Chapter 17: Sense Organs: The Eye And The Ear

Front 1

accommodation

Back 1

Normal adjustment of the eye to focus on objects from far to near. The ciliary body adjusts the lens (rounding it) and the pupil constricts. When the eye focuses from near to far, the ciliary body flattens the lens and the pupil dilates.

Front 2

anterior chamber

Back 2

Area behind the cornea and in front of the lens and iris. It contains aqueous humor.

Front 3

aqueous humor

Back 3

Fluid produced by the ciliary body and found in the anterior chamber. A humor is any fluid, including blood and lymph.

Front 4

biconvex

Back 4

Consisting of two surfaces that are rounded, elevated, and curved evenly, like part of a sphere.

The lens of the eye is a biconvex body.

Front 5

choroid

Back 5

Middle, vascular layer of the eye, between the retina and the sclera.

Front 6

ciliary body

Back 6

Structure surrounding the lens that connects the choroid and iris. It contains ciliary muscles, which control the shape of the lens, and it secretes aqueous humor.

Front 7

cone

Back 7

Photoreceptor cell in the retina that transforms light energy into a nerve impulse.

Cones are responsible for color and central vision.

Front 8

conjunctiva

Back 8

Delicate membrane lining the undersurface of the eyelids and covering the anterior eyeball.

Front 9

cornea

Back 9

Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball.

Front 10

fovea centralis

Back 10

Tiny pit or depression in the retina that is the region of clearest vision.

Front 11

fundus of the eye

Back 11

Posterior, inner part of the eye.

Front 12

iris

Back 12

Pigmented (colored) layer that opens and closes to allow more or less light into the eye.

The central opening of the iris is the pupil.

Front 13

lens

Back 13

Transparent, biconvex body behind the pupil of the eye.

It bends (refracts) light rays to bring them into focus on the retina.

Front 14

macula

Back 14

Yellowish region on the retina lateral to and slightly below the optic disc; contains the fovea centralis, which is the area of clearest vision.

Front 15

optic chiasm

Back 15

Point at which optic nerve fibers cross in the brain.

Front 16

optic disc

Back 16

Region at the back of the eye where the optic nerve meets the retina. It is the blind spot of the eye because it contains only nerve fibers, no rods or cones, and is thus insensitive to light.

Front 17

optic nerve

Back 17

Cranial nerve carrying impulses from the retina to the brain (cerebral cortex).

Front 18

pupil

Back 18

Central opening of the eye, surrounded by the iris, through which light rays pass. It appears dark.

Front 19

refraction

Back 19

Bending of light rays by the cornea, lens, and fluids of the eye to bring the rays into focus on the retina.

Refract means to break.

Front 20

retina

Back 20

Light-sensitive nerve cell layer of the eye containing photoreceptor cells (rods and cones).

Front 21

rod

Back 21

Photoreceptor cell of the retina essential for vision in dim light and for peripheral vision.

Front 22

sclera

Back 22

Tough, white outer coat of the eyeball.

Front 23

thalamus

Back 23

Relay center of the brain. Optic nerve fibers pass through the thalamus on their way to the cerebral cortex.

Front 24

vitreous humor

Back 24

Soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball.

Front 25

aque/o

Back 25

water

Front 26

blephar/o

Back 26

eyelid

Front 27

conjunctiv/o

Back 27

conjunctiva

Front 28

cor/o

Back 28

pupil

Front 29

corne/o

Back 29

cornea

Front 30

cycl/o

Back 30

ciliary body or muscle of the eye.

Front 31

dacry/o

Back 31

tears, tear duct

Front 32

ir/o, irid/o

Back 32

iris (colored portion of the eye around the pupil.

Front 33

kerat/o

Back 33

cornea

Front 34

lacrim/o

Back 34

tears

Front 35

ocul/o

Back 35

eye

Front 36

ophthalm/o

Back 36

eye

Front 37

opt/o, optic/o

Back 37

eye, vision

Front 38

palpebr/o

Back 38

eyelid

Front 39

papill/o

Back 39

optic disc; nipple-like

Front 40

phac/o, phak/o

Back 40

lens of the eye

Front 41

pupill/o

Back 41

pupil

Front 42

retin/o

Back 42

retina

Front 43

scler/o

Back 43

sclera (white of the eye); hard

Front 44

uve/o

Back 44

uvea; vascular layer of the eye (iris, ciliary body, and choroid)

Front 45

vitre/o

Back 45

glassy

Front 46

ambly/o

Back 46

dull, dim

Front 47

dipl/o

Back 47

double

Front 48

glauc/o

Back 48

gray

Front 49

mi/o

Back 49

smaller, less

Front 50

mydr/o

Back 50

widen, enlarge

Front 51

nyct/o

Back 51

night

Front 52

phot/o

Back 52

light

Front 53

presby/o

Back 53

old age

Front 54

scot/o

Back 54

darkness

Front 55

xer/o

Back 55

dry

Front 56

-opia

Back 56

vision

Front 57

-opsia

Back 57

vision

Front 58

-tropia

Back 58

to turn

Front 59

astigmatism

Back 59

Defective curvature of the cornea or lens of the eye.

Front 60

hyperopia
(hypermetropia)

Back 60

Farsightedness

Front 61

myopia

Back 61

Nearsightedness

Front 62

presbyopia

Back 62

Impairment of vision as a result of old age.

Front 63

cataract

Back 63

Clouding of the lens, causing decreased vision.

Front 64

chalazion

Back 64

Small, hard, cystic mass (granuloma) on the eyelid.

Front 65

diabetic retinopathy

Back 65

Retinal effects of diabetes mellitus include micro aneurysms, hemorrhages, dilation of retinal veins, and neovascularization (new blood vessels form in the retina).

Front 66

macular edema

Back 66

Occurs as fluid leaks from blood vessels into the retina and vision is blurred.

Front 67

Exudates

Back 67

Fluid leaking from the blood appear in the retina as yellow-white spots.

Front 68

glaucoma

Back 68

Increased intraocular pressure results in damage to the retina and optic nerve with loss of vision.

Front 69

hordeolum
(stye or sty)

Back 69

Localized purulent, inflammatory staphylococcal infection of a sebaceous gland in the eyelid.

Front 70

macular degeneration

Back 70

Progressive damage to the macula of the retina.

Front 71

drusen

Back 71

Atrophy and degeneration of retinal cells and deposits of clumps of extracellular debris.

Front 72

nystagmus

Back 72

Repetitive rhythmic movements of one or both eyes.

Front 73

blepharitis

Back 73

Inflammation of eyelid, causing redness, crusting, and swelling along lid margins.

Front 74

chalazion

Back 74

Granuloma formed around an inflamed sebaceous gland.

Front 75

dacryocystitis

Back 75

Blockage, inflammation, and infection of a nasolacrimal duct and lacrimal sac, causing redness and swelling in the region between the nose and the lower lid.

Front 76

ectropion

Back 76

Outward sagging and eversion of the eyelid, leading to improper lacrimation and corneal drying and ulceration.

Front 77

entropion

Back 77

Inversion of the eyelid, causing lashes to rub against the eye; corneal abrasion may result.

Front 78

Hordeolum (stye)

Back 78

Infection of a sebaceous gland producing a small, superficial white nodule along lid margin.

Front 79

ptosis

Back 79

Drooping of upper lid margin as a result of neuromuscular problems or trauma.

Front 80

xanthelasma

Back 80

Raised yellowish plaque on eyelid caused by lipid disorder

xantha/o = yellow
-elasma = plate

Front 81

retinal detachment

Back 81

Two layers of the retina separate from each other.

Front 82

photopsia

Back 82

Bright flashed of light.

Front 83

floaters

Back 83

Black spots or filmy shapes, which are vitreous clumps that detach from the retina.

Front 84

strabismus

Back 84

Abnormal deviation of the eye.

Front 85

esotropia

Back 85

One eye turns inward; cross-eyed.

Front 86

exotropia

Back 86

One eye turns outward; wall-eyed.

Front 87

hypertropia

Back 87

Upward deviation of one eye.

Front 88

hypotropia

Back 88

Downward deviation of one eye.

Front 89

amblyopia

Back 89

Partial loss of vision or lazy eye.

Front 90

diplopia

Back 90

Double vision.

Front 91

fluorescein angiography

Back 91

Intravenous injection of fluorescein (a dye) followed by serial photographs of the retina through dilated pupils.

Front 92

ophthalmoscopy

Back 92

Visual examination of the interior of the eye.

Front 93

slit lamp microscopy

Back 93

Examination of anterior ocular structures under a microscopic magnification.

Front 94

visual acuity test

Back 94

Clarity of vision is assessed.

Front 95

Snellen chart

Back 95

Distance vision test at 20 feet.

Front 96

visual field test

Back 96

Measurement of the area (peripheral and central) within which objects are seen when the eyes are fixed, looking straight ahead without movement of the head.

Front 97

enucleation

Back 97

Removal of the entire eyeball

Front 98

keratoplasty

Back 98

Surgical repair of the cornea.

Front 99

laser photocoagulation

Back 99

Intense, precisely focused light beam (argon laser) creates an inflammatory reaction that seals retinal tears and leaky retinal blood vessels.

Front 100

LASIK

Back 100

Use of an excimer laser to correct errors of refraction (myopia, hyperopia, and astigmatism).

Front 101

phacoemulsification

Back 101

Ultrasonic vibrations break up the lens, which then is aspirated through the ultrasonic probe.

Front 102

scleral buckle

Back 102

Suture of a silicone band to the sclera over a detached portion of the retina.

Front 103

auditory canal

Back 103

Channel that leads from the pinna to the eardrum.

Front 104

auditory meatus

Back 104

Auditory canal.

Front 105

auditory nerve fibers

Back 105

Carry impulses from the inner ear to the brain (cerebral cortex).

These fibers compose the vestibulocochlear nerve (cranial nerve VIII).

Front 106

auditory tube

Back 106

Channel between the middle ear and the nasopharynx; eustachian tube.

Front 107

auricle

Back 107

Flap of the ear; the protruding part of the external ear, or pinna.

Front 108

cerumen

Back 108

Waxy substance secreted by the external ear; also called ear wax.

Front 109

cochlea

Back 109

Snail-shaped, spirally would tube in the inner ear; contains hearing-sensitive receptor cells.

Front 110

endolymph

Back 110

Fluid within the labyrinth of the inner ear.

Front 111

eustachian tube

Back 111

Auditory tube.

Front 112

incus

Back 112

Second osscile (bone) of the middle ear.

incus means anvil.

Front 113

labyrinth

Back 113

Maze-like series of canals of the inner ear. This includes the cochlea, vestibule, and semicircular canals.

Front 114

malleus

Back 114

First ossicle of the middle ear;

malleus means hammer.

Front 115

organ of Corti

Back 115

Sensitive auditory receptor area found in the cochlea of the inner ear.

Front 116

ossicle

Back 116

Small bone of the ear; includes the malleus, incus, and stapes.

Front 117

oval window

Back 117

Membrane between the middle ear and the inner ear.

Front 118

perilymph

Back 118

Fluid contained in the labyrinth of the inner ear.

Front 119

pinna

Back 119

Auricle; flap of the ear.

Front 120

semicircular canals

Back 120

Passages in the inner ear associated with maintaining equilibrium.

Front 121

stapes

Back 121

Third ossicle of the middle ear.

Stapes means stirrup.

Front 122

tympanic membrane

Back 122

Membrane between the outer and the middle ear; also called the eardrum.

Front 123

vestibule

Back 123

Central cavity of the labyrinth, connecting the semicircular canals and the cochlea.

The vestibule contains two structures, the saccule and utricle, that help to maintain equilibrium.

Front 124

acous/o

Back 124

hearing

Front 125

audi/o

Back 125

hearing; the sense of hearing

Front 126

audit/o

Back 126

hearing

Front 127

aur/o, auricul/o

Back 127

ear

Front 128

cochle/o

Back 128

cochlea

Front 129

mastoid/o

Back 129

mastoid process

Front 130

myring/o

Back 130

eardrum, tympanic membrane

Front 131

ossicul/o

Back 131

ossicle

Front 132

ot/o

Back 132

ear

Front 133

salping/o

Back 133

eustachian tube, auditory tube

Front 134

staped/o

Back 134

stapes (third bone of the middle ear)

Front 135

tympan/o

Back 135

eardrum,
tympanic membrane

Front 136

vestibul/o

Back 136

vestibule

Front 137

-acusis or -cusis

Back 137

hearing

Front 138

-meter

Back 138

instrument to measure

Front 139

-otia

Back 139

ear condition

Front 140

acoustic neuroma

Back 140

Benign tumor arising from the acoustic vestibulocochlear nerve (eighth cranial nerve) in the brain.

Front 141

cholesteatoma

Back 141

Collection of skin cells and cholesterol in a sac within the middle ear.

Front 142

deafness

Back 142

Loss of the ability to hear.

Front 143

nerve deafness
(sensorineural hearing loss)

Back 143

Hearing loss due to the impairment of the cochlea or auditory (acoustic) nerve.

Front 144

Meniere disease

Back 144

Disorder of the labyrinth of the inner ear; elevated endolymph pressure within the cochlea (cochlea hydrops) and semicircular canals (vestibular hydrops).

Front 145

otitis media

Back 145

Inflammation of the middle ear.

Front 146

serour otitis media

Back 146

A noninfectious inflammation with accumulation of serous fluid.

Front 147

otosclerosis

Back 147

Hardening of the bony tissue of the middle ear.

Front 148

ankylosis

Back 148

Stiffening of the stapes bone.

Front 149

tinnitus

Back 149

Sensation of noises (ringing, buzzing, whistling, booming) in the ears.

Front 150

vertigo

Back 150

Sensation of irregular or whirling motion either of oneself or of external objects.

Front 151

audiometry

Back 151

Testing the sense of hearing.

Front 152

cochlear implant procedure

Back 152

Surgical insertion of a device that allows sensorineural hearing-impaired persons to understand speech.

Front 153

ear thermometry

Back 153

Measurement of the temperature of the tympanic membrane by detection of infrared radiation from the eardrum.

Front 154

otoscopy

Back 154

Visual examination of the ear canal with an otoscope.

Front 155

tuning fork test

Back 155

Test of the ear conduction using a vibration source (tuning fork).

Rinne test - tuning fork against base of mastoid process
Weber test - tuning fork in center of forehead