Ears, Nose, Throat, Eyes, and Vision System

This is Medical Terminology Unit 8 of 17. (Previous - Medical Terminology Unit 7 of 17: Endocrine System)

This unit discusses the Ears, Nose, Throat, Eyes and Vision System.

Unit Objectives

Anatomomy of the Ear

Your ear has three main parts: outer, middle, and inner. All three parts of the ear are used in hearing.

Sound waves travel through your outer ear. These sound waves reach your middle ear, where they make your eardrum move or vibrate. The vibrations are transmitted through three tiny bones, referred to as ossicles in your middle ear. The bones in the middle ear are named after their shape. The malleus is shaped like a hammer; the incus is shaped like an anvil, and the stapes is shaped like a stirrup. The malleus is attached to the tympanic membrane.
The tympanic membrane (ear drum) is a thin partition located between the external auditory canal and the middle ear.

The inner ear is located in a large cavity in the temporal bones of the cranium or skull. The inner ear contains both bony and membranous structures that are surrounded by fluids. There are two sensory organs, the cochlea, where the organs of hearing are found, and the vestibular apparatus.  The cochlea contains three canals that are filled with fluids.

In the inner ear, the organ of Corti contains the receptor cells which are affected by the sound vibrations and results in nerve impulses being forwarded to the brain for interpretation.  Your brain, in turn, recognizes the impulses as sounds.

 The inner ear is also involved in balance.

Hearing Loss

Reasons for Hearing Loss

  • Heredity
  • Ear infections
  • Meningitis
  • Trauma
  • Certain medicines
  • Long-term exposure to loud noises
  • Aging

Possible Treatments

  • Hearing Aid
  • Cochlear implants
  • Special training
  • Certain medicines
  • Surgery

There are two main types of hearing loss. The first type occurs when your inner ear or auditory nerve is damaged and the result is permanent hearing loss. The other kind of hearing loss occurs when sound waves cannot reach your inner ear. There can be several reasons why this happens.  Ear wax can build-up in your ear canal, or a puncture in your ear drum are examples of conditions that can result in hearing loss. Untreated, hearing problems can become worse.  Possible treatments include hearing aids, cochlear implants, special training, certain medicines and surgery.

Ear Disorders and Diseases

Acoustic neuroma is a non-cancerous tumor that develops on the nerve that connects the ear to the brain. The tumor usually grows slowly,  As it grows, it presses against the hearing and balance nerves. 

Symptoms include: 

  • loss of hearing on one side
  • ringing in the ears
  • dizziness and balance problems
  • Diagnostic tests include ear exams, hearing tests, and scans.

Treatment: if the tumor stays small, you may only need to have it followed regularly by a physician. If you do need treatment surgery and radiation are options. If the tumors affect both hearing nerves, it is often because of a genetic disorder called neurofibromatosis. The tumor can also eventually cause numbness or paralysis of the face or press against the brain and become life-threatening.

If you are lightheaded and feel that you will lose your balance, then you are experiencing dizziness. Vertigo is a sensation of motion in which an individual’s or their surroundings seem to whirl around.

Ear infections are common in babies and young children. Most often, the infection affects the middle ear and is called otitis media. Symptoms include: tugging or pulling at the ears, crying, ear drainage, trouble sleeping, balance difficulties and hearing problems. Treatment includes pain relievers, medicines such as antibiotics and with repeated infections small tubes inside their ears.

Meniere’s disease can cause severe dizziness, a roaring sound in your ears called tinnitus, hearing that comes and goes and the feeling of ear pressure or pain. It usually affects just one ear and it is a common cause of hearing loss.

Scientists do not know the cause of this disorder. They believe it has to do with the fluid levels or the mixing of the fluids in the canals of your inner ear.

Symptoms can occur suddenly and happen every day or as seldom as once a year.

Treatment:  There is no cure.  However, you may control symptoms by changing your diet or taking medicine so that your body retains less fluids. Severe cases may require surgery.

Noise is all around us from TV to lawn mowers.  Harmful sounds that are too  loud or loud sounds over a long time can damage sensitive structure of the inner ear and cause noise-induced hearing loss.  Hazardous sound levels are louder than 80 decibels, which isn’t as loud as traffic on a busy street.  Listening to loud music, especially on headphones, is a common cause of noise-induced hearing loss.

Tinnitus is described as a ringing or roaring in your ears and can affect one’s hearing, working and even sleeping. Causes of tinnitus include hearing loss, exposure to loud noises or medicines you may be taking for a different problem. Tinnitus may also be a symptom of other health problems, such as as allergies, high or low blood pressure, tumors and problems in the heart, blood vessels, jaw and neck. Treatments include hearing aids, sound-masking devices, and medicines.

Nose and Throat


The nose is the external opening to the respiratory tracts that acts as a filter and humidifier for the air you breathe, removing dust, germs and irritants. It warms and moistens the air to keep your lungs and tubes that lead to them from drying out. Your nose also contains the nerve cells that help your sense of smell. When there is a problem with your nose, your whole body can suffer. For example, the stuffy nose of the common cold, can make it hard for you to breathe, sleep or get comfortable.


  • The pharynx, commonly called the throat, connects the mouth and nose to the larynx.
  • The larynx, commonly called the voice box, connects the pharynx with the trachea.
  • The trachea, commonly called the windpipe, serves as a pathway for air to reach the chest.

An allergy is a reaction of your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one substance such as:  pollen, dust mites, mold spores, pet dander, food, insect stings and medicines.

Cause of allergies:  Scientists think both genes and the environment have something to do with it.  Normally your immune system fights germs. In most allergic reactions, however, it is responding to a false alarm.

Symptoms of allergies include: runny nose, sneezing, itching, rashes, swelling or asthma. If you have a severe reaction called anaphylaxis, it can be life-threatening.

Common cold:  the most common illness, easily spread by touching your eyes, or nose after you touch surfaces with cold germs on them, you can breathe in the germs. No cure, but treatment includes getting rest, drinking fluids, gargling with warm salt water, using cough drops or throat sprays and taking cold medicines.

Hay  Fever is usually trigged by a change in season and is related to the trees, weeds, and grasses releasing tiny pollen grains into the air. Symptoms include: sneezing, coughing, postnasal drip, itching eyes, nose and throat, and dark circles under the eyes.

Treatment: Taking medicines and using nasal sprays can relieve symptoms.

Nasal Cavity Disorders

  • Deviated septum is a shifting of the wall that divides the nasal cavity into halves.

  • Nasal polyps are soft growths that develop on the lining of your nose or sinuses.

  • Nosebleed is bleeding or hemorrhaging from the nose.

  • Rhinitis is an inflammation of the nose and sinuses sometimes caused by allergies. The main symptom is a runny nose.

  • Sinusitis means your sinuses are infected or inflamed. Your sinuses are hollow air spaces within the bones surrounding the nose which produce mucus which drains into the nose. If your nose is swollen, this can block the sinuses and result in pain and infection. Sinusitis can be acute (less than four weeks) or chronic, lasting much longer. Symptoms: fever, weakness, fatigue, cough, congestion and postnasal drip. Treatments include antibiotics, decongestants and pain relievers, saline nasal sprays and vaporizers.

Nasal Cancer

Nasal cancer is also called cancer of the nasal cavity or cancer of the paranasal sinus.

The paranasal sinuses are small hollow spaces around the nose. They are lined with cells that make mucus, which keeps your nose from drying out. The nasal cavity is the passageway just behind your nose through which air passes on the way to your throat as you breathe.

Cancer of the nasal cavity and paranasal sinuses is rare. Men are more likely than women to develop it and most patients are older than 45.

Infections may eventually become a symptom, but there can be no symptoms at first, making it harder to diagnose in the early stages. 

Treatment options include surgery, radiation and chemotherapy.

Throat Disorders

Some disorders of the throat are the same conditions that occur in the nasal cavity such as allergies and the common cold. There are also other conditions that are associated with the throat.

Coughing is a reflex that keeps your throat and airways clear. While it can be annoying it helps your body heal or protect itself. Coughs can be acute or chronic. Various causes of coughs include:  asthma, allergies, chronic obstructive pulmonary disease (COPD), gastroesophageal reflux disease (GERD), smoking, croup in young children and some medicines. Treatment include drinking water or adding water to the air you breathe, taking antihistamines and cough medicines.

Diphtheria is a serious bacterial infection which affects the nose and throat. Symptoms include bad sore throat, swollen glands, fever and chills.  Not treated it produces a poison in the body that can cause serious complications such as heart failure or paralysis.  Preventive treatment include the diphtheria, pertussis and tetanus (DPT) vaccine. Children are immunized with the vaccine, but the protection does not last.  Adults should have a booster every ten years.

Streptococcal Infections called strep for short are categorized into two types:  Group A and Group B.  Antibiotics are used to treat both.

  • Group A causes strep throat, scarlet fever, impetigo, toxic shock syndrome and cellulitis.

  • Group B can cause blood infections, pneumonia and meningitis in newborns. A screening test during pregnancy can tell if you have it. If present, then IV antibiotics during labor can save the baby’s life.  Strep B can cause urinary tract infections, blood infections, skin infections and pneumonia in adults.

Head and Neck Cancers

Head and neck cancer includes cancers of the mouth, nose, sinuses, salivary glands, throat and lymph nodes in the neck. Most begin in the moist tissues that line the mouth, nose and throat. Symptoms include: a lump or sore that does not heal, a sore throat that does not go away, trouble swallowing, or a change or hoarseness in the voice.

Risk factors include: using tobacco or alcohol. In fact, 85% of head and neck cancers are linked to tobacco use, including smoking and smokeless tobacco. If found early, these cancers are often curable.

Treatments may include surgery, radiation therapy, chemotherapy, or a combination. Treatments can affect eating, speaking or even breathing, so patients may require rehabilitation.

Anatomy of the Eye

The sclera is the tough white outer covering of the eyeball.

The cornea is clear and has a curved surface that allows light to enter the eye.

The iris is the colored part of the eye that shrinks and expands so the pupil can adjust to the incoming light.

The lens is the clear part of the eye behind the iris that help to focus the light onto the retina.

The retina contains the light sensitive receptor cells that carry images to the brain through the optic nerve.

The optic nerve is a bundle of more than one million nerve fibers that carries visual messages from the retina to the brain.

Eye Disorders and Diseases

A cataract is a clouding of the lens in your eye that affects your vision. Cataracts are very common in older people. Common symptoms are: blurry vision, colors that seem faded, glare, not being able to see well at night, double vision and needing frequent prescription changes in your eye wear. Treatments include new glasses, brighter lighting, magnifying lenses as well as surgery. The cloudy lens has to be removed and replaced with an artificial lens.

Color Blindness is another eye disorder. There are three main kinds of color vision defects. Red-green color vision defects are the most common. This type occurs in men more than in women. The other major types are blue-yelllow color vision defects and a complete absence of color vision. Most color blindness is genetic and there is no treatment.

Diabetic retinopathy occurs when diabetes damages the tiny blood vessels inside your retina. Symptoms include blurry or double vision, rings, flashing lights or blank spots, dark or floating spots, pain or pressure in one or both eyes and problems with peripheral vision. Treatment often includes laser treatment or surgery.

Glaucoma is the leading cause of blindness in the US.  It usually occurs when the fluid pressure inside the eyes slowly rises, damaging the optic nerve.  Often there are no symptoms at first, but a comprehensive eye exam can detect it.

People at risk include: 

  • African Americans over age 40
  • Other people over age 60, especially Mexican Americans
  • People with a family history of glaucoma

Treatment includes prescription eye drops and/or surgery.

Your eyes can get infections from bacteria, fungi or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common infections are: 

  • Conjunctivitis, also know as pinkeye. Causes include bacterial or viral infection, allergies,  and substances that cause irritation such as contact lens products, or eye drops.

  • A stye is a bump on the eyelid that happens when bacteria from your skin get into the hair follicle of an eyelash

Symptoms of eye infections may include redness, itching, swelling, discharge, pain, or problems with vision.  Treatment depends on the cause of the infection and may include compresses, eye drops, creams or antibiotics.

Macular degeneration, or age-related macular degeneration (AMD) is a leading cause of vision loss in Americans 60 and older that destroys your sharp, central vision. Without central vision you cannot see objects clearly and cannot read  or drive.

Macular degeneration does not hurt, but it causes cells in the macula to die.  In some cases, the disease advances so slowly that people do not notice a change in their vision.  Treatment can slow vision loss but it cannot restore lost vision.  Regular comprehensive eye exams can detect AMD before vision loss occurs.

Farsightedness, hyperopia, myopia, nearsightedness are all considered refractive errors.  Your cornea is the clear front part of your eye.  It is like a window that controls and focuses the light coming into the eye.  If your cornea has an irregular shape, the light does not focus properly.  Things looks blurry.  This is a refractive error.

Four common types of refractive errors are

  • Myopia, or nearsightedness - clear vision close up but blurry in the distance
  • Hyperopia, or farsightedness - clear vision in the distance but blurry close up
  • Presbyopia - inability to focus close up as a result of aging
  • Astigmatism -  focus problems caused by the cornea

Treatment includes glasses or contact lenses.  Laser eye surgery may also be a possibility.

Eye Cancers

Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up of muscles, skin and nerves. If the cancer starts inside the eyeball it’s called intraocular cancer. The most common intraocular cancers in adults are melanoma and lymphoma.

The most common eye cancer in children is retinoblastoma, which starts in the cells of the retina.

Cancer can also spread to the eye from other parts of the body.

Treatment for eye cancer varies by the type and by how advanced it is. It may include surgery, radiation therapy, freezing or heat therapy, or laser therapy.

Ears and Eyes Combining Forms

Word Part   Meaning   Key Term
blephar/o   eyelid   blepharoplasty
choroid/o   choroid   choroidoiritis
conjunctiv/o   conjunctiva   conjunctivitis
myring/o   eardrum   myringotomy
ot/o   ear   otorrhea
retin/o   retina   retinopathy
tympan/o   eardrum    tympanoplasty

(Next - Medical Terminology Unit 9 of 17: Nervous System)

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