Chapter 17 Sense Organs: The Eye and the Ear Copyright © 2011, 2008, 2005 by Saunders, an imprint...

Chapter 17Sense Organs: The Eye and the Ear

Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 1


Chapter Goals

• Identify locations and functions of the major parts of the eye and ear.

• Name the combining forms, prefixes, and suffixes most commonly used to describe these organs and their parts.

• Describe the pathologic conditions that may affect the eye and ear.


Chapter Goals (cont’d)

• Identify clinical procedures that pertain to ophthalmology and otology.

• Apply your new knowledge to understanding medical terms in their proper contexts, such as medical reports and records.


Introduction


The Eye

http://www.youtube.com/watch?v=gvozcv8pS3c


The Eye (cont’d)


The Eye (cont’d)

• Pupil• Conjunctiva• Cornea• Sclera• Choroid• Iris• Ciliary body• Lens• Fundus

• Anterior chamber• Aqueous humor• Vitreous chamber• Vitreous humor• Retina• Optic nerve• Optic disc• Macula• Fovea centralis


Visual Pathways from Retina to Cortexhttp://www.youtube.com/watch?v=NfLgzTSL-U0


QUICK QUIZ:

1. What is the soft, jellylike material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball?A. scleraB. vitreous humorC. aqueous humorD. fovea centralis


TerminologySTRUCTURES AND FLUIDS

• aque/o water• blephar/o eyelid• conjunctiv/o conjunctiva• cor/o pupil• corne/o cornea• cycl/o ciliary body

Combining FormCombining Form MeaningMeaning


Terminology (cont’d)STRUCTURES AND FLUIDS

• dacry/o tears, tear duct• ir/o iris• irid/o iris• kerat/o cornea• lacrim/o tears• ocul/o eye




• ophthalm/o eye• opt/o eye, vision• optic/o eye, vision• palpebr/o eyelid• papill/o optic disc• phac/o lens of the eye




• phak/o lens of the eye• pupill/o pupil• retin/o retina• scler/o sclera (white of the eye)• uve/o uvea• vitre/o glassy



Terminology (cont’d)CONDITIONS

• ambly/o dull, dim• dipl/o double• glauc/o gray• mi/o smaller, less• mydr/o widen, enlarge• nyct/o night




• phot/o light• presby/o old age• scot/o darkness• xer/o dry

Presbyopia is a condition in which the lens of the eye loses its ability to focus, making it difficult to see objects up close scotodinia dizziness with blurring of vision and headache




• -opia vision• -opsia vision• -tropia to turn

SuffixSuffix MeaningMeaning


QUICK QUIZ:

1. Which term means inflammation of the eyelid?

A. ophthalmoplegiaB. keratitisC. blepharitisD. blepharoptosis


Errors of Refraction

• Astigmatism: defective curvature of the cornea or lens of the eye

• http://www.youtube.com/watch?v=6DKGgslFXbA

• Hyperopia: farsightedness• Myopia: nearsightedness• Presbyopia: impairment of vision due to

old age reducing lens accommodation


Errors of Refraction (cont’d)


Abnormal Conditions

Cataract: clouding of the lens


Abnormal Conditions (cont’d)

Chalazion: small, hard, cystic mass on eyelid; formed as a result of chronic inflammation of sebaceous gland along margin of eyelid


Abnormal Conditions (cont’d)• Diabetic retinopathy - retinal effects caused by

diabetes mellitus include: microaneurysms hemorrhages dilation of retinal veinsneovascularization


Abnormal Conditions (cont’d)

Glaucoma: increased intraocular pressure damages retina and optic nerve


Abnormal Conditions (cont’d)• Hordeolum (stye): staph infection of a sebaceous gland in the

eyelid• Macular degeneration: progressive damage to the macular of

the retina• Nystagmus: repetitive rhythmic movements of one or both

eyes.• Strabismus: abnormal deviation of the eye


Abnormal Conditions (cont’d)• Retinal detachment: two layers of the retina separate from

each otherPhotopsia: bright flashes of lightFloaters: vitreous clumps of retinaScleral buckle: belt to buckle retina to scleraPneumatic retinopexy: gas bubble injected in vitreous cavity to

help reattach retina


Chapter 17Lesson 17.2


Diagnostic Procedures• Fluorescein angiography: dye injection to examine blood flow

in the retina• Ophthalmoscopy: visual examination of eye interior through

dilated pupil• Slit lamp microscopy: magnified view of expanded number of

eye structures


Diagnostic Procedures (cont’d)Visual acuity test: assesses clarity of vision


Diagnostic Procedures (cont’d)Visual field test: measures visual fields when eyes are fixed

forward


Treatment• Enucleation: removal of entire eyeball• Laser photocoagulation: Argon laser creates inflammatory

reaction that seals retinal tears and leaky blood vessels• LASIK: laser to correct errors of refraction by sculpting the

cornea


Treatment (cont’d)

Keratoplasty: surgical repair of the cornea


Treatment (cont’d)

Scleral buckle: suture of silicone band to sclera over detached portion of retina


Treatment (cont’d)• Phacoemulsification: ultrasound to break up lens for

aspiration for cataract removal• Vitrectomy: removal of vitreous and replacing it with a clear

solution


Chapter 17Lesson 17.3


The Ear

ANATOMY AND PHYSIOLOGY

Outer ear receives sound waves.Sound waves travel to middle ear.Sound vibrations reach inner ear

(labyrinth).


Anatomy of the Ear


Anatomy of the Ear (cont’d)


Ear Anatomy and Physiology

• Outer earPinna or auricle: projecting flapExternal auditory meatus (auditory

canal)


Ear Anatomy and Physiology (cont’d)• Middle ear

Tympanic membrane (eardrum)Malleus Incus StapesOval windowEustachian tube


Ear Anatomy and Physiology (cont’d)• Inner ear: labyrinth

CochleaAuditory nerve fibers


Ear Anatomy and Physiology (cont’d)• Balance and equilibriumVestibule Semicircular canals


QUICK QUIZ:

2. What is the snail-shaped, spirally wound tube in the inner ear that contains hearing-sensitive receptor cells?

A. pinnaB. auricleC. ossicleD. cochlea


COMBINING FORMS

• acous/o hearing• audi/o hearing• audit/o hearing• aur/o ear• auricul/o ear• cochle/o cochlea• mastoid/o mastoid process


TerminologyTerminology


COMBINING FORMS

• myring/o eardrum, tympanic membrane• ossicul/o ossicle• ot/o ear• salping/o Eustachian tube• staped/o stapes• tyman/o eardrum, tympanic membrane • vestibul/o vestibule


Terminology (cont’d)Terminology (cont’d)


SUFFIXES

• -acusis or-cusis hearing• -meter instrument for measure• -otia ear condition

SuffixSuffix MeaningMeaning

Terminology (cont’d)Terminology (cont’d)


Symptoms and Pathologic Conditions• Acoustic neuroma: benign tumor arising from

8th cranial nerve, causes tinnitus, vertigo, dizziness, and decreased hearing

• Cholesteatoma: skin cells and cholesterol in a sac in the middle ear (cyst-like mass associated with chronic infections)

• http://www.youtube.com/watch?v=WYvvXhrOVRw

• Deafness: loss of ability to hear


Symptoms and Pathologic Conditions (cont’d)• Ménière disease: disorder of labyrinth

with elevated endolymph pressure in cochlea and semicircular canals causing tinnitus, sensitivity to sound, progressive hearing loss, headache, nausea, and vertigo

• Otitis media: inflammation of middle ear• Otosclerosis: hardening of bony tissue in

labyrinth


Symptoms and Pathologic Conditions (cont’d)• Tinnitus: sensation of noises (ringing, buzzing,

whistling, booming) in ears• http://www.youtube.com/watch?v=uJIoVXJ4RJU• Vertigo: sensation of irregular motion (whirling)

from disease of inner ear or nerve carrying messages from semicircular canals


Clinical Procedures

• Audiometry: audiometer is an electric device to determine hearing loss by frequency

• http://www.youtube.com/watch?v=IYgEFGut1V4• Cochlear implant: Surgically implanted device allowing

sensorineural hearing-impaired persons to understand speech

• Ear thermometry: body temperature measured with infrared radiation from the eardrum



Clinical Procedures (cont’d)

• Otoscopy: visual examination of ear with small, hand-held scope

• http://www.youtube.com/watch?v=iIbaq15t1L0• Tuning fork test

Rinne: hearing test using a vibrating fork against the mastoid bone (bone conduction) and in front of the auditory meatus (air conduction)

Weber: fork is placed on the center of the forehead; normal hearing has equal loudness in both ears.

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