose fat without losing muscle mass. Caution: If you are already too thin and exercise too much, you risk causing permanent damage to your overall health. Body fat is necessary for normal development and tissue repair.

Body Composition

Exercise will increase your percentage of muscle tissue to fat.

Strength and Muscle Development

Exercise can help build muscle strength and endurance safely, without the use of steroids. By slowly increasing the resistance that your muscles have to move, you increase muscle strength and endurance.

Flexibility

Flexibility decreases the risk of injury. By using stretching exercises and/or isotonic or isokinetic weight training, you can increase your level of flexibility while building healthy muscle mass.

• Hormones are the chemicals released by endocrine glands that regulate specific bodily functions.

• Grand mal epilepsy is the most serious. The sufferer loses consciousness and displays uncontrolled, often drastic movements. After the seizure, the sufferer usually falls asleep for a short time. It is important not to move the person during the seizure, but rather move any objects that may cause injury. Remain calm until the person regains awareness because he/she generally will be disoriented immediately after awakening.
• Petit mal epilepsy has fewer outward signs. Sufferers may just seem to lose concentration or awareness momentarily. They do not have convulsions or extreme movements. Petit mal epilepsy mostly affects children, who usually "grow out of it."
• Psychomotor epilepsy is characterized by repetitious movements during seizures.

Vitamins, minerals, and water are essential for the body to use nutrients properly.

The kidneys make up the body's filtering system. Each kidney contains about 1 million nephrons, made up of tubes and capillaries. As the blood enters the kidneys, the nephrons remove substances from the blood, return what the body needs, and eliminate the rest as urine. All of the body's blood is filtered about once an hour. In that time, the kidneys process about 50 gallons of fluid and remove about one-half gallon of urine.

The ureters are the tubes that lead from the kidneys to the bladder.

The bladder stores urine.

The urethra is the opening through which the urine flows. The flow of urine is controlled by a sphincter muscle; when the muscle relaxes, urine is allowed to flow out of the bladder.

Urine is the body's liquid waste.

Exercisers can fall into three broad categories: beginner, sporadic, and experienced. Each of these types should adhere to the FITT principle (Frequency, Intensity, Time, Type) when creating and following an exercise program.

• Frequency refers to how often you exercise. For all categories of exercisers, 3-5 times per week is excellent.

• Intensity refers to how hard you work out. One way to measure the intensity of your workout is to monitor your target zone.

  Your target zone for exercise heart rate is defined as 60 percent to 80 percent of your maximum heart rate. Find your maximum heart rate by: 1) subtracting your age from 220; 2) multiplying the difference by .6; and 3) multiplying that same number by .8. The result is your target zone.

  For example, if you are 15 years old:

  1) 220 - 15 = 205 (maximum heart rate)

  2) 205 x .6 = 123 (You want to get your heart rate to at least this number.)

  3) 205 x .8 = 164 (You don't want your heart rate to go above this number.)

  This 15 year-old's exercise program should keep his/her heart rate in the target zone of 123-164 beats per minute.

  Beginning exercisers should stay in the lower half of the target zone. Sporadic exercisers should stay in the lower half of the target zone, going higher as fitness improves. Experienced exercisers should remain in the target zone.

• Time refers to the duration of your workout.

  Beginning exercisers should exercise at least 15 minutes and build as fitness improves. Sporadic exercisers should exercise 20 minutes, going higher as fitness improves. All exercisers should build to 30 minutes, and experienced exercisers can probably start there. Exercising in the target zone for 30 minutes, 3 to 5 times a week, is an excellent program of aerobic exercise. It is fine to build the duration (time) factor even higher if you have the time to do so.

• Type refers to the type of activity you do for exercise. Virtually any sport or activity that increases your heart rate and will allow you to stay in your target zone, following the rules above, is an acceptable form of exercise.

A bruise is caused by a blow to the muscle that causes injury to the tissue under the skin. It can be treated with ice packs.

Strains occur when muscles are overworked. They can be treated with rest and ice for 24 hours. Most strains can be avoided by warming up properly.

Tendinitis occurs when the tendon (connective tissue of the muscles and bones) is stretched or torn. It can be treated with rest.

Pulled or torn muscles occur when one of the large muscles is torn from its point of attachment. It should be treated with ice on the spot and then by a medical professional because if the blood supply is cut off from the muscle, it can damage the muscle permanently. Most pulled muscles can be avoided with proper warm up and staying within your physical limitations.

Muscle cramps occur when the muscle contracts tightly and will not relax. Usually it results from some type of irritation within the muscle, caused by a lack of nutrients or oxygen within the muscle. This deficiency can be caused by a loss of water and electrolytes or muscle fatigue. Muscle cramps can be treated with heat and massage. They can be prevented by warming up properly and drinking plenty of fluids. Caution: Muscle cramps during swimming can cause drowning. If you suffer muscle cramps while you are swimming, do not panic. You will float if your body is relaxed. Try to massage the cramped muscles in the water until they relax to a point where you can get out of the water or alert someone to help you.

Hernias are weaknesses in the support muscles, often in the abdominal and groin areas. Part of the underlying organs or tissue may push through the weak area. Hernias usually are caused by over exertion, especially in lifting heavy objects incorrectly. Surgery is required to correct the problem.

Other Injuries

There are two major types of injuries to the skeletal system associated with exercise.

A sprain is an injury to some tissue surrounding a joint. Ligaments can be stretched or torn, and cartilage can be torn or pulled out from the bone. Minor sprains can be treated with the PRICE model. (Physician, Rest, Ice, Compression, Elevation)

A dislocation occurs when the end of the bone is pushed out of its joint. Ligaments holding the bones can be severely stretched or torn. Only medical professionals should treat dislocations because there are several blood vessels and nerves surrounding joints.

Eyeball

The eyeball wall is made up of three sections: sclera, choroid, and retina.

The sclera is the white portion of the eye. It is a tough outer coating that helps to maintain the eye's shape and protect the inner workings. It forms the cornea. The cornea is clear and covers the surface of the eyeball. It contains multiple nerve endings that make it very sensitive to touch sensations.

The choroid contains the iris, pupil, lens, aqueous and vitreous humors, and the muscles and ligaments that control the structures of the eye. The iris is the colored portion of the eye. It contains the pupil. The pupil controls the amount of light that enters the eye. Two sets of muscles act to control the pupil's opening and closing. The lens lies behind the pupil and controls the focus of the image sent to the retina. The lens is curved, and muscles within the eye change its shape so that the image is focused exactly on the retina. The aqueous humor is a watery fluid that maintains pressure within the eye and provides nutrients. The vitreous humor is a thicker fluid that keeps the eyeball firm.

The retina contains the nerve cells for sight--rods and cones--and controls the processes for sight. The rods are specialized cells that register light and darkness. They contain a photosensitive chemical called visual purple that allows night vision. There are approximately 125 million rods in the retina. The cones are responsible for bright light and color vision. There are approximately 7 million cones in the retina.

Optic Nerve

The optic nerve is a large nerve cable that connects the eye with the brain. The "blind spot" is the visual area where the optic nerve enters the eye.

• Read and watch TV in a well-lighted room.
• Sit at a comfortable distance from the TV.
• Rest your eyes periodically.
• Avoid rubbing your eyes.
• Avoid bright sunlight.
• Wear protective eyewear when taking part in activities that could cause eye injuries.
• Get regular eye exams.

The lacrimal glands produce tears. Tears are composed mainly of water with a small amount of salt and mucus. Tears keep the eye moist and remove particles that get onto the eye's surface. Salt has a natural antiseptic effect. Tears reach the surface of the eye through small ducts. Some tears evaporate, and others drain into the nasal cavity through ducts in the inner corners of the eye. If tear production is greater than the ability to drain, the tears flow over the lower lid of the eye.

The eyebrows protect the eye from outside particles, perspiration, and sunlight.

The eyelids protect the eye by covering the surface. The eyes have a reflex action that causes periodic blinking to moisten the eyes and blinking in response to a "threat" to the eye.

Eyelashes help keep foreign objects out of the eyes. Oil secreted from glands on the eyelid keeps the eyelashes from sticking together.

The conjunctiva is a mucous membrane attached to the inner surface of the eyelid that extends over the surface of the eyeball, forming a continuous covering over the eye.