1. The Eyes and Ears
Chapter 11

2. Related Word Parts (Combining Forms)
Eyes
Primary Function
Receptor organs for the sense of sight
Related Word Parts (Combining Forms)
opt/i, opt/o, optic/o
ophthalm/o
OD= Right Eye (oculus dexter)
OS= Left Eye (oculus sinister)
OU= Each Eye (oculus uterque) or Both Eyes (oculi uterque

3. Structures of the Eyes
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4. Adnexa: structures outside the eyeball
Structures of the eye
Adnexa: structures outside the eyeball
Orbit, eye muscles, eyelids, eyelashes, conjunctiva, lacrimal apparatus
Adexa=Accessory or adjoining anatominal part. Is Plural
Eyeball: also known as the globe
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5. Structures of the eye
Orbit- eye socket. Bony cavity that contains and protects the eyeball and its associated muscles, blood vessels, nerves. Muscles- arranged in three pairs FIG 11.2, p.339 oblique- superior and inferior rectus-superior, inferior, lateral, medial Binocular vision (bin=2, ocul=eye, ar=pertaining to) musculs of each eye work together to make depth perception possible. Eyelids (2), Eyebrows, Eyelashes= protect the eyeball from foreign matter, excessive light and injuries. Conjunctiva=transparent membrane that line the underside of each eyelid to form a protective covering of each eyeball Lacrimal Apparatus= structures that produce, store, and remove tears Glands-secrete Fluid-maintains moisture Canal-collects and empties Sac-holds Duct-passageway that drains excess tears into the nose.

6. Eye Muscles

7. EYeball Made of three layers
Sclera (white of the eye)-maintain shape, tough fibrous layer that protects inner layer,
scler/o=white of the eye and means hard.
Choroid-middle layer that contains many blood vessels and provides blood supply
Retina-receives nerve impulses and transmits to brain via the optic nerve
Aqueous Humor – Fluid that nourishes the intraocular structures and helps to maintain shape of eye. Constantly filtered and drained. Intraocular pressure.
Rods and Cones – receives images and converts them to nerve impulses and transmits to brain (optic nerve)
Optic Disk (blind spot) – nerve endings enter the optic nerve (no rods or cones)
Iris – Surrounds the pupil and contains muscles to dilate and constric
Cornea – Outer layer of the eye. Structure that focuses light rays entering the eye
Pupil – Permits light to enter the eye
Lens – Clear, flexible, curved that focuses images on the retina

8. Actions of the eye
Accommodation-process where eyes make adjustments for seeing objects at varies distances Convergence-simultaneous inward movement of the eye toward each other. Maintains singular binocular vision Refraction-ability of the lens to bend light rays so they focus on the retina Visual acuity- ability to distinguish object detail and shape at a distance.

9. Medial Specialites
Opthalmologist= MD that specializes in diagnosing an treating of disorders of the eye including SX Optometrist= Primary eye care including diagnosing diseases and conditions and measuring accuracy. Optician= health care practitioner who fits, designs, and dispenses lenses fo vision correction

10. Eye PAthology
Conjunctivitis= pinkeye, inflammation caused by infection or allergy. Very contagueos Corneal Abrasion= scratch or irritation to the outer layer of the cornea. Diabetic Retinopathy= damage to the retina due to uncontrolled diabetes Cataract= loss of transparency of the lens that causes a progressive loss of visual clarity. (usually due to ageing) Floaters= (phot= light + opsia= view of) particles of cellular debris that float and cast shadows on the retina. Can be a indication of retina detachment, especially what accompanied by photopsia Photopsia= flashes of light , can be caused by migraines. Retinal detachment= separation of some or all of the retina from the choroid. Can causes blindness if not treated quickly or properly. Caused primarily from head trauma.

11. Glaucoma
Open-angle = (chronic)- Meshwork becomes blocked causing a pressure to build up. No symptoms until optic nerve becomes damaged, but can be detected with eye examines. Closed-angle (acute)- Opening between cornea and iris narrows so that fluid does not reach meshwork. Cause sudden increase in pressure that produces severe pain, nausea, redness and blurred vision. Blindness can occur in as little as two days if not treated.

12. Macular degeneration
Progressive condition in which the macula at the center of the retina is damaged resulting in loss of central vision but not total blindness. (macul=spot + ar= ?) Age related--older people and most common cause of severe vision loss in those over 60. Dry– 90% of all cases, slow deterioration of the cells of the macula Wet—advanced form of dry, new blood vessels growing beneath the retina leak blood and fluid which damages cells. Usually result in rapid and severe vision loss.

13. Functional Defects
Diplopia= (dipl=double + opia=vision condition) Usually a symptom of an underlying disorder i.e. brain injury Heminaopia= (hemi=? + an=? +opia=?) Monochromatism= mono=one+chromat=color+ism=condition) Genetic condition caused by deficiencies in or the absence of certain types of cones in the retina Nyctalopia= (nyctal=night+opia+?) Photophobia=(phot/o= light+ photo=?) can be caused by migraines, excessive wearing of contact lenses, drug use, inflammation, TBI

14. Refractive disorders
Focusing problem that occurs when the lens an cornea do not bend light so that it focuses properly on the retina Astigmatism-Condition in which the eye does not focus properly because of uneven curvatures of the cornea Hyperopia- (farsightedness) defect in which light rays focus beyond the retina Myopia-(nearsightedness) defect in which light rays focus in front of the retina Scotoma-known as blind spot.

15. Diagnostic procedures
Snellen Chart=?? Refraction test= determines refractive error so the best corrective lens can be prescribed Dilation= Fluorescein staining= fluorescent dye is applied to the surface of the eye to detect corneal abrasions PERRLA- (PERL) Tonometry- (ton=tension + metry=measure) measure of intraocular pressure . Increase pressure is a indication of glaucoma.

16. Laser treatment
LASIK=Laser-Assisted in Situ Keratomileusis (kerat=cornea + mileusis=carving + in situ=in tis original place -used to treat conditions that are caused by the shape of the cornea. -flap is created in the surface of the cornea to change the shape Photocoagulation- use to treat wet macular degeneration by sealing leaking or damaged blood vessels

17. EYES and vision
Primary Function -Receptor organs for the sense of hearing -Helps to maintain balance Related Word Parts -acous/o, acoust/o, Auditory (audit=hearing + ory= pertaining to) pertaining to the sense of hearing Acoustic (acous=hearing or sound + tic=pertaining to) AD=auris dexter or right ear AS=auris sinister= left eat AU=auris uterque =both ears

18. Normal action
Air conduction= sound waves enter ear-ravel down the auditory canal-strike the tympanic membrane Bone conduction=eardrum vibrates and causes auditory ossicles of the middle ear to vibrate-vibrations transmit sound waves through the middle ear to the oval window Sensorineural conduction=inner ear receives sound waves and relay they to the auditory nerve for transmission of the brain

19. Outer ear
Primary Function -transmits sound waves to the middle ear Pinna= external portion of the ear. Captures sound waves and transmits them into the external auditory canal External Auditory Canal=transmits sound waves to the tympanic membrane (eardrum) of the middle ear Cerumen= (earwax) secreted by the ceruminous gland. Helps trap small incests, dust, debris from entering the middle ear.

20. Middle Ear
Located between the outer and inner ear and transmit sound across the space between these two parts Tympanic membrane=transmits sound waves by vibration Mastoid process=temporal bane that contains hollow air space that surrounds the middle ear. Auditory occicles=Three small bones that transmit sound waves from the eardrums to the inner ear by vibration. -malleus=hammer -incus=anvil -stapes=stirrup Eustachian tubes=Narrow tube that leads from the middle ear to the nasal cavity and the throat. Equalizes air pressure within the middle air with that of the outside atmosphere

21. Inner ear
Receives sound vibrations and transmits them to the brain Contains sensory receptors for hearing and balance Oval Window=under the base of the stapes , membrane that separates the middle ear from the inner ear. Vibrations enter the inner ear here. Cochlea= sounds vibrations are converted into nerve impulses. Semicircular canals=contains endo-lymph and sensitive hair cells; bending of these hair cells in response to movement of the head sets up impulses in nerve fibers to help maintain equilibrium Acoustic nerves=Transmits information to the brain; two parts -cochlear nerves = transmits sound -vestibular nerves = balance and head position

22. Structures of the Ears

23. Specialities
Audiologist-Specializes in the measurement of hearing function and in the rehabilitation of persons with hearing impairments Speech Language Pathologist= assist people with swallowing, speech and communication disoders.

24. Pathology
Outer Ear Impacted cerumen= accumulation of ear wax; impacted means lodged in place Otalgia= earache or pain in the ear Otitis= imflammation of the ear;; otitis externa=of the external auditory canal Otorrhea= any discharge from the ear (could be CSF) Otorrhagia= bleeding from the ear Middle Ear Baratrauma= pressure related condition caused by pressure changes or when the euctachian tube is blocked. Mastioditis= inflammation of any part of the mastiod bone. Otitis media = inflammation of the middle ear. Acute associated with upper respiratoty infection most common in children

25. Pathology cont.
Inner ear Vertigo= dizziness, LOB, nausea vomiting associated by inner ear problems Tinnitus= ringing, buzzing or roaring. Associated with hearing loss or prolonged exposure to load noises. Concussions Menieres disease= chronic disorder in which the amount of fluid in the inner ear increases. Can result in vertigo, hearing loss, tinnitus

26. Hearing Loss
Deafness Presbycusis (presby= old age + cusis= hearing) gradual loss of earing due to ageing Conductive hearing loss= sound waves are not allowed to pass from the air to the fluid filled inner ear. Can be caused by buildup of wax, fluid or excess fluid in the middle ear, punctured eardrum. Can usually be treated. Sensorineural hearing loss= known as nerve deafness. Nerve or hair cells are damaged. Can be due to age, noise exposure or acoustic neuroma. Noise induced Nerve damaged caused by repeated exposure to loud noises -above 85 decibels can cause damage -105 is portable music players on high with headphones Fig p. 353

27. Treatments
Otoplasty= repair, restoration, alteration of the pinna Ear tubes= (tymanostomy tubes) ventilating tubes placed through the eardrums to provide dranage and relieve pressure. Mastoidectomy= surgical removial of the mastoid cells. Used to treat mastoiditis or in preparation for cochlear implant. Myingotomy= small incision in the eardrum to relieve pressure or to create a opening for the placement of tubes. Vestibular rehabilitation therapy= physical therapy to treat balance disorders

28. Treatments for hearing loss
Assistive listening device= transmits, process or amplifies sound; used with or without hearing aid. Helps with eliminating distracting background noise. Cochlear implant= electronic device that bypasses damaged portions of the ear and stimulates auditory nerve.. Electrodes implanted in the cochlea receive signals and stimulate the auditory nerve. Brain receives signals and perceives them as sound. May take several months to adjust to the difference in speech. Hearing Aids Analog HA= external electronic device that uses microphone to detect and amplify sounds Digital HA= computer chip to convert sound into codes that can be filtered before being amplified