1. Chapter13 Knowledge Assignment Eyes & Ears Roberto Ayala Bio 120

2. Pressure Equalizing Tube Abbreviated as: PE tube. Small sections of hollow tubing that are surgically inserted through the ear drum.

• Alleviates chronic ear infection andfluid buildup in the ear.

3. Most frequently performed on children.

4. PE tubes remain in place for about a year, then fall out naturally. 5. Complications include:

1. Infection due to water, bacteria entering the tubes.

6. 2. PE tubes may need to be surgically removed if they fail to fall out. Photos Left: PE tube in ear drum. Right: Various PE tubes using a penny for scale. 7. Eye, Ear, Nose, and Throat Abbreviated as: EENT. The field of study is called Otolaryngology, Practitioners are called otolaryngologists or otorhinolaryngologists. Recognized as a specialty in the U,S, in the year 1924. The American Academy of Otolaryngology oversees the specialty.Medical school graduates face five years of training to qualify for specialty board examinations. Two years of further specialty training is available. Many practitioners take additional specialized training in specific areas related to their interests. .Otorhinolaryngologists are also trained as surgeons. One of the side benefits to patients is no need for to get a referral for a surgical procedure performed on the head and neck regions. 8. Bone Conduction Abbreviated as: BC. Bone conduction is the principle behind the Rinne and Weber tuning-fork tests. In both tests, how loud the patient is able to perceive sound determines what typeof hearing loss could be affecting them. Conductive Hearing Loss Occurs when sound waves are unableto pass through the outer or middle ear. Typically caused by earwax buildup,inflammation of the outer ear (otitis externa), inner ear (otitis media), or a perforatedeardrum. Sensorineural Hearing Loss Occurs when sound is unable to be perceived by the cranial nerve, the inner ear, or the brain. Typically caused by congenital defects, sudden or/and progressive exposure to loud noise (concerts, iPods), inflammatory diseases (mumps, meningitis) , drugs (aspirin), and physical trauma. Both Rinne and Weber tests are no substitute for modern audiometry tests. 9. Both Ears Abbreviated as: AU. Derived from the Latin phrase aures unitas, or both ears. Usage Risk : AS, AD, and AU are left ear, right ear, and both ears. When in doubt, write out both ears, rather than risk an abbreviation. Further confusion can rise between AU and AUD (doctor of audiology), and AV (antrioventricular). 10. Otitis Media Abbreviated as: OM. Known as a middle ear infection and commonly found in children, this condition is caused when pathogens move into the middle ear from the pharynx through the eustachian tubes. Fluid can accumulate in the middle ear, causing further discomfort and infection. Untreated, hearing loss, and eardrum damage can occur. A Pressure Equalizing Tube (PE tube) can be surgically inserted through theeardrum to relieve pressure and drain accumulated liquid trapped in the middle ear cavity. Right: A well developed case of otitis media. 11. Emmetropia Abbreviated as: EM Emmetropia is a state of normal vision. A person with normal vision possesses vision of 20/20 acuity or better.In life science terms, normal vision occurs when light entering the eye is focused directly on the retina.Light that is focused in front of the retina is the cause of near sightedness. Light that has a focal point behind the retina causes far sightedness. 12. Exotropia Abbreviated as: XT Is the condition where one eye turns outward while the second eye remains at a normal state of gaze. Is one of the more common forms of strabismus, an eye condition where the eyes become misaligned.Most Frequently develops in children age 2-4, although adult onset is possible. Causes are main;y unknown. Development in children is linked with cerebral palsy, Down syndrome, and brain tumors. Main symptoms are an outward turning eye, loss of vision, loss of visualalignment, and sensitivity to light. Exotropia can sometimes be treated with special glasses and eye exercises. Surgery to correct improper eye muscle adjustment is the typical treatment An illustration of exotropia affecting the left eye. 13. Left Eye Abbreviated as: OS The left eye is abbreviated as OS, or oculus sinister. The right eye is abbreviated as OD, or oculus dexter.Both eyes are abbreviated as OU.The terms are based from Latin. Because left dominance was thought to be evil, the term sinister was applied as a descriptor to the left side of the body. Right dominance was given the term dexter, which means fortunate, skillful, and proper. 14. Extraocular Movement Abbreviated as: EOM Extraocular Movement refers to the motion and alignment of the muscles that move the eyes.A chart showing eye gaze direction and eye muscle activation. 15. Visual Acuity Abbreviated as: VA Visual acuity is a test that determines the smallest object that can be read or seen from a standardized eye chart mounted 14-20 feet away. The eyes are tested both singularly and as a pair. If contacts or glasses are worn, the test may be repeated with them on/off. A Snellen chart with letters of various sizes and other charts may be used to gauge visual accuity. Basic visual acuity is measured by the standard of 20/20 vision.