The Eyes and The Eyes and EarsEars

The EyeThe Eye

The eye is a globe shaped, hollow The eye is a globe shaped, hollow structure set within a bony cavitystructure set within a bony cavity The bony cavity or orbit houses the The bony cavity or orbit houses the

eyeball and assorted structureseyeball and assorted structures Eye musclesEye muscles NervesNerves Blood vesselsBlood vessels

Most of the eyeball is protected from Most of the eyeball is protected from trauma by the orbit’s bony cavitytrauma by the orbit’s bony cavity

The wall of the eye is comprised of three The wall of the eye is comprised of three layerslayers Sclera-Sclera- white outer layer of the eyeball is white outer layer of the eyeball is

composed of fibrous connective tissuecomposed of fibrous connective tissue Cornea-Cornea- is a transparent domed structure is a transparent domed structure

formed by the scleraformed by the sclera the cornea also protects the front part of the eye the cornea also protects the front part of the eye

from injuryfrom injury Is the first part of the eye that refracts light rays.Is the first part of the eye that refracts light rays. The cornea is avascular (without blood vessels or The cornea is avascular (without blood vessels or

capillaries)capillaries) Choroid-Choroid- lies below the sclera lies below the sclera

Contains blood vessels and dark pigmented tissue Contains blood vessels and dark pigmented tissue that prevents glare within the eyeball by absorbing that prevents glare within the eyeball by absorbing light.light.

CiliaryCiliary Body- is the anterior portion of the Body- is the anterior portion of the choroidchoroid

Iris-Iris- the colored portion of the eye the colored portion of the eye Retina-Retina- lines the posterior two thirds portion lines the posterior two thirds portion

of the eyeball and contains rods and conesof the eyeball and contains rods and cones The sensory receptors for visionThe sensory receptors for vision

Rod-Rod- a rod-shaped receptor in the retina of the eye that is a rod-shaped receptor in the retina of the eye that is sensitive to dim light but not colorsensitive to dim light but not color

Cone-Cone- a cone-shaped cell sensitive to light and color in a cone-shaped cell sensitive to light and color in the retina of the eye of a human being or any other the retina of the eye of a human being or any other vertebrate animal. There are three different types of cone vertebrate animal. There are three different types of cone cells, responding to blue, green, or red light.cells, responding to blue, green, or red light.

Pupil-Pupil- the opening in the center of the iris the opening in the center of the iris The amount of light entering the eye is controlled The amount of light entering the eye is controlled

by contractions and dilations of the pupilby contractions and dilations of the pupil Optic disk-Optic disk- the retinal nerve fibers unite the retinal nerve fibers unite

herehere The optic disk is known as the “blind spot” The optic disk is known as the “blind spot”

because the optic disk has no rods or conesbecause the optic disk has no rods or cones Optic nerve-Optic nerve- formed from the retinal fibers formed from the retinal fibers

and cross through the wall of the eyeballand cross through the wall of the eyeball

MyopiaMyopia NearsightednessNearsightedness

Unable to see clearly objects that are far awayUnable to see clearly objects that are far away HyperopiaHyperopia

FarsightednessFarsightedness Able to see distant objects better than nearby onesAble to see distant objects better than nearby ones

ErythropiaErythropia Objects that are not red appear redObjects that are not red appear red

XanthopiaXanthopia Objects that are not yellow appear as yellowObjects that are not yellow appear as yellow

DiplopiaDiplopia Double visionDouble vision

EmmetropiaEmmetropia Normal visionNormal vision

AstigmatismAstigmatism A defect in a lens that prevents light rays from meeting at a A defect in a lens that prevents light rays from meeting at a

single point producing an imperfect image (blurred vision)single point producing an imperfect image (blurred vision)

Emmetropia Hypertropia

MyopiaAstigmatism

1. Lacrimal Gland1. Lacrimal Gland Is located above the Is located above the

outer corner or each eyeouter corner or each eye These glands produce These glands produce

tears, which keep the tears, which keep the eyeballs moisteyeballs moist

2. Lacrimal Sac2. Lacrimal Sac Collects tearsCollects tears

3. Nasolacrimal ducts3. Nasolacrimal ducts Tears are drained to the Tears are drained to the

nose thru the these nose thru the these ducts then expelled from ducts then expelled from the body thru the nose. the body thru the nose.

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Blephar/oBlephar/o eyelideyelidblepharospasmblepharospasm

Choroid/oChoroid/o choroidchoroid choroidopathychoroidopathy Corne/oCorne/o corneacornea corneitiscorneitis Cor/oCor/o pupilpupil anisocoriaanisocoria Dacry/oDacry/o teartear dacryorrheadacryorrhea Lacrim/oLacrim/oteartear lacrimationlacrimation Dipl/oDipl/o doubledouble diplopiadiplopia

Irid/oIrid/o irisiris iridoplegiairidoplegia Kerat/oKerat/o horny tissue, hard, corneahorny tissue, hard, cornea

keratoplastykeratoplasty

Ocul/o Ocul/o eyeeye intraocularintraocular Ophthalm/oOphthalm/o eyeeye ophthalm/o/scopeophthalm/o/scope Opt/oOpt/o eye,visioneye,vision opticoptic Retin/oRetin/o retinaretina

retinopathyretinopathy Scler/oScler/o hardening,sclerahardening,sclera scler/itisscler/itis

-opia-opia visionvision amblyopiaamblyopia -opsia-opsia visionvision heteropsiaheteropsia -ptosis-ptosis prolapse, downward prolapse, downward

displacementdisplacementblepharoptosisblepharoptosis

AchromatopsiaAchromatopsia- color blindness, more common - color blindness, more common in menin men

Astigmatism-Astigmatism- blurred vision due to defect in the blurred vision due to defect in the curvature of the cornea and lenscurvature of the cornea and lens

Cataract-Cataract- opacity (cloudiness) of the lens as opacity (cloudiness) of the lens as result of protein deposits on its surface that result of protein deposits on its surface that slowly builds up until vision is lostslowly builds up until vision is lost

Conjunctivitis-Conjunctivitis- inflammation of the conjunctiva inflammation of the conjunctiva that can be caused by bacteria, allergy, irritation, that can be caused by bacteria, allergy, irritation, or a foreign body; also called “pinkeye”or a foreign body; also called “pinkeye”

Diabetic retinopathy-Diabetic retinopathy- retinal damage marked retinal damage marked by aneurismal dilation of blood vesselsby aneurismal dilation of blood vessels

Esotropia-Esotropia- strabismus in which there is strabismus in which there is deviation of the visual axis of one eye toward deviation of the visual axis of one eye toward that of the other eye resulting in diplopia that of the other eye resulting in diplopia (double vision) also called “cross eyed”(double vision) also called “cross eyed”

Glaucoma-Glaucoma- increased intraocular pressure increased intraocular pressure caused by the failure of the aqueous humor caused by the failure of the aqueous humor (the transparent fluid that circulates in the (the transparent fluid that circulates in the eye chamber) to drain, which results in eye chamber) to drain, which results in atrophy of the optic nerve and eventually atrophy of the optic nerve and eventually may lead to blindness.may lead to blindness.

Strabismus-Strabismus- muscular eye disorder in which muscular eye disorder in which the eyes turn from the normal position so the eyes turn from the normal position so that they deviate in different directionsthat they deviate in different directions

Hordeolum-Hordeolum- small purulent (relating to, small purulent (relating to, containing, or consisting of pus) containing, or consisting of pus) inflammatory infection of the sebaceous inflammatory infection of the sebaceous gland of the eyelid; also called a “sty”gland of the eyelid; also called a “sty”

Macular degeneration-Macular degeneration- breakdown of the breakdown of the tissues in the macula resulting in loss of tissues in the macula resulting in loss of central visioncentral vision

Photophobia-Photophobia- unusual intolerance and unusual intolerance and insensitivity to light; occurs in diseases such insensitivity to light; occurs in diseases such as measles, meningitis, inflammation of the as measles, meningitis, inflammation of the eyes, measles and rubellaeyes, measles and rubella

Retinal detachment-Retinal detachment- separation of the separation of the retina from the choroid, which disrupts retina from the choroid, which disrupts vision and results in blindness if not vision and results in blindness if not treated.treated.

Tonometry-Tonometry- measuring of the measuring of the intraocular pressure by determining intraocular pressure by determining the resistance of the eyeball to the resistance of the eyeball to indention by an applied force; used indention by an applied force; used to detect glaucomato detect glaucoma

Visual acuity test-Visual acuity test- standard test of standard test of visual acuity using the “ E-Chart”visual acuity using the “ E-Chart”

Cataract surgery-Cataract surgery- excision of cataracts by excision of cataracts by surgical removal of the lenssurgical removal of the lens

Corneal transplant-Corneal transplant- (keratoplasty) surgical (keratoplasty) surgical transplantation of a donor cornea (from a transplantation of a donor cornea (from a cadaver) into the eye of a recipientcadaver) into the eye of a recipient

Extracapsular surgery-Extracapsular surgery- excision of most of excision of most of the lens, followed by insertion of an the lens, followed by insertion of an intraocular lens transplantintraocular lens transplant

Phacoemulsification-Phacoemulsification- excision of the lens by excision of the lens by ultrasonic vibrations that break the lens into ultrasonic vibrations that break the lens into tiny pieces which are then suctioned out of the tiny pieces which are then suctioned out of the eye.eye.

The EarThe Ear

The EarsThe EarsThe ears and their The ears and their accessory structures are accessory structures are the receptor organs that the receptor organs that enable us to hear and enable us to hear and maintain our balance.maintain our balance.

Each ear consists of three Each ear consists of three divisionsdivisions

The external ear, the middle ear, and The external ear, the middle ear, and the inner earthe inner ear The External and Middle earThe External and Middle ear

Conducts sound waves through the earConducts sound waves through the ear The Inner earThe Inner ear

Contains auditory structures that receive the Contains auditory structures that receive the sound waves and transmits them to the brain for sound waves and transmits them to the brain for interpretation.interpretation.

Contains specialized receptors that maintain Contains specialized receptors that maintain balance and equilibrium regardless of changes balance and equilibrium regardless of changes in the body position or motionin the body position or motion

The External EarThe External Ear

the outside part of the ear, consisting of the outside part of the ear, consisting of the auricle and auditory canalthe auricle and auditory canal Auricle-the part of the external ear that Auricle-the part of the external ear that

projects outward from the head projects outward from the head ***WARNING******WARNING*** do not confuse with the do not confuse with the auricle in the heart-an ear-shaped muscular auricle in the heart-an ear-shaped muscular part that sticks out from the surface of each part that sticks out from the surface of each upper chamber atrium of the heart.upper chamber atrium of the heart.

Auditory Canal- a passage from the outer ear Auditory Canal- a passage from the outer ear to the ear drum along which sound waves to the ear drum along which sound waves traveltravel

The Middle EarThe Middle Ear The narrow air-filled space between the ear The narrow air-filled space between the ear

drum and the outer wall of the inner ear drum and the outer wall of the inner ear containing the three tiny bones that transmit containing the three tiny bones that transmit sound vibrationssound vibrations 1. 1. IncusIncus-a small anvil-shaped bone in the middle -a small anvil-shaped bone in the middle

ear of mammalsear of mammals 2. 2. StapesStapes-a small stirrup-shaped bone in the -a small stirrup-shaped bone in the

middle ear of mammals, the innermost of the three middle ear of mammals, the innermost of the three small bones that transmit vibration to the inner earsmall bones that transmit vibration to the inner ear

3. 3. MalleusMalleus- a hammer-shaped bone, the outermost - a hammer-shaped bone, the outermost of three small bones in the middle ear that transmit of three small bones in the middle ear that transmit sound waves from the eardrum to the inner ear.sound waves from the eardrum to the inner ear.

Bones of the Bones of the Middle EarMiddle Ear

1. 1. IncusIncus2. Stapes2. Stapes3. 3. MalleousMalleous

The Inner EarThe Inner Ear The fluid-filled part of the ear, including The fluid-filled part of the ear, including

the cochlea, which is responsible for the cochlea, which is responsible for hearing, and the semicircular canals, hearing, and the semicircular canals, which control balancewhich control balance CochleaCochlea- a spiral structure in the inner ear - a spiral structure in the inner ear

that looks like a snail shell and contains tiny that looks like a snail shell and contains tiny hair cells whose movement is interpreted by hair cells whose movement is interpreted by the brain as soundthe brain as sound

Semicircular canals-Semicircular canals- each of three tubes in each of three tubes in the inner ear, semicircular in shape and set at the inner ear, semicircular in shape and set at right angles to one another, that help to right angles to one another, that help to maintain balancemaintain balance

Recap of the Ear Structure

Eardrum Eardrum

A membrane of thin skin and fibrous A membrane of thin skin and fibrous tissue that vibrates in response to tissue that vibrates in response to sound waves, located between the sound waves, located between the external and the middle ear.external and the middle ear.

Pathology of the EarPathology of the Ear Acoustic neuroma-Acoustic neuroma- a benign tumor that develops a benign tumor that develops

on the auditory nerve causing hearing loss, loss of on the auditory nerve causing hearing loss, loss of balance, and headachesbalance, and headaches

AnacusisAnacusis-total deafness; complete hearing loss-total deafness; complete hearing loss Conductive hearing lose-Conductive hearing lose- hearing loss due to an hearing loss due to an

impairment in the transmission of sound because of impairment in the transmission of sound because of an obstruction of the ear canal or damage to the an obstruction of the ear canal or damage to the

eardrum or ossicles (a small bone,eardrum or ossicles (a small bone, especially one of especially one of three bones of the middle ear in humans)three bones of the middle ear in humans)

Meniere disease-Meniere disease- rare disorder of unknown rare disorder of unknown etiology within the labyrinth (structure consisting of etiology within the labyrinth (structure consisting of connected cavities or canal)connected cavities or canal)

Pathology continuedPathology continued Otitis media-Otitis media- a painful inflammation of the middle ear a painful inflammation of the middle ear

that can cause dizziness and temporary hearing lossthat can cause dizziness and temporary hearing loss OtosclerosisOtosclerosis- a hereditary disease of the inner ear in - a hereditary disease of the inner ear in

which spongy bone growth leads to progressive which spongy bone growth leads to progressive hearing impairmenthearing impairment

PresbycusisPresbycusis- impairment of hearing resulting from the - impairment of hearing resulting from the aging processaging process

TinnitusTinnitus- a continual noise in the ear, e.g. a ringing or - a continual noise in the ear, e.g. a ringing or roaring, usually caused by damage to the hair cells of roaring, usually caused by damage to the hair cells of the inner earthe inner ear

VertigoVertigo- a condition in which somebody feels a - a condition in which somebody feels a sensation of whirling or tilting that causes a loss of sensation of whirling or tilting that causes a loss of balancebalance

DiagnosticDiagnostic

AudiometryAudiometry- test that measures hearing - test that measures hearing acuity of various sound frequenciesacuity of various sound frequencies

OtoscopyOtoscopy- visual examination of the ear; - visual examination of the ear; especially the eardrum using an otoscopeespecially the eardrum using an otoscope

Rinne test-Rinne test- hearing acuity test that is hearing acuity test that is performed with a vibrating tuning fork performed with a vibrating tuning fork placed on the mastoid process, then in placed on the mastoid process, then in front of the external auditory canal to front of the external auditory canal to test bone and air conductiontest bone and air conduction

TherapeuticTherapeutic Cochlear implant-Cochlear implant- electronic transmitter electronic transmitter

that is surgically implanted into the that is surgically implanted into the cochlea of a deaf person; performed to cochlea of a deaf person; performed to restore hearing lossrestore hearing loss

Myringoplasty-Myringoplasty- surgical repair of a surgical repair of a perforated eardrum with a tissue graftperforated eardrum with a tissue graft

Myringotomy-Myringotomy-incision of the eardrum to incision of the eardrum to relieve pressure and release pus or serous relieve pressure and release pus or serous fluid from the middle ear or to insert fluid from the middle ear or to insert tympanostomy tubes surgically in the tympanostomy tubes surgically in the eardrumeardrum

Combining formsCombining forms

Acous/oAcous/o hearinghearing Audi/oAudi/o hearinghearing Myring/oMyring/o tympanic membranetympanic membrane Tympan/oTympan/o tympanic membranetympanic membrane Ot/oOt/o earear Salping/oSalping/o tube (usually tube (usually

fallopian fallopian or or eustachian) eustachian) auditory auditory tubetube

Suffixes Suffixes

-acusis-acusis hearinghearing -tropia-tropia turningturning